Effect of Irrigation Water Type and the Level of Humic Acid Addition on the Growth and Corms Yield of Gladiolus Plants

Abstract

The experiment was carried out inside a canopy of green saran at the research station of the Department of Horticulture and Garden Engineering - Faculty of Agriculture - University of Tikrit for the period from February 28, 2023 to August 6, 2023, for the purpose of studying the effect of adding humic acid at four levels 0, 3, 5, 7 mg anvil^-1 and three types of irrigation water: irrigation with river water, irrigation with well water and alternating irrigation.  And the overlap between them in the characteristics of vegetative growth and cormat yield of the Gladiolus hybrid plant Amsterdam. Treatment with irrigation water types began from the first day after planting corms in plastic anvils. The first addition of humic acid began 30 days after planting, the second addition 15 days after the first addition and the third addition 15 days after the second addition. The experiment was designed with a splinter cutting system with a complete random sector design and three repeaters. The results showed that the treatment of irrigation with river water achieved a statistically significant superiority in the following studied characteristics: vegetative plant height 66.33 cm, leaf length 46.956 cm, leaf area 106.074 cm², dry weight of leaves 0.752 g plant^-1, Relative content of chlorophyll 17.063 Spad Unit, number of corms 3.297 corm^-1, diameter of corms 33.690 mm. Treatment with humic acid at a concentration of 5 mg anvil^-1 achieved statistically significant superiority in vegetative plant height 64.118 cm, leaf length 47.331 cm, leaf area 104.750 cm², dry leaf weight 0.681 g plant-1, relative chlorophyll content 16.814 Spad Unit, number of corms 3.556 corm^-1. Treatment with humic acid at a concentration of 7 mg anvil^-1 also achieved a significant superiority in the characteristic of a cormate diameter of 33.690 mm.