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Not AvailableAiming at verifying the effect of host on the development, the biology of Rhyzopertha Dominica (Fab.) was studied on paddy variety, Sumati, Maize Hybrid DHM-111 and sorghum variety M 35-1 during 2009-10 in the Department of Entomology, College of Agriculture, Rajendranagar, Hyderabad. The biological parameters assessed were egg duration, egg hatching percentage, total larval and pupal period, total development period, fecundity, male and female longevity, sex ratio, pre-oviposition, oviposition and post oviposition period. When R. Dominica was reared on paddy, maize and sorghum the egg period was lowest in paddy variety sumati (6.57) and highest in maize hybrid DHM 111 (7.72). The egg hatching percentage is lowest in Maize Hybrid, DHM-111 (68.48±3.95) and highest in case of sorghum var. M 35-1 (73.65±5.12). The total larval and pupal period shortest in sorghum var. M 35-1 (35.35±1.95) and highest in Maize Hybrid, DHM-111 (43.85±1.45). The shortest total developmental period of 42.17±2.13 and 41.63±2.17 were recorded in male and female of R. Dominica in sorghum var. M 35-1 and the longest developmental period of 51.57±1.28 and 50.77±1.14 were recoreded in males and females of R. Dominica in case of Maize Hybrid, DHM-111. In all the three hosts it was found that the longevity of female was longer than male. The shortest pre-oviposition, oviposition and post oviposition periods of 4.03±0.67, 31.33±2.41, 6.13±0.73 days were recorded in Maize Hybrid DHM- 111 respectively. The results obtained shows that among the three host grains used for the study, Maize hybrid was found to be the least preferred host, followed by paddy variety, Sumati and sorghum variety, M 35-1.Not Availabl

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Field application of Rice husk ash and inmidazole is beneficial to rice plantSilicon (Si) has been implicated to reduce damage by rice pests. In this study we validate the field efficacy of rice husk ash (RHA) and imidazole, alone and in combination, against damage by yellow stem borer (YSB) under field conditions for two seasons in five rice cultivars. Field application of RHA and imidazole, either alone or in combination, enhanced Si deposition (43–59.8 mg g −1 ) in stem tissues of rice plants as compared to untreated control (30.2 mg g −1 ). Deposited Si caused significant wearing of mandible incisors, and lowered larval density, thereby decreasing YSB damage and increasing the grain yield significantly. RHA and imidazole did not alter the total sugars and total phenol content in rice cultivars. Field application of imidazole along with RHA at vegetative phase and again at booting stage was on par with insecticidal treatment (carbofuran 3G) with respect to per cent damage, larval density and grain yield. The B: C ratio in the Si treatments varied from 1.16 to 1.31 and T4-RHA +imidazole (applied twice) was at par with one granular insecticide application (1.32) but higher than the untreated control (1.0). RHA and imidazole can be integrated as one of the eco-friendly components in the present scenario of climate change for the management of YSB in rice.Not Availabl

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Not AvailablePromoter or carrier-induced silicon transportation into rice (Oryza sativa L.) in relation to yellow stem borer, Scirpophaga incertulas (Walker) and blast (Pyricularia grisea) disease resistance has been investigated. Simple amino acids, such as histidine, imidazole, glutamic acid, glycine and glutamine significantly enhanced the levels of Si(OH) 4 in the stem and 14–18% silicon transport into the leaf surface, as evidenced by scanning electron micrograph (SEM) and silicon mapping studies. Studies on plants grown with these molecules in greenhouse (500 mmoles of the carrier X twice) or 1500 mmoles of the carrier X four times in field were conducted. The work has led to the identification of a novel class of bio-compatible molecules, which exhibit remarkable resistance to damage by yellow stem borer and blast infections and generate higher dry matter and increased yields.Not Availabl

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Not AvailableThe Asian rice gall midge (ARGM) has emerged as a model gall forming pest of rice. The ARGM infestation of rice results in failure of panicle formation and economic loss. Understanding the molecular basis of ARGM-rice interactions is very crucial in order to control this devastating pest of rice. The current investigation was devised to identify bacterial communities present in the ARGM and in addition the bacterial diversity in the maggots during their interaction with susceptible or resistant rice varieties. Sequencing of 16S rRNA bacterial gene (V3-V4 region) revealed differences in the microflora of the ARGM maggots feeding on susceptible or resistant rice hosts. Results revealed that Wolbachia was the predominant bacterium in pupae and adults while Pseudomonas was predominant in maggots. Further, we observed that members of proteobacteria were predominant across all the samples. There was high species diversity in maggots isolated from susceptible rice and a high representation of unclassified bacteria in maggots isolated from resistant rice. This is the first study that reports variation of microbiome of the ARGM, based on host phenotype from which it was isolated, and results suggest that these variations could have an important role in host’s susceptibility.Not Availabl

