Growth, production and fluorescence characteristics of chlorophyll a in peanut under saline conditions

Abstract

The objective of this study was to evaluate variables of the growth, production and the fluorescence characteristics of emission of the chlorophyll a in two genetic materials of peanut irrigated with water of different salinities. The experiment was conducted in a greenhouse at Campina Grande - PB, during the period of June to September, 2004. A 5 x 2 factorial scheme was adopted using a completely randomized design with six replications; the five levels of water salinity - ECw were (Control, water of the municipal supply system - 0.4; 1.5; 3.0; 4.5 and 6.0 dS m^-1) and two cultivars (BR-1 and L-7). All the analyzed variables of growth and production were affected significantly by the salinity of the irrigation water, the number of leaves and leaf area decreased respectively 4.1 and 8.7% per unit increase of salinity, while the number of fruits and weight of 10 seeds had a total decrease of 36.0 and 78.3% between 0.4 and 6.0 dS m^-1 of ECw. The dry weight of shoot of BR-1 and L-7 cultivars was reduced 13.9 and 11.6% with per unit increase of water salinity, respectively. From the threshold salinity of 1.095 dS m^-1 the number of fruits decreased 7.7% for unit increase of the ECw. No significant alterations were observed in the parameters associated to the emission of the fluorescence of chlorophyll a due to salt stress. The cultivar BR-1 showed more sensitivity to the salinity of the irrigation water than the L-7.