~FFECT OF SEED-SOAKING ON THE GROWTH AND DEVELOPMENT OF CROP PLANTS

~FFECT

OF SEED-SOAKING ON THE

GROWTH AND DEVELOPMENT

OF CROP PLANTS

I. .Finger Millet (Eleusine cor(lcana Gaertn.)

BY M. J. DAWSON

Agricultural College and Research Institute, Hebbal, Bangalore-24

p,. E-sEEDJNG hardening of plants has been suggested as one of the methods of increasing yields of crops grown under adverse conditions like drought, poor fertility, etc .. and conflicting results about its efficacy have been reported in the literature. The results of a study of the influence of pre-seeding hardening in the Finger millet (Eieusine coracana ),

a major cereal food crop of the Mysore State. are reported in this paper.

Since the work of Genkel and co-workers ((:f. May et a/ ... 1962), attempts have been made to standardize the techinique of pre-seeding hardening for specific crop plants. This aspect, however, is yet to receive the attention it deserves in arid regions.

It is claimed that excessive water loss could be prevented by har-dening thus influencing the water economy of plants (Crafts eta/., 1949). The physiological basis of "hardening" is said to involve a number of physico-chemical changes, the chief among them being (i) greater hy-dration of colloids, (ii) higher viscosity and elasticity of the protoplasm, (iii) increase in bound water. (iv) increase in the intensity of respiration and photosynthesis, (v) increase in hydrophilic colloids and decrease in lypophilic colloids, (vi) increase in the temperature required for pro-tein coagulation, (vii) more intense transpiration, (viii) lower water deficit and (ix) more eflicient root system ((f Genkel. 1946, 1961; Genkel and Badanova, 1959, as quoted by May era/., 1962; Chinoy, 1960). All these characteristics are believed to contribute to acceleration in germination, resistance to heat, drought and other adverse environ-mental conditions and thus to increase in crop yields.

EFFECT OF SEED-SOAKING ON GROW1H ₅₃

of treatment and stage of seedling development are critical (cf. Chinoy, 1960; Crocker and Barton, 1957). The treatment does not seem to affect the percentage germination substantially. Genkel's findings were based on experiments in pots and field plots. He obtained yield increases of 44 to 74% in pots, while in field conditions, the yield increases were low but significant. Zubenco (1959) obtained 30 to 40% increases in maize yield and Mart'yanova (1960), 16 to 55% increase in barley yields. Although some plant physiologists have recognized this phe-nomenon, intensive research from the standpoint of practical appli-cation is yet to be undertaken (Kursanova, 1956).

MATERIAL AND METHODS

Three experiments were conducted during 1963 and 1964, with unhardened and hardened seeds. Two experiments, one in pots and the other in a field, were conducted during the season July-December 1963. The third experiment was conducted during the summer season beginning January 1964. Pots, each nine inches in diameter with capa-city to hold about four Kg. of air-d1y soil, were used for the pot experi-ments. The field experiment consisted of plots each 6 ft. by 6 ft. The soil was light brown sandy loam with poor fertility as well as water-holding capacity for all the three experiments. The treatments were replicated 16, 13 and 14 times respectively in experiments I, II and Til.

Seeds of Eleusine coracana (vernacular name: Ragi), variety H

22, were soaked in a quantity of distilled water about 50% of their weight and left overnight in a dark shade. After 24 hours, the (swollen) seeds were gradually dried under a shade at a temperature of about 27o C. After three days, these as well as unhardened (control) seeds were sepa-rately sown in earthen nursery pans containing equal amounts of soil-compost mixture. The seedlings when thirty days old were transplanted two in each pot (later thinned to one) and thirty-six in each plot. The experiments were conducted in wire netted cage and ali cultural operations, watering, etc., were given uniformly.

Periodical observations were made on growth and vigour. At the end of the experiment the crops were harvested after recording the number of ear-bearing tillers and the shoot height. The shoot weight and the grain weight were recorded on oven-dry basis. These data (tiller number, shoot height, shoot weight and grain weight in the case of the pot experiments and grain yield and straw yield in the case of the field plot experiment) were statistically analysed. The root systems were thoroughly washed free of soil. The volume of the roots were measured by water displacement avoiding air bubbles.

RESULTS AND CONCLUSIONS

54 'vi. J. DAWSON

TABLE f

Mean l'alues of tiller number. shoot height. shoot weight and grain 1reight in Finger millet

--- --~

·-··---~---·----·---

---·-Theoretical F.

Control Treatment Calculated F.

---~~-5~;; p ]~,;, p

---- - - --·

-Experiment l (1963)

Tiller number per

plant 3·7 7·4 11·9 4· 54 8·68

Shoot height per plant 31 · 2 inches 38·8 inches 42·5

Shoot weight per plant 23·4 gm. 36·4 gm. 18·8

Grain weight per plant 21·6 gm. 33 ·8 gm. II· 3

Experiment II (1963)

Straw weight per plot 316·0 gm. 380·0 gm. 35·2 4·75 9·33

Straw weight per plant 8·8 gm. 10·5 gm.

