Corn yield in Southern Serbia in dependence on climatic conditions of the year.

Corn yields are unstable and largely depends on climatic conditions, hybrids and breeding \ntechnology. The aim of this paper is to analyze the variation of corn yield in the period from 2000 to \n2009 from the viewpoint of rainfall and temperature regimes. Based on the information given by the \nRepublic Hidrometeorological institute and Agricultural expert and education service in Leskovac, \nit is analyzed the influence of rainfall and medium temperature of air on the yields of corns in South \nSerbia (Leskovac). The special emphasis places on precipitation during the three summer months \n(June - August), because it is considered critical for the yield. Out of nine tested years, there were \nseparated two with unfavourable (2000 and 2008) and two with favourable climatic conditions for \nthe production of corn (2002 and 2005). So, the average corn yield in unfavourable years was 1.7 t \nha-1 relatively 1.4 t ha-1 when the amount of rainfall in the critical months (June - August) was 89 \nmm relatively 137 mm and the average air temperature in the same period 21.7º C relatively 20.9 \nºC. The average yield of corn in favourable years was 4.1 t ha-1 relatively 5.7 t ha-1 when the \namount of rainfall (June-August) was 257 mm relatively 242 mm and the average temperature of \n21,4 ºC relatively 19,8 ºC. For the yield of corn it is not important total quantity of rainfall during \nthe year or vegetation, but their arrangement in stages when corn has a great need for water. To \nachieve genetic potential for yield, which is more than 10 t ha-1 (early hybrids) or more than 15 t ha- \n1 (late hybrids), in addition to hybrids and crop management it is necessary benignity agro climatic \nconditions of the region, especially enough rainfall and their regular schedule.