Tolerance of precocious dwarf cashew clones to salt stress during rootstock formation stage

Abstract

This study was conducted to evaluate the tolerance of precocious dwarf cashew clones to irrigation with waters of different salinity levels during rootstock formation. The experimental design consisted of randomized blocks, arranged in a 5 x 3 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.4; 1.2; 2.0; 2.8 and 3.6 dS m-1) and three clones of precocious dwarf cashew (Faga 11, Embrapa 51, CCP 76), with three replicates. Water salinity above 0.4 dS m-1 inhibited chlorophyll synthesis and growth, but led to cashew seedlings with the Dickson Quality Index (DQI) higher than the acceptable limit. Based on the relative yield of the total dry mass, the clones Faga 11, Embrapa 51 and CCP 76, at the highest salinity level studied, were classified as moderately sensitive, sensitive and moderately tolerant, respectively. There was interaction between water salinity and precocious dwarf cashew clones for chlorophyll a content, chlorophyll b content and DQI at 75 days after sowing.