To understand the impact of climate change on water resources, this research investigates long-term rainfall trends and anomalies across Northeastern India (NEI), covering Assam and Meghalaya (A&M); Nagaland, Manipur, Mizoram, and Tripura (NMMT); and Sub-Himalayan West Bengal and Sikkim (SHWB&S) using different statistical tests including innovative trend analysis (ITA). The study scrutinizes 146 years of rainfall statistics, trend analyses, variability, and probability distribution changes to comprehend its implications. Furthermore, the change in the assured rainfall probabilities was also worked out to understand the impact on rainfed agriculture of Northeastern India. Comparative analysis between all India (AI) and NEI reveals that NEI receives nearly double the annual rainfall compared to AI (2051 mm and 1086 mm, respectively). Despite resembling broad rainfall patterns, NEI displays intra-regional variations, underscoring the necessity for region-specific adaptation strategies. Statistical characteristics like the coefficient of skewness (CS) and coefficient of kurtosis indicate skewed rainfall distributions, notably during the winter seasons in NMMT (CS~1.6) and SHWB&S (CS~1.5). Trend analyses reveal declining rainfall trends, especially conspicuous in NEI’s winter (−1.88) and monsoon (−2.9) seasons, where the rate of decrease was higher in the last three decades. The return periods of assured rainfall at 50% and 75% probability levels also increased sharply during the winter and monsoon seasons by over 30% during the recent half, posing challenges for rainfed upland hill farming. Furthermore, this study highlights increasing variability and negative anomalies in monsoon rainfall over NEI, exacerbating decreasing rainfall trends and significantly impacting agricultural productivity. These findings underscore the urgency for adaptive measures tailored to evolving rainfall patterns, ensuring sustainable agricultural practices and efficient water resource management.

This study analyzed the impact of weather variables on insect pest dynamics and their diversity in the radish ecosystem through field experiments conducted for two years at a locality in the eastern Himalayas. The relationship with weather variables was studied with six different dates of sowing, and diversity was assessed using standard indices. Various organic management options were also evaluated. Results revealed that temperature had a positive impact, whereas relative humidity and rainfall negatively affected the population of insect pests. The radish ecosystem harbors diverse insect species, including natural enemies, with higher species richness (4.8–5.2) and lower year-to-year variability. Organic management strategies such as neem oil, Beauveria bassiana, and Metarhizium robertsii demonstrated good efficacy against flea beetles without compromising yield, resulting in 39.76%, 39.39%, and 38.71% pest reduction over control, respectively. These biopesticides also recorded less than half to one-fourth reduction in natural predators like coccinellids compared to cypermethrin, a chemical pesticide (74%). The study suggests that, under projected climate change with higher temperatures, pest populations are assumed to increase. Considering the insect diversity of the eastern Himalayas, organic management strategies will be an adaptation strategy to conserve biodiversity while ensuring environment-friendly pest management.

Study was carried out to find out the effect of plant bioregulators on growth and flower of in vitro raised hybrid gerbera plants under shade net. The findings of the investigation revealed that GA3 100 ppm accelerated both vegetative growth and flowering characters such as stalk length, number of flowers per plant, flower diameter throughout the investigation period from January to June 2011.

Introduction: The eastern Himalayan region of India with diverse agro-climatic conditions is one of the important hotspots of the world’s biodiversity. A wide range of genetic variability of plant species like Colocasia is available in the region which is consumed by the local tribes.Materials and methods: A field study was conducted during 2022–23 to evaluate the yield, biochemical, mineral, and an-tioxidant parameters of 30 Colocasia esculenta L. Schott. genotypes under a split-plot design with three replications.Results and discussion: Significant (p < 0.05) variations were observed among genotypes for all traits. Tamachongkham exhibited the highest corm weight and yield, while Tamitin recorded the maximum cormel weight and total yield. Megha Taro-2 and Megha Taro-1 had the highest cormel numbers and cormel yield, respectively. In mineral composition, Tamitin had the highest N, K, Zn, Cu, and Mn, Tagitung White recorded the highest P, and BCC-2 had the highest Fe and Ca + Mg. Biochemically, Tamachongkham had the highest dry matter content; Khweng-2 had the highest starch, total sugar, and reducing sugar; Rengama had the highest crude protein, and crude fiber; and Mairang Local had the highest ash content. A significant positive correlation was observed between total yield and corm, cormel yield, cormel weight, and corm weight, while correlations with starch and other parameters were non-significant. Total phenolic content and anthocyanin were significantly correlated with Ferric Reducing Antioxidant Power (FRAP). Genotype-by-trait biplot analysis using the first two principal components (PC1: 19.4%, PC2: 14%) high-lighted total sugar, reducing sugar, cormel numbers, crude fiber, anthocyanin, and FRAP as major contributors to phenotypic diversity. The observed variations indicate the potential of these genotypes for future breeding programs aimed at improving taro production in the Eastern Himalayas.