Effect of different irrigation water levels and planting patterns on Egyptian cotton productivity and some water relations

;There were no significant differences between the two planting patterns in dry weight per plant, leaf area index (LAI), crop growth rate (CGR), final plant height, number of open bolls per plant, boll eight, seed index, lint %, seed oil % , seed cotton yield , lint yield and oil yield in both seasons. Application of irrigation water every 14 days interval with different water amounts had a significant effect on all growth and agronomic traits in the two seasons. Adding irrigation water with amount equal to 110% of soil moisture content of FC resulted in a significant increase in dry weight per plant, LAI, CGR and plant height, number of open bolls per plant, boll weight, seed index, lint %, seed oil % , seed cotton yield , lint yield and oil yield compared: with water amount equal to 80 and 85% of FC at all sampling dates in both seasons. Application of irrigation water equal to 100 and 90 of FC were statistically at par with 110% of FC in all mentioned traits in the two seasons. Although, beds pattern was equivalent to ridges pattern in growth and yields, beds pattern was less in amount of applied irrigation water and water consumptive use and it saved 616 and 596 m. applied water than ridges pattern in the two seasons. Water application efficiency (WAE) for seed cotton, lint, oil and cottonseed meal yields (kg/ m. applied water) and water consumptive use efficiency (WUE) for seed cotton yield (kg/ m. water consumptive use) were increased by application of beds irrigations compared with ridges irrigation. Amount of applied irrigation water and water consumptive use were increased by increasing irrigation levels. However, WAE and WUE were increased by decreasing irrigation level from 110 to 90 of FC and then they decreased.The highest amounts of applied water 3308 and 3242 m. /feddan were recorded by ridges irrigation with the high irrigation level (110% FC) in both seasons. Beds irrigation with water amount equal to 90% FC saved 954 and 937 m. water/feddan than ridges irrigation with water amount equal to 110% FC, although they were equivalent in high seed cotton, lint and oil yields. Also, this treatment recorded the best WAE for seed cotton, lint, oil, cottonseed meal yields and the best WUE for seed cotton yield.