Integration of chemical and manual control methods for sustainable weed management in inbred and hybrid rice

Akm Mominul Islam,Ahmed Khairul Hasan,Fahima Sultana Popy,Md Parvez Anwar

doi:10.3329/jbau.v15i2.35057

Akm Mominul Islam, Ahmed Khairul Hasan + Show 2 more

Open Access

https://doi.org/10.3329/jbau.v15i2.35057

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Abstract

Herbicidal weed control is gaining popularity in the developing countries but its efficacy still remains unclear. Therefore, an experiment was conducted to find out appropriate weed management practices for inbred and hybrid rice. The experiment comprised of inbred and hybrid varieties (two of each), and eight weed control treatments arranged in randomized complete block design with three replicates. Hybrid varieties performed better in terms of yield attributes and yield than inbred varieties. The highest grain yield (5.3 t ha−1) was obtained from the hybrid Agrodhan-12 and the lowest one (4.3 t ha−1) was from inbred Binadhan-7. Weed free treatment resulted in the highest grain yield (6.1 t ha−1) and the lowest one was with weedy treatment (1.96 t ha−1). The highest grain yield was obtained from Agrodhan-12 in weed free condition (6.9 t ha-1), while the lowest value was in inbred BRRI dhan49 under weedy condition (1.73 t ha−1). Weed-free treatment and the treatments of Pretilachlor fb Penoxsolum, Pretilachlor fb hand weeding, and Pendimethalin fb hand weeding showed similar performances in reducing weed density and eventually resulted in similar and the highest grain yield. Based on these results it may conclude that Pretilachlor applied at 2 days after transplanting (DAT) fb Penoxsolum at 21 DAT is the best weed management option. But from sustainability viewpoint, Pretilachlor or Pendimethalin applied at 2 DAT along with one hand weeding at 35 DAT may be recommended for effective weed management in inbred and hybrid rice during monsoon season.J. Bangladesh Agril. Univ. 15(2): 158-166, December 2017

Highlights

Weeds are endemic in crops, and the most important biotic constraint in rice production
Weed composition: The weed species found in the weedy plots of the experimental field are shown in Percent reduction in weed density and biomass: Variation in weed density and biomass reduction over control was observed among the weed control treatments at different days after transplanting (DAT) (Table 4)
Apart from the season long weed free and weedy treatments, the highest percentage of reduction in weed density and biomass was observed in Pretilachlor fb with one hand weeding, and the lowest was in Pendimethalin fb 2,4-D dimethyl amine at 45 DAT (Table 4)

Summary

Introduction

Weeds are endemic in crops, and the most important biotic constraint in rice production. Studies reported that uncontrolled growth of weeds causing 16–48% reduction in monsoon rice yield (Mamun, 1990; Rashid et al, 2007). Manual weeding is mainly practiced here in Bangladesh, which is laborious and time consuming (Mamun, 1990). This is becoming less common in Asian countries because of labour scarcity at critical time of weeding and increasing labour costs (Kumar and Ladha, 2011; Chauhan, 2012). Use of herbicides may be an alternative method in controlling weeds more and effectively at low cost (Rashid et al, 2007; Hussain et al, 2008). The application of herbicide can increased 60–82% rice yield compared with season-long weedy plots (Ahmed and Chauhan, 2014). Anwar et al (2012) reported herbicide as the most efficient and costeffective tool for weed management in rice

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