Emerging Minor Diseases of Rice in India: Losses and Management Strategies

Rice (Oryza sativa L) being one of the imperative food crops of the word contributes immensely to the food and nutritional security of India. The cultivation of rice is changed over the decades from a simple cultivation practices to the advanced cultivation to increase yield. Increased in rice yields especially after 1960s is mainly due to the introduction of high yielding semi-dwarf varieties which requires more inputs like chemical fertilizers, water and other resources. As a result, India achieved self sufficiency in rice and currently producing more than 115 MT of rice to meet country’s demand. Now India is exporting rice to other nations and earning foreign returns. With the change in rice cultivation practices, problems also aroused side by side. A number of biotic and abiotic stresses emerged as major constraints for rice cultivation in diverse agro-climatic conditions and growing ecologies. Diseases are the major biotic constraints to rice which can reduce the yields by 20–100% based on severity. Major diseases like blast, brown spot, bacterial blight, sheath blight and tungro still causing more damage and new minor diseases like bakanae, false smut, grain discoloration, early seedling blight, narrow brown spot, sheath rot have emerged as major problems. The losses due to these diseases may 1–100% based on the growing conditions, varietal susceptibility etc.., At present no significant source of resistance available for any of the above emerging diseases. But looking into the severity of these diseases, it is very important to address them by following integrated management practices like cultural, mechanical, biological and finally chemical control. But more emphasis has to be given to screen gerrmplasm against these diseases and identify stable source of resistance. Finally utilizing these sources in resistance breeding program by employing molecular breeding tools like marker assisted selection (MAS), marker assisted back cross breeding (MABB), gene pyramiding and transgenic tools. The present chapter discusses the importance of these emerging minor diseases of rice, the losses and possible management measures including resistance breeding

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Not AvailableRed rice genotypes are characterized by their huge nutritional values. Apart from this property, they also possess valuable sources of resistance to many biotic and abiotic stresses. In the present investigation, a total of 215 red rice accessions collected from north east and other parts of India were screened for their resistance against brown plant hopper (BPH) at National Rice Research Institute (NRRI), Cuttack by following modified screening technique. The results showed, among 215 genotypes, 4 were highly resistant, 11 were resistant and 13 were moderately resistant against BPH. The rest 187 genotypes were either susceptible or highly susceptible. The mechanism of resistance in these identified lines was studied. The nymphal survivility and development was lower in resistant genotypes (Mata Meher 43.33%) after 5day of releaseas compared to susceptible check TN-1 (100% survivility). Similarly the nymphal developmental period was less in resistant lines than TN-1 (100% nymphs were developed in to adult) after 15thdays of release. The highly resistant genotype Matameher has shown lowest FPLI index (6.75) as compared to resistant(R), moderately resistant (MR) and susceptible(S) reactionNot Availabl

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Not AvailableRed rice is the reservoir of large amount of phytochemicals such as carotenoids, phenolics, alkaloids, nitrogen and organosulfur containing compounds, possesses antioxidant properties, richer source of protein, zinc and have nutritive and medicinal value. Present study examines the utility of red rice accessions for their resistance against Brown planthopper (BPH), a damaging insect pest of rice. A total of 215 red rice accessions along with susceptible check TN1, resistance checks PTB-33 and Salkathi were evaluated under greenhouse condition of the National Rice Research Institute (NRRI), Cuttack. Accessions were screened using standard seed box technique for mass screening followed by replicated screening for the confirmation of resistant reaction. Only four accessions, namely, matameher, manipuri black sonahanan and hormonona were found to be highly resistant (score-1) while eleven showed resistant reaction (Score-3) and 13 were moderately resitant (Score-5) to BPH. Mechanism of resistance was studied in the resistant accessions through the method of antixenosis or nymphal preference to plants. Matameher and manipuri black showed least nymphal preference as compared to the susceptible check TN1. Resistant genotypes identified and confirmed in the present study can be grown as resistant varieties in BPH endemic areas and also can be utilised in resistance breeding programme to develop BPH-resistant varieties with other desired traits.ICAR-NRR

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