author(s)
Nayan Kishor Adhikary, Pranab Barma, Jayanta Tarafdar and Gautam Saha

abstract
Five soybean varieties, JS-335, JS-9305, KDSB-2042, KSL-441 and KSL-20 were screened against whitefly and yellow mosaic disease in the field. The highest and lowest prevalence of yellow mosaic virus (YMV) was recorded in JS-335 and JS-9305 respectively and incidence ranged from 5.83 to 45.00% during first year, 2011 and 7.50 to 44.17% during second year, 2012. There was a poor and insignificant quadratic polynomial relationship (y = -0.173x² + 11.06x – 175.5 & R² = 0.285) between temperature and whitefly population build up in soybean field. The relationship between relative humidity and whitefly population build up in the field was found significant but negatively correlated (y = -0.019x² + 3.517x - 154.5 & R² = 0.678). The increase of whitefly population in the field was positively correlated with the spread of YMV in the soybean field (Y= 0.001x² - 0.055x + 1.498 & R² = 0.324).