Seed production in birdsfoot trefoil (Lotus corniculatus L ) : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Seed Technology at Massey University, Palmerston North, New Zealand

(1)Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author..

(2) SEED PRODUCTION IN BIRDSFOOT TREFOIL. ( Lotus corn iculatu s L . ). A thesis presented in partial fulfillment of the requirements for the Degree of Doctor of Philosophy in Seed Technology at Massey University Palmerston North New. Zealand. QINGFENG LI. 1989.

(3) i. A B S T R A C T. T h i s t he s i s p roduc t i o n. re p o rt s. t he. re s u lt s o f. o f b i rds f o ot. t re f o i l. t h ree ye a rs '. re s e a rc h o n s e e d. ( Lo t u s c o rn i c u l a t u s L . ) .. P re v i o u s. w o rk b y o t h e r re s e a rc h e rs h a s sugge s t e d t h a t a p ro t racted f l o we ring p e riod i s a ma j o r f a c t o r l imit ing seed p roduct i on i n this legume . The re s e a rch p ro g ra mme w a s begun i n cause ( s ) the. 1986. w i t h an. of t h i s prot ra c t ed fl owering period .. g ro w t h. a n d f l o w e ri n g be h a v i o u r o f. d i f f e re n t t ime 5o f t h e ye a r, f l o w e ri n g. p a t t e rn. p roduc t i on. of. deve l o pme n t. in. shoot s. this. it. was. plant. i n ve s t i ga t i on. By c a re fu l ly examining. t a gg e d. shoot s. f o rmed a t. ident i f i e d t h a t t h e p ro t ra cted is. c a u s e d by. w i t h t h e c a p a c i t y t o f lo we r .. o f new shoots. of the. the. cont inuous. The. cont inuous. rep l a c i n g o l de r f lowe ring shoot s was the. ma i n c a u s e of t he long f lowering peri o d . Re s u l t s o f the f i rs t ye a r' s re s e a rch a l s o s howed that seed yie l d i s prima ri l y det e rmined by the number of i n f l o re s cences produced .. I n t u rn ,. i n f l o re s cence numbe rs a re. p rima ri l y dependent on the number o f shoot s a va i l able a t the t ime o f f l owering .. I t was sugge s t e d b y t h e re s u l t s t h a t manipu l a t ion. n umbe r a n d b ra n c h i n g of. shoot s. s h o u ld be. an. o f the. imp o rt a n t m a n a gemen t. s t rategy f o r improving s e e d product i on in t h i s p l ant .. The. s e c o n d s t age o f the st udy invo l ved a number of hand remova l and. c ut t i n g t re at men t s de s i gned to s ho o t. i nve s t i g a t e the pos s ib l e e f fe c t s o f. remov a l on p l a n t g rowth a n d s eed p ro duct ion .. H a nd remova l o f. c rown s h o o t s a f fec ted b ranching beh a v i o u r i n t h i s p l a nt .. Removal o f. young c rown shoo t s a t d i f f e rent g rowth s t ages re sulted in a range o f p lant. s t ru c t u ra l. f o rms w h i c h i n f l ue n c e d s e e d p roduct i on potent i a l .. Cut t in g t re a t ment s ,. the ma j o r e f f e c t of wh i c h was to remove a s e c t ion.

(4) . .. li. of s hoot. f rom t he. showed no obvious. top,. beneficia l. effect s. on. seed. a. mo re. yie ld in birdsfoot t refoil.. In. the. t hird. p r a c ti c a l. s t age. s i t u a tion. S upe r ) ). p l a nt s. st age. g r o wn. s it u a t io n s .. we r e. whic h. e x t e nded. p l a nt. in. e t h ofume s a t e. inv e s ti g a t e. r e gu l a t ing. (Nort ron ) s hoot. and. c h emic a l s. fatty. a l coho l s. growth and deve lopment.. involved both widely spaced individua l p l ant s a. Results. to. g r owt h. were used t o manipu l a t e. Re s e a rc h at t hi s and. in. ( PP 3 3 3 ) ,. (p a c l ob u t razol (Fatol. s t udi e s. sward. s ho w e d. to. simu l a t e. PP333. that. c omme r c i a l l y is. a. p ractised. p romi s in g. p re -p e a k. flowe ring s hoot manipul a tor which a c t s by p romoting branching. Nearly a. 4 0 % in c r e a s e in seed yie ld w a s con s ist ent ly obtainedin two y e a r s '. expe riment s. when this. p re-bud s t age in. s w a rd. However,. sit u a tions. we re. e a r ly flowe ring when. app lied. f lowe ring.. Fatol. S upe r. p e a k flowering shoot manipul ator,. v a l ue. s t a ge.. at. shoot manipulator because. and. p l a n t s,. applied during t h e Nort ron. e a r ly p l a n t. Nort ron was of limit ed va lue when it. f l owe ring growth. to the. chemic a l. but. for. was. use. le s s in. effective in. the. n a r ro w. row. was. s ome. from t he. showed it s. deve lopment used as. of its injurious s howed. time. value s t age.. a post-peak. effect on p l ant. potentia l. as. a. post-. p a rticul a r ly when applied to spa ced sward or. situations.. s wa rd. s e ed. This. reduces. p rodu c t ion. c u r rent l y pra cticed in New Ze a l and for birdsfoot t refoi l .. it s. s y s t ems.

(5) i ii. ACKNOWLEDGEMENTS. I. would l i ke to expre s s my s in c e r e grat i t ude to D r .. Mur rQy J .. Hill ,. my ch i e f s upe rvi s o r a nd D i re c t o r o f the Seed Technology Cent re ,. for. h i s w i s e s upe rvis ion t h ro ughout t he work a n d pat ience in reading and c o r rect i n g t h i s manus c r ipt .. I. am a l s o g r e a t l y i n d e b t e d t o P r o f e s s o r R . G .. Chu,. my e o - s up e rv i s o r s ,. T homa s. f o r t he i r w a rm enc our agemen t ,. and D r .. Alex .. g uidance w i t h. t h e f ie l d work a n d c o n s t r uct ive c ri t i c i sm and p a t ie n t c o r re c t i o n o f t h i s manus c r ipt .. My s in c e r e thanks a re a l s o extended t o :. Or .. John G .. H ampt on and O r .. P e t e r Coo lp e a r f o r the i r w i s e a dv i c e ,. w a rm enc o uragement and const ruc t ive c r i t i c i sm o f t h i s work .. Mr . M .. H a re a nd D r .. p r ope r t y a n d f o r. P.. Ro l s t o n f o r a l l owing me to us e D S I R' s Ao rangi. t he i r. kind e n c o u r a geme n t ,. wise. s ug ge s t i on s and. c o n s t ruct ive c r i t i c i s m: of this work .. Ray and Ka ren John s t one , s t ude n t s. in the. C ra i g Mc�i l l ,. M r s Dulcie Humphrey and the. Seed Te chn o l og y Ce nt re f o r their unde r s t anding and. h e lp i n s o many ways .. The M i s s E . L .. H e l l a b y I ndige n o us G r a s s l ands Resea rch T r us t a nd the. Helen E . Ake r s Scho l a r s h ip for f inanc i a l s uppo rt ..

(6) iv. A l l my f r i ends f o r t he i r h e lp and encou ragement .. F in a l l y , l ove ,. my deep e s t g r a t it ude t o my pa rent s and my daughte r ,. emo t i o n a l s uppo rt. and e n c o u r a gement. h a ve been inva luable t o. me . M y t hanks a re a l s o i ndebted t o my w i f e , Chunying, s uppo rt and enc o u r agement .. who s e. f o r h e r devoted.

(7) V. TABLE OF CONTEN T S. ABS TRACT. i. ACKNOWLEDGEMEN T S. iii. TABLE O F CONTENTS. V. L I S T OF TABL E S. ix. L I S T OF F I GURE S. xi. L I S T OF P LATE S. xiii. L I S T OF AP P E ND ICES. xiv. GENERAL INTRODUCT ION. CHAPTER 1 :. 1. L I TE RATURE REVIEW 1.1. Origin and dist r ibut i o n. 6. 1.2. Agronomic value. 7. 1.3. De s c r ipt ion o f t he p l a n t. 1.4. 1.5. 15. 1.3.1. Be low g round pa r t s. 15. 1.3.2. Above g round p a r t s. 16. Reproduct ive s t ruct u re s. 18. 1.4.1. F lowe r. 18. 1.4.2. Pod. 19. 1.4.3. Seed. 20. Growth and devel opment o f t h e plant. 21. 1.5.1. Vege t a t ive g rowth. 21. 1 . 5 .2. Reproduct ive g rowt h. 22.

(8) vi. 1.5.3. 1.6. F a c t o r s i n f luenc ing g r owth and development. 23. 1.5.3.1. Envi ronment a l f a ct o r s. 23. 1.5 .3.2. I n t e r n a l f a c t o rs. 24. Seed p roduction. 27. 1.6.1. P o l l in a t i o n. 27. 1.6.2. Seed deve l opment. 28. 1.6.3. Seed yield and yie l d c omponent s. 28. 1.6.4. Main ob s t a c l e s f o r s e e d product i o n. 30. 1.6.5. Management f o r h i gh s eed yield. 31. CHAP TER 2 : CONTRIBUT I ON OF VEGETAT I VE GROWTH TO REPRODUCTIVE GROWTH 2 .1. I nt roduct i o n. 36. 2 .2. Mat e r i a l s and Methods. 37. 2 .3. Re sult s. 39. 2.3.1. Shoot s ys t em. 39. 2 .3.2. P lant gene r a l growth. 43. 2.3.3. Shoot dynamics and t i s s ue t u rnove r. 45. 2 .3.4. F lowe r c a r rying abi l it y of d i f fe rent shoot groups. 2 .3.5. Con t r ibut i on o f d i f f e rent shoot g roups t o f l owe r ing pattern. 2.4. 50. D i s cu s s i on. 52 56. C HAP T E R 3 : SEED DEVELOPMENT AND SEED Y I E LD COMPONENTS 3.1. Int roduct io n. 60. 3 .2. Mat e r i a l s and Methods. 61.

(9) vii. 3.3. Re s u l t s. 63. 3.3.1. F lowe r a n d p o d deve l opment. 63. 3.3.2. Change s in s eed yie l d components. 63. 3.3.3. Abo rt i on at d i f f e rent s t age s of f l owe r deve l opment. 3.3.4. Seed deve lopment and the qu a l it y o f seeds h a rve s t ed a t d i f f e rent t ime s. 3.3.5. 68. Seed do rmancy and h a rdseed deve l opment. 3.4. 65. D i s c us s ion. 70 71. CHAP T E R 4 : S HOOT MAN I PULAT I ON TO IMPROVE SEED PRODUC T I ON 4.1. Int roduct ion. 80. 4.2. Mat e r i a l s and Met hods. 83. 4.3. Re sult s. 85. 4.3.1. E f fect o f shoot manipulat ion o n shoot growth and deve l opment. 4 .3.2. E f fect o f hand removal of shoot s on f lowe r ing pat t e rn. 4.3.3. E f fect. of. 97. E f fe c t o f cut t ing t re a tment o n s e e d p rodu c t i o n. 4.4. 93. E f fect o f f lowe r remova l on vege t a t ive growth. 4.3.5. 86. hand remova l o f shoot s on. seed yield componen t s and seed yie l d 4.3.4. 85. D i s c u s s ion. 99 101.

