اثرهاي انواع مختلف تنك و پوشش بر عارضه پژمردگي و خشكيدگي خوشه خرماي مضافتي در ناحيه جيرفت

EFFECTS OF DIFFERENT BUNCH COVERS AND THINNING METHODS ON DATE BUNCH FADING DISORDER OF `MAZAFATIʹ CULTIVAR IN JIROFT REGION

In recent years, date bunch fading disorder has caused heavy economic damage in date plantations of Jiroft region. It takes place when fruit is changing from khalal to rutab stage. Sudden drop of air humidity along with high temperature and blowing hot and dry winds have an important role on incidence and development of disorder. In this study, the effects of two agromanagement factors, including different thinning methods [thinning one third of inflorescence tip at pollination stage (T1), one third of inflorescence tip at pollination stage + 10% of central strands at kimri stage (T2), one third of central strands at kimri stage (T3) and control (T4)] and bunch covers [aluminum foil (Cl), mat-like basket (C2), wax (C3) and control (C4) I were studied as a factorial experiment in form of randomized complete block design with 16 treatmeants and 4 replications in Jiroft region during 2002-2003. The two years data were combined and the means of treatments were compared using Duncanʹs multiple range test. Sampling for determining of damage rate and fruit characteristics within the treatments was done at harvesting time. The results showed significant differences among different treatments of bunch covers and thinning methods, although the effect of hunch covers was more significant than thinning methods. The means of damage percentage in hunch covers (C2), (Cl), (C3) and (C4) were 6.79, 10.62, 16.92 and 19.16and the means of damage percentage in thinning treatment (T1), (T2), (T3) and (T4) were 8.32, 12.56, 13.2 and 19.4, respectively. Effects of both factors (thinning and covering) on some fruit characters such as fruit weight, length, diameter and volume, as well as, stone diameter were significant. Among the treatments, mat like-basket and thinning one third of the inflorescence tip had the most significant effects on reducing disorder damage and improvement fruit quantity and quality of the `Mazafatiʹ in Jiroft region.