Weather based rules for yellow mosaic disease prediction on soybean in Madhya Pradesh

Abstract

The yellow mosaic disease (YMD) found to be one of the major constraints in soybean production in Madhya Pradesh. For timely management of this disease and for reducing the calendar based prophylactic pesticides spray, this study was conducted to screen out critical weather limits for peak YMD incidence. Field experiments as well as farmers field survey were conducted during kharif seasons of 2015 to 2019 in four districts viz. Tikamgarh, Chhatarpur, Datia and Jabalpur of Madhya Pradesh to record spacio-temporal variability of whitefly and YMD on soybean. Isolation of DNA from the infected soybean leaf samples was executed as per the standardized protocol of DNA isolation and molecular level identification of mungbean yellow mosaic India virus (MYMIV) was carried out as well. It was noted that the preceding week’s weather conditions significantly influenced the peak YMD incidence during the study periods. It was observed that maximum temperature, sunshine hours, number of whitefly population were positively related with YMD at the significant level; while the rainfall, evening relative humidity were negatively related. A weather based rule was worked out for peak prediction of YMD in soybean during the previous two weeks period when the following conditions were satisfied: Whitefly population per plant was above 12, maximum temperature was above 33°C and passive phase of monsoon was for more than a week. The transmission rate was found to be higher when dry period coincide with maximum temperature above 33°C for greater than or equal to 5days. This weather based rule for peak YMD prediction was also validated.