(10) v i ii. CHAP TER 5 : EFFECT OF PRE-P EAK F LOWERING CHEMICAL MANI PULATION ON P LANT GROWTH AND SEED P RODUCT I ON 5.1. Int roduct ion. 105. 5.2. Mat e r i a l s and Met hods. 106. 5.3. Re s ult s. 111. 5.3.1. E f fe c t o f P P 3 3 3 on plant growth and deve l opment. 111. 5.3.2. E f fe ct of P P 3 3 3 on f lowe r ing pat t e rn. 115. 5 .3.3. E f fe c t o f P P 3 3 3 on seed yield,. yield. c omponen t s and seed qua l it y 5.4. Discus s ion. 117 120. CHAP TER 6 : EFFECT OF P O S T - P EAK FLOWERING CHEMICAL MAN I PULAT I ON ON SEED PRODUCT ION 6.1. Int roduc t i o n. 125. 6 .2. Mat e r i a l s a nd Met h ods. 12 6. 6.3. Re sult s. 128. 6.3.1. E f f e c t on plant gene r a l growt h. 128. 6.3.2. E f f e c t on f lowe ring p a t t e rn. 131. 6.3.3. E f fect s on seed yie l d componen t s. 134. 6.3.4. E f fect s o n seed yield a nd seed qua l i t y. 136. D i s c us s i o n. 137. CHAP TER 7 : GENERAL D I SCU S S I ON AND SUMMARY. 141. B IB L I GRAPHY. 148. AP P END ICES. 169. 6.4.

(11) ix. L I S T OF TABLES. TABLE. PAGE. 2 . 1 . E f f e c t of c l ipping on shoot deve lopment. 41. 2 . 2 . Node deve l opment in d i f f e rent shoot age g roup. 46. 2 . 3 . Month ly i n c r e a s e in s hoot inte rnode length i n d i f f e rent shoot age g roups 2 . 4 . S h o o t s urviva l ,. 46. n umb e r of shoot s pe r p l a n t and. c omponent s o f t he s h oot populat ion a t d i f f e rent t ime s. 48. 2 . 5 . Numb e r s and p e rcent a ge s o f d i f f e rent s i zed leave s on d i f f e rent s i zed s hoot s 2.6.. 48. F i r s t f lowe r appea r ance po s it ion and relat ive f l ower bea r ing abi l i t y of shoo t s f rom d i f fe rent a ge g r o up s. 50. 2 . 7 . N umber o f f lo r e t s p e r i n f l o re s cence a t d i f fe rent p o s i t i o n s a long a shoot. 51. 2 . 8 . Numb e r of f lo r e t s pe r i n f l o re s cence i n d i f ferent s hoot a ge g roups a t d i f f e rent t ime s. 51. 2 . 9 . Cont r ibut io n o f d i f fe rent shoot a ge group s to t ot a l i n f l o r e s cence popul a t ion. 55. 3 . 1 . Ge rminat ion results in f re shly ha rve s t e d seeds and seeds a ft e r air drying. 69. 3 . 2 . Qua l it y of s eeds ha rve s t ed a t d i f f e rent t ime s. 70. 3 . 3 . H a rdseededn e s s and met hods o f b r e a k ing hard s e eds. 71.

(12) X. 4 . 1 . Hand removal exp e r iment a l det a i l s. 84. 4 . 2 . E f f e c t o f new s hoot removal o n the s u rv i v a l. 4 .3.. o f o ld shoot s. 86. S e e d y i e lds i n hand remova l t reatment s. 93. 4 . 4 . E f fe c t s of f l o we r remova l on vege t a t ive growt h. 99. 5. 1 . Expe r iment a l det a i l s f o r P P 3 3 3 t re a tmen t s. 110. 5.2. E f f e c t of P P 3 3 3 t reatment s on shoot length. 113. 5. 3 . E f fe c t o f P P 3 3 3 t reatment s on p lant g r ow t h and b ranching. 113. 5. 4 . E f fe c t o f P P 3 3 3 t reatment on dry mat t e r d i s t r ibut i o n. 114. 5 . 5. E f f e c t o f P P 3 3 3 t reatment o n pho t o s ynthe s i s and a s s imi l a t e d i s t r ibut ion. 114. 5 . 6 . E f fect of P P 3 3 3 t re a tme n t s on f l o re t and pod numbe r s 5.7.. 119. Seed y i e l d s and ha rve s t index o f P P 3 3 3 t re a tment s i n spaced p l an t s and i n swa rd p l a n t s. 119. 6 . 1 . Expe riment a l det a i l s f o r Nort ron and F a t o l Supe r t reatment s. 127. 6 . 2. Seed y i e l d components in Nort ron and F a t o l Supe r t reatment s. 136. 6 . 3 . S eed y i e lds i n No r t ron and Fat o l S upe r t reatme n t s. 136.

(13) xi. L I ST OF F I GURES. F I GURE. P AGE. 2 . 1 . Gene r a l p l ant growth s howing above -ground growth dry mat t e r changes with t ime. 44. 2 . 2 . Re l a t ions h ip between l e a f numbe r s and node 49. n ode numbe r s per s h o o t 2 . 3 . F l owe r ing p a t t e rn on t agged p l a n t s and on p l a nt s i n quadrat s. 53. 2 . 4 . F l owe r ing durat ion i n each shoot group and t o t a l 54. f l owe r i ng du rat ion o f t h e plant s. 3 . 1 . Change s in s eed y i e l d component s du r ing t he p e r i o d o f f l owe r ing. 66. 3 . 2 . Numb e r of f lowe r buds , open f l o re t s and pods p e r i n f l o re s cence a t d i f f e rent t imes. 66. 4 . 1 . F lower i ng patt e rn in hand remova l t re a tments. 88. ( S TC s it e , spaced plant s ) 4 . 2 . Change i n f l o ret numbers i n hand remova l t re a tment s with t ime. ( S TC s i t e ,. 1 987/88). 94. 4 . 3 . F lo re t numbe r s a nd pod numbers i n hand remova l t reatment s. ( S TC s i t e ,. 1987/88). 95. 4 . 4 . S e e d numbers pe r pod in hand remova l t re a tme n t s. ( S TC s it e ,. 1987 / 8 8 ). 96. 4 . 5 . 1 , 0 0 0 -s e ed we ight s in hand remov a l t re a tmen t s. ( STC s i t e ,. 1987/88). 96.

(14) xii. 4.6.. Seed y ie lds i n hand remova l t rea tment s ( STC s i t e ,. 1987 / 8 8 ). 98. 4 . 7 . F lowe r in g p a t t e r n in Cut ( S TC s i t e ,. t re a tme nt s. 1987 / 8 8 ). 100. 4 . 8 . Fl owe r i n g p a t t e r n in Cut ( S TC s i t e ,. (H). (L). t reatment s. 1 987 / 8 8 ). 100. 4 . 9 . Flowe r ing p a t t e r n in cutt ing t rea t ment s ( Ao r a n g i s i t e ,. s w a rd plant s ,. 1987 / 8 8 ). 100. 5 . 1 . F lo we r ing p a t t e r n s in P P 3 3 3 t rea tment s ( S T C s it e ,. spaced plant s ,. 1987/88). 116. 5 . 2 . F lo we r ing pat t e rn s in PP 3 3 3 t re a t ment s ( Ao ra ng i s it e ,. s w a rd p l ant s ,. 1987 /88). 5 . 3 . F lo we r ing p a t t e rns in P P 3 3 3 t re at ment s ( S TC s it e ,. swa rd plant s ,. 116 116. 1988/89). 5 . 4 . Changes in f lo ret numbe r s i n P P 3 3 3 t re atment s w i t h t ime. ( S TC s i t e ,. 1 9 87 / 8 8 ). 118. 6 . 1 . F lo w e r ing p a t t e rns in Nort ron t reatment s ( S TC s i t e ,. spaced plant s ,. 1987/88). 132. 6 . 2 . F l o we r ing p a t t e rns in Nort ron t re a tmen t s ( Ao rangi s i t e ,. sward p l a nt s ,. 1987/88). 132. 6 . 3 . F l o we r ing p a t t e rns in F a t o l Super t reatment s ( S TC s it e ,. s paced p l a nt s ,. 1987/88). 133. 6 . 4 . F lowe r ing p a t t e rns in F a t o l S upe r t re atmen t s ( Ao rangi s i t e , s w a rd p l a nt s ,. 1987 / 8 8 ). 133. 6 . 5 . Changes i n f lo ret numbe r s i n Nort ron t re a t ment s with t ime. ( S TC s i t e ,. 1987/88). 135. 6 . 6 . Changes in f loret numbe r s in Fat o l Supe r t reatment s with t ime. ( S TC s it e ,. 1987/88). 135.

(15) xiii. L I S T OF P LATE S. P LATE. P AGE. 1 . 1 . A v i e w o f the Lot us corn i c ul a t us c rop a t p e a k flower ing. ( 6 Janua r y 1 9 8 8 ). 6. 2 . 1 . Lot u s c o rn i c ul a t us plant s howing t a gg i ng t o ident i fy months of shoot p roduct ion. 40. 2 . 2 . L o t us c o rnicu l a t us plant showing mont h l y t agging fo r a s s e s s ing changes i n node numbe r s and shoot length. 40. 2 . 3 . L o t us c o rn i c ul at u s L . p l a n t. 42. 3 . 1 . F lo w e r a n d pod development s e quence. 64. 3 . 2 . Re p roduct i ve abort ion a t d i ffe rent s t ages. 67. 4 . 1 . P l a n t st r u c t u re a ft e r new s hoot remo v a l ( 2 9 November 1 9 8 7 ). 87. 4 . 2 ( a - e ) . P l ant shoot s t a t us in four h a n d remova l t re a tment s. ( phot o t a ken on 6 Janu a r y 1 9 8 8 ). 89. 5 . 1 . E ffe ct s o f P P 3 3 3 t re atment on p l a n t g rowth and branch i ng ( 2 9 Novembe r 1 9 8 7 ). 112. 6 . 1 . E ffect s o f No rt ron t re a tment on p lant g rowth ( 2 9 November 1 9 8 7 ). 129. 6 . 2 . E ffect s o f Fatal S up e r t reatment on plant g rowth. ( 2 9 November 1 9 8 7 ). 130.

(16) xiv. L I S T OF APPEND ICES. APP END I X. Append i x 1 .. P AGE. D ay length change. a t P a lme r s t o n Nort h ,. New Zea land . Appendix 2 .. 169. Monthly tempe r a t u re change a t P a lme r s t on North. 170. Appendix 3 .. Monthly r a i n fa l l a t P a lme r s ton North. 171. Appendix 4 .. Seed yield and y i e l d component s. Appendix 5 .. Seed y ie lds o f c u t t ing t re atments on spaced p l ant s and. ( S TC ,. 198 6-87). swa rd p l an t s. 172. Appendix 6 .. Seed yield and y i e ld component s. Appendix 7 .. Seed qua l i t y a s s e s sment fo r s eeds h a rv e s t e d. ( 1 987-8 8 ). from diffe rent t re atment s Appendix 8 .. 172. 173. 174. Mu lt ip le-regre s s i o n ana l y s i s of seed y i e l d a nd y i e l d components. 175.

