Determination of the best pollination time of Barhee and Zahidi date cultivars
2011
Marashi ,Seyyed Samih
Pollination time is one of the most important factors affecting fruit set and yield in date palm determined as related to female flowers' receptivity period and this period may vary among different cultivars and climatic conditions. To determine the best pollination time of two desirable and commercial date cultivars, Barhee and Zahidi, for increasing fruit set and yield, the present research including two separate experiments for the two above mentioned cultivars, each of them in a latin square design (6 × 6), was carried out in Ahwaz region during 2005 and 2006 growing seasons. The treatments of each experiment were comprised of pollination of female spathes, 1 to 2 days before cracking, at the day of cracking and 2, 4, 6 and 8 days after cracking. Each treatment was applied to a cluster and each palm was taken into account as a replication. At 4th and 15th weeks after pollination, initial and final fruit set was calculated for each cluster, respectively. By harvesting experimental bunches of each palm at tamar stage, fruit yields per bunch and palm and quantitative characteristics including weight, length and diameter of fruits and seeds were measured for each treatment. The results showed that, pollination 1 to 2 days before spathe cracking in Barhee cultivar and pollination 1 to 2 days before spathe cracking as same as pollination at the day of spathe cracking in Zahidi cultivar, were significantly higher than other treatments in fruit set. Delaying pollination up to 8 days after spathe cracking resulted in continuous decrease of fruit set and yield in both cultivars. This delay did not accompany with any significant change in fruit characteristics in Barhee cultivar but delaying pollination for 6 to 8 days after spathe cracking in Zahidi cultivar, probably due to natural bunch thinning, resulted in a significant increase of fruit weight and diameter. If reducing frequency and increasing efficiency of pollination practice in the tested cultivars must be considered too, pollination may be postponed up to the day of spathe cracking, in Barhee cultivar, and up to 4 days after spathe cracking, in Zahidi cultivar.
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