M. A. Bacha, M. A. El-Hamady and H. M. Abo-Asker
The effect of irrigation on vegetative growth and fruiting of Balady orange trees grown in Riyadh region was studied aiming at reducing the effect of different environmental stresses especially heat stress in order to improve vegetative growth and fruit properties during 1989 and 1990 seasons.
Trees were irrigated at 4, 6, 8 days intervals during the period from 1st of June till the end of September heat stress peaks in both seasons.
Results showed that irrigation at 4 days intervals had the highest number and length of shoot that developed during the summer and autumn growth flushes compared to irrigation treatments of 6 or 8 days intervals. Also, irrigation every 4 days increased the growth of roots and lead chlorophyll content than the other treatments. Yield was not significantly affected by any of the irrigation and irrigation every 4 days had increased most of these properties. Furthermore, some chemical properties of the fruits were significantly affected, and irrigation every 4 days has lower TSS % and acidity. Neither vitamin C nor TSS / acidity ratio were influenced by the irrigation treatments.
In conclusion, irrigation every 4 days is the best irrigation treatment in Riyadh region forBalady orange trees since it gave the best vegetative growth and fruit properties.