(17) 1. GENERAL INTRODUCT ION. c o rn i c u l a t us L . ,. Lot us l e g ume. c ommo n l y k n o w n a s. i n t r o d uc e d i n t o N e w. ( Th oms o n ,. 1 9 22 ) .. Z e a l and. bi rds foot. a b o ut. one. t re f o i l ,. hund red. yea rs. is. a. ago. I t has sh own p romi s e a s a pa s t ure s p e c i e s in a re a s. whe re e nvi ronme nt a l condit ions a re c o n s ide red t o b e t o o h a r s h f o r the good p e r f o rman c e of other p a s t ure legume s , c l o ve r and l uc e rne n umb e r. of. ( H unt and Wagne r ,. advant ages. f o r a ge c rop .. s uch as wh i t e c l ove r ,. 1 9 6 3 ) . Unde r the s e condit ions , a. h a v e been n o t e d f o r Lo t us c o r n i c ul a t us. as a. L o t us c o rn i c ul a t us p r o duce s we l l in a r e a s whe re s o i l s. a r e i n fe rt i le , a c i d , d r y o r p o o r l y dra ined ( Robinson , Ch a r lt on et. 1 9 60 ; C h a r l t on ,. red. 1983) .. A l t h o ugh. it. al . , is. 197 8 ;. 1 9 3 4 ; Chevrette. Morton ,. 1981;. o f t e n c l a imed t o. be. S c o t t a nd. a p o o r - l a nd. c rop ,. Lot us c o rnicul a t us a l s o grows we l l in f e rt i le s o i l s and unde r. good. e n v i r o nme n t a l. a pp l i c a t i o n ,. 1 9 63 ) .. s i t ua t i o n s. season. re sponds. (Va rney,. Once e s t a b l i shed,. l o n g - l i ved p e rma n a n t p a s t ure late. It. we l l. to. f e rt i l i z e r. and the r e f o re c o ul d b e a h i g h l y p r o d uc t ive. f e rt i l e p a s t ure W a gn e r ,. condit ion s .. 1958 ;. 1 9 62 ;. in. H un t a n d. i t pr o v i d e s high ly p roduct ive and. for hay,. f o r a g e p r o d uc t i v i t y. H ughe s ,. l e g ume. f o r a ge. a l l o wsi t. and s i l a g e .. t o ma k e. a. I t s h i gh. s ub s t a n t i a l. c o n t ribut i o n f o r the even s uppl y o f anima l feed ava i l able dur ing the late. s umme r. S uc k ling , 1981) .. a n d a ut umn. 1960;. Davis ,. ( M a cD o n a l d ,. 1969;. Cha r l t o n ,. L o t us c o r n i c ul a t us c ompa r e s. other c ommon l egume s C h a r lt o n ,. 1 97 1 ;. 194 6 ;. (MacDona l d ,. Davi s. 1 97 3 ;. John a n d Lanc a s h ire ,. S uc k l ing , 1981) ,. 1 957 ;. Greenwood and S heath,. f av o u r a b l y in. 1946 ;. a n d Be l l ,. f e e d v a l ue. 1960;. and i t s. Smi t h ,. with 1964;. n o n - b l o a t ing. n a t ure i s a un ique and v a l uable c h a r a c t e r which mak e s i t s upe r i o r to.

(18) 2. o t he r common legume s in s ome c i rcums t ances Lotus. c o rn i c u l a t u s. pos s e s s e s a. ( Ma r t en and Jo rdan ,. 197 9 ) .. n o t a b l e n i t r o ge n - fixa t i o n a b i l i t y. w h i c h ma k e s i t a va luable pa s t u re spec ies , pa rt i c u l a rly when grown i n a mixt u re w i t h g r a s s e s. I n New Z e a l and,. ( B rophy et a l . ,. 1987). be cause o f t he ge nera lly fa vou rable c l imat e ,. c lo ve r s. p l ay a domi nant role a s pa s t u re legumes i n mo s t farming systems . The amount of r e s e a rch on Lotus c o r n i c u l a t u s has unt i l rece nt l y occupied o n l y a ma r g i n a l p l a c e p ro g ramme .. Howeve r ,. in. the. c o u n t ry ' s p a s t u re. s c i e n c e r e s e a rch. w i t h t he n e e d t o deve lop p roduct ive p a s t u re on. l a nd a re a s t r a dit i o n a l l y rega rded a s po o r ,. t he advantages o f Lot us. c o rn i c u l a t u s a s a fo rage legume h a ve become bet t e r recogn i zed .. The d i ffi c u l t y of ach i e v i n g a h igh s eed y i e ld in Lo t u s c o r n i c u l a t u s is. frequent ly quoted a s a ma j o r fac t o r l imi t ing i t s mo re w ide spread p a s t u re s y s t ems .. u s e in. w h i c h ma y s e v e r e l y l imit and Be u s i l ;n c k ,. 1983) .. A numb e r of a s pe c t s h ave b e e n i dent i fied the s e e d p roduct ion o f t h i s p l ant. (McGraw. T h e inde t e rm i n a t e growth habit o f the plant. r e su l t s i n a n extende d flowe r ing pe r iod w h i c h may make i t d i ffi c u l t to. h a rves t. McGr a w , s eed. t he. 1988) .. at. c ro p Also,. h a r ve s t i n g .. w i t h m a x i mum. seed. recovery. pod deh i s cence o ft e n It. has. been. ( B e u s i l �n c k. and. l e a d s t o a heavy l o s s o f. sugge s t e d. that. l o w a s s im i l a t e. dis t r ibut i on t o reproduct ive pa r t s might b e impo rtant i n l imit ing the potent i a l fo r h igh s eed y i e l d i n this p l an t and Hen s o n , As. a. 1 9 7 0 ; McG r a w and Beu s i l •:· nck,. result. of. these. facto r s. ( Ma cDona l d ,. 1946;. Seaney. 1 9 8 3 ; McG r a w et a l . ,. 1986) .. c o mme r c i a l. c o rn i c u l a t u s a re o f ten low and unre l i ab le .. s e ed y i e l d s. in. Lot u s. S e a ney and Henson. ( 1 9 7 Q). h ave s t ated that 5 0 - 1 7 5 kg/ h a i s a commo n l y h a r ve s t e d comme rc i a l seed yield,. while 2 0 0 - 5 7 5 kg / ha i s among the h ighe s t yie l d which c a n only.

(19) 3. be obt a in e d occ a s i on a l ly .. The c ur rent resea rch p ro gramme commenced a s a r e s ult o f the need fo r a bet t e r unde r s t anding o f t h i s plant and the need for the devel opment o f appropr iate mana gement s t ra t egies fo r bet t e r seed p roduct ion . pod d e h i s c e n c e. cha ra c t e r. a n d the. low. a s s im i l a t e c o n t r ib ut i on t o. r e p r o d uc t i v e g r o w t h i n t h i s p l a n t h a v e p r ev i o us. r e s e a r c he r s. g.,. 1 957 ;. that. t he. ( B uc k ov i c ,. McG r a w a n d Be us e l i n c k ,. emph a s i s. fl o we r i n g p e r i o d. of t h e. o f t h i s p l a nt , s hoot. a l r e a dy b e e n e xp l o red by. Ande r s o n ,. 1983) .. c ur r e n t. c o n t r i b ut i on o f d i ffe r e n t pa t t e rn .. 1952 ;. The. It. resea rch. 1955;. was. Met c a l fe et. t he r e fo r e de c i ded. s h o uld be o n t h e l o n g. w i t h p a r t i c ul a r age g r o up s. interest. t o t he. in the. l o n g fl owe r i ng. The s t udy a l s o examined p o s s i b l e management s y s t ems wh ich. could be used to overcome the prot racted fl ower ing s equence by s hoot man i p ul a t ion s t r a t e g i e s . p r e s en t. Wh i le the. us e of Lotus c o rn i c ul a t us. r e s t r i c t e d to ce r t a i n a g r onomic. s i t uat ions ,. it. is at. i s pos s ible. that more wide sp re a d u s e c o uld be ach ieved i n the fut ure as a re s ult o f a bett e r unde r s t anding of i t s rep roduct ive c h a r a ct e r s and s ucce s s i n a c h ie v i ng a. s uffi c ient a n d r e l i a b l e s e e d s upply t h r o ugh be t t e r. seed c rop management technique s .. The p r e s ent s t udy w a s divided into four pa r t s , p a r t i c ul a r a s pe c t .. P a rt. one. ( Chapt e r 3 ). e a c h empha s i s in g one. i nvolves a. s e r i e s o f fie ld. e xpe r imen t s de s i gned t o p r ovide ba s i c info rma t ion on t h e growth a nd d e v e l o pme n t. o f the. r e l a t i o n s h ip w i t h t h e. plant ,. ma i n l y. its. fl o w e r ing p a t t e rn .. shoot. s y s t em,. and. its. P a r t i c ul a r a t t e n t i o n h a s. b e e n d i rect e d t owa rds t h e cont r ib ut i on made by d i ffe rent shoot a ge g roups t o the d urat ion and inte n s i t y o f flowe r ing . 4). de a l s w i t h. P a rt two. ( Ch apt e r. flowe r a n d s eed deve l opme n t a n d t he c o n t r ib ut i on o f.

(20) 4. indi v i dua l seed y i e l d comp o n e n t s t o t o t a l seed yield . some s e e d charact e r s ,. In t h i s p a r t. s uch a s ha rdseededne s s a nd dormancy behaviou r ,. a re a l s o inve s t i ga t e d . Based o n the info rmat i o n obt a ined i n the fi r s t t w o pa r t s ,. p a r t t h ree. ( Chapt e r 5 ). i n v o l v i n g h a n d r emo v a l o f s h o o t s cutt ing t reatment s . on inve s t igat ing. comp r i s e s a s e r i e s o f expe r iment s f r o m d i ffe re n t. a g e g roups ,. and. I n this p a rt part i c u l a r emph a s is has been pl aced. the e ffect s o f phys i c a l shoot man ipu l a t ion o f plant. g r owth in o rde r t o p ro vide det a i led info rma t i on on the po s s ib i l it y o f u s ing shoot manipu l a t ion t o improve seed y i e l d in bi rds foot t re fo i l . In pa rt. fo u r ,. which. i n c l u de s. Chapt e r s. 5 a nd. 6,. t r e a tme n t s. we r e. extended t o a mo r e p r a ct i c a l s ituation u s ing p l a n t growt h regu l a t ing chemic a l s to man ip u l a t e both pre- and p o s t - peak flowe ring shoots favou r o f improved seed y i e l d .. in.

(21) 5. Plate 1 . 1 . A view o f the L o t u s corn icula t u s crop at peak f lo we r i ng (6 January 1 9 88).

(22) 6. CHAP TER I :. Be fo r e. L I TERATURE REVIEW. s t a rt ing this. review ,. it. s e ems. h e l p ful to g i ve. s ome b r i e f. de fin i t i o n s o f s ome te rms us e d i n t h i s w o r k which may otherwise c a use c o n fus i on . The t e rm ' b i rds fo o t t re fo i l ' , s pe c i e s L o t us. c o rn i c ul a t us. L. ,. is. also. de s c r ibe o t h e r s p e c i e s o f t he g e n us. Lo t us. 1946). The. a ngus t i s s imus L . , s pe c i e s Lot us. w h i c h c o ul d l e a d to t ime ,. us e d i n the. e.g.,. Lo t u s ,. a nd t re fo i l .. l i t e r a t ure t o. Lotus t h a t a re o f a g r i c ul t ur a l. i nc l uding Lot us ul igi n o s us Schk .. imp o rt a nc e , C av . ,. a lthough mo s t l y us ed for the. syn .. Lotus pedunculatus. a n d L o t us h i spidus D e s f. c o rn i c ula t us L .. a l s o has seve r a l synonyms. i t s c o n fus i o n w i t h othe r s pe c i e s. b i rd s fo o t t re fo i l ,. ( MacDon a l d ,. fr om t ime t o. broadle aved b i rds foot t re fo i l. The work de s c ribed here i s concent rated on. b i rdsfoot t refo i l ,. the. ' t rue '. Lotus c o rnicul a t us L .. 1 . 1 . O r i g i n and dis t r ib ut i o n. Lotus c o rn i c ul a t us L .. ( b i r d s foot t re fo i l ). i s a peren n i a l legume which. is t h o ught i n i t i a l l y to h a ve come from the Medi t e r ranean ba s i n ,. s ince. the g r e a t e s t dive r s it y of wild p l a nt s and d i s t r ibut i on of the species was. fo und to. Robins on. o c c ur t h e r e. ( 1 93 4 ) ,. ( S e a ne y a n d H e n s on ,. 1 97 0 ). Acco rding t o. the fi r s t de s c ript ion o f t h i s p l ant w a s. i n Ge r a rd ' s H e rbal in 1 5 9 7 ,. wh i l e E l l i s '. ( 17 7 4 ). in Eng l i s h. repo rt on t h e use o f. b i rds foot t re fo i l a s a feed fo r c a t t l e i n England c o uld b e rega rde d a s t h e e a r l i e s t use o f t h i s Rob i n s o n ' s review. ( 1 934) ,. species. in a g r i c ul t ur e .. By t he t ime o f. bi rds foot t re fo i l had been wi de ly found i n. E urope. ( with t h e e xcept ion o f F i n l and) , a s we l l a s in Rus s i a , Afr i c a ,. India ,. and great e r A s i a .. In Ma cDona ld' s l a t e r revi e w. (1946) ,. exte nded.

