RESULTS AND DISCUSSION
4.1 Crop growth components .1 Plant population m -2
4.1.7 Leaf Area Index (LAI)
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At 20 DAS, the highest breadth of leaf was recorded in V2M7 (0.52 cm) which was statistically insignificant with V2M6 (0.51 cm). The second highest (0.49 cm) breadth of leaf was found in V2M3 that was also statistically similar to V2M6. The third highest breadth of leaf was observed in V1M7 (0.48 cm) which was statistically non-significant with V2M5 and V2M3. While the lowest breadth of leaf (0.39 cm) was recorded in V1M1, V2M1 and they were statistically similar to V1M4 (0.41 cm). The V1M1 and V2M1
decreased breadth of leaves by 33.33% compared to V2M7 due to no management and V1M4 reduced by 26.83% due to no irrigation. The remaining all other treatments showed more or less same breadth of leaf.
At 40 DAS, the maximum breadth of leaf (0.87 cm) was recorded in V1M7 that was statistically different from others. The second maximum leaf breadth was observed in V2M7 (0.81 cm) which was statistically insignificant with V1M6 (0.79 cm). The V1M6
treatment showed 10.13% lower breadth of leaf compared to V1M7 due to no pest management. The third maximum leaf breadth was reported in V1M5 (0.75 cm) that was statistically non-significant with V1M6. On the contrary, the minimum breadth of leaf was found in V2M1 (0.55 cm) which was statistically similar to V1M1 (0.60 cm). The second minimum breadth of leaf (0.62 cm) was recorded in V1M4 that was statistically similar to V2M4 (0.65 cm). The V1M4 and V2M4 treatments decreased leaf breadth by 40.32% and 33.85% respectively compared to V1M7 due to no irrigation. All other treatments showed more or less same breadth of leaf at this growth stage.
At 80 DAS, the maximum breadth of leaf (1.63 cm) was recorded in V1M7 that was statistically different from others. The second maximum leaf breadth was observed in V1M6 (1.47 cm) which was statistically insignificant with V1M5 (1.41 cm). The V1M6
treatment showed 10.88% lower breadth of leaf compared to V1M7 due to no pest management. The third maximum leaf breadth was reported in V1M3 (1.33 cm) that was statistically non-significant with V1M5 and V2M7. On the contrary, the minimum breadth of leaf was found in V2M1 (1.05 cm) which was statistically similar to V1M1
(1.07 cm), V1M4, V2M2 and V2M4. The second minimum breadth of leaf (1.20 cm) was recorded in V2M3 and V2M5 that was statistically similar to V2M2 (1.09 cm) and V1M4. The V2M3 and V2M5 treatments decreased leaf breadth by 35.83% compared to V1M7
due to no weeding and thinning, respectively. All other treatments showed more or less same breadth of leaf at this growth stage.
54 V1= BARI Gom-30 and V2= BARI Gom-32
Figure 13. Effects of variety on leaf area index of wheat at different growth stages (LSD(0.05)= 0.021, 0.036 and 0.159 at 20, 40 and 80 DAS, respectively).
4.1.7.2 Effects of agronomic managements
Statistically significant variation was observed on leaf area index of wheat by the influence of different types of agronomic management at 20, 40 and 80 DAS (Appendix X & Fig. 14). At 20 DAS, the maximum leaf area index was recorded in M7 (0.20) that was statistically dissimilar to others. On the contrary, the minimum leaf area index 0.03 was found in M1 (no management) which was statistically dissimilar to others and all other treatments showed leaf area index between the two at this growth stage.
M1: Control (no management), M2: No fertilizer but all other managements, M3: No weeding but all other managements, M4: No irrigation but all other managements, M5: No thinning but all other managements, M6: No pesticides but all other managements and M7: Complete management (recommended).
Figure 14. Effects of agronomic managements on leaf area index of wheat at different growth stages (LSD(0.05)= 0.011, 0.049 and 0.187 at 20, 40 and 80 DAS, respectively).
0 0.2 0.4 0.6 0.8 1 1.2 1.4
2 0 4 0 8 0
Leaf area index
Days after sowing (DAS)
V1 V2
0 0.5 1 1.5 2 2.5
2 0 4 0 8 0
Laef areaindex
Days after sowing (DAS)
M1 M2 M3 M4 M5 M6 M7
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At 40 DAS, maximum leaf area index (0.85) was also recorded in M7 which was statistically different from others. The second maximum leaf area index (0.52) was found in M6 (no pesticides) that was statistically dissimilar to other treatment. The M6
treatment decreased leaf area index by 63.46% compared to M7 (complete management). The third maximum leaf index (0.42) was recorded in M5 (no thinning) that was statistically significant with others and it decreased leaf area index by 23.81%
compared to M7. While the minimum leaf area index (0.11) was reported in M1 (no management) which was statistically similar to M4 treatment and remaining two treatments showed leaf area index between them.
