Interaction effect
4.1.2. Dry weight hill −1 Effect of herbicide
Dry weight hill−1 increased exponentially with time. Dry weight hill−1 was significantly affected by different weed control treatments (Figure 4 and Appendix IV). From the early stages, distinct differences were visible among the weed control treatments in dry weight hill−1 production. Among all the weed control treatments, Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 25 g ha−1 (W3) achieved the highest dry weight hill−1 (2.46, 17.00, 33.82 and 56.80 g at 20, 45, 70 DAT and at harvest, respectively) throughout the growing period which was statistically identical with W2 (2.32 g), W1 (2.25 g) at 20 DAT and W2 (33.70 g) at 70 DAT. On the other hand, the lowest dry weight hill−1 (1.81, 11.75, 32.01 and 51.31 g at 20, 45, 70 DAT and at harvest, respectively) throughout the growing period was observed in no weeding treatment (W0). Similar results were observed by Bhuiyan et al. (2011a).
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W0 – No herbicide Used (Control), W1 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 15 g ha−1, W2 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 20 g ha−1 and W3 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 25 g ha−1.
Figure 4. Effect of herbicide on dry weight hill−1 of transplant aman rice at different days after transplanting (DAT) and at harvest (LSD(0.05)value
= 0.24, 0.63, 0.14 and 0.48 at 20 DAT, 45 DAT, 70 DAT and harvest, respectively).
Effect of variety
Dry weight hill−1 is the material, which was dried to a constant weight. Total dry weight hill−1 production indicates the production potential of a crop. A high dry weight hill−1 production is the first perquisite for high yield. Total dry weight hill−1 of roots, leaves, leaf sheath + stem and/or panicles of all varieties were measured at 20, 45, 70 DAT and at harvest. It was evident from Figure 4 and Appendix IV that irrespective of treatments dry weight hill−1 of all the varieties significantly varied at all sampling dates. Figure 5 shows that BRRI dhan70 (V1) achieved the highest dry weight throughout the growingperiod (2.23, 15.24, 34.65 and 55.55 g hill−1 at 20, 45, 70 DAT and at harvest, respectively) which was statistically identical with BRRI dhan79 (33.47 g hill−1) at 70 DAT.
0 10 20 30 40 50 60
20 DAT 45 DAT 70 DAT Harvest
Dry weight hill−1 (g)
Days After Transplanting
W0 W1 W2 W3
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V1 – BRRI dhan70, V2 – BRRI dhan79 and V3 – BRRI dhan80.
Figure 5. Effect of variety on dry weight hill−1 of transplant aman rice at different days after transplanting (DAT) and at harvest (LSD(0.05) value
= NS, 0.47, 1.37 and 0.22 at 20 DAT, 45 DAT, 70 DAT and harvest, respectively).
On the other hand, the lower amount of dry weight production was observed in BRRI dhan80 (V3) throughout the growing period (2.19, 14.33, 31.39 and 52.29 g hill−1 at 20, 45, 70 DAT and at harvest, respectively). This may be due to the highest number of tiller mortality.
Interaction effect
The interaction of weed control treatments and variety had significant effect on dry weight hill−1 production throughout the growing period (Table 2 and Appendix IV). All the weed control treatments gave higher dry weight over time and gave lower dry weight at no weeding. The treatment combination of Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 25 g ha−1 with BRRI dhan70 (W3V1) produced the highest dry weight over time (2.80, 18.86, 38.29 and 69.84 g hill−1 at 20, 45, 70 DAT and at harvest, respectively). On the other hand, the treatment combination of no weeding with BRRI dhan80 (W0V3) produced the lowest dry weight over time (1.69, 11.26, 29.61 and 44.96 g hill−1 at 20, 45, 70 DAT and at harvest, respectively) which was statistically identical
0 10 20 30 40 50 60
20 DAT 45 DAT 70 DAT Harvest
Dry weight hill−1 (g)
Days After transplanting
V1 V2 V3
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with W0V2 (1.80 g hill−1) at 20 DAT and similar with W0V2 (29.80 g hill−1) and W0V2 (29.99 g hill−1) at 70 DAT.
Table 2. Interaction effect of herbicide and variety on dry weight hill−1 of transplant aman rice at different days after transplanting (DAT) and at harvest.
Treatment combination
Dry weight hill−1 (g)
20 DAT 45 DAT 70 DAT Harvest
W0V1 1.94 f 18.86 a 29.99 fg 46.84 i
W0V2 1.80 g 12.70 f 29.80 fg 45.70 j
W0V3 1.69 g 11.26 g 29.61 g 44.96 k
W1V1 2.09 cd 8.65 h 34.97 cd 51.59 f
W1V2 2.59 bc 12.86 f 36.44 bc 62.00 b
W1V3 2.68 b 13.75 e 34.29 d 60.73 c
W2V1 2.54 c 14.65 d 37.58 ab 57.17 d
W2V2 2.04 ef 16.24 c 32.03 e 60.87 c
W2V3 2.17 d 17.10 b 31.85 e 47.50 h
W3V1 2.80 a 18.86 a 38.29 a 69.84 a
W3V2 2.18 d 16.98 b 31.34 ef 47.86 g
W3V3 1.97 f 15.15 d 31.85 e 52.69 e
LSD(0.05) 0.11 0.55 1.58 0.25
CV (%) 9.75 9.13 9.57 7.27
In a column, means having similar letter(s) are statistically similar and those having dissimilar letter(s) differ significantly as per 0.05 level of probability
W0 – No herbicide Used (Control), W1 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 15 g ha−1, W2 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 20 g ha−1 and W3 – Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 25 g ha−1.
V1 – BRRI dhan70, V2 – BRRI dhan79 and V3 – BRRI dhan80.
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4.1.3 Number of effective tillers hill
−1Effect of herbicide
The number of effective tillers hill−1 was significantly influenced by different herbicide treatment (Table 3 and Appendix V). Weed control by Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 20 g ha−1 (W2) gave the maximum effective tiller (15.59). On the other hand, no weed control (W0) treatment in the field gave the minimum effective tiller (8.56). These results were dissimilar to the findings of Hasanuzzaman et al. (2008) and Raju et al. (2003) who stated that use of weedicide (Ronstar 25 EC, Safener and Butachlor) gave the highest effective tiller.
Effect of variety
Productive tillers unit area−1 determined the final yield of rice. This is why it is said that the higher the effective tillers, the higher the yield. It was evident from (Table 3 and Appendix V) that variety had significant effect on numbers of effective tiller hill−1. BRRI dhan70 (V1) produced higher number (13.65) and BRRI dhan79 (V2) produced lower number (9.86) of productive tiller. Similar results were observed by Jones et al. (1996). The same result was reported by Peng et al. (1996). He found a negative correlation between maximum tiller number and percentage of productive tillers. On the other hand, the dissimilar result was reported by Hossen (2014). Found that BRRI dhan70 produced maximum effective tillers hill−1.
Interaction effect
Effective tiller hill−1 was significantly affected by the interaction of herbicide and variety (Table 3 and Appendix V). The highest effective tiller (18.87) was obtained from the combination Metsulfuron methyl 10% + Chlorimuron ethyl 2% @ 20 g ha−1 with BRRI dhan70 (W2V1). On the other hand, the lowest number of effective tillers (6.75) was found from the combination ofno herbicide with BRRI dhan79 (W0V2). The similar findings were reported by
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Khan and Tarique (2011), Hassan et al. (2010) and Ashraf et al. (2006) who stated that effective tillers hill−1 varied due to various varieties and weed control treatments.