and 7 days (second count). Extension of the germination period was not an option in the study even though ISTA allows for extended germination period.
Evaluations of the four different ex- perimental treatments were conducted at the same time, to allow for a comparison of the ease by which evaluation is done. This implied that the setup for germina- tion was also done at the same time. The participants were asked to give the char- acter ‘A’ if the combination of treatment and seed lot was easy to evaluate. If it was very diffi cult to judge the seedlings, the character ‘E’ should be given. The letter in between were also used for intermedi- ate results. An example of the evaluation sheets is shown at the end of the article. Participants were asked to evaluate the seedlings and to report the germination re- sult obtained on the recording sheets. They were also asked to complete the testing and return completed recording sheets within
5 weeks from receiving the samples.
Statistics
The results of the validation study was cu- mulated by the Danish Plant Directorate (Anders Lomholt) and analysed in close cooperation with ISTA’s Statistical and Germination Committee (Sylvain Gré- goire, Ronald Don, Michael Kruse, Gün- ter Müller and Kirk Remond).
Z-scores were calculated for all labora- tories and experimental treatments. The z-score values were used to identify out- liers and each laboratory performance in the validation study.
A mixed effects ANOVA model was used, considering that there was a bino- mial response variable. Laboratory and seed lots were used as random effects in the model and treatment as the only fi xed effect in the model. The ANOVA analysis was used to identify any signifi cant differ- ence between treatments.
Results
The ANOVA overall signifi cance test in- dicates which treatments are different and has different letters if there is signifi cance. Below is given tables of treatment means including the letters indicating signifi cant differences.
Comments to results
Figure 1 to 3 shows a signifi cant differ- ence between the seed that were grown in KNO3 and those not grown in the KNO3
solution. The data also showed a trend that the KNO3 treatment was enhanced
by pre-chilling, but there were no statisti- cal signifi cance to support this trend. The positive effect of KNO3 was par-
ticular visible at the fi rst count (see graph 1 and 2). Here the absolute differences were far greater than at the fi nal count. The statistical signifi cance between treat- ments was, however, of similar magnitude at the fi rst count and the fi nal count. The
Figure 1 Differences between treatments after the first count.
Source Nparm DF DFDen F Ratio Prob > F
Treatment 3 3 87 5,8164 0,0011
Level Least Sq Mean
Prechill and KN03 A 88,85
KNO3 A B 86,80
Prechill and Water B C 82,22
Water C 78,01
Levels not connected by same letter are signifi cantly different.
Figure 2 Differences between treatments in the normal seedling after the final count.
Source Nparm DF DFDen F Ratio Prob > F
Treatment 3 3 87 6,6758 0,0004
Level Least Sq Mean
KNO3 A 93,22
Prechill and KN03 A 92,81
Water B 91,82
Prechill and Water B 91,41
Levels not connected by same letter are signifi cantly different.
Figure 3 Differences between treatments in the abnormal seedling after the final count.
Source Nparm DF DFDen F Ratio Prob > F
Treatment 3 3 87 5,8043 0,0012
Level Least Sq Mean
Prechill and Water A 5,46
Water A B 4,83
Prechill and KN03 B C 4,61
KNO3 C 3,87
Levels not connected by same letter are signifi cantly different.
reason for this difference was a much greater difference between laboratories at the fi rst count, meaning a larger experi- mental error.
The improvement of germination at the fi nal count was 1– 2 percent by using KNO3. Even though the difference was
signifi cant the absolute values were very small. This implies none or very slight nu- tritious effects of KNO3 on the rape seed.
The slight increase in normal seedling at the fi nal count when using KNO3 seems to
come from the fraction of abnormal seed- ling, which has a signifi cant decrease. The positive effect of KNO3 was equal-
ly visible on any of the three seed lots (see graph 2). All three seed lots had highest number of normal seedling using KNO3
both at the fi rst and fi nal count.
The character ‘Ease of evaluation’ in- troduced for this study showed quite a bit of variation. Perhaps because it was the fi rst time the laboratories used the char- acter or perhaps because it was diffi cult to quantify the ease of evaluation. In graph 3, the letters (A to E) are transformed into numbers (1 to 5, where 1 = A and 5 = E). The graph shows an average value for the participating laboratories and the picture is clear that KNO3 makes it much easier to
evaluate the seedlings.
Graph 1 and 2 showed that it was pos- sible to judge many more seedlings at the fi rst count as normal, when they had been KNO3 treated. This implies that they were
more developed, a fact that was supported by the analysists observations. The more developed a seedling is, the easier it is to evaluate.
Conclusions
The positive effects of KNO3 treatment on
rape seed germination are: • a slightly increased germination
percentage
• more normal seedling and fewer abnormal
• eases evaluation of the seedling
Participating laboratories
DKDL0100, LTDL0100, FIDL0100 ILDL0100, GBDL0400, PLDL0600 NODL0100, EEDL0100, LVDL0100 SEDL0200
Graph 1 Comparison of treatments. Number of seedlings at the first and final count.
Graph 2 Effect of treatment on different seed lots with different germination percentage.
Graph 3 Evaluation of seedling in three seed lots after using four treatments. Low number means easy evaluation.