The Role of Humic Acid and Proline on Growth, Chemical Constituents and Yield Quantity and Quality of Three Flax Cultivars Grown under Saline Soil Conditions

Abstract

In order to mitigate the salinity effects on flax grown on moderate saline sandy soil (3275 -3430 ppm) and irrigated with moderate saline water (2300 -2460 ppm) field experiments were carried out at the experimental Station of the Faculty of Agriculture, Wadi El-Natrun district El-Behera Governorate—Egypt, during two successive winter seasons of 2012/2013 and 2013/2014. Three flax varieties (Opal, Giza-8 and Mayic) were grown and treated with some chemical additives humic acid (50 kg/fed) and/or foliar applied proline (Control, 50 and 100 mg/L). The results showed the positive responses of Giza-8 variety to the combined application of humic acid and proline and mitigated the salinity effects of soil and irrigation water and reflected on most of the studied characters. Such results indicate the potentiality of mitigation the hazardous effect of sa-linity with these chemical additives. The data indicated that the highest seed yield, straw yield and oil yield were obtained at humic acid (50 kg/fed) with foliar treatment of proline at rate of (100 mg/L). The interaction of proline at (100 mg/L) with humic acid at rate of (50 kg/fed) improved plant fresh and dry weight in all flax cultivars under salinity conditions. Fresh weight increased by 66.6%, 48.7% and 65.5% over controls for Opal, Giza-8 and Mayic varieties, respectively. The in-teraction of proline at (100 mg/L) with humic acid at rate of (50 kg/fed) with Giza-8 variety gave the highest values of seed yield, straw yield and oil yield.