Development of regression models in ber genotypes under the agroclimatic conditions of south-western region of Punjab, India

The field experiment was conducted at PAU, Regional Station, Bathinda, for consecutive 7 years (2003–2009) to study the crop growth behavior and yield characteristics of ber fruit crop and an attempt was made to correlate the ber fruit characteristics with weather parameters over the years. The seven years data on fruit characteristics and weather parameters were taken on yearly basis and correlations were developed between ber fruit yield, fruit weight, acidity, pulp percentage, TSS and corresponding weather parameters namely minimum temperature, maximum temperature, morning relative humidity, evening relative humidity and rainfall. The regression analysis was done for four varieties of ber viz., Umran, Wailati, Chhuhara and Seb and the most suitable variety best suited for the weather conditions of southwestern region was worked out. The most sensitive period for fruit yield sensitivity appears to be during November to March months for the ber varieties under study. Different varieties responded differently with weather parameters for their different characteristics. The multiple regression models were developed on the basis of critical periods pertaining to crop yield characteristics for different varieties separately and it was found that 80–90% variation in fruit yield and yield attributing characters were explained by weather parameters.