ABSTRACT
Onion (Allium cepa L.) stands as a crucial bulb crop and a primary commercial vegetable crop in India. Among the various maladies affecting bulb and seed development, purple blotch, caused by Alternaria porri, stands out as one of the most devastating. This ailment inflicts extensive damage on both bulb and seed crops. Through an extensive roving survey, we have unveiled the disease's prevalence, enabling the identification of disease hotspots in the major onion cultivation regions of southern Karnataka. A total of 28 hotspot regions were identified in the eight districts surveyed for purple blotch disease severity in onions. Notably, the highest mean of percent disease index (PDI) was recorded in Chikkamagaluru (51.12%), while Chamarajanagara showed the lowest mean PDI (23.35%). Among all surveyed villages, the most severe disease prevalence was observed in Koverahatti village within Hiriyur taluk of Chitradurga district, with a PDI of 64.47%. On the other hand, the lowest disease severity was noted in Uttamballi village (16.89%) in Kollegala taluk, Chamarajanagara district.
ABSTRACT
The experiment was conducted to study the comparative performance and blast disease screening 80 diverse rice cultivars including land races, obsolete varieties, modern cultivars and released varieties, local prevailing cultivars and advanced breeding/varietal lines as AICRIP testing trials for two successive seasons during Kharif-2021 and Kharif-2022 at AHRS Ponnampet, Karnataka- India, The results from ANOVA revealed that, MSS due to genotypes, were significant (p<0.01 and p<0.05) for all the yield traits studied. GYKH was varied from 270.65-6039.89, while 940.17-6039.88 with mean grain yield Kg/ha of 3596.01 and 3483.92 kg/ha during Kh-21 and Kh-22. High GCV and PCV with high heritability coupled with high GAM were observed for GYKH, while the remaining traits revealed low to medium GCV and PCV, heritability coupled with low to medium GAM. Correlation analysis revealed that significant and positive association was observed for PH, DFF, PL and GYKH. PCAs revealed that PC1, PC2 and PC3 showed 32.45%, 29.66% and 14.83% of contribution with 76.94% of total variation during Kharif-21 and 33.20%, 29.67% and 14.33% of contribution with 77.20% of variation for the studied traits during Kharif-22 respectively. Field screening of leaf and neck blast under natural hot spot area among 80 diverse genotypes resulted in identification of resistant sources as KPR-1, KPR-2, KHP-5, Mud-1014, IET-28515 and Kajajaya with promising yield performances.