Yield response of sugarcane to weather variations in north east Andhra Pradesh, India

The influence of the meteorological parameters: maximum and minimum temperatures, relative humidity, rainfall and duration of sunshine, on sugarcane yield, is studied by fitting third-degree response function models using the long-period experimental data at the Regional Agricultural Research Station at Anakapalle (17°38′N, 83°01′E), Andhra Pradesh, India. These models give the quantitative response in the yield brought about by a unit change in the meteorological parameters at each stage of the crop growth. The maximum and minimum temperatures and relative humidity during the first three months of the crop (germination and tillering phases), are found to have a profound influence on the yield. Above normal temperatures and drier conditions at this time seem to be favourable for good yields. Presuming that the year-to-year variations of the meteorological parameters are largely the reflections of the broad synoptic systems prevailing over and around the area of study, an attempt has been made to identify the macrometeorological situations that critically affect the sugarcane yield. This is accomplished through selected case studies of weather situations during the critical periods obtained above, for some poor-yield and good-yield years. This study helps in fixing the favourable and unfavourable macrometeorological systems, which could be useful for issuing special agrometeorological forecasts for sugarcane growers and crop-outlook statement