Results and Discussion
4.1 Experiment 1: Effect of potassium on the growth and yield of wheat under water stress condition
4.1.2 Interaction effect of water stress condition and potassium fertilizer on different plant growth parameters of wheat
4.1.1.6 Number of spikelet per spike
4.1.1.6.1 Effect of water stress condition on number of spikelet per spike
Number of spikelet per spike of wheat showed statistically significant variation due to different levels of irrigation (Figure 4.11). The maximum number of spikelet per spike
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(57.9) was observed from treatment I1, where water was applied in vegetative stage and it had no significant difference with treatment I2 and I3 except I0 (Table 4.4). Whereas the minimum numbers of spikelet per spike (53.8) was observed from I0 which was significantly different from the treatment I1 producing maximum spikelet per spike. Naser (1996) reported that the highest number of grains per spike were recorded when two irrigations were applied.
I0 = Control (normal irrigation), I1 = Water stress at vegetative stage, I2 = Water stress at flower initiation stage, I3 = Water stress at milking stages.
Figure 4.11: Effect of water stress condition on number of spikelet per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
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4.1.1.6.2 Effect of different doses of potassium fertilizer on number of spikelet per spike
There was a statistically significant variation was observed in terms of number of spikelet per spike of wheat due to different levels of potassium fertilizer (Figure 4.12). The maximum number of spikelet per spike (57.25) was observed from K3 treatment, which was statistically similar to K1 and K2 but significantly different with K0 (Table 4.5). The minimum number of spikelet per spike (54.90) was observed in K0 which was significantly different from the treatment K3.
K0 = 0 kg K/ha K1 = 60 kg K/ha K2 = 90 kg K/ha K3 = 120 kg K/ha
Figure 4.12: Effect of different doses of potassium fertilizer on number of spikelet per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
79 4.1.1.7 Number of fertile florets per spike
4.1.1.7.1 Effect of water stress condition on number of fertile florets per spike
Number of fertile florets varied due to application irrigation in different growth stage of wheat. Maximum number of fertile florets (61.40) were found from the treatments I0 and I2
(Figure 4.13), both of them were statistically similar to each other (Table 4.4). Minimum number of fertile florets (58.40) were found in the treatment I3 where water stress was provided in the milking stage, it was statistically similar to treatment I2 (58.50) but significantly different with other treatments.
I0 = Control (normal irrigation), I1 = Water stress at vegetative stage, I2 = Water stress at flower initiation stage, I3 = Water stress at milking stages.
Figure 4.13: Effect of water stress condition on number of fertile florets per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
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4.1.1.7.2 Effect of different doses of potassium fertilizer on number of fertile florets per spike
Number of fertile florets varied due to different doses of potassium fertilizer in wheat.
Maximum number of fertile florets (61.25) were found from the treatments K3 and it was statistically similar with treatment K1 and K0 (Figure 4.14). Minimum number of fertile florets (58.90) were found in the treatment K2 where 90 kg K/ha potassium was provided; it was significantly different with other treatments but statistically similar with treatment K1
(Table 4.5). Results indicated that highest amount of potassium application induced in the production of higher number fertile floret.
K0 = 0 kg K/ha K1 = 60 kg K/ha K2 = 90 kg K/ha K3 = 120 kg K/ha.
Figure 4.14: Effect of different doses of potassium fertilizer on number of fertile florets per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
81 4.1.1.8 Filled grain per spike
4.1.1.8.1 Effect of water stress condition on number of filled grains per spike
Number of filled grains per spike of wheat showed statistically significant variation due to different levels of irrigation (Figure 4.15). The maximum number of filled grains per spike (43.0) was observed from I0 which was statistically similar with I2 (42.10) and I3 (41.90), whereas the minimum number (39.80) was observed from I1 and it was significantly different from all other treatments (Table 4.4). Gupta et al. (2001) reported that number of grains decreased to a greater extent when water stress was imposed at the anthesis stage.
I0 = Control (normal irrigation), I1 = Water stress at vegetative stage, I2 = Water stress at flower initiation stage, I3 = Water stress at milking stages.
Figure 4.15: Effect of water stress condition on number of filled grains per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
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4.1.1.8.2 Effect of different doses of potassium fertilizer on number of filled grains per spike
Statistically significant variation was observed in terms of number of filled grains per spike of wheat due to different levels of potassium fertilizer (Figure 4.16). The maximum number of filled grains per spike (42.18) was observed from K3 treatment, having significant difference with other treatments (Table 4.5). While the minimum number of filled grains per spike (41.40) was found in K1 followed by K2 (41.41), both of them were statistically similar to treatment K0. Results indicated that, 60 kg K/ha and 90kg K/ha potassium application had no significant difference with K0 that is 0 kg K/ha potassium application in case of producing filled grains per spike. Only 120 kg K/ha potassium application resulted into higher filled grain production.
K0 = 0 kg K/ha K1 = 60 kg K/ha K2 = 90 kg K/ha K3 = 120 kg K/ha
Figure 4.16: Effect of different doses of potassium fertilizer on number of filled grains per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
83 4.1.1.9 Number of unfilled grains per spike
4.1.1.9.1 Effect of water stress condition on number of unfilled grains per spike
Number of unfilled grains per spike of wheat showed statistically significant variation due to different levels of irrigation (Figure 4.17). The maximum number of unfilled grains per spike (4.70) was observed from I1. The minimum number of unfilled grains per spike (3.25) was observed from I0 which was closely followed (3.60) by in treatment I2 (Table 4.4).Both of them are statistically similar to each other but significantly different with I0.
I0 = Control (normal irrigation), I1 = Water stress at vegetative stage, I2 = Water stress at flower initiation stage, I3 = Water stress at milking stages.
Figure 4.17: Effect of water stress condition on number of unfilled grains per spike of wheat.
Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
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4.1.1.9.2 Effect of different doses of potassium fertilizer on number of unfilled grains per spike
Statistically significant variation was observed in terms of number of unfilled grains per spike of wheat due to different levels of potassium fertilizer (Figure 4.18). The maximum number of unfilled grains per spike (4.70) was observed from K2 treatment, while the minimum number of unfilled grains per spike (3.60) was found in K3 (Table 4.5).
K0 = 0 kg K/ha K1 = 60 kg K/ha K2 = 90 kg K/ha K3 = 120 kg K/ha
Figure 4.18: Effect of different doses of potassium fertilizer on number of unfilled grains per spike of wheat. Different letters indicate treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.
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Table 4.4 Effect of water stress on yield contributing characters of wheat
Irrigation
Number of spikelet per
spike
Number of fertile florets per
spike
Number of filled grain per spike
Number of un-field grain per
spike
Total grains per
spike
1000 grains weight (g)
I0 53.81b 61.40a 43.0a 3.25b 46.25a 52.40a
I1 57.90a 58.53b 39.80b 4.70a 44.40b 52.0a
I2 56.55ab 58.50a 42.10a 3.60b 45.60ab 52.30a
I3 56.71ab 58.40b 41.90a 3.83ab 45.70ab 50.90b
LSD (0.05) 1.29 5.53 1.74 0.97 1.43 1.62
CV% 6.5 2.70 8.5 4.7 7.00 7.96
I0 = Control (normal irrigation), I1 = Water stress at vegetative stage, I2 = Water stress at flower initiation stage, I3 = Water stress at milking stages.
Different letters indicates treatments are statistically dissimilar at 0.05 level of probability while similar letters indicate treatments are similar.