Growth, yield and quality of three greenhouse cucumber cultivars in relation two types of water applied at different growth stages

Abstract

Two levels of salinity of irrigation water (I: well water with EC 2.61 ds.m"', II: desalinized water with EC 0.39 ds.m"1) were applied to three greenhouse cucumber cultivars; Alasil, Alia and Copra; at various stages of growth and for different time durations, to study the effect of irrigation water salinity on growth, quantity and quality of cucumber production. Five irrigation treatments (IT) were applied; (IT1) irrigation with desalinized water for the whole experimental period; which was 105 days, (IT2) irrigation with desalinized water from the beginning of experiment until the beginning of flowering stage (30 days) then irrigation with well water, (IT3) irrigation with desalinized water until the beginning of fruit setting stage (35 days) then irrigation with well water, (IT4) irrigation with local well water (35 days) then irrigation with desalinized water until the end of the experiment, and (IT5) irrigation with well water for the whole experimental period. Vegetative growth traits recorded were: plant height, leaf number, leaf area, leaf fresh and dry weight. Fruit growth traits were; length, diameter, firmness, number, fresh and dry weight. Early and total yield were also recorded. Salinity during the entire growing period and (IT5) significantly reduced early and total yield by 46.8% and 28.3% respectively. Also, it reflected higher negative results in all traits, except fruit dry weight. The negative effect of salinity on most traits was less severe when IT4 was applied. No significant differences were found between IT2 and IT3, since they resulted in intermediate negative effect in all studied traits; except for early yield. Significant differences among cultivars were found in fruit growth traits especially yield and its components. Highest values for fruit weight, early and total yield were recorded in Copra followed by Alia and Alasil, respectively. Considering that all traits were less severely affected by IT4 and that total yield was only reduced by 7.2% as compared to IT1, it can be concluded that the use of salinized irrigation water until fruit setting stage followed by desalinized water for greenhouse cucumber production is recommended to save the high cost of water desalinization.