Efficacy of pre- and post-emergence herbicide combinations on weed control in no-till mechanically transplanted rice

No-till mechanized-transplanted rice was evaluated for different combinations of pre- and post-emergence herbicides to determine feasible, economically viable weed management options to control complex weed flora in rice fields. All pre-emergence herbicides significantly reduced the population of grassy weeds; of these, pendimethalin resulted in the greatest reductions (83%) at 15 days after transplanting (DAT). Among five post-emergence herbicide treatments, the combination of bispyribac-sodium (10%SP) + pyrazosulfuron (10%WP) was found to be the most effective in controlling all weed flora at both 35 and 55 DAT. The sequential application of pendimethalin (pre-emergence) followed bispyribac-sodium + pyrazosulfuron (post-emergence) resulted in significantly higher rice grain yield (4.4 t-ha−1) and relative gross-margin (417 USD-ha−1) than all other treatments. A strong negative correlation was observed between rice grain yield and weed biomass, and a strong positive correlation between rice grain yield and weed control efficiency. Our findings demonstrate the potential to combine pre- and post-emergence herbicides in no-till mechanized-transplanted rice; these findings have applications globally in regions where rice is established by no-till or mechanized transplanting

Hymenopteran parasitoid complex and fall armyworm: a case study in eastern India

Abstract Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) has significantly affected maize crop yields, production efficiency, and farmers’ incomes in the Indian Eastern Gangetic Plains region since it was first observed in India in 2018. A lack of awareness by maize growers of the appropriate selection, method, and timing of insecticide application not only creates a barrier to sustainable FAW control but also contributes to increased environmental pollution, reduced human health and increased production costs. We demonstrated that FAW inflicted the most damage in early whorl growth stage of maize, regardless of whether chemical insecticides were applied. FAW egg masses and larvae collected from maize fields in which no insecticides had been sprayed showed high parasitism rates by parasitoid wasps; in contrast fields that had been sprayed had much lower rates of parasitism on FAW. Ten hymenopteran parasitoids were observed in maize fields across the study region, suggesting a diversity of natural methods to suppress FAW in maize at different growth stages. These included two FAW egg parasitoids and eight FAW larval parasitoids. Microplitis manilae Ashmead was the most abundant FAW larval parasitoid species, and Telenomus cf. remus was the dominant FAW egg parasitoid species. Endemic FAW parasitoids such as those observed in this study have great potential as part of a sustainable, cost-effective agroecological management strategy, which can be integrated with other methods to achieve effective control of FAW

Application of innovation platforms to catalyse adoption of conservation agriculture practices in South Asia

Conservation agriculture-based sustainable intensification (CASI) is a package of practices that could improve the sustainability of smallholder farm productivity and profitability. However, existing extension systems are unable to facilitate widespread adoption to have the impact necessary to meet food security and livelihood requirements. This paper examines the utility of ‘Innovation Platforms’ (IPs) as a tool to catalyse adoption of CASI for smallholder farmers in South Asia and generate opportunities for rural micro-entrepreneurship in areas with high rates of poverty, small farm sizes and complex labour markets. We established 37 village-level and five District-level IPs across the Eastern Gangetic Plains of Nepal, Bangladesh, and India. IPs allowed widespread uptake of CASI with benefits to smallholder farmers, input and output suppliers, and enabled extension systems to be more efficient. There was variability across locations with different modes of IPs established, building on existing farmer or community youth groups, and enabling micro-entrepreneur business opportunities. IPs were effective in developing trust in communities, among stakeholders, empowering rural youth and women through direct engagement. Ensuring strong ownership was key. Further work is needed to provide opportunities for high-level policy support to assist IPs to have a wider impact in supporting large-scale adoption of CASI