(23) 7. a re a s. o f us e. i nc l ude d T ibet ,. Aus t ra l i a ,. N e w Z e a l a n d a n d N o r t h and. S o ut h Ame r i c a .. The o c c ur r e n c e o f L o t us about 1 8 6 4 ,. c o r n i c ul a t us. a c c o rding t o Thoms o n. in N e w Z e a l a n d da t e s b a c k t o. ( 1 922) .. t h e fi r s t p e r s o n t o de s c r i be t h i s p l a n t. Levy. eva l ua t i o n. 200. c ul t i v a r s. o f L o t us. ( Cha r l t o n e t a l . ,. 1978. ) ,. from t h e Med i t e r r a n n e a n Re g i o n ,. 25. of i t s. S ince t h e n the n umbe r o f. c ult i v a r s int roduced h a s i n c r e a s e d s t eadi ly . t hen. appea red t o be. w i t h c o n s ide r a t ion. p o s s i b l e a g r i c ul t ur a l use i n t h i s c o unt ry .. mo re. (1918). By 1 9 7 8 the re h a d been. c o r n i c u l a t us. a v a i l ab l e. i n c l ud i ng 6 4. from E urope ,. f r o m S o ut h Ame r i c a ,. 23. fo r 31. from. U . S . S . R . and 21 from No rth Ame r i c a .. Despite i t s. l o n g h i s t o ry ,. pub l i s hed report s ,. as. reviewed by Rob i n s o n. and S e a n e y and H e n s o n did n o t begin unt i l earl ier. in. its. i t s w i de s p r e a d d i s t r ib ut i on and n ume rous. (1970) ,. 1 9 00. or late r .. e a r l y h i s t o ry. a t t r i b ut a b l e t o. t he. ext r eme. quant i t i e s o f s e e d ( Bo ite l ,. 1 . 2,. great. is. ( 1 934) ,. MacD o n a l d. (1946). i n t e r e s t i n Lotus c o r n i c ul a t us. The fa i l ure t o use t h i s pe r h a p s ,. at. least. spe c i e s. pa r t i a l ly,. d i ffi c ul t y i n h a r ve s t i ng s ub s t a n t i a l. 1893,. cited b y Robin s o n ,. 1934) .. Agronomic v a l ue. T h e us e o f Lot us. c o rn i c ul a t us. in a g r ic ul t ure da t e s b a c k beyond i t s. a c t ua l c ul t ure and recogn i t i o n a s a v a l ub l e c rop p lant . Many pioneer a g r i c ul t ur a l i s t s. h a ve me n t i o n e d the. c o r n i c u l a t us. t he i r. MacDona ld,. in. 1946) .. pape rs. Ac c o r d i n g t o. a g r i c ul t ur a l me r i t. (e . g .. W o r l i dge ,. Rob i n s o n. (1934) ,. of L o t us. 1681,. c i t e d by. Ellis. (1774). is.

(24) 8. c re d i t e d. as. the. f irst. pe r s o n. a g r i c ul t ur e va l ue .. In. that t h e T yne g ra s s. ( w i ld vet c h ). t re f o i l ) for. 177 4 ,. to. h e wrote:. a. 'I. us e f ul. a c c o un t. of. its. c a n a f f i rm i t f o r t r ut h ,. and the Lady - f inge r gra s s. ( b i rds f oot. a re the t wo best s o r t s o f nat ura l me adow gra s s e s t h a t a re ,. f e e d i n g a n d f a t t e n i n g t he. i ndeed,. g i ve. conie s ,. de e r a n d r a c e - h o r s e s ,. or,. f o r feeding and f a t t en ing any othe r s o rt o f cat t l e that w i l l. e a t t hem,. whet he r g iven t o t hem a s gr a s s o r hay . '. Ande r s on. cited. Ma c D o n a l d ,. d i s c us s e d. the. a nd emph a s i s e d. its. by. a g r i c ul t u r a l. v a l ue. 1946) of. also. de s c r ib e d. b i rd s f o o t. t re f o i l ,. and. compa r a t i ve pa l a t ab i l ity w i t h many othe r n a t i ve p l ant s . Martyn c i t e d b y Ma cD o n a l d , qua l it y e qua l , do ub t l e s s be ( 1855,. 1946). s t a t e d t h a t b i r ds f o o t. i f n o t s upe r i o r , cult ivated t o. c i ted by Ma cDona ld,. as n ut r i t ious a s c l ove r .. t re f o i l. t o mo s t o f the t ref o i l s ,. g o o d a dv a n t a ge. 1946). a l one . '. c it e d by MacDona ld ,. Rob i nson. ( 1934). f ul l b l o om abo ut. and. t r e f o i l by the 1946) ,. 'i s. of. Mo r t o n. cons ide re d bi rds foot t re f o i l t o be. for s a le by a s eedsman in Londo n , o f bi rds f oot. ( 17 7 9 ,. a nd might. Late r ,. s t a ted th at ,. by 1 8 1 0 ,. of b i rds foot t r e f o i l had become an a rt i c l e o f comme r c e ,. me r i t. ( 1777,. s eed. be ing l i s ted. indicat i ng recogn it ion o f the. f a rm i n g p ub l i c .. Sinclair. (1826,. e s t imated t h a t the p l ant would produce at. 1 0 2 0 9 pounds per a c re. ( appa rent l y ,. g reen mat e r i a l ) .. T h i s may be t h e e a r l i e s t quant it ive me a s urement of b i rds f o ot t re f o i l as. an. a g r i c ul t u r a l. MacDona ld, V i a nne this. 1946) ,. (187 0 ) ,. s pe c i e s .. e.g.. L a w s on. It. s h o ul d be. many. (1843) ,. researchers. Low. (1847 ) ,. ( c i t e d by. Lecoq. ( 1 8 62 ) ,. a l s o recogn i zed the va l ue o f. s p e c i a l l y p o i n t e d o ut. Steb l e r a n d Sch roet e r. that. ( c ited b y MacDona l d ,. among t h e 1946) ,. in. p re s e n t e d a c o mp r e h e n s i ve d i s c us s i o n o f b i rds f o o t t re f o i l ,. i n c l uding i t s de s c ript i o n , v a l ue ,. Late r ,. Vi lmorin-Andr ieux ( 1 8 9 2 ) ,. p i o n e e r w o r ke r s , 1889,. p l a nt .. a n d us e ,. wh i c h. adapt i on ,. s e rv e d a s. a. c ul t ure ,. p roduc t i o n ,. t ur n i n g po i n t. in. n ut r it ive. i nt e re s t and.

(25) 9. studies on b i rds foot t refo i l . The beginn ing o f t h e t went ieth century, a s point ed out b y Se aney and Henson. ( 197 0 ). i n t he i r revi e w ,. h e r a lded. a rea l e xpan s i o n in t refo i l c u l t u re .. Lotus c o rn i cu l a t u s i s a nut r i t ious he rbage p lant both for g r a z ing and hay .. With the. d e v e l opme n t. o f mode r n. a n a ly t i c a l. t e c h n i qu e s ,. mo re. a c c u r a t e qu a n t i t i v e eva l u a t i o n s we re made which confi rmed its h igh qua l it y a s a p a s t u re spe c i e s . t refo i l ,. in t e rms o f c rude p rotein ,. a nd v a r i o u s i n di c a t o r s. mine ral. wh i c h. a re is. usually. u sed. as. t he. s im i l a r ,. o r s ome t ime s. t h a t of the common ly u s ed h igh qua l ity pa s t u re legume s ,. s u c h a s c l o ve r s , Smi t h ,. Lanc a s h i re ,. e l em e n t s ,. readi l y fe rmentable c a rbohydrate. o f fe e d i n g v a l u e o f a p l a nt ,. h ighe r t h a n ,. 1960 ;. The chemi c a l compo s it i on of b i rds foot. luce rne a n d s a i n fo i n. 1964;. Cha r l t on ,. 1971 ,. ( M a cDonald,. 1 9 7 3 ; Van Soest ,. 1946;. Suc k l ing,. 1975;. John and. 1981) .. Lot u s c o rn i c u l at u s h a s a l s o been s hown t o be a va luable. fo r age c rop. s ince i t s p ro t e i n content rema i n s h igh unt i l ve ry l a t e in the g rowing s e a s on. (MacDonald,. 1 9 4 6 ; Suc k l i n g ,. 1 9 6 0 ) . Th i s is po s s ib l y r e l a t ed t o. i t s long flowe r ing pe r iod and t he fa ct t h a t i t s rep roduct ive growth o c c up i e s v e r y l i t t le of the t ot a l g r owth p e r iod . and Lanc a s h i re. (1981) ,. Acco rding t o John. the l a t e s e a s o n ' s s t emmy growth o f b i rds foot. t re fo i l is mo r e palat able t o l ive s t o c k than lucerne .. Th e. non-b l o a t ing. rumi n a n t. c h a ra c t e r. a n imal fa rming .. of lotus. species. has. a dv a n t a g e s. I t h a s b e e n we l l e s t ab l i shed that. h a ve a h ig h e r feed va lue in many c i r cums t ances than g r a s s e s 1970) .. H oweve r ,. s uch a s. in. legume s ( Ulya t t ,. t he o c c u r rence of b l oat fo l l owing g r a z ing o f l egumes. r e d and wh i t e c love r a nd l u ce rne h a s. d i s c o u raged t he mo re.

(26) 10. w i de s p re a d u s e o f t h e s e l i ve s t oc k .. imp o r t a n t p r o t e i n s ou r c e s. T h e n on - b l o a t ing c h a r a ct e r o f l o t u s. s a t i s fa c t o r y ( 1979). le gume s a s. a l t e rn a t i v e. l e g ume s. in pa stures .. fo r. s p e c i e s ma k e s t hem M a rt e n. and J o r d a n. showed t h a t sub s t itution o f a pure s t and o f Lotus c o rn i c u l a t u s. fo r one -t h i rd o f a luce rne-g r a s s p a s t u re s y s t em gave a 2 3 %. increase. i n da i l y we i ght g a i n s in lambs .. I t h a s been s u ggested t hat a dis advant a ge o f b i rd s foot t re fo i l a s a fo r a ge p l a n t. is. dige s t ib i l it y. ( John and Lanc a s h i r e ,. ( 1 9 62 ). its. fou n d t h a t. h i gh. l i gn i n c o nt e n t 1981). a lt hough l ive s t o c k. w h i c h a ffe c t s. its. a n ima l. Howeve r , Hen s o n and Schoth. .. fou n d l o t u s he rbage. l e s s a c c e p t a b l e t h a n other commo n leg ume s ,. s omew h a t. they re adily c on s umed it. once they bec ame a c c u s t omed t o i t .. Depending on p a s t u r e type condit ions ,. etc . ). and. (e . g .. c l ima t e ,. m a n a g e me n t. s o i l fe rt i l i t y and mo i s tu r e. me t h o d s ,. the. p e r fo rm a n c e. bi rds fo o t t re fo i l a s a p a s t u re p l a n t d i ffe rs great l y . is. not. as. Ho weve r ,. p r oduc t i ve a s. c l o ve r s. a nd luce rne. t h e r e a r e p l ent y o f s i t u a t i o n s. Gene r a l ly ,. of it. i n m a n y s i t u a t i on s .. in which b i rd s fo o t t re fo i l. h a s outyie lded t h e s e legumes whe re t h e envi ronment i s l e s s favourable fo r t he good pe r fo rmance o f l e gume spe c ies a n d mo i s t u re s u c h Wagne r ,. 1 9 63 ;. ( 1 94 6 ). has. amo u n t s. as w h i t e. and r e d c l ove r s. T a y l o r et a l . ,. 1973;. fo r. hay. and l u c e rne. Lambe rt et a l . ,. a l s o s h own t h a t b i rds fo o t. o f he r b a g e b o t h. requ i r i n g h igh fe r t i l ity. 1974). swa rd. ( 1 97 1 ). s i t u a t i o n s mo s t. i n Scot l a nd. MacDonald. t re fo i l p r od u c e d c omp a r ab l e. a n d fo r g r a z i n g. in. a. c omp a r a t i v e exp e r imen t s i n v o l v i n g c l ove r s and lu c e r n e . Cha r lt o n ' s work. ( Hunt and. s e r ie s. of. S imi l a r l y ,. h a s shown that in b o t h spaced and. of t h e b i r d s fo o t. t r e fo i l. cultivars. t ested. pe r fo rme d s a t i s fa c t o r i ly c ompa r e d w i t h w h i t e and red c l ove r s unde r.

