Optimization of Fungicide Spray Schedules for Effective Control of Alternaria Blight in Cumin

Abstract

Cumin (Cuminum cyminum L.) is an important seed spice crop widely cultivated in arid and semi-arid regions. Among the diseases affecting cumin, Alternaria blight caused by Alternaria burnsii is one of the most destructive, leading to significant yield losses. Field experiments were conducted over two consecutive years using different fungicide combinations and spray sequences. Results revealed that application of 3–4 foliar sprays of recommended fungicides, namely Mancozeb, Azoxystrobin, and Difenoconazole, starting at 45 days after sowing and repeated at 15-day intervals, significantly reduced disease severity by 53–66 per cent over control. Evaluation of new fungicide molecules (combination fungicides) indicated that foliar application of Azoxystrobin + Difenoconazole @ 0.5 ml/l was most effective, recording 79 per cent reduction in disease intensity along with significant yield improvement. The study concludes that strategic fungicide scheduling and use of combination fungicides with multiple modes of action are highly effective in managing Alternaria blight of cumin and enhancing crop productivity.