Many benefits ofTrichodermainoculation for improving crop production have been documented, including growth and yield enhancement and the alleviation of biotic and abiotic stresses. However, because rice is usually cultivated under continuous flooding that creates anaerobic soil conditions, this limits the benefits of these beneficial fungi. Cultivating rice with the methods of the System of Rice Intensification (SRI) provides rice plants with a more favorable environment for their colonization by beneficial microbes in the soil because the soil is more aerobic under SRI management and contains more organic matter. This study evaluated the effects ofTrichodermainoculation of rice plants under SRI management compared with transplanted and flooded rice plants, considering also the effects of different means of fertilization and different varieties in rice. Experiments were conducted in 2015 and 2016 under the tropical climate of Nepal’s western terai (plains) during both the rainy season (July to November) and the dry season (March to July). The results indicated significantly better performance (P = 0.01) associated withTrichodermainoculation for both seasons and for both systems of crop management in terms of grain yield and other growth-contributing factors, compared to non-inoculated rice cropping. Relatively higher effects on grain yield were recorded also with organic compared to inorganic fertilization; for unimproved (heirloom) varieties compared with improved varieties; and from SRI vs. conventional flooded crop management. The yield increase withTrichodermatreatments across all trials was 31% higher than in untreated plots (4.9 vs 4.5 mt ha⁻¹). WithTrichodermatreatment, yields compared with non-treated plots were 24% higher with organic SRI (6.38 vs 5.13 mt ha⁻¹) and 52% higher with non-organic SRI (6.38 vs 3.53 mt ha⁻¹). With regard to varietal differences, under SRI managementTrichodermainoculation of the improved variety Sukhadhan-3 led to 26% higher yield (6.35 vs 5.04 mt ha⁻¹), and with the heirloom variety Tilkidhan, yield was 41% higher (6.29 vs 4.45 mt ha⁻¹). Economic analysis indicated that expanding the organic cultivation of local landraces under SRI management should be profitable for farmers where such rice has a good market price due to its premium quality and high demand and when SRI enhances yield. These varieties’ present low yields can be significantly increased by integratingTrichodermabio-inoculation with SRI cultural methods. Other recent research has shown that such inoculation can be managed profitably by farmers themselves.

Background. Fresh vegetables such as tomato should have low microbial population for safe consumption and long storage life. The aerobic bacterial count (ABC) and coliform bacterial count (CBC), yeast, and mold population are the most widely used microbial indicators in fresh vegetables which should be lower than 4 log CFU g⁻¹for safe consumption. The stages of the supply chain, postharvest handling methods, and crop varieties had significant effects on microbial population. ABC, CBC, yeast, and mold population were significantly highest (P<0.05) at retail market (5.59, 4.38, 2.60, and 3.14 log CFU g⁻¹, resp.), followed by wholesale market (4.72, 4.71, 2.43, and 2.44 log CFU g⁻¹, resp.), and were least at farm gate (3.89, 3.63, 2.38, and 2.03 log CFU g⁻¹, resp.). Improved postharvest practices (washing in clean water and grading and packaging in clean plastic crate) helped to reduce ABC, CBC, and mold population by 2.51, 32.70, and 29.86 percentage as compared to the conventional method (no washing and no grading and packaging in mud plastered bamboo baskets). Among varieties, Pusa ruby had the lowest microbial load of 2.58, 4.53, 0.96, and 1.77 log CFU g⁻¹for ABC, CBC, yeast, and mold count, respectively. Significantly negative correlation (P<0.05) was observed between fruit pH & ABC and pH & mold count. Although the microbial quality of fresh tomato is safe in the local market of western Terai of Nepal both in conventional and in improved practices however still it is essential to follow improved postharvest handling practices in production and marketing of newly introduced tomato cultivars (high-pH cultivars) for ensuring the safe availability of fresh tomato in the market.

