Predicting chickpea (Cicer arietinum L.) yield through different regression models in central Punjab under climate change scenario

Abstract

Chickpea (Cicer arietinum L.) yield was predicted by developing three different statistical models i.e. basic model (model 1), modified model (model 2) and reformed model (model 3) with special focus on three districts of central Punjab, namely Amritsar, Ludhiana and Patiala. These statistical models have been developed by analyzing the long series of actual crop yield data and data on climatic parameters (minimum and maximum temperature, relative humidity, bright sunshine hours and rainfall on weekly basis). The sensitive periods for chickpea with respect to weather parameters were identified for different weather parameters by using correlation and selected windows with high correlation values were taken for further regression analysis. In the first basic model, the multiple regression technique was used to predict the crop yield by using only weather parameters. The second model is modified model, where technology trend was taken as one of the extra variable in multiple regressions. In the third model, multiple regression analysis was done by using more terms and named as reformed model. Regression equations were developed separately for all the three models and were used to predict chickpea yield. The data for a period of 42 years (1971–2012) was used to develop the forecast model and data of subsequent three years (2013–2015) was used to validate the models. For Ludhiana, among all the three models, basic model and modified model explained up to 75% variation in chickpea yield due to weather parameters while reformed model explained highest i.e. 85% variation in chickpea yield due to weather parameters. In case of Amritsar district, basic, modified and reformed model explained 46, 48 and 57% variation in chickpea yield, respectively. In case of Patiala, the reformed model was the best fitted model to explain chickpea yield as it explained upto 60% variation in chickpea yield followed by modified model which explained upto 54% variation. Whereas, basic model explained 50% variation in chickpea yield. The results revealed that the reformed model was best fitted for Ludhiana, Patiala and Amritsar region as far as chickpea yield was concerned.