Rice production system of Kerala has become so fragile that the conservation of this system is hindered by several hurdles taking it to the cross-roads. One of the factors contributing to this is the climatic variability observed during the recent years. Dry spells during the monsoon season and heavy rains in summer season, which are parts of the climatic aberrations taking place all over the world, have become quite frequent in Kerala also. In this context attempts were made to analyze the temporal variations in rainfall and temperature recorded over twenty-five years (1984–2008) at the Regional Agricultural Research Station (Southern Zone), Vellayani, Kerala. The onset of monsoon has been advanced to May from June. A declining in trend is observed in rainfall and the number of rainy days during the month of June and an increasing trend in October. The decreasing trend of rainfall in June could be attributed to the decline in rainfall during the 23rd and 24th standard weeks, which mark the beginning of the South West monsoon and cropping season. The diurnal temperature variation has narrowed significantly during the months of April and May mainly due to the increasing trend in minimum temperature recorded during these months. Maximum temperature during the initial and latter part of the South West monsoon is also higher than the normal. In recent years the monsoon exhibits a shy trend during the initial phase. The study indicated the need for suitable adaptation strategies including adjustments in the date of planting, developing high yielding varieties with good degree of tolerance to high temperature, drought and flood so as to decrease the vulnerability of rice production system to climatic variability.
Climate variability, Rainfall trend, Rice production
