HI
Date cultivation
Pollination
Dates are wind or insect pollinated naturally, and natural pollination can be practiced in seedling orchards with 1:1 ratios of males to females. In most commercial orchards, however, only one male is grown for every 50 females, and pollination is accomplished artificially. Traditionally, a few strands of male flowers are laid among females in inflorescence by hand. Hand pollination is laborious, requiring up to 700 man-days of work for an average sized planting. More commonly, pollen is collected from male inflorescences, dried, and stored up to a year in refrigeration if females are not immediately ready for pollination. Pollen is generally blown onto receptive female inflorescences by a machine, hand-held puffers, or placed first onto cotton balls, which then are placed into inflorescences. The period of female receptivity is as little as 3 and as many as 30 days after the female spathe opens. Fruit set is often lower with artificial pollination, but adequate, and decreases the need for thinning and reduces expense.
Fruit
Fruit are drupes, 1-3" long, dark brown, thick skinned, with thick sweet flesh and a large seed in the center. Unlike other drupes, the endocarp is thin and membranous, instead of thick and bony. Immature fruit are green, yellow, or red. Several hundred to just over 1000 fruit are borne in each bunch, which can weigh up to 80 pounds. Fruit go through 5 distinct stages as they mature over 6-8 months, given the following Arabic names: Hababouk, Kimri, Khalal, Rutab and Tamar. Fruit grow rapidly in the first 2 stages, then turn their characteristic color, lose water, and accumulate sugar in the Khalal stage, and finally ripen completely in the last 2 stages. Fruit thinning is practiced at pollination time, or sometimes 6-8 weeks after pollination. Thinning is accomplished by bunch thinning, where some strands or portions thereof are removed, or by complete bunch removal, or both.
Soils and Climate
Soils - deep, well drained loamy soils, most tolerant of crop plants to high pH and salinity, commercial fruit production requires considerable water. Flood irrigation is applied several times per year.
Climate - hot, dry climate, pollination and seed set disfavored by temperatures below the mid 70s F, tolerate higher temperatures than most other fruit crops; mid-summer temperatures of 100-110 °F are typical in date production, can tolerate light freezing (to 20-23 F) in winter, a cool winter helps to synchronize flowering and ripening of fruit, extremely resistant to wind damage.
Propagation
Dates are propagated by offshoots, which are suckers growing from the trunks.
Rootstocks - None
Planting Design, Training, Pruning
Dates are planted about 25-35 ft apart, yielding about 50 plants per acre on average. A tendency toward slightly higher densities of up to 60 or so per acre has occurred more recently. Cultivars such as ‘Khadrawy' that are dwarf can be planted at much higher densities. Very little pruning and training is involved in the production of any palm fruits. Dates have persistent leaves, which must be pruned off to allow access to fruit and crowns; old fruit stalks are pruned off as well.
Maturity
At full maturity, dates are dark brown and have very low water content. However, they may be harvested prior to full maturity for special markets. In the Khalal or 3rd of 5 developmental stages, dates are firm, crisp, moist (50-85% water content), and have their characteristic color, usually red or yellow.
Harvest Method
Dates are hand harvested, generally by cutting entire bunches at one time. In some cases, individual fruit may be picked, where bunches are shaken to remove only the ripe fruit. Each palm may be picked up to 8 times over a period of 2-3 months to obtain consistent maturity.
Postharvest Handling
Fresh dates (Khalal stage) are washed and packed in 10 lb cardboard boxes still on the stems. Immature and over-mature fruit are removed, as well as damaged or small fruit at the proper maturity. In regions that can expect rain at harvest, fruit are harvested a bit early and dehydrated; areas with hot, dry winds at harvest may rehydrate fruit in water to improve texture and taste. Dates may be pitted prior to packing, depending on intended market.
Storage
Dates at full maturity store remarkably well compared to other fruits, owing to their low water content. Ripe dates do not experience chilling injury, and can be stored at 32-34°F for a year or more if humidity is kept below 20%. Fresh dates (Khalal stage) can be stored for up to 8 weeks under the same conditions.
Regards
Ashwini