(27) 11. t he s ame e xp e r imen t a l condit o n s .. S uc k l ing. t re fo i l w i t h five wh i t e c l ove r s ,. ( 1960). compa red b i rds foot. t wo red c lo ve r s and s eve r a l other. legume s wh i c h were a l l commonly used in p a s t ur e s in New Z e a l and . r e s ult s. The. s h o we d t h a t b i rds foot t re fo i l o ut yie lded a l l s p e c i e s except. red c l o ve r .. The. i n fe r i o r p r o d uc t i o n b y b i r d s fo o t. l e g um e s. un d e r. fa v o r a b l e. t r e fo i l. e n v i r o n me n t a l. c omp a r e d t o. condit ions. is. other. l a rg e l y. a t t r i b ut e d t o it s s l ow e s t a b l i s hme nt and t he r e fo re l e s s c ompet it ive n a t ur e .. A l t h o ugh t h e he rb age y i e l d s p roduc e d in e s t ab l i s hed l o t us. s t ands c an be h ighe r than t h a t p roduced by othe r legume s at the s ame s t a ge ,. its. playing an spec i e s .. s low e a r ly growth impo rt ant. ( MacDo n a l d ,. 1 9 4 6 ; D a v i s a nd Be l l ,. S uc k l in g ,. 1 9 6 2;. B ux t o n a nd We d i n , 1 9 81 ) .. the. chances. of itS. r o l e i n a m i xed pa s t ure w i t h m o r e aggre s s ive. 1960;. She at h ,. o ft e n de c r e a s e s. 1960;. D a v ie s '. 1957;. P a r s o n and Davi s , 1970;. 19 61;. Taylor et al . ,. exp e r imen t. P e a c o ck and W i l s i e , Scholl. 1 97 3 ;. at Abe r y s t wyt h. and B r unk ,. G re e n w o o d a n d. (1969). a l so s howed. t h a t a lt h o ugh t he growth of l o t us wa s compa rable w i t h c lo ve rs , e s t ab l i s hment b e h a v i o ur h inde r e d i t s p o s s ib l e. role a s. poo r. a p romi s i n g. p l a n t fo r h i l l land p a s t ur e s i n Wa le s .. It. i s e s s e nt i a l t o cho o s e t h e mo s t. b i r d s fo o t. t r e fo i l. s ui t ab l e management met hods. b a s e d p a s t ur e s .. s e n s i t ive to c on t i n uous g r a zing ,. Si n c e b i r d s fo o t. t h at. Davi s and Be l l. b i rds fo o t. t r e fo i l. ( 1957). is. t h i s s y s t em leaves l e s s chance fo r. r e c o ve ry g r o w t h a n d w i l l e ve n t ua l l y e l imi n a t e p a s t ur e .. t r e fo i l. fo r. the. species. and Van Ke u�en e t a l . ,. c o ul d be. ret a ined in. (1969). from a noted. a p a s t ure a n d c o ul d. p roduc e sat i s fa c t o r i l y w i t h a rot a t i o n a l g r a z ing s y s t em o f about t wo weeks. graz ing. and. fo u r. weeks. rest .. Henson. and. Schoth. ( 1 9 6 2).

(28) 12. cons ide red t h a t t he u s e of a cont i nuous g r a z ing system s ho u l d o n l y be r e c omme n d e d b i rds fo o t. fo r. t r e fo i l ,. Davis a n d B e l l (1968 ). on. s em i e r e c t. a n d by m a i n t a i n i n g a. ( 1957) ,. and Van. p o s i t i ve. cat t le g r a z in g. Smit h and Ne l s on. Keu ren. pe r s i s t e n c e. et. g.. and. 'Emp i re '. t yp e s. of. c o n t inuous ly h igh r e s idue .. ( 1967) ,. Van Keu ren and Davis. h a ve. a l l h i g h l i g h t e d the. (1969). p r oduc t i v i t y. r e spo n s e s. of lotus. not. sub j e c t e d t o cont inuous g r a z i ng .. Mixt u r e s o f b i r d s foot t re fo i l w i t h non-aggre s s ive g r a s s spe c i e s have s h ow n b e t t e r pe r fo rmance t h a n b i rds fo o t t re fo i l a l one . expe r imen t s. ( 1946). a n d fo r g r a z i n g . grasses. were. pr a t e n s e , (1961). c learly shown t h i s He c o n s ide r e d. those. that. in pa s t u re s u s e d both fo r hay. that. produced. t h e mo s t. an. open. s u i t a b l e c omp a n i o n. s w a rd. cu l t i v a r was. a. such. Parsons. D a c t yl i s glome r a t a a n d P o a pr a t e n s i s .. found t h a t. Ma cDonald ' s. as. P h l e um. and Davis. r a t h e r t h a n a n e a r ly s e a s on D . glome r a t a. late. l e s s c ompet i t i ve and h e n c e mo re compat ib l e w i t h. lotus .. Unde r s t rong compet i t ion b i rds foot t re fo i l was event ua l ly e l iminated from p a s t u r e. ( Chevret te et a l . ,. Depe nding on t he g r owth habit. 1960) .. invo lve d ,. t he re spon s e t o de fo l iat ion. d i ffe r s between v a r i e t i e s of b i rds fo o t t re fo i l . t yp e s. Semi - e re c t. 'Emp i re '. a re mo r e pe r s i s t e n t a n d w i l l p r oduce bett e r u nde r i n t e n s i ve. de fo l i a t i on t h a n t he e re c t r e c ommended fo r g r a z ing , p r o du c t ion. ( Seaney ,. 'V i k in g '. t ype .. The forme r a re the refo re. wh i le the l a t t e r type i s enco u raged fo r hay. 197 5 ) .. D e s p i t e the extens ive ove rs e a s u s e o f b i rd s foot t re fo i l fo r h a y , h a s n o t been gene r a l l y recommended fo r t h i s purpo s e S c ot t. and C h a r l t o n. (1983). s t ated that. 't h e r e i s. it. in Ne w Z e a la nd .. l i t t l e doubt t hat.

(29) 13. other. s p ec i e s ,. p a rt i c u l a r l y. l u c ern e ,. wi l l. produc t ive f o r hay produ c t i o n i n Ne w Z e a l a nd . is. l i k e l y t o h a ve a ro l e a s. drie r regio n s ,. Lotu s. a gr i c u l t ure a s is. is. Thus bird s f oot t ref o i l. a gra z ing s p e c i es. b e c om i n g. a f o rage m o dera t e. ( Ch a rl t on e t a l . ,. i n t h e l e s s f ert i l e. 1 9 7 8;. m o re. i mp o rt a n t. in. New. a. Z ea l a n d. l egume f o r u s e under condit i o n s where s o i l to. low,. p a rt i c u l a r l y. S c ot t and Charlton ,. in. d ry. s it uat ions. 1 9 83 ). S e a s o n a l product ion o f Lotus c o rn i c u l a t u s sugges t s i t s ma jo r as. b e mo re. a s does Maku Y�t u s i n the l e s s fert i le wet t e r region s '. c o rn i c u l a t u s. fert i l ity. gen e r a l ly. f e ed s u pp l y f o r late. s e a s o n p roduct i on .. ro le is. As men t i oned ea rl ier,. Lotus corn i c u l a t u s i s l e s s product ive during the early gro wing s ea s on ( s pr i n g ) .. H o wever,. its. l a t er s e a s o n growt h ,. c on d i t ion s wh i c h o ften occurs o t h e r legume s . b et t e r t h a n. in. part ic u l a rl y under dry. in the New Zea l and summe r ,. The herbage qua l i t y of t h i s s ome o t her l egumes. such. overy ields. later p roduct ion is as. a lso. G ra s s l a nd s M a k u J.at u s. ( Lo t u s pedunculatus Cav . s yn . Lot u s u l igin o s u s Schk ) . C h a r l t o n ( 1 9 7 1 ) f o u n d t h a t d i g i s t ib i l i t y o f b i rd s f o o t h i g h e r t h a n t h a t o f L o t u s pedun c u l a t u s , f l owering s t ages of growt h .. t ref o i l. was. s i g n i f i c a nt ly. both i n t he veget a t ive and. Scott and Charlton. ( 1 9 83 ). ment ioned that. t h e later s t emmy growth o f Lotus c o rn i c u l a t u s wa s eaten mo re re adi ly t h a n that o f lucerne .. Among the other advant ages o f b i rds foot t re f o i l as a p a s t u re plant i s i t s pers i st ence , a c h a ra c t e r wh ich h a s been recogn i z ed f o r s ome t ime . I n Canada ,. Chevret t e et a l . ,. (1960). f ound that b i rds foot t re f o i l wa s. more pers i s t ant than lucern e in long t e rm leys on imperfe c t l y dra ined s o i ls .. It a l s o pers i s t ed l onger t han Ladino or a l s i ke c l overs on the.

(30) 14. two s o i l type o n wh ich the s e c rops we r e compa red . {1 9 83 ). S cott and Charlton. s tated that birds f o o t tre f o i l wa s the mo s t pe r s i s tent legume. and o f ten the o nly rema i n i ng p roductive legume when g r a z ing is la x , and. a f te r. f e r ti l i ty h a d b e e n d e p le te d .. i n v o lv i ng c l o ve r s , S cott {1 9 85 ) te s te d. in. luc e rne ,. In. an. e v a lu a ti o n tr i a l. lotu s a n d other c ommonly used legume s ,. s ho wed tha t lo tu s spe c i e s we re supe r i o r to o th e r spe c i e s te r m s. of. p e r s i s te n c e ,. w i th. L o tu s. c o r n i c u la tu s be ing. s upe r i o r to o the r lotu s spe c ie s .. B i rds f oot tre f o i l has o f ten been r e f e r red to a s a d ro ught re s i s tant p o o r la nd pla n t. {Cha r lton et al . ,. S c o tt a n d C h a rlto n , the a s pe c ts. 1 9 83 ) .. o f g r o wth ,. I ts. 1 9 7 8;. Greenwood and She a th ,. 1 9 81 ;. r e s ponse to s o il mo i s tu re stre s s in. r e p rodu c ti o n ,. a nd mo r ta lity wa s bette r tha n. w h i te clove r , but n o t a s g o o d a s luc e rne. { F oulds ,. 1 9 7 8) .. Wh i le mo s t repo rts cla im that b i rds f oot tre f o i l i s drought re s i s tant { Ch a rlton e t a l . ,. 1 9 7 8;. r e p o rts. th a t. s ta t i n g. S c ott and Cha rlto n , it. imp e r f e c tly d r a ined s o ils M o r to n. {1 9 81 ). d r a i ne d. w i ll. also. { Rob in s on ,. 1 9 83 ) ,. pe r f o rm. 1 9 3 4;. the re a re some. s a t i s f a c to r i ly. Chev rette e t al . ,. on. 1960) .. repo rted b i rd s f o o t tre f o i l tole rated a c id and poo rly. P a k ihi. c o a s ta l s o i ls. be tte r. th a n wh i te. c lo v e r. These f e a tu r e s will a s s i s t b i rds f oot tre f o i l gain a recogn i z ed pla ce among c ommonly used legume s .. B i rd s f o o t tre foil h a s u s ually been cons idered a s a p o o r - land f o r a ge c r op. be c a u s e. legume s . do e s. i t p e r f o r ms. H o weve r ,. b e tte r. in. such. s i tu a ti o n s. th a n o th e r. i t i s e r roneous to conclude th a t b i rdsfoot tre f o i l. n o t r e spond t o b e tte r. s o il conditio n s .. shown that with liming and f e rtili z a tion ,. Va r ious. repo r ts. h a ve. the produ ction o f b i rds foot.

