Foliar Spraying With Protein Hydrolysates Preparation From Shrimp by-products Improves Growth, Yield And Quality Of Lettuce (Lactuca sativa L. ) Grown Under Salinity Conditions

The experiment was carried out during the winter season 2019-2018 in Al-Hartha district/Basrah Governorateto study the effects of shrimp by-product prepared by Alcalase and Flavourzyme enzyme as a foliar application on lettuce (Lactuca sativa L.) growth, yield and quality grown under salinity conditions. Shrimp by-product protein hydrolysates were spray-applied (3 and 6 ml. L-1 ) additional to control treatment. Randomized Complete Block Design (R.C.B.D.) was used as factorial experiment .Treatment means were compared by using Least Significant Differences (L.S.D.) at a probability of 0.05. The results showed that spraying with protein hydrolysates had a significant effect on most studied characters compared to control treatment. Results showed that foliar application with (T2) significantly increased the total leaves number, leaves area, shoot fresh weight, total yield, total phenols , total soluble solids (TSS %),vitamin C dry mater, K+ and K+/Na+ content in addition were recorded significantly decrease of nitrate, Na+ ,CL- and Ion leakage contents, while foliar application with (T4) significantly increased in the plant height. The result showed that spraying six times (S6) were significant increases in these growth characters comparing with four sprays (S4), while decreased nitrate, Na+,CL- and Ion leakage contents when spraying six times(S6). The interaction between treatments and spraying number show significantly increased in some characters, the (T2 S6) had the highest value shoot fresh weight 1036.0 g and total yield 24.311 tone.donum-1.