EFFECTS OF THINNING METHODS ON DATE BUNCH FADING DISORDER AT POLLINATION AND KIMRI STAGES

Date bunch fading disorder is one of the most important problems for date growers in southern Iran. Therefore, the effects of time and methods of bunch thinning were studied with a split plot experiment in Randomized Complete Block Design with 4 replications during 2003-2005. The treatments were comprised of thinning time at two levels (pollination and kimri stages) as the main plots and thinning methods at five levels (control, cutting back 10 and 30% of bunch tip, cutting back 10 and 30% of central strands) as subplots. The experiment was carried out on the ‘Kabkab’ cultivar in Bushehr province. The results showed that thinning treatments caused significant decrease (α=0.05) in fading disorder in experimental cultivars. The minimum percent of fading disorder in ‘Kabkab’ was observed when cutting back 30 and 10% of bunch tips and 30% of central strands, respectively. Time of thinning showed no significant effect on any of the characteristics. The interaction of time and methods of thinning treatments on fading disorder were significant at 5% level. Also, increasing of weight, length and fruit diameter were seen after bunch thinning. Thinning 30% of bunch tip in ‘Kabkab’ caused significant increase in pulp to seed ratio in comparison with control and other treatments. TSS was increased after bunch thinning significantly. Time and thinning methods had no significant effect on pH, ripening time and humidity percent.