(31) 15. tre f o i l cou ld be increased s ign i f icant l y Hunt and Wagne r ,. (Varney,. 1 9 5 8 ; Hughe s ,. 1 9 62 ;. 1963) .. 1 . 3 . De s c r iption o f the p l ant. 1 . 3 . 1 . Be l o w ground pa rts. The. root s y s t em of b i rd s f o o t tre f o i l cons i s ts p r ima r i l y of a s trong. tap root with numerous branche s . The long, p r im a r y r o o t. is. tape ring and u s u a l l y fo rked. s u rmo unted by a de n s e c r o wn. f r om wh i c h the s h o o t. s y s tem eme rge s . Depending o n the growth s tage ,. t h e dime n s i o n s o f the. root s y s t em va ry, but a f u l ly deve loped root s y s tem could we l l exceed 1 metre in depth and 0 . 7 5 metre in width ( MacDona ld, mu c h l a rge r r o o t s y s te m th a n t h a t o c c u r s. in. 1 9 4 6 ) . This is a. red c l o ve r .. The. root. s y s tem o f b i rdsfoot tre f o i l i s n o t a s deep a s tha t o f luce rne , b u t i s m o r e e xte ns ive in d i s tr i bution . p o int o f wa te r upta k e ,. Cons ide r ing tha t r oots a re t he ma in. the di f f e re n c e s. in the r o o t s y s tems of the. th ree legume s may e xp l a in why b i rds foot tre f o i l and l u c e rne a re mo re r e s i s tant to wate r s t re s s t h a n c l ove r 1 97 8 ;. S c o t t and C h a r l to n ,. ( Ch a r l t on et a l . ,. 1 9 7 8 ; F au lds ,. 1983) .. A majo r d i f ference between Lotu s c o rnicu l a t u s and Lotu s pedunc u l a t u s is. th a t t h e f o rme r s e l dom p o s s e s s e s. f requently. r h i z oma to u s. Ba rnett ( 1 9 7 1 ). ( S h e a th ,. rh i z ome s. 1981) .. wh i l e t h e. D e s p i te th i s ,. l a tte r i s Wa s s o n a nd. obse rved tha t the old woody s tems o f b i rds f oot tre f o i l. a re c ap a b l e o f p rodu c ing s ome. r h i z oma t ou s s hoots ,. common s ituati o n s the plant i s n o n - rh i z oma t ou s .. a lt h ough in mo s t.

(32) 16. 1 . 3 . 2. Above-ground parts. There a re c o n s iderab l e v a ri a ti on s L o tus c o rn i c u l a tus , wh i c h. in the above-ground morph o logy o f. in terms o f s i ze,. shape and growth h abit,. a re i n f l u en c ed b y g en o ty p e and. en v i ro nmen t .. a l l of. The s tem o f. b i rds f o o t trefo i l i s u s u a l ly green and squ a re i n cro s s s ection i n its u p per. reg i o n s. des p i te b e i n g. en v i r o n m e n t a l ( MacDona ld ,. c o n d i ti o n s ,. r o u n d a t th e b a s e .. s tem s. may. r ea c h. 1. U n der. o p t i ma l. metre i n. l en g th. 1946) .. Mo s t morph o l ogic a l v a r i a tions occur in the gro wth habit and branch ing behaviour . The stems may be pros trate, to M a c D o n a l d. (1946) ,. i n the more pro s tra te type the s tems a rising. f ro m th e s eed l i n g , e s t a b l i s h ed. s h o rt,. or. pl ant,. c o n s idera b l e heigh t .. a s c ending , or erec t . Ac cording. l a ter f rom th e buds. l ie. on. th e g r o u n d. I n �enera l ,. o n th e c ro wn. w i th o u t. of. th e. rea c h i n g. any. th e i n tern odes o f th i s p l a n t a re. wi th some elongation towa rds the midd l e or near th e a pex o f. th e s tem d u r i n g th e s ea s o n. o f mo s t ra p i d g ro wth .. B a s ed on th ei r. growth habit, two d i s ti nct types of birds foot tref o i l were recogn i s ed ( S eaney and Hen s o n , ' Vi k ing ' The. 1970) ,. - - - the erec t. a s a typi c a l repres entative). ' E u ro pea n '. b ec a u s e o f. i ts. type i s. u p r i g h t g ro wth. l a te ma tu r i n g ,. type. ( cu l tivar. and s emierec t ' Empire'. type .. c o n s i dered m o r e s u i ta b l e f o r u s e a s hab i t. productiv i ty under g ra z ing pres s u re . h a rd y ,. ' Eu ropea n '. w i th. and. les s. The s emierect. m a n y b ra n c h ed. c o n s idered mo re s u i t a b l e f o r g ra z i n g. ( S ea n ey ,. hay. p er s i s ten c e a n d ' Empire'. l ea f y 1975). s tem s. type i s a nd. is. Ho wever,. it. s h o u l d be borne i n mind tha t the gro wth h a b i t o f the s h o o ts vari es w i del y among th e n umero u s. c u l ti v a rs. o f b i rds f o o t tref o i l ,. i n c l ude many i ntermedi a te f o rms i n terms o f s hoot morph o l ogy .. wh i c h.

(33) 17. Ap a r t. f rom. variation s. in. ( p a rt i c u l a r l y p h o t o p e r i o d ) b i rds f o o t t re f o i l .. g e n o t yp e ,. e n v i r o nme n t a l. factors. g r e a t l y i n f l u e n c e the g rowt h h a b i t o f. Rhykerd et. in. s h o rt. days o r low l ight inten sit i e s t he le a f : s t em r a t io te nds t o be. lowe r. al . ,. ( 1 9 5 9b ). repo rted t h a t. than i n p l a n t s g rown under long days . McKee. ( 1 9 62 ). grown. r o s e t t e t yp e. unde r. s h o rt. days had a. p ro s t r a t e ,. s t a t e d that plant s of. g rowth. compa r e d t o the mo re e rect f o rm o f plant s g rown unde r long days . series. of. s tudie s. u s i n g c o n t r o l l e d e n v i r o nme n t a l. va r i e t y ident i f i c a t i on s , o f t he. ' V i k in g '. ' Emp i r e '. t ype. N it t l e r and Kenny. ( 1965). In a. condit ions. for. foun d that p lant s. we re e a s i l y d i s t ingu i s hed f rom p l a n t s. t ype by t h e i r r e s p o n s e to pho t ope r i o d in t e rms. o f the. of. shoot. length a n d numbe r .. The b ra n c h ing o f b i r d s f o o t t re f o i l a l s o va r i e s g r e a t l y . (1946). Ma c D on a l d. s h o wed t h a t t h i s p l a n t w a s domi n a t e d b y t h e s h o o t s a r i s ing. f r om the. c rown a re a .. Alth ough many s ma l l l at e ra l b r anches appea red. f rom l e a f axi l s o f t he c rown shoot s , the s e lateral b ranches we re much sma l l e r t h a n t h e ma in s h o ot s . H e a t h ' s pape r. (1949). also. S imi l a r l y ,. t he p l a nt s. in Hugh e s a nd. s h o w t h a t b i rds foot t r e fo i l. is. comp ri s ed. ma i n l y of st ems f rom the c rown and ve ry few sma l l l a t e r a l s t ruct u re s f r om l e a f axi l s . in. Smith. ( 1 9 6 2 ) , Ne l s o n and Smith. e a r ly s p r in g t he re wa s. g r o wth but t h a t r e s idu a l s tubb l e .. s u b s equent. a b a s a l f lush of shoot s. f ound that. a va i l a b l e. for. regrowth o c c u r red f rom a x i l l a ry buds on. They men t ioned that b r a nches a r o s e ma i n l y f rom the. uppe r a x i l l a r y r e g i on of t he s h o o t s b ranche s .. ( 1 9 6 8a , b ). r a t h e r than the ba s a l. or l o w e r.

(34) 18. The leaves o f b i rd s f oot t re f o i l a re bo rne a l t e rn a t e ly a long oppos ite s ide s. of t he s t em .. Each l e a f c o n s i s t s of. the t e r m i n a l end of e a s i l y m i s t a ke n. for. b i rd s f o o t t re f o i l Le a f l e t s. the p e t i o le and 2 s t i pu l e s. ( H eyn ,. 5. at. at. a nd H e n s o n ,. The t rue. s t ip u l e s. the base o f the. a l t h ough t h e. r o u n de d t o o b l a n c e o l a t e between v a r i e t i e s. 3 a t t a ched to. the b a s e wh i ch c o u l d be. 1976) .. a re s ma l l p r o j e c t i o n s. a re t yp i c a l ly obo v a t e ,. l e a f l et s ,. in. leaf .. s h ape m a y va ry f r om. ( M a cDonald,. 1946;. Se aney. 1970) .. 1 . 4 . Rep roduct ive s t ructures. 1 . 4 . 1 . F l owe r s. The i n f lore s ce n c e o f b i rds foot t re f o i l i s a t ypical umbe l c on s i s t ing of. v a r y i n g n umbe r s. pedice l s t o a. long peduncle .. u n i t e d sepa l s pet a l s .. The. ( usua lly. 4 - 8). of. f l o re t s. a t t a c h e d by. s h o rt. Each f l o ret con s i s t s o f a c a ly x with 5. a n d a t yp i c a l pap i l i o n a c e o u s. r e p r o duc t i v e pa r t s. of. the. l e gume. f l o w e r a re. corolla with. 5. t yp i c a l o f the. s t ructure s in the Legumi n o s ae. with 9 f u s e d plus one s ep a r a t e s t amens. as. s i mp l e. ma le. s t r u c t u re s. ( Ma cD o n a l d ,. 1946;. and. one. S e a ne y and H e n s on ,. f rom a l ight to dark ye l low, r e d s t r ipe s. p i st i l 1970) .. as. f ema l e. P e t a l c o l o u r m a y va ry. a nd may be t inged with f a int o ra nge o r. ( Jones and C rawf ord,. 1 97 7 ;. Abbot t ,. 1 9 81 ) .. C o l o u r a t the. k e e l t ip can be ye l l o w , b rown , o r red a t d i f f e rent s t ages W i l s ie ,. 1963) .. s t r u c t u re. ( Bu z ze l l and.

(35) 19. 1 . 4 . 2 . P ods. S e ve r a l. pods. pedu n c l e ,. a r e b o rne. at. a lmo s t. r ight. g i v i n g t he appe a r a n c e o f. c y l indr ica l ,. and. b r o wn. to. a ng l e s. a b ird' s. a l mo s t. black. to t h e t ip of t he. foot . at. P o ds. a re. ma t u r i t y .. long , Af t e r. po l l in a t i o n ,. p o d s deve lop. rap idly a nd r e a ch ma x i mum s i z e i n about. t h ree w e e k s ,. but. a n o the r. c ondi t i on s , 1956; 1988) .. it t a k e s. f o r the pods to mature. Winch , Winch. 1 95 8 ; ( 1958). V i k ing o f 2 5 m m. Seaney. ( l engt h ). Buba r ,. 1 95 8 ) .. into mature. s eeds .. wee ks ,. ( Ande r s on ,. and Hen s o n ,. depend ing on wea ther 1 9 5 5 ; Wiggans et a l . ,. 1970;. Beu s e l i n c k a nd McG r a w ,. ment ioned ave rage p o d dime n s ions i n the cult i v a r. 2 0- 7 0 ovu l e s p e r ova ry , 1949;. 1-3. by 3 mm. ( di amet e r ) .. B i rd s f o o t t re f o i l has. t h e a ve r a ge numbe r b e i ng about. Howeve r ,. only about. 45. ( G i le s ,. 4 0 % o f the s e ovu l e s deve lop. Ave r a g e pod n umbe r pe r. i n f l o r e s c ence varies. c o n s iderably i n d i f ferent e n v i ronme nt a l condit ions a nd i n d i f f e rent f lowe r ing s e a s on s .. The numbe r of pods p e r i n f l o re s cence c o u ld be a s. low a s 2 i n t h e late f lowe r ing s e a s o n Seeds. a re. He n s on , p r ob lems (Kelly,. a t t a c hed t o. 1 9 7 0). .. P od s. t h e vent r a l. In a. w i t h p o d deh i s cence ,. s ut u re. o f t h e pod. r e a d i ly de h i s c e a t ma t u r i t y ,. d u r i n g s e e d p r odu c t i o n 1988) .. ( Beu s e l i n c k a nd McG r a w ,. a n d h a r ve s t i n g. 1988) .. ( Seaney and. c re a t i n g s e ve re in this. s pe c i e s. s t udy o f t h e morpho l o g i c a l f a c t o r s a s s o c i a t e d Buckovic. (1952). sugge s t e d t h a t the d i f f e rent i a l. lo s s o f mo i s t u r e f rom e xo c a rp and me s o c a rp t i s sue r e s u lted i n t en s i o n between f ib re laye r s wh i ch c a u s e s sepa rat i o n a n d t w i s t ing o f the t wo v a l ve s o f t he pod . c o nt e n t .. Pods deh i s c e a t 40- 6 0 % o f the i r o ri g i n a l mo i st u re. Met c a l f e e t a l .. in d i r e c t l y. in f l u e n c e d. ( 1 957 ). i n d i c a t ed t h a t. p o d deh i s c e n ce b y equ i l i b r a t i n g mo i s t u re. c ontent o f t h e pod w i t h low leve l s o f humidit y . c o ntent ,. r e l a t i v e humi d i t y. Around 1 0% mo i s t u r e. o r 3 0% relat ive humi d i t y s eemed t o b e the. 't r igge r '. f o r pod.

