Dr. ASHALATHA K. V.SANTHOSHA KUMARA M. A.2018-03-202018-03-202015-06http://krishikosh.egranth.ac.in/handle/1/5810042149Soybean (Glycine max (L.) Merrill) is known as Golden bean and miracle crop of 20thcentury. The research data for soybean was collected based on the experiment conducted by All India Co-ordinated Research Project (AICRP) on soybean and meteorological data (on maximum temperature, minimum temperature, rainfall, relative humidity) were collected from meteorological observatory of Main Agricultural Research Station of UAS, Dharwad for the year 2011 to 2014. The technique of model fitting, correlation analysis, simple linear regression, multiple linear regression, backward regression and path analysis were adopted in respect to study the fluctuations and to study the impact of weather parameters on soybean yield. Correlation study revealed that among the weather parameters the maximum temperature (upto 30 0C) was significant and positively correlated with yield of soybean in case of both JS-335 and DSb-21. Hence, selection of model based on maximum temperature is preferable. Test weight and plant height were significantly and positively correlated with maximum and minimum temperature. For soybean yield, plant height and test weight exponential model, cubic and quadratic models were found to be significant. In case of multiple linear regressions, among the weather parameters, maximum temperature was contributing significantly to the yield of soybean similar result was supported by backward regression analysis. Path analysis for yield revealed that all the characters such as plant height, days to fifty per cent flowering, test weight and days to maturity had positive correlation with yield. Days to maturity and test weight has high direct effect on yield of soybean. Plant height, days to fifty per cent flowering and test weight have exhibited indirect positive effect on the yield. The total indirect effect of days to maturity was negative. The study revealed that there is a genuine relationship between test weight and days to fifty per cent flowering with soybean yield.ennullThesis