EFFECT OF POLLINATION FREQUENCY AND POLLEN CONCENTRATION ON YIELD ANDFRUIT CHARACTERISTICS OF MECHANICALLY POLLINATED DATE PALM TREES (PHOENIX-DACTYLIFERA VAR. KHALAS)

An experiment was carried in Al-Ain region, the largest date productio n district of the United Arab Emirates (UAE), during the production ye ars 1993 and 1994. The experiment tested the contribution of two polle n concentrations (1:10 and 1:5 on a volume basis) and three frequencie s of mechanical application (two, three and four times) to yield and f ruit characteristics of dates of variety Khalas (one of the most prest igious varieties in UAE) in comparison with the current manual applica tion method (control). The experiment followed a balanced block design with eight replicates. Significant variations existed in yield and fr uit characteristics among the various treatments. Although pollen conc entration did not have a significant effect on these variations, the e ffect of the frequency of pollen application and its respective intera ction with pollen concentration was significant; these results were co nsistent in both years. Highest average bunch mass was 5.66 kg resulti ng from pollinating the bunch twice with a 1:10 concentration but this was not significantly different from the average mass of bunches that were hand pollinated (control 5.46 kg). In general increased pollen a pplication resulting from either higher mixture concentrations or more frequent applications resulted in more fruit drop and consequently a significant drop in yield. (C) 1997 Silsoe Research Institute.