Impact of Multiple Insect-Pest Incidence on Yield in Basmati Rice

The experiments for determining the multiple insect-pest incidence on yield loss in basmati rice was conducted for two crop seasons. Five treatments were, viz. application of imidacloprid in vegetative stage; application of granular insecticide in vegetative stage; application of higher dose of Urea; augmentive releases of yellow stem borer egg mass at vegetative and booting stage; untreated control. During both the years, the correlation between grain yield and dead heart, leaf folder damage and planthopper population at 50 and 65 DAT and white ear at maturity was negative. The analysis of variance of regression analysis of yield Vs damage levels at different crop growth stages during both the years revealed a significant linear relationship. The yield loss was highly related to incidence of stem borer and leaf folder damage at 50 and 65 DAT during both the years. For integrated pest management, effective monitoring of stem borer and leaf folder from 50 to 65 DAT is required, which appeared as a critical crop growth stage. The farmers should remain cautious during this period to prevent yield loss

Antibiosis components and antioxidant defense of rice as mechanism of resistance to brown planthopper, Nilaparvata lugens (Stål)

The role of antibiosis components and antioxidant defense of rice genotypes, namely CR3006-8-2, RP4918-221, KAUM182-1, T12, IHRT-ME-25, W1263, Ptb33 (resistant check) and TN1 (susceptible check) was studied by phenotyping them against brown planthopper (BPH). Three genotypes, namely KAUM182-1, RP4918-221 and CR3006-8-2 were resistant to BPH and significantly low damage score (1.97–3.00); honeydew excretion area (46.76–49.64 mm2); nymphal survival (60.60–66.40%) and growth index (2.98–3.86) was recorded on them. Higher constitutive and induced level of soluble phenolics, peroxidase and polyphenol oxidase was observed in resistant genotypes without and with BPH infestation. A negative relationship between honeydew excretion, nymphal emergence, growth index and nymphal survival was observed with these biochemical constituents. Likewise, a reverse trend was observed between nymphal development period and biochemical constituents. These genotypes have emerged as a new source of resistance to BPH which can be used in hybridization programme to breed durable BPH resistant rice varieties

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Not AvailableAbundance of brown plant hopper (BPH) Nilaparvatalugens (Stål) (Delphacidae: Homoptera) is modulated by prevalent weather conditions of rice growing seasons and locations. Categorization of BPH adults caught in light traps (nos/week/trap) into low, moderate and high and formulation of criteria accounting weather variables [maximum/ minimum/ mean temperature (ÚC), morning/evening/mean relative humidity (%), rainfall (mm) and sunshine hours (h/day) and wind speed (km/h)] during kharif of 2011-16 for four locations viz., Ludhiana (Punjab), Chinsurah (West Bengal), Raipur (Chhattisgarh) and Aduthurai (Tamil Nadu) with associated rules for weather based BPH prediction. Validation of BPH predictions for kharif 2017 indicated 96, 87, 73 and 61% accuracies in respect of Aduthurai (TN), Raipur (CG), Ludhiana (PB) and Chinsurah (WB). Future weather based predictions of BPH based on climatic projections of representative concentration pathway (RCP) 4.5 for 2020, 2050 and 2080 indicated absence of high population at Chinsurah (WB) during all time periods of 2020-2080. Progressively reducing BPH abundance from past (2011) to all future periods was noticed at Aduthurai (TN). ‘High’ BPH from 2020 and beyond over 2011 and 2016 at Raipur (CG) and reducing ‘high’ but increasing ‘moderate’ category between 2020-2050 but the reverse in 2080 at Ludhiana (PB) were predicted indicating requirement of continued monitoring strategies put in place at these locations. The observed spatial variability of climate change influence on BPH implied a need for zonation mapping of rice insects including BPH for IndiaNot Availabl