CYCLIC IRRIGATION OF SALINE AND NON-SALINE WATER INFLUENCE GROWTH AND YIELD OF LETTUCE CULTIVARS UNDER GREENHOUSE CONDITIONS

Two sources of water (well water, EC 4.5 dS m^-1, and desalinized water, EC 0.5 dS m^-1) were applied to three lettuce cultivars (Sahara, Sharp Shooter and Summer Time). Drip irrigation system was used for six days per week under a greenhouse conditions.
Six cyclic irrigation treatments were imposed.
These were irrigation with either sources of water for the whole growth season (85 days), irrigation with desalinized water for four days then with well water for two days, irrigation with desalinized water for three days then with well water for three days, irrigation with desalinized water for two days then with well water for four days and irrigation with desalinized water for one day then with well water for five days.
Results revealed that head traits were not affected by water quality except when irrigated continuously with well water.
No significant differences were found in most traits when lettuce was irrigated with three days or more with desalinized water.
Continuous irrigation with well water reduced total yield by 25% and 19.8% and marketable yield by 27% and 32% significantly in the first and the second seasons respectively.
Significant differences among cultivars were found in most traits.
Highest values for total and marketable yield were observed for Sahara followed by Sharp Shooter and Summer Time.
All traits were less affected when lettuce was irrigated with desalinized and well water of the same period (three days each) and total yield was only reduced by 6.2 and 7.7%, at the first and second seasons compared to continuous irrigation with desalinized water respectively.
It is concluded that irrigation with desalinized water for three days followed by another three days with well water is recommended for greenhouse lettuce production to reduce the high cost of water desalinization.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

A.A. Alsadon, M.A. Wahb-allah, S.O. Khalil

Lactuca sativa L., salinity, water quality, cultivars, desalinized water

https://doi.org/10.17660/ActaHortic.2008.801.155