RESPONSE OF GLADIOLUS PLANTS TO WATER REGIME AND GLUTATHIONE UNDER DIFFERENT IRRIGATION SYSTEMS IN NEWLY RECLAIMED SOILS

The present work was carried out to investigate the efficiency of glutathione to overcome the harmful effect of water deficit on growth parameters and reproductive characters as well as some physiological and chemical aspects of gladiolus plants grown under surface and subsurface drip irrigation. Results showed that decreasing the amount of irrigation water from 1882 to 1129 m³ / fad., reduced significantly plant height, total leaf area and number of leaves per plant as well as water content of plant. The same trend could be noticed regarding to flowering and corms production except vase life. Also, the photosynthetic pigments content, total carbohydrates, nitrogen, phosphorus and potassium contents in the leaf tissues were significantly reduced with decreasing the amount of irrigation water. On the contrary, proline content exhibited a remarkable increase with increasing drought stress. Foliar application of glutathione promoted all the aforementioned growth parameters and reproductive characters as well as chemical constituents compared with untreated plants. Also, foliar application of glutathione (400 ppm) at 30 and 60 days after planting could be used to improve drought tolerance and economic yield of gladiolus plants. Furthermore, there was little difference between the values of the above mentioned characters studied in gladiolus plants irrigated by surface and subsurface drip irrigation.