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Biological control through the use of antagonistic micro-organisms is a potential and non-chemical means of managing plant diseases. Alternaria porri causes purple blotch disease mostly in onion. In this study, three different entomopathogenic fungi, viz. Beauveria bassiana, Metarhizium anisopliae and Verticillium lecanii, were tested against A. porri. All the three entomopathogenic fungi showed inhibitory effect against A. porri subjected to in vitro studies under dual culture technique, spore (conidial) germination, food poisoning (mycelia germination) and seed germination. The percentage inhibition of mycelial growth (PIMG) of A. porri (69.24, 56.17, and 45.81%) and the percentage inhibition of conidial germination (CG) (97.81, 42.11, and 67.69%) were observed for B. bassiana, V. lecanii and M. anisopliae, respectively. Seed germination index was found to be maximum with M. anisopliae (5557 ± 107.7) and B. bassiana (4390 ± 129.9). B. bassiana exhibited efficient antagonism against A. porri showing the highest PIMG and CG with moderate seed germination index. Microscopic examination showed the disintegrated edge of conidia which had turned black and also stopped the growth of germ tube. Hence, these entomopathogenic fungi were found to be more effective antagonistic organisms and also moderately promote seed vigour index (4390 ± 129.9) as well as plant growth. The present study indicated that the entomopathogenic fungi evaluated have shown significant inhibition of A. porri. Thus, there is a possibility of exploiting them in the management of the disease.

Traditional rice varieties (TRVs) form important components of genetic reservoir. TRVs used in study viz., Rajamudi, Ratnachoodi and Jeerigesanna are photosensitive. They may exhibit Genotype by Environment (G×E) interactions for grain yield and quality traits. Hence, present experiment was conducted to understand responses of yield and quality traits in selected traditional along with improved varieties of rice over five different locations of Karnataka using additive main effects and multiplicative interaction (AMMI) model and bi-plots were developed following GGE bi-plot methodology. AMMI analysis revealed that there existed significant GE interaction among ten rice varieties and genotypes and environments were diverse in nature. IPCA1 and IPCA2 together explained more than 75% of GE interaction for yield and quality traits and maximum GE interaction was explained by IPCA (Interaction Principle Component Analysis) 1. BR-2655 and Ratnachoodi were found to be most stable varieties and Mugadsiri was found to be most unstable variety for grain yield. Jeerigesanna and BPT-5204 were stable for gel consistency and amylose content respectively. Among rice varieties used, BR-2655 was found to be the best variety since it recorded highest grain yield and also it was stable performer for grain yield and also amylose content across five different locations.

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