At 80 DAS, the highest leaf area index was observed in M7 (2.10) which was statistically significant with others. The second highest leaf area index (1.44) was recorded in M6 that was statistically significant with others and it decreased leaf area index by 45.83% compared to M7. Whereas the lowest leaf area index (0.19) was found in M1 which was statistically similar to M4 (0.32). The second lowest leaf area index (0.53) was recorded in M2 (no fertilizer) that was statistically dissimilar to others and it decreased leaf area index compared to M7. Similar results were also found by Nadim et al. (2013), Asif et al. (2012) and Bazzaz et al. (2008).
4.1.7.3 Interaction of variety and agronomic managements
Interaction effect of variety and agronomic managements showed significant differences on leaf area index at different growth stages of wheat (Appendix X & Table 7). At 20 DAS, the highest leaf area index was recorded in V2M7 (0.24) which was statistically significant with others. The second highest (0.16) leaf area index was found in V2M6 that was also statistically similar to V1M7 (0.15). The third highest leaf area index was observed in V2M5 (0.12) which was statistically non-significant with V1M6. While the lowest leaf area index (0.03) was recorded in V1M1 and V2M1. The remaining all other treatments showed more or less similar leaf area index.
At 40 DAS, the maximum leaf area index (0.89) was recorded in V1M7 that was statistically different from others. The second maximum leaf area index was observed in V2M7 (0.81) which was statistically significant with others. The third maximum leaf area index was reported in V1M6 (0.56) that was statistically non-significant with V2M6
(0.49). On the contrary, the minimum leaf area index was found in V2M1 (0.10) which was statistically similar to V1M1 (0.12), V1M4 (0.15) and V2M4 (0.14). The second minimum leaf area index (0.20) was recorded in V2M2 that was statistically similar to V1M2 (0.26). All other treatments showed more or less similar leaf area index at this growth stage.
At 80 DAS, the maximum leaf area index (2.88) was recorded in V1M7 that was statistically different from others. The second maximum leaf area index was observed in V1M6 (1.88) which was statistically significant with others. The V1M6 treatment showed 53.19% lower leaf area index compared to V1M7 due to no pest management.
The third maximum leaf area index was reported in V1M5 (1.40) that was statistically non-significant with V2M7. On the contrary, the minimum leaf area index was found in V2M1 (0.16) which was statistically similar to V1M1, V1M4, V2M2 and V2M4.
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The second minimum leaf area index (0.52) was recorded in V2M3 that was statistically similar to V1M2 (0.69) and V2M5 (0.72). All other treatments showed more or less same breadth of leaf at this growth stage.
Table 7. Interaction of variety and agronomic managements on leaf area index of wheat at different growth stages
Treatment combinations
Leaf area index (LAI) at
20 DAS 40 DAS 80 DAS
V1M1
V1M2
V1M3
V1M4
V1M5
V1M6
V1M7
V2M1
V2M2
V2M3
V2M4
V2M5
V2M6
V2M7
0.03 h 0.05 fg 0.62 e 0.04 fg 0.07 e 0.11 cd 0.15 b 0.03 gh 0.06 ef 0.10 d 0.05 ef 0.12 c 0.16 b 0.24 a
0.12 k 0.26 hi 0.33 fg 0.15 jk 0.44 de 0.56 c 0.89 a 0.10 k 0.20 ij 0.29 gh 0.14 jk 0.40 ef 0.49 cd 0.81 b
0.22 g 0.69 e 1.00 d 0.33 fg 1.40 c 1.89 b 2.88 a 0.16 g 0.36 fg 0.52 ef 0.30 fg 0.72 de 0.99 d 1.33 c
LSD(0.05) 0.016 0.070 0.265
CV (%) 10.08 11.18 17.20
In a column mean values having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly as per 5% level of probability.
V1: BARI Gom-30, V2: BARI Gom-32, M1: Control (no management), M2: No fertilizer but all other managements, M3: No weeding but all other managements, M4: No irrigation but all other managements, M5: No thinning but all other managements, M6: No pesticides but all other managements and M7: Complete management (recommended).