Thirty date palms of each of Khalas and Khassab cultivars at 6-7 years of age were selected randomly in Al-Fairooz Farm in Khabourah, Batina region. The aim was to improve fruit production and quality by fertilizer application. Experimental treatments were applied in a factorial design and included: organic peat alone with 1000g urea divided into 5 and 4 equal doses mixed with 500g triple superphosphate and 800g K2SO4 and with or without micronutrients. The control included no organic or mineral fertilizer. Mineral fertilizer tended to increase Khassab strand weight and decrease fruit number. The highest number and yield was associated with the smallest length and diameter and was produced by NPK + micronutrients and organic peat. In Khalas no significant differences were observed in fruit number, weight and size, but NPK 5 or 4 nitrogen doses with micronutrients and organic peat produced the highest yield. Four nitrogen doses with phosphate and K2SO4 increased Khalas yield by 22% over the control and 24.7% over organic peat. The same treatment increased Khassab yield by 77.5% over the control and 130% over organic peat. On the other hand, five nitrogen doses increased the yield of Khalas by 17.8% over the control and 20.4 % over organic peat. On Khassab it increased the yield by 63% over the control and 112.4% over peat. Five nitrogen doses in Khalas produced higher weight of strand, number of fruit per strand, weight and length of fruit and yield than 4 doses. It produced lower strand weight, fruit length and diameter, and higher yield and number of fruit per strand than 4 doses on Khassab. In both cultivars, number and weight of fruit/strand and weight of fruit were lower in Rutab than Bisir stage. However, diameter was reduced and yield was increased in Khassab, whereas in Khalas both fruit length and yield were reduced from Bisir to Rutab.
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