The Effect of Rains on the Production of Wheat in Jordan.

Abstract

Productivity of field crops in Jordan is low and extremely variable. Although several physical and cultural factors contribute to the extreme variation of productivity, rainfall could be considered as the most influencing factor. Other factors contributing to the low and fluctuating productivity are more static and less variable than rainfall.
Therefore, study of the relation between wheat productivity and the amount distribution of rainfall is of great importance. Stepwise regression is used to evaluate the impact of two weeks, monthly and seasonal rainfall upon wheat productivity.
It is found that two weeks rainfall is the most important factor in contributing to wheat productivity; 92% of the variance of productivity is explained by variation in the two weeks of rainfall alone. When monthly rainfall is used, the percentage of explained variance varies throughout the country between 6% to 93%. Seasonal rainfall explains between 4% to 77% of the variance. The area of wheat production in Jordan is divided accordingly into regional patterns like areas of early, late and midseason cultivation.