Integrated management of anthracnose and pod blight diseases of soybean(Glycine max) using fungicide, varietal resistance, and altered sowing dates

Anthracnose disease, incited by Colletotrichum truncatum, is one of the major constraints in the soybean [Glycine max (L.) Merill] production worldwide. A field experiment was conducted during rainy (kharif) seasons of 2018 and 2019 at N E Borlaug Crop Research Centre, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, Uttarakhand to assess the combined effect of host resistance, altered sowing dates, and judicious use of fungicide in soybean under natural conditions. Two soybean varieties, viz. PS 1042 and PS 1092, with three different dates of sowing and six spray schedules consisted of propiconazole, Trichoderma harzianum, and garlic extract were tested for their integrated effect on foliar anthracnose and pod blight diseases. Both varieties were significantly different in terms of disease severity and yield. The experiment was laid out in a split-split plot of 2 × 3 × 6 factorial design with three replications. Variety PS 1042 produced significantly higher yields (22.24 and 23.00 q/ha) than PS 1092 (16.02 and 18.37 q/ha) during both the seasons. In both the varieties, early sowing (27th June) increased the likelihood of disease and decreased yield, whereas sowing at first week of July (4th July) reduced disease severity and thereby, increased yield. Among all the treatments, the combination spray schedules of propiconazole with T. harzinaum and with garlic extract were found most effective or comparable with two sprays of propiconazole and gave comparatively higher yield, viz. 20.47, 20.26 and 20.76 q/ha, respectively, than control (18.30 q/ha) and other treatments. It was observed that integration of moderately resistant variety (PS 1042), seed treatment with T. harzianum (10 g/kg seed), sowing at first week of July, one foliar application of propiconazole (0.1%) at the time of first appearance of symptoms and second spray of T. harzianum (1%) after 15 days of first spray, was very effective in terms of reducing disease severity and increasing yield.