The Defining of the relationship between cotton growing time and the illness of wiltness (verticillium dahliae kleb.) in the conditions of Diyarbakır

Ill 3- ABSTRACT The defining of the relationship between cotton growing time and the illness of wiltness (Verticillium dahliae Kleb.) in the conditions of Diyarbakır. irfan ERDEMCI 2000 This study has been carried out to detemine the effect of the different growing times on the factor of cotton wilting illness {Verticillium dahliae Kleb.) and relatedly the effect of the pottencial illness on the productivity. The test has been tried in three different growing priods according to the parcells order divided in the test design of coincidence blocks. Which had already been effected by the disease in a field of a farmer in the vailey of Dicle River in Üçtepe village of Bismil, Diyarbakır in the years of 1998-1999 ( 26th April, 11 * May and 25 * May, 1998; 20 th April, 5 * May and 20 * May, 1999). In 1998 Nazilli 87 type that is well-ressistant to the disease and Delta Pine 50 types were partly-resistant to the disease were used but in 1 999 the number of types has been increased to three. In addition to the types mentioned above the sensitive Sayar 314 type has also been used. According to the obtained findings it has been observed that the rate of the disease dicreases as the growing period gets late but there is a negative (oppositte) relationship of the disease rate on the productivity stastically. Kay words: Cotton, teypes of cotton, Verticillium dahliae, growing time, the rate of the disease, illness indekx, Productivity factors.