Alleviate the Adverse Effect of Irrigation with Drainage Water on Garlic Plants by Using Glycine Betaine and Sodium Nitroprusside

This experiment was conducted during the two consecutive winter seasons of 2022/2023 and 2023/2024 at the Experimental Farm of Vegetable Crops, Medicinal and Aromatic plants, Horticulture Research Institute, Agricultural Research Center, Dokki, Giza, Egypt, to study the effect of irrigation with saline water and foliar applications of glycine betaine (GB) and sodium nitroprusside (SNP) on vegetative growth, chemical composition and yield of two garlic cultivars (Sids-40 and Balady) grown in sandy soil under drip irrigation system. Treatments were the combination among two cultivars and two foliar treatments and four saline irrigation water treatments; i.e., 1000, 2000, 3000 and 4000 ppm (prepared by diluted drainage water of Karun lake, Fayoum Governorate) and tap water of E.C 256 ppm as control. The results emphasized that all measured growth characteristics decreased gradually as garlic plants were irrigated with saline water up to 4000 ppm. Balady cultivar recorded higher vegetative growth and N and K uptake values. On the other hand, Sids-40 cultivar recorded the higher values of neck diameter, bulb diameter and average cloves weight. The higher significant proline content and protein % recorded with the Balady cultivar Thus, Balady cultivar was more salt-tolerant compared with Sids-40 cultivar. As the saline water level increased above 1000 ppm the vegetative growth and yield decreased. The saline water level of 1000 ppm significantly increased the vegetative growth, chemical content and the yield in both seasons. The triple interaction among the Balady cultivar, saline level of 1000 ppm and the foliar application of GB improved the plant length, leaves number/plant, leaves area, leaves dry weight, bulb fresh weight, bulb dry matter, chlorophyll content and the bulb weight yield, while the highest significant content of proline was obtained by Balady cultivar, saline level of 4000 ppm and the foliar application of GB in both seasons.