FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET
3.2.2 The Germination Experiments
The germination patterns for the six germination experiments are presented in Figures 6-11. The final germination percentages and mean germination times (M.G.T.) with least significant differences at P is equal or greater than 0.05 are presented in Table 2 [Pop-up] and Table 3 [Pop-up]. The formula used to calculate the M.G.T. for individual replicates was:-
Σ(G x T)
(M.G.T.) = --------------
F
Where T = the day on which germination count was made
G = the number of seeds germinated on the day of the count
F = final number of seeds which germinated in each replicate
This formula was used in all germination experiments (Battle & Whittington 1969a).
All significant differences referred to in this section and thereafter unless otherwise indicated are at significance level P is equal or greater than 0.05.
The six germination tests were carried out over a period of time and therefore direct comparison of seed lots across experiments is not valid. Statistical analyses were only carried out within each germination test.
The first germination test (Experiment 1) carried out under standard (i.e. optimal) conditions for germination showed that seed lots 1, 2, 3 & 4 had almost completed germination after four days, while Lot 5 had an extended germination period (Figure 6). Lots 1, 3 & 4 reached higher final germination percentages than Lots 2 & 5 Table 2. Lot 2 was significantly lower than Lots 1, 3 & 4 and Lot 5 was significantly lower than Lot 2.
The most rapid germination occurred with Lots 3 & 4 which were not significantly different from each other (Table 3). Lots 1 2 & 5 however, respectively showed progressively slower mean germination times, and were all significantly different from each other. The M.G.T. for Lot 5 was more than twice the M.G.T. for Lots 3 & 4.
In Experiment 2 carried out 7.5°C, there was a delay in the onset of observable germination and an extended germination period for all five seed lots (Figure 7). All final germination percentages were lower than the respective germinations in Experiment 1. Lots 1, 3 & 4 had similar final germination percentages. Lots 2 & 5 were both significantly lower than Lots 1, 3 & 4.
All mean germination times were about three times longer than the respective times in Experiment 1 (Table 3). Lots 4 & 3 had similar times which were faster than the other seed lots. Lots 1, 2 & 5 showed progressively slower mean germination times and were all significantly different except for Lots 1 and 3. The overall order of speed of germination was the same as that obtained in Experiment 1.
The tests on the seeds which remained ungerminated from Experiment 2 allowed the seeds to be divided into three categories viz:- those which could germinate at standard temperature but not at 7.5°C, those which probably could not germinate because they contained undersized, shrivelled, or absent true seeds and those which appeared normal but did not germinate (Table 4).
Lots 1, 4 & 5 showed very similar percentages inhibited by temperature with Lots 2 and 3 showing a higher and lower inhibited percentage. Lots 1, 3 & 4 showed very low percentages of observably inferior true seeds while Lots 2 & 5 showed higher percentages. Lot 1 also showed a very low percentage of apparently normal ungerminated seeds, while Lots 2, 3 & 4 showed higher percentages. Lot 5 was considerably higher than the others.
When the respective temperature inhibited germinations are added to the final germinations obtained in Experiment 2, the sum of the germinations are very similar to the final values obtained in Experiment 1, except for Lot 5 which is 10% higher.
In Experiment 3 (i) carried out at standard temperatures with seed advanced in water, there were no large improvements in the final germinations compared with Experiment 1, except with Lot 5 which reached a substantially higher germination (Figure 8). Lot 1 produced significantly more germinated seeds than Lot 5, but Lot 2 which had an intermediate value was not significantly different from either of these lots (Table 2). Mean germination times were all significantly different and faster than the respective times obtained in Experiment 1 (Table 3). Lot 1 had the shortest germination time and Lot 5 the longest.
Experiment 3 (ii) carried out at 7.5°C, with seed advanced in water, produced lower final germination percentages than those obtained in Experiments 1 and 3 (i), except for Lots 3 & 5 which produced more germinated seeds in this experiment than in Experiment 1 (Figure 9).
However, all respective final germinations were greater than those obtained in Experiment 2, (also run at 7.5°C). Lots 1, 3 & 4 produced similar values under these conditions. Lots 2 & 5 produced significantly lower germination values than the other three but were not significantly different from each other (Table 2).
All mean germination times were longer than the respective times in Experiments 1 & 3 (ii) but shorter than the respective times in Experiment 2. The germination time for Lot 1 was significantly shorter than Lots 2, 3 & 4. which were not significantly different from each other. The time for Lot 5 was significantly longer than all the other Lots (Table 3).
In Experiment 4 carried out at standard temperatures with GA3 solution in the petri-dishes, the final germination percentages were very similar to the respective Figures obtained in Experiment 1 (Figure 10). However, Lot 5 reached a considerably higher germination percentage than in Experiment 1. As in other experiments Lots 1, 3 & 4 were very similar, and Lots 2 & 5 were significantly lower than the other 3 (Table 2).
Mean germination times were also similar to the respective times obtained in Experiment 1. Lots 1, 2 & 3 had slightly shorter times, and Lots 4 & 5 slightly longer times in this experiment. The shortest mean germination times were obtained with Lots 1, 3 & 4, which were not significantly different from each other. Lot 2 had a significantly longer time than Lots 1, 3 & 4; Lot 5 a significantly longer time than Lot 2 (Table 3).
The final germination test (Experiment 5) run at standard temperatures with seed advanced in GA3 solution, (Figure 11) showed final germination percentages very similar to the respective germination percentages obtained in Experiment 3 (i) (seed advanced in water at standard temperatures). Lot 1 reached a significantly higher final germination than Lot 5, but Lot 2, which was intermediate, was not significantly different from either Lot used in this experiment (Table 2).
All mean germination times were faster than the respective times obtained in Experiment 3 (i). The time for Lot 1 was significantly faster than the time for Lot 2, which was significantly faster than the time for Lot 5 (Table 3).
FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET
[Introduction & Contents] [Chapter One] [Chapter Two] [Chapter Three] [Chapter Four] [Chapter Five] [Chapter Six] [Chapter Seven]
[3.2.1] [3.2.2] [3.2.3] [3.2.4]
