Effect of artificial inoculation methods for disease development of downy mildew and white rust in Brassica juncea (L.)

Abstract

Per cent disease index DM: for downy mildew, soil+spray treatment was most effective method given highest per cent disease index (48.33 %) lowest in seed (27.67 %). PDI (WR): For white rust disease index was highest in soil+spray (57.67%) at 21 DAI (days after inoculation) and minimum seed + soil (48.33 %). In case of soil+spray maximum (44.67 %) at 14 DAI, and minimum seed + soil (35.33 %). It was found that combination treatments were effective at both 14 &21 DAI. Incubation period (IP), was most effective in combination soil+ spray treatment for both DM and WR (most effective for disease appearance) and was followed by lesser for in other seed +spray treatment compared to soil +spray. Alone spray treatment incubation period is most effective and followed by soil than seed treatment had much (IP) and found least effective. WR pustule size: At 14 DAI, the pustule size were small (S:0.5-1.0 mm) in alone treatments viz., seed, soil and spray; medium in soil+spray, seed+spray and seed+soil mixed treatments. At 21 DAI, the pustule size went to medium(M: 1-3mm) in seed, soil and spray and became large (L: 3-4mm) in case of mixed viz., soil+spray, seed +spray and seed+soil indicated as effective treatments to increase disease indices.