(36) 20. deh i s c e n ce .. Rapid drying,. r e s u l t i ng. in. rapid loss. of. mo i s t u r e ,. encou rages a h igh inc i dence o f deh i s cence , w h i l e pods which a re dried s lowly do not l ow. ( Buckovi c ,. 1.4.3.. The. deh i s ce even t hough the pe rcent age of pod mo i s t u re i s 1 9 52 ) .. Seeds. s ee d s. of. b i rds f o o t t re f o i l a r e. S e a ney a n d H e n s on ' V i k ing'. ( 1 9 7 0). s ma l l .. M e a s u reme n t s quo t ed by. s howed t he a ve r a ge d imen s i o n s. t o be 1 . 4 mm long 1 . 2 mm w ide ,. and 0 . 9 mm t h i c k .. we ight s v a ry c o n s ide r ably i n d i f f e rent rep o rt s , 1 . 57g et. ( Ma c D on a l d ,. .2...1..,. 1966;. 1946;. Rob i n s o n ,. Beu s e l inck. 1949;. f rom o l i v e g r e e n , Hens o n ,. H a rd. t o brown ,. s eed of. 1 000- seed. ranging f rom 0 . 9 2 g t o. Ande r s on ,. a nd McG r a w ,. c o n s ide r a b l e v a r i a t i o n in s eed c o l o u r. of. 1988) .. 1 9 55 ;. Albrecht sen. The re. is. in b i rd s foot t re f o i l ,. and s ome t ime s a lmo st b l a c k. also. ranging. ( Se aney and. 1 970) .. s eeds. a re p r e s e n t. in. a. l a r g e p e r c e n t age. e s pe c i a l l y when the c rop is hand-h a r ve s t e d .. i n ma t u r e. I n New Yo r k ,. s eeds ,. Brown. f ound t h a t h a nd ha rve sted seed con t a ined up t o 90% h a rd s ee d , t he. a. amo u n t. h a rve s t e d .. o f h a rd s e e d f e l l. to about. P e rcent age of ha rd seed. met hods a f t e r h a r ve s t . MacDonald. (1955) wh i l e. 4 0 % when s e e d w a s ma ch ine. is. a l s o i n f l u e n c e d by h a ndl ing. (1946). reported that a c rop cut and. c u red i n t he f i e l d for a pe r i od of 10 days had an ave rage ge rminat i on of o n l y 7 % .. Howeve r ,. i n a s imi l a r a re a ,. cut at t he s ame t ime , w i lted, t o swea t ,. and then dried,. s e eds obt a i ned f rom a c rop. cooked ove r night ,. st a c ked f o r 1 8 hours. gave a n a ve r a ge ge rmina t ion of. 81% .. It i s. not c le a r whethe r t he f i rs t t reatment p r omoted h a rd seed deve lopment , o r t he. s e c o n d t re a tmen t s o f t e n e d h a rd seed .. In the nat u r a l habitat.

(37) 21. T a y l o r �a l .. ( 1 9 73 ). repo rted that 4 5 - 5 4 % o f Lotus corni c u l a t u s s eeds. o c c u r ring o n or ne a r the s o i l s u r f a c e were h a rd seeds .. 1 . 5 . Growth a n d deve l opment of t he p l ant. 1 . 5 . 1 . Vege t a t i ve growth. The mo s t s u i t able t empe rature for b i rds foot t re f o i l seed ge rminat ion i s about. ° 20 c .. ° Ge rm i n a t ion i s de l a yed be l o w 1 5 c ,. and reduced by temp e r a t u re s above 3 0 °c Best. and both de l ayed. ( Wo ods and MacDona ld ,. 1971) .. f ie l d emergen c e i s a ch i eved when s e e d s a re p l a c e d i n a f i rm ,. s mo o t h. soil. 1 9 63) .. be d ,. at. a dept h. of. 0 . 5 - 1 . 0 cm. ( S t i c k l e r a n d Wa s s om ,. F i e ld eme rgence o f birdsfoot t r e f o i l i s a l s o a f fected b y s o i l. mo i s t u re. c o ndit i o n s ,. ge rmin a t i on b e i ng de l a yed b y a. s o i l mo i s t u r e. s t re s s o f 4 . 5 atm and comp l ete ly inhibited by a s o i l mo i s t u re s t re s s o f 1 1 a t m ( Woods a n d Ma cDon a l d ,. 1965, 1971) .. The s e e d l i n g growth rate o f b i rds foot t re f o i l i s s lo w c ompa red with othe r c ommo nly u s ed f o rage (McKe e ,. 1 9 62 ;. and Wed i n ,. Smi t h ,. 1 9 62;. 1 9 7 0; S e aney ,. legume s. such. as. Ne l s on a n d Smit h ,. l u c e rne 1968a,. 1 9 7 5 ; McKe r s i e and Tome s ,. and red c l ove r b,. 1969;. Buxt on. 1 9 8 2 ) . Th i s f a c t o r. can d i rec t l y a f fe c t i t s s l o w e s t ab l i s hmen t a n d hence subs equent l a c k of. c omp e t i t i v e. ability. in. comp a r i ng the e s t ab l i shme n t. a. m i xe d p a s t u r e. s it u a t i on .. S t ud i e s. o f b i rds f oo t t re f o i l w i t h o r without a. comp a n i o n c rop demon s t rate t h a t c omp a n i on c rops a re o ft e n det r iment a l to. s e e d l i ng g r o w t h and p e r s i s t a nc e. 1 9 6 0;. S c h o l l and Brun k ,. i n p r a ct i ce ,. 1 9 62 ;. ( Wi n c h ,. 1958;. Chevr e t t e e t a l . ,. W a ke f ie ld and S k a l and,. 1 9 6 5 ) . Howeve r ,. mixt u re with l e s s aggre s s ive g r a s s e s i s recommended f o r.

(38) 22. bet t e r. p e r f o rm a n c e. ( MacD o n a l d ,. of. the. p a s t u re. or. 1 9 4 6 ; Ande rson and Met c a lfe ,. The r e growth o f b i rds f oot t re f o i l and r e d c l o ve r. ( Smit h ,. 1962 ;. for. h igher. s eed. yie lds. 1957) .. i s a l s o l ow compa red w i t h luce rne. Smi t h and Ne l s o n ,. 1 9 6 7 ) . T h i s f e a t u re i s. po s s ib l y re l a t e d t o i t s lower root reserve s . Unlike luce rne in which there mo s t. is. at. l e a s t one root. v i gou rou s. r e s e rve a c cumu l a t i o n pe r i o d du r i n g the. g r o w i ng s e a s o n ,. lot u s maint a i n s. a. ve ry. low. root. re s e rv e level t h roughout t h e growing s e a s o n unt i l t he app roach o f the cold. s e a s on. re s e r v e s. ( Sm i t h ,. f o rc e. 1962 ;. t he p l a n t. Heichel. to. re ly on. et. g.,. 1985). The. low. root. c u r r e n t p h o t o s yn t he s i s. f rom. re s id ua l g reen t i s su e s for recove ry growt h . This exp l a i n s the p l ant ' s slow. re c o ve r y g r o w t h r a t e a n d i t s. ( Smit h a n d S obe r a l s ke ,. l o w t o l e r ance t o h e avy g r a z ing. 1975) .. De s p i t e t he s l ow e st ab l i s hment and s l ow rec ove ry growt h o f b i rds foot t re f o i l ,. its late s e a s on growth rate is i n many c a s e s as good a s ,. e v e n be t t e r t h a n , and l u c e rne Davies ,. or. o t he r c ommon f o r a ge le gume s such a s w h i t e c l over. ( MacDonald,. 1 9 6 9 ; Cha r l t on ,. 1946; 1 97 3 ;. D a v i s and Be l l ,. 1 9 57 ;. G reenwood and Sheath ,. S u c k l ing ,. 1960;. 1981) .. 1 . 5 . 2 . Reproduct ive growth. Reprodu c t ive growth commences in response t o daylengt h s exceeding 1 4 h o u rs Kenny,. i n e a r l y s umme r 1964,. 1965) .. ( Jo f f e ,. F l owe r i n g o c c u r s. l o w e r l at e r a l branche s ) , t he. s t em c o n t i n u e s. 195 8 ;. to. McKee ,. 1 9 62 ,. 1 9 63 ;. f i r s t a t t he. N i t t l e r and. l o we r n ode s. (or. t h e n progre s s e s up the s t em o n b ra nche s a s e longate. f r o m t h e t ip .. F l o w e r i n g and s e e d.

(39) 23. s e t t i n g l a sts f rom e a rly s umme r unt i l l a t e summe r o r e a r l y aut umn when u n f a v o u r ab l y. shortening. p h o t ope r i o d s. produ c t i o n . A f t e r po l lina t i o n , 20. days ,. p revent. ( An de r s o n ,. is. f lower. pods develop rapidly dur ing the f i r s t. then c o n t i nue t he i r de ve l o pmen t a t a. p o d m a t u r i t y s t a ge. furthe r. reached at. about. 30. s l ower r a t e. days. t i l l t he. a f t e r po l l i nat i o n. 1955) .. 1 . 5 . 3 . F ac t o r s i n f l uencing growth and deve l opment. 1 . 5 . 3 . 1 . Envi ronment a l f a c t o r s. Amon g t he e n v i ronment a l mo i s t u re. status. factors,. a re t he. mo s t. p h o t ope r i o d , c omm o n l y. t empe r a t u re a nd s o i l. used. indi c a t o r s. of. the. a da p t a t ion and agronomic va lue o f a p l a nt t o spec i f i c s it u a t ions .. B i r d s f o ot t re f o i l. is. a t yp i c a l qu a n t i t a t i ve. l o ngda y p l a n t w i t h a. min imum 1 4 - 1 4 . 5 hours daylength requ i rement and s a t u r a t i o n a t 16 the. h o u r s d a y l e ng t h f o r f l owe r ing . quant i t a t ive. re s p o n s e. of. Jo f f e ' s expe riment. this. plant. to. (1958). pho t o p e r i o d. about s howed. in. t ha t. b i rd s f o ot t re f o i l requ i red 1 6 o r mo re hours day length f o r maximum f l o we r ing response . At a day lengt h o f 1 5 hou r s , the numbe r , deg r e e of f lo r a l primodium deve l opme nt was b l o om i ng w a s s ho w i n g t h a t. sparse .. (1963). At. c o n f i rme d Jo f f e ' s. 1 4 h ou r s ,. f i n d in g s by. 1 4 - 1 4 . 5 h o u r s daylengt h i s a c r i t i c a l daylength f o r t he. p l ant to f lo we r , d a yl e ngt h s .. McKee. re s t ricted .. rate and. but f l owe ring i s p r o fu s e only at 1 6 h o u r s or l onge r. By 1 9 6 4 ,. t h e r e s ponse o f b i rds foot t re f o i l t o day length. h a d been we l l recogn i zed so that N i t t e r and Kenny a b l e t o use i t as an a id for spec i e s ident i f i c a t ion .. (1964,. 1965). were.

