Effect of Ascorbic and Humic Compounds Pre-Treatment on Growth Characteristics of Some Sugarcane Varieties under Salinity Stress

SUGARCANE (Saccharum spp.) shows high sensitivity to salinity at various growth stages. A pot experiment was conducted at the Agricultural Research Center, Giza (latitude of 28.76 °N and longitude of 29.23 °E) under natural conditions in November 2015/2016 and 2016/2017. The present work was carried out to find out the influence of four soaking treatments (without soaking, tap water, ascorbic and/or humic acid) and three levels of salt stress (tap water, 3000 and 6000ppm NaCl) on some growth traits of three sugarcane varieties (viz. G.84-47, G.2003-47 and G.2003-49). The concentration of both ascorbic and humic acid was 1.0mM. After soaking in ascorbic and/or humic acids, five pieces of 2-budded sets were grown in plastic pots (45x50cm) containing soil of clay mixed with sand at 2:1. Emergence %, growth measurements (stalk height, stalk diameter, leaf area, stalk fresh weight, stalk dry weight, root fresh weight, root dry weight, total chlorophyll and proline content) were recorded. The results indicated that increasing salinity levels under all soaking treatments was accompanied with a gradual reduction in all studied traits of the evaluated sugarcane varieties, except proline content, which showed an opposite trend. Under conditions of this work, the commercial G.84/47 cane variety showed higher tolerance to raising salinity level up to 6000ppm in irrigation water over the other two ones. Meanwhile, soaking cane cuttings of the tested varieties in ascorbic and/or humic acids can be recommended to improve their growth traits when canes irrigated with saline water.