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Not AvailableExpert systems are computer programs (may be extended to mobile interfaces) that solve problems by mimicking human reasoning processes, relying on logic, rules of thumb opinion and experience. Rice Expert System has been developed for extension professionals and farmers to act as an interface to diagnose the field problems. Generally farmers face problems like choosing suitable varieties, knowledge on pesticides/fungicides application, pest and disease problems, yield losses etc. which conventionally difficult to address. An attempt was made to develop an expert system for rice varieties, pests and diseases to aid in the decision making at farm level. This expert system consists of series of questions and answers to diagnose the problem, to browse directly major pests/diseases/varieties, to access information on better crop protection measures, commonly used pesticides for rice and frequently asked questions.On line expert system is a dynamic system to diagnose pest and disease problems at field level. The alpha version of the system was successfully hosted on public domain and can be upgraded for various ecosystems. This facility is expected to aid and enhance the performance of progressive farmers and agricultural extension personnel and reduce the time required to tackle biotic stresses without waiting for an expert advice. Further this system can be integrated with mobile phones to reach each and every farmer of the country.This has been designed to help extension workers, farmers and other stakeholders in identifying the field problems they face in Indian rice fields. The diagnostics is basically based on the stage of the crop, but has options to select or search at any point based on symptoms, type of problems. The tool helps to identify the possible causal agent and the management options in brief. Varietal and management techniques can also be browsed through based on the agro-climatic conditions across the country. Similar comprehensive expert systems across the major crops in India will help extension system to be more effective. Key words : Expert systems, Interface, suitable varieties, agro-climatic conditions.Not Availabl

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Not AvailableRice (Oryza sativa L.) was grown in pots with pyridine N-oxide (PNO), 4-morpholino pyridine N-oxide (MNO), and sodium meta silicate as the sources for silicon. Aliquots of these were added in fortnightly intervals to seedlings through anthesis stage. The plants were monitored for plant growth characteristics, chlorophyll content (SPAD values), photosystem 2 activity (variable to maximum fluorescence ratio of dark adapted leaves), and for blast and yellow stem borer resistance. Deposition of silica in the leaves was monitored by scanning electron microscopy and silicon mapping. PNO or MNO application resulted in significant silicon accumulation in leaf bundle sheath cells. Application of PNO and MNO imparted disease and pest resistance by increasing silicon uptake of rice plants.Not Availabl

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Not AvailableSUMMARY : Pre-breeding lines with known source of gall midge resistance through Gm1 gene in the elite backgrounds were evaluated in a replicated trial under greenhouse conditions at IIRR, Rajendranagar, Hyderabad against biotype1 and in field at Jagtial and Warangal against biotype 3 and 4, respectively. Screening of 15 day old seedlings of the test lines against gall midge biotype 1 was carried out by releasing gall midge adults. Field screening for biotype 3 and 4M was carried out under natural infestation in endemic areas. Scoring for damage was done when at least 50% of the susceptible check plants exhibited damage symptoms as silver shoots. Data on total number of plants and number of plants with silver shoots were taken. Per cent plant damage and silver shoots was calculated. Among 38 prebreeding lines, chosen with phenotypic acceptability, 12 lines showed nil damage from four crosses against biotype 1 and 6 lines against biotype 3. Of these RNR17927-1 (Tellahamsa X JGL11690) andRNR19872, RNR19875, RNR19880, RNR19881 and RNR19883(MTU1010/JGL3855) were found resistant against both biotype 1 and 3 but susceptible to biotype 4M.Not Availabl

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Delineation of larval instars of an insect is important in morphological and physiological studies. We applied Dyar’s rule to morphometric measurements of larval instars from field populations of the yellow stem borer (YSB), Scirpophaga incertulas (Walk.) collected on two paddy cultivars over three seasons. The conventional head capsule width (HCW) measurement was compared with mandibular width (MW) of larvae from both field and laboratory populations. Frequency distribution of HCW showed seven peaks with size overlaps indicating seven instars in field populations. Distinct size classes were observed in MW with means of 0.042, 0.083, 0.125, 0.166, 0.208, 0.250 and 0.291 mm for 1st, 2nd, 3rd , 4th, 5th, 6th and 7th instars, respectively, in the field population. However, size classes fell into five instars from HCW and MW measurements of larvae reared on cut paddy stems under constant temperature (25 ± 1°C) and humidity (60± 5%) indicating two additional, late larval instars under variable field conditions. For the same instar, mean HCW size slightly varied and was overlapping while mean MW size was identical between field and laboratory populations for each of the first five common larval instars.Not AvailableNot Availabl