Índices fenológicos e fisiológicos de amendoim sob estresse salino.

Abstract

The experiment was lead in greenhouse located at Agricultural Engineering Department of the Technology and Sciences Center of the Campina Grande Federal University - PB, during the period of June, 03td to September, 15th, 2004. The effect of different concentrations leaves in the irrigation water was studied - CEa (N0 - water of the supplying system (Boqueirão); N1 - 1,5 dS.m-1, N2 - 3 dS.m-1; N3 - 4,5 dS.m-1 and N4 - 6,0 dS.m-1) - on the fenological and physiological indices in peanut plants (Hypogaea Arachis L.) cultivars BR-1 and L-7. It was used a factorial arrangement 5x2 on a completely randomized designer, with six repetitions. The irrigation waters had been prepared with NaCl salt. Had been evaluated: germination percentage (%G), emergency speed index (IVE); vigor study, done through the evaluation of growth/development through dry matter of shoot (MSPA); root dry matter (MSR) and total dry matter (MST); The evaluations of the growth had been carried through to the 20, 35 and 45 DAS, for variables: height of the plant (AP), leaf number (NF), leaves dry matter (MSF) and stems dry matter (MSC). To the end of the experimental period (105 days after sowing - 105 DAS), had been evaluated: height of the plant (AP), leaf number (NF), leaf area (AF), reason of leaf area (RAF), leaves dry matter (MSF), caules (MSC), root (MSR); from the data of dry matter it was calculated allocation of biomass for leaves (ABF), stems (ABC), roots (ABR) and fruits (ABFRUT), as well as the relation root/shoot (R/PA); number of fruits production variable (NFRUT), dry matter of the fruits (MS FRUT), total dry matter of the seeds (MSS), weight of 10 seeds (P10S) and had been determined free texts of soluble carbohydrate, amino acids and soluble proteins and the average water consumption to the end of the experimental period. In the germination phase the CEa reduced the emergency speed and drew out the period of germination, but it did not influence the germination process; it did not influence the vigor of seedling, evaluated to the 10 days after sowing. Until the 20 DAS the CEa it did not affect the growth variable. From the 35 DAS plants height was the first variable of growth to show reduction. To the 45 DAS all studied variable of growth had decreased with the increase of the salinity. To the end of the experimental period all the variable of growth except dry matter of the root had suffered reductions. The leaves area decreased 8.99%, the relation root/shoot and the reason of leaves area had increased with the increase of the CEa. The allocation of biomass for leaves and roots increased 25.26% and 73.43% with the unitary increase of the CEa, the allocation of biomass for stems increased 38.93% and 54.50% to cultivars BR-1 and L-7, respectively and the allocation of biomass for the fruits diminished 38.94% in the level of 6,0dSm-1. The fruits number production, dry matter of the fruits, the seeds and weight of 10 seeds had decreased 11,36%; 16,68%; 17,87% and 85.93%, respectively. The texts of the organic carbohydrate solutes and N-aminossolúveis had increased 8.69% and 7.67%, respectively, with the unitary increase of the CEa, the protein texts had reduced 3.0% to cultivate BR-1 and were 75.98% greater in the 0,4 level of 6,0dSm-1 compared dSm-1. The water consumption to the end of the experimental period decreased with the increase of the salinity of the irrigation water.