Grain weight per plot 264·0 gm. 367·0 gm. 28·2

Grain weight per plant 7·3 gm. 10·2 gm.

Experiment III (1964)

Tiller number per

plant 2·4 3·4 9·1 4·67 9·07

Shoot height per plant 19 · 3 inches 22·4 inches 15·0

Shoot weight per plant 20·1 gm. 36·7 gm. 43·3

Grain weight per plant 12·6 gm. 17·2 gm. 27·2

by about 24 hours than those from controls. During the early stage of growth, the former were advanced by one leaf stage. For most part of the growing period, the 'treatment' plants were deeper green in colour than the controls. There was also early emergence of ears and about this time the plants rapidly turned pale green, while there was no such rapid change in the controls. The 'treatment' plants thus matured earlier by a week than the controls. Highly significant increases due to the treatment were seen in tiller number, plant height, shoot weight and grain weight in all the experiments (Table 1). The percentage increases in the case of tiller number, shoot weight and grain weight were more than 40% (Table 11). The beneficial influence of hardening treatment was also seen in the yield components (Table I [J),

EFFECT OF SEED-SOAKING 01\ GROWTH

TABLE [[

Percentage increase in yield characters due to hardening treatment in Finger millet

Experiment

rr

rrr

Tiller number 100·0 41·6 71 Shoot height 24·3 16·0 18 Shoot weight 55·5 20·2 82·5 69 Grain weight 56·4 39·0 36·5 46

*

55

The root system of the hardened plants was, in general, more branching and extensive (deeper) and heavier than that in the unhardened plants. There was an increase also in the volume of the root system. (Table IV). These characters of the root system could have greatly contributed to better exploitation of soil water and nutrition. The generally lower yields obtained in experiment Ill could be due to summer conditions.

TABLE fff

Ear length and 1000-grain weight in Finger millet as influenced by hardening

---~~-~---~--~----~~---~----Experiment I Experiment fll

Ear length (em.)

Control Hardened

6·5 7·5 6·0 6·5

TABLE

rv

1000-grain weight (gm.)

Control Hardened

2·7 3·0 2·5 2·8

---·-

---Plant \\'eight, root weight, and root volume in Finger millet as influenced by hardening

Experiment I Experiment ffl

Control Hardened Control Hardened

---~~--~~---~ -~-~~~----~ ~----~---~

Weight per plant (gm.) 50·4 78·0 37·8 61·2 Weight of roots per plant

2·9

(gm.) 4·2 2·8 3·7

Volume of roots per plant

(mi.) 26·0 28·8 20·3 23·8

~-

-~-~-~

5G

SuMMARY

Tt was observed from three experiments, two in pots and one in the field, that the crop from seeds of Finger millet, soaked in water and dried before sowing, gave increase in grain yield of the order of 40%, as compared to that from untreated seeds. The plants from treated seeds were also characterised by a more rapid vegetative growth ·md more extensive root system.

ACKNOWLEDGEMENTS

The author is indebted to Dr. H. R. Arekeri. Joint Director of Agriculture, for encouragement, Dr. H. C. Govindu, Economic Bota-nist, for facilities and Dr. R. D. Asana, Professor of Botany, l.A.R.I., New Delhi, for kindly going through the manuscript.

REFERENCFS

J. CROCKER, W. AND BARTON, L. V. (1957). Physiolof(V ()/' Sadv. Chronica Botanica Co., Waltham, Mass., U.S.A .. p. 67.

2. CHINOY, J. J. (1960). Report on activities at some sessions of Plant Physiology Section of the IX fnternational Congress held during August 1959 at Montreal, Canada. Ind. Jour. Pl. Ph.l•siol .. 3, 84-103.

3. CRAFTS, A. S., CURRIER, H. B. AND STOCKING, C. R. (1949). Water in the Physio-logy ()/ Plants. Chronica Botanica Co., Waltham, Mass., U.S.A., p. 208.

4. KURSANOVA, A. L. (1956). Recent advances in plant physiology in the U.S.S.R. Ann. Rev. Pl. Physiol., 7, 401-36.

5. MAR"r'YANOVA, K. L. 1960. Results of field experiments with barley seed which had undergone a pre-seeding hardening to droughts. Trans. Pl. Physiol. (Fiziol. Rast.), 7, 301-02.

f>. MAY, L. H., MILTHORPE, E. J. AND MILTHORPE, F. L. (1962). Pre-sowing hard-ening of plants to drought. An appraisal of the contributions by P. A. Genkel. Field Crop Ahst., 15, 93-98.

7. RoBERTs, W. 0. ( 1948). Prevention of mineral deficiency by soaking seed in nutrient solution. Jour. Agri. Sci., 38, 458.