EFFECT OF 24-EPIBRASSINOLIDE TO ALLIVIATE PEPPER PLANTS (Capsicum annuum L.) GROWN UNDER SALT STREES

Abstract

This experiment was conducted at the vegetable field of Horticulture department, College of Agriculture, Baghdad University, Abu Ghraib for two successive seasons 2013 and 2014 to study the effect of 24-epibrassinolide to mitigate the impact of salt stress and its reflect on growth and yield of sweet pepper " California Wonder ". Nested design with three replicates was adapted. The experiment included 12 treatments which is watering plants with three levels of irrigation wells water (1.9, 2.0) ds m-1 (for two seasons respectively), 3 and 5 ds m-1 of NaCl, with four brassinolide treatments (0, 0.1, 0.3, and 0.6) mg L-1. Least significant difference (LSD) at 5% probability was used to compare the means.The results of experiment showed that salinity caused decreasing in all studied traits, while application of brassinolide caused alleviating of plant growth under salt stress. The study showed superior of brassinolide treatment 0.6 mg L-1 with low level of irrigation water salinity (wells water) on all other treatments in all parameters, it caused increasing in nutrient content K, P and ratio in leaves, also increased chlorophyll content in leaves. Brassinolide with wells water treatment caused increasing plant height, branches number, leaves area and dry weight of vegetative growth. Brassinolide was active of mitigating the impact of salt stress on plant it was superior by increasing all parameters on other treatments under the same salinity level.