Performance study of some T. aman varieties under normal transplanting and double transplanting system

Abstract

The experiment was conducted to study the performance of three T. Aman varieties (BR22, BRRI dhan46 and BRRI dhan49) under normal transplanting with 30, 45 and 60 days old seedlings and double transplanting ( 30 days + 30 days) system at Plant Physiology Division of Bangladesh Rice Research Institute, Joydebpur, Gazipur during T. Aman season, 2013. Interaction effect was significant only for days to maximum flowering and sterility percentage. BR22 required longer duration to complete flowering when transplanted with 60 days old seedlings, while sterility percentage was higher in BRRIdhan 49 when transplanted with same aged seedlings. Photosynthetic rate, LAI, total dry matter production, yield contributing characters and harvest index of tested varieties were insignificant under different transplanting methods; these parameters contributed to produce similar grain yield. The results revealed that rice varieties BR22, BRRI dhan46 and BRRI dhan49 showed similar performance under normal transplanting with different aged seedlings and double transplanting in respect of photosynthetic rate, tillering pattern, LAI, total dry matter production and grain yield during T. Aman season.

Farmers’ Rice Yield in Fallow - T. Aman Rice - Fallow Cropping Pattern Due to Variability in Genotype And Management

“…The pattern of yield response in BRRI dhan49 to seedling age was similar to that reported by Hasanuzzaman et al (2014) for the same variety who found decreased yield with increased seedling age of 25 day-old onward. On the contrary, no significant yield variation for seedling age in the range of 30 to 60 days was found for BRRI dhan49 (Yasmeen et al, 2016). A lower yield was achieved in both the varieties when the seedling density was used over 3 per hill; which corroborates with the var.…”

Double transplanting of rice as a contingency approach to escape climate change impacts

“…It has been reported that seedlings of one decimal primary nursery area can cover three decimals of area in secondary nursery and these seedlings are enough for occupying 24 decimals area in main field [33]. Yasmeen et al [21] did not find significant variations in leaf area index, dry matter accumulation at later stages of crop growth and speculated similar photosynthetic rate under various transplanting methods as the reason behind it. However, they observed higher yield attributes and yield under DT method as compared to single transplanting of similar aged seedlings (Table 7).…”

“…• Sometimes, tiller mortality (later formed tillers) is observed specifically after transplanting from secondary nursery to main field, making low growth of crop under DT system. Yasmeen et al [21] noticed lowest number of tillers at post flowering stage due to mortality of later formed tillers.…”

“…This allows the seedlings to become tall and stout enough to avoid the submergence problem. This method is labour and time consuming but comparatively more economic as the yield of rice under DT is more than the yield of rice from normal transplanting of same aged seedlings [21].…”

“…In Assam, primary, secondary nurseries and main field were locally known as Bechan bari, Bolon bari and Dhan bari, respectively [14]. As compared to direct transplanting to main field, a greater number of seedlings (generally, 6-12/hill) are maintained at less spacing of 8-12 cm × 8-12 cm covering 65-70 hills/m 2 land area in secondary nursery [2,21]. In each nursery, nutrient, water managements and plant protection strategies were ensured properly to nurture the seedlings well.…”