(40) 24. B i rds f o o t. t re f o i l. f l o we r i n g .. By. photope riod,. is. re l a t i ve l y. u s ing d i f f e rent. Joffe. (1958 ) ,. i n s e n s i t i v e t o t empe r a t u re f o r c o mb i n a t i o n s. N i t t e r and Kenny. have s hown t h a t e ither con st ant tempe r a t u res temp e r a t ure. ° ° (27/13 C-30 /20 c,. regimes. of. t e mpe r a t u r e a n d. ( 1 9 64). a n d Long e t a l .. ° ( 1 3-30 c). d a y / n ight ). C t �89). o r a l ternat ing. had l i t t l e e f fect. on plant f l owe ring .. 1 . 5 . 3 . 2 . I n t e rn a l fact o r s. The. inte rna l. f a c t o rs. gove r n ing a. p l a n t ' s g r o wt h. a n d d e v e l opment. ma i n l y invo lve t h e plant ' s a s s imi l a t i on c apa c i t y and t h e a l locat ion o f a s s imi l a t e to diffe rent p a rt s .. S t u d i e s o n a s s im i l at i o n c h a r a c t e r s c a r r i ed o u t (1959a,. by a numbe r o f. b) ,. Sh ibles. o f b i rd s f o o t t re f o i l h a ve been. resea rchers. a n d M a cD onc.-. l ct. (1966,. 1 9 67 ) ,. Smith and N e l s on. 1969 ) ,. a n d G re ub and W e d i n. ( 1 9 62 ) ,. ( 1 9 67 ) ,. ( 1 97 1 a ,. i n c l ud i n g Rh yke rd et Smi t h. ( 1 9 62 ) ,. Ne l s on and Smi t h. b). Its. al .. Coope r. (1968a,. b,. a s s imi l a t i o n r a t e w a s. rep o rt e d t o b e c ompa r a b l e w i t h t h a t o f othe r commonly u s ed legume s s u c h as w h i t e c l ove r and l u c e rne . l o w e r p h o t o s ynthet i c r a t e t h a n A s s i mi l a t i o n Ra t e ). I n gene ra l , b i rJ s f oot t re f o i l h a s a l u c e rne ,. h o weve r a h i ghe r NAR. a c h i e v e d f ro m a h i ghe r c a rbon d i o x i de f i x a t i o n. r a t e in l u c e rne w a s o f t e n o f f s e t by a la rge r l e a f a re a re s u lted i n a h ighe r RGR ( Re l a t i ve G rowth Ra t e ) The. a s s imi l a t e part i t i o n i n g b e t w e e n root s. b i r d s f o o t t re f o i l was Ne l s on. ( 1 9 67 ) ,. ( Net. in b i rd s f oot t r e f o i l .. a nd aboveground pa rt s in. s t ud i e d i n det a i l by Smi t h. and Ne l s on and Smi t h. rat io wh i c h. (1968a,. b,. ( 1962) ,. 1969) .. Smi t h a nd. C a rbohydrate. r e s e rves i n roots f o l low a cyc l i c p a t t e rn of u t i l i z a t ion and st o rage , root. re s e r v e s be ing v e r y l o w a f t e r t he. i n i t i a l s p r i n g growth a n d.

(41) 25. du r i ng t h e ent i re growing s e a s on unt i l coo l s e a s on co ndi t i ons cause growth. to. dece a s e .. D u r ing the. rep res ent o n l y about p lant .. t he. roots. and. of. c rown .. the. S i nce. r e s i du a l. root. r e s e rve s. (1985). s t a t ed t hat in. of a s s imi l a t e wa s d i s t r ibut ed into. the. regrowth. root. r e s e rve s o r o n the a s s im i l a t ion. green. p a r t i t i o n i ng o f a s s imi l a t e t o t he. H e i c h e l et a l .. l e s s than 10%. de f o l i a t i o n depends e i t h e r on abi l it y. the. 1 5 % o f the t o t a l ava i l ab l e c a rbohydrate o f the. In a mo re recent s tu dy ,. b i rd s f o o t t re f o i l ,. growing s e a s o n ,. part s. of. of. the. the. p l ant s. plant ,. after. t he. low. r o o t may be a pa r t i a l explanat ion o f. r e a s o n w h y b i rd s f o o t t re f o i l h a s. a. s l ow r e c overy g r o w t h a ft e r. c u t t ing o r heavy gra z i ng .. T h e pa r t i t ion ing o f a s s im i l a t e among t he aboveground p a rt s plant. was. c a re fu l l y e xa m i ne d b y McG r a w a n d Be u s e l i n c k. McGraw e t a l . ,. (1986) .. I t was found that t he s t ems ,. a c c ount f o r mo st o f t h e dry ma t t e r. ( DM). pod. de h i s c e n c e. s t a ge. d i s t r ibut ion o f a e r i a l DM . n i t rogen ,. accounts. (1983). and. i n c luding leave s ,. accumu l a t i on t h roughout the. p e r iod f rom l a t e vege t a t i ve growth unt i l pod deh i scence . the. o f the. for. only. O t h e r e lemen t s ,. 4%. The seed a t 1 0%. of. t he. s u ch a s phosphorus and. we re f ound to be pre sent i n higher propo r t i o n s in the seed .. An import ant point made in the paper by McGraw e t a l . du r i ng s eed f i l l ing ,. the. Such re s u lt s. was that. f r a c t i o n a l a c cumu l a t ion of DM and various. e l emen t s rema ined r e l a t ively s t able in s t ems , in. leave s .. (1986). but ma rkedly dec re a sed. ind i c a t e that s eed development i n bi rds foot. t re fo i l re l i e s mo re o n t he c u r rent s upply o f a s s im i l a t e f rom le a ve s t ha n. on. stocks P a in ,. the. r e d i s t r ib u t i o n. of. the. food. r e s e r ve s. as occurs i n s ome o t h e r p l a n t s s u ch as ma i z e 1978) .. f r om vege t a t ive ( Bunt ing ,. 1975;.

(42) 26. Floral. abort ion. c o rn i c u l a t u s , Buba r ,. 1 95 8 ;. is. a. c o mmo n l y. p a r t i c u l a r l y a t t he Jof fe ,. 1958 ;. S t eph e n s o n a nd W i n s o r ,. 1985) .. S e a ne y ,. p h e n ome n o n. f l owe r b u d s t a ge. Seaney and Hen s o n ,. 1 97 0 ;. in. Lotus. ( Gi le s ,. 1949;. S t ephens on ,. 1984;. I n c omp l e t e s e l f - i ncomp a t i b i l i t y and. s e l f - s t e r i l i t y a r e ma j o r c a u s e s 1931;. reco rded. o f abo rt i o n in t h i s s pec i e s. 1 9 6 4 ; D ob r o f s ky and Grant ,. ( S i l ow,. 1 9 8 0 a , b ) . Howeve r , even when. e a ch f lower is out c ro s s e d a l a rge propo rt ion of f lo re t s s t i l l produce aborted pods e f fe c t s. of. phot ope r i o d ,. ( St ep h e n s o n , po s s i b l e. 1984) .. c au s a l. and t empe r a t u r e ,. Jo f f e. f a c t o rs ,. (1958). i n ve s t i g a t e d t h e. i n c l u d i n g b o r o n t r e a tme nt ,. on t he abo r t i o n o f t h e. f l owe r buds .. None o f the f a c t o r s t e s t ed we re found t o s at i s fact o r i ly e xpl a i n the cause. of bud abo r t i o n .. c o n s i de r e d t h a t supp l y ). In a mo re. recent . ,,. s t udy S t ephe n s o n. t he a v a i l ab i l it y o f ma t e r n a l. r e s ou rce. ( 1 984). ( a s s im i l a t e. p l a yed a k e y r o le in regu l a t ing t h e abo rt ion o f. i n f l o re s cences .. Abo r t i on h a s a l s o been reported to o c c u r f requent ly at o t he r s t a ge s o f rep roduct ive deve l o pment . Se aney and Hen s on of. seed product i o n of. the 2 0 - 7 0 ovu l e s. ( 1 97 0 ). Lot u s c o rnicu l a t u s ment ioned that. only 4 0 % of. in an ova r y deve lop int o mat u re s eeds .. S tephenson. (1984). reported t h a t. ma t u re. f r u i t a nd t h a t t h re e o f e v e r y f i ve w h i c h. abo r t e d .. i n t he i r review. only. one. of. e v e r y t h r e e f l o we r s p roduced a init iated fruits. H e a l s o d i smis sed t h e po s s ib i l i t y o f abo r t ion be ing c a u s ed. by po l l in a t ion f a i lu re us ing cont r o l l e d p o l l inat i o n exp e r iment s . s ugge s t e d that. it. wa s a. lack. of a s s imi l a t e. po l l i n a t i o n f a i l u re w h i c h l im i t e d t h e spec i e s .. s upp l y ,. He. rather than a. rep r o duct i v e o u t pu t. in. thi s.

(43) 27. 1.6.. Seed p rodu c t i o n. 1 . 6 . 1 . P o l l inat i o n. Lot u s c o r n i cu l a t u s i s pr ima r i ly c ro s s -po l l i n ated 1945) ,. but. cro s s e s. between. repo r t e d t o b e a s e f fect ive 1946) .. f l o r et s. Bade r and Ande r s on. an. i n d i v i du a l. a s c r o s s e s bet ween p l a n t s. I n s e c t s o f t he Hymenopt e r a ,. a re cons i de red t o be. of. ( T ome a nd Joh n s o n , were. ( Ma c D o n a l d ,. pa r t i c u l a r ly t h e l a rge bumb lebee ,. ' t he only e f fect ive po l l inat o r s '. ( 1 9 62 b ). p l ant. ( Knut h ,. 1908) .. found that p o l len-col lect i ng bees a re mo re. e f f i c ie n t t h a n n e c t a r -co l l e c t o r s .. The numb e r of. s eeds. set. per pod. i n c r e a s e s w i t h t h e number o f v i s i t s t o t he f loret by t he bee a n d the t ime. spent by e a ch. bee. K r opa l o v a and N e db a l ova honey bee s is. h igh ,. Mo r s e. f ound that. ( 1 956). at. the. ( 1 97 8 ). f l o re t. (Morse,. 1956) .. K ub i s o v a -. f ound t h a t t he po l l i n a t i on. r a t e by. with 3 - 6 f lowe r s po l l inated pe r bee pe r minut e . a. p o pu l a t i o n. one bee p e r 0 . 9 M - 2. of. wa s. s u f f ic ient f o r a l l f lowe r s t o be po l l inated .. The s e l f - s t e r i l e c h a racte r o f b i rds f oot t re fo i l h a s been known f o r a long t ime . As f a r b a ck a s 1 9 3 1 it was f ound found t h a t in t he absence of i n s e c t s o n l y 8 . 7 - 3 0 . 3 s e eds were obse rved per 1 0 0 f lowe r s 1931) .. Even w h e n f l owe r s we re a rt i f ic i a l ly s e l f -p o l l i n a ted ,. ( S ilow, the seed. y i e l d only i n c r e a s e d t o a maximum of 4 1 6 s eeds pe r 1 0 0 f lowe r s which is. less. than. pol linat ion .. o n e - t ent h S e a ne y. i n c o mp a t i b i l i t y ,. the. (1964). seeds. a. result. of. obt a i n e d s im i l a r ind i c a t i o n s. ob s e r v i n g. p o l l i n a t e d f l owe r s .. f o rmed a s. only. r a re. seed. f o rm � t i o n. c ro s s ­. of. self­. in. self­. The e x a c t me c h a n i s m o f s e l f - incompat ib i l it y in. b i rds f o ot t re f o i l is s t i l l unc l e a r a t t he pre s ent t ime , a lt hough many researcher s. have. i de n t i f i e d. that. both. morph o l o g i c a l. and.