Influence of Sowing Dates on Incidence and Severity of Post Flowering Stalk Rot of Maize caused by Fusarium verticillioides

摘要

Field experiments were conducted during kharif 2012 and 2013 at Rajasthan College of Agriculture, MPUAT, Udaipur (Rajasthan) to evaluate the effect of date of sowing on the development of post flowering stalk rot (PFSR) due to Fusarium verticillioides. Of the 12 dates of sowing from 5th May to 25th August, maximum mean disease severity (88.2%) and minimum grain yield (1158 g/10 plants) and fodder yield (1363g/10 plants), were recorded when the crop was planted on 5th July 2012 and 2013 followed by 25'” June 2012 and 2013, 5th May 2012 and 2013. The disease severity in maize crop planted in May and August was significantly less on the other dates in June and July. Resuhs of average disease rating and inoculum density of F. verticillioides studies indicated that the plants were susceptible to PFSR infection irrespective of sowing dates however, higher disease severity (6.6 to 8.4) with heavy inoculum (14.3 to 14.7 cfu X l0~4/g soil) was recorded when the crop was sown between 5th June to 15th July.The crop sown after 25thJuly had lower disease intensity and inoculum density from 5.8 to 4.2 and 11.5 to 8.4 cfti x 10~4Vg soil, respectively than that planted before as the critical stage of susceptibility matched with tasselling. The observations on meteorological conditions in relation to PFSR development revealed that minimum temperature (24.4-25.8 C), maximum temperature (33.3-35.8 C), RH (44.5-54.5%) and rainfall (4.0-6.0 mm) were most favorable for the development of PFSR.