Blast, caused by Pyricularia oryzae (teleomorph Magnaporthe oryzae), is one of the most devastating diseases in rice, causing 10-30% yield losses and threatening Nepal’s food and nutritional security. The Himalayan foothills are hotspots for blast fungus diversity, leading to the rapid emergence of pathotypes that overcome resistance in mega rice varieties. In 2022, a neck blast epidemic devastated 5,000 hectares of Hardinath-1, a dry winter/spring rice variety in Chitwan, causing nearly 100% yield loss. The changing climate, especially during panicle initiation stages, has become more favourable for neck blast development. We reviewed 40 years of research and development on rice blast in Nepal, analysing historical weather patterns and mapping the incidence and severity of the disease across the country based on empirical observations and field experiments. Using historical data on rice blast incidence and climate information, we show that rice blast pressure is increasing intensively and changing weather patterns are becoming more favourable for rice blast epidemics. We identify emerging issues in rice blast and propose integrated strategies for effective management in Nepal. Key approaches include developing durable blast-resistant and climate-resilient rice varieties using molecular markers and genomic tools and speed breeding, forecasting disease and pathotype emergence, and combining these with careful use of modern fungicides, plant defence activators, and biological control. Additionally, adjusting planting times, managing weeds, optimising agronomic practices, and ensuring proper water and nutrient management are essential for sustainable blast management.

Participatory action research was conducted in Luinyata VDC of Bajhang district during main rice-growing season of 2012 to evaluate the effects of cultivation practices in rice varieties. The experiment was in factorial randomized complete block design, where two methods of cultivations: System of rice intensification (SRI) and conventional transplanting (CT) and 3 different varieties: Khumal-4, Thapachini and Hansaraj Basmati were evaluated. Data were collected on grain yield, number of tillers, panicle length and number of filled and unfilled grains per panicle. Results averaged across the three varieties showed significantly better crop performance with SRI practices: higher number of tillers per hill, panicles per hill, tillers per m2, panicles per m2, and grain yield. The values of these parameters comparing SRI with conventional practice were, respectively, 24.5 vs. 11.3, 21.5 vs. 9.5, 305 vs. 273, 273.5 vs. 233.8, and 7.6 vs. 4.46 tha-1. Among the varieties evaluated, the highest yield was achieved with the Thapachini (8.11tha-1) using SRI methods. Average yield increase across the three varieties with SRI practice was 70% compared CT. These results indicate the practical relevance of SRI principles for increasing rice production in mountainous regions of Nepal.

In anaerobic soil disinfestation (ASD), soil amended with a carbon source undergoes anaerobic conditions accompanied by changes in microbial community composition and an increase in the concentration of organic acids, primarily acetic and butyric acids, and gases that are deleterious to plant pathogens, insects, and potentially to weeds. The purpose of this study was to explore the efficacy of ASD with different carbon sources on inactivation of propagules of a variety of weed species. Germination and viability of propagules of common lambsquarters (Chenopodium album L.), black nightshade (Solanum nigrum L.), yellow nutsedge (Cyperus esculentus L.), common pokeweed (Phytolacca decandra L.), barnyardgrass (Echinochloa crus-galli L.), dandelion (Taraxacum officinale (Weber)), and redroot pigweed (Amaranthus retroflexus L.) were tested using different rates of four carbon sources: molasses, wheat bran, mustard greens biomass, and raw chicken manure. Wheat bran was the most effective carbon source for inactivation of all weed propagules, followed by molasses and mustard greens biomass. Carbon sources were mixed with soil, which was irrigated to saturation and covered with plastic to promote anaerobic conditions for three weeks. Chicken manure inactivated all the tested species except A. retroflexus compared to the anaerobic control. Rates of carbon sources applied in soil were weakly but significantly correlated (r > 0.42 and p < 0.04) with weed seed mortality or germination inhibition (E. crus-galli) for all the tested carbon sources and weed species except for chicken manure for C. album, A. retroflexus, and S. nigrum. Laboratory tests to confirm organic acid toxicity showed that 1000 µL L⁻¹ acetic plus 1000 µL L⁻¹ butyric acids for at least 60 h inhibited of sprouting of C. esculentus tubers and E. crusgalli seeds, whereas 120 h or exposure was required to inhibit C. album seed germination. Anaerobic soil disinfestation effectively suppressed weed seed germination and viability when wheat bran, molasses and mustard greens biomass were used as carbon sources. This approach could be adopted for weed management in organic systems or any farming system where priority is given to environmentally sustainable practices.