Biorational Approaches for Purple Blotch Disease of Garlic (Allium sativum L.) Incited by Alternaria porri (Ellis) Cif

Garlic (Allium sativum L.) is the second most important bulb crop after onion. It is a major spice crop. Garlic is attacked by many diseases, one of which is Purple blotch. This study was aimed to determine the effect of botanicals and bio-agent on purple blotch disease of garlic caused by Alternaria porri. The research work was undertaken at Central Research Farm (CRF) Sam Higginbottom University of Agriculture, Technology and Sciences, SHUATS, Naini, Prayagraj during Rabi in 2022-23. A randomized block design with eight treatments was employed including T0 (Control - untreated) , T1 ( Azoxystrobin @0.1% as treated check), T2 (Trichoderma harzianum @10g/litre) , T3 (Lantana camara leaf extract @10%), T4 (Azadirachta indica leaf extract @10%), T5 (Henna leaf extract @2% + Licorice root extract @2% + Rosemary leaf extract @2% ), T6 (Licorice root extract @10%) and T7 (Neem cake @50g/m2). The treatments led to significant decrease in purple blotch severity in garlic.The results revealed that among the treatments, T7 showed minimum disease intensity (4.33, 18.74 and 26.35%) at 30, 60 and 90 days after sowing (DAS) respectively; while maximum disease intensity was recorded in T0 (10.42, 25.52 and 34.68%). T7 also recorded maximum plant height (24.02, 34.01 and 45.71cm) at 30, 60 and 90 DAS, respectively and highest yield of 4.46t/ha. Maximum number of leaves were recorded with T3 (5.53, 7.5 and 9.4) at 30, 60 and 90 DAS respectively. Fungicide usage is increasing day by day that can lead to negative effect on human and soil health in the long run, so there is need to find effective and economic alternatives preferably some bio-agents and botanicals.