Spatial and Temporal Rainfall Analysis of the Bidi Tobacco Growing Areas of India.

Abstract

The monsoon extremities, such as heavy rainfall, drought, and cyclones are becoming frequent across India and causing substantial damage to commercial crops. To predict/identify the trend in rainfall of Bidi tobacco growing areas were studied for variability, trend, and detection of any change in monthly rainfall over the years (1990-2020) using Mann-Kendall trend analysis and Sen’s slope tests. Monthly rainfall in three unique Bidi production zones has shown distinct trends. A positive trend was observed in March, April, August, September, November, and December while negative trends were in June and July months in Gujarat. During the crop growth period, the trend is positive except in October, the magnitude of change was negligible. However, supplemental irrigation is to be planned during water deficit periods of the nursery (June and July) and critical crop growth periods. In Karnataka, a positive trend from February to October was observed while a negative trend during November, December, and January. The magnitude was high in January (+) and September (-) and significant. The period of negative trend has coincided with the harvesting hence, the crop may not get affected. However, high rainfall during the crop growth period causes a detrimental effect. To mitigate the inundation proper drainage facility should be created through field channels to flush out excess water to avoid saturation at the root zone as this crop is especially extremely sensitive to poor aeration and anaerobic conditions. A positive trend was observed in January, February, March, June, August, and September months in Andhra Pradesh, whereas a negative trend was high in October & November which coincided with crop growth and might significantly affect Bidi tobacco. The positive trend in rainfall during June is high and the same can be utilized for nursery during July-August through proper moisture conservation measures.