ANDRADE, J. R.; http://lattes.cnpq.br/5930705532699742; ANDRADE, Jailma Ribeiro de.
Resumo:
The cowpea, also known as bean-string beans or macassar, constitutes the main subsistence
crop in the North and Northeast of Brazil, especially in the Interior Northeast. In Northeastern
Brazil waters used in irrigation have, in most cases, the concentration of salts in the range of
electrical conductivity from 0.1 to 3.0 dS m"1, can its use in agriculture, allied to intense
evaporation and lack of adequate soil drainage, causing salinity problems. Given the above
objective to identify cowpea tolerant and sensitive to salinity of irrigation water based on
biomass production and photosynthetic pigments in northeastern Brazil. The experiment was
conducted in a greenhouse in a greenhouse at the Federal University of Campina Grande
(UFCG). Seeds of 10 different genotypes of cowpea, assigned by Embrapa Meio Norte,
located in the city of Teresina, PI, sown in polyethylene pots with capacity for 20L of soil.
The treatments consisted of the combination of two factors: salinity of irrigation water, with
four levels and ten different genotypes. The statistical design was a completely randomized
design with three replications, being studied factors arranged in a 10 x 4 factorial. 40
proposed treatments were arranged in 120 portions, ie vessels 120 spaced 0.5 m 0.5 m
between plants and between lines. At 65 days after sowing were determined the total leaf area,
dry weight variables: dry weight of shoot, dry weight, root dry weight and total dry weight of
seeds; physiological parameters: SP AD index, chlorophyll a , b, and total carotenoids,
chlorophyll a relationship: chlorophyll b and total chlorophyll ratio: carotenoids. The
variables were analyzed statistically by F test at 5% probability. For statistical analysis we
used the computer program ESAL-SISVAR. The salinity of the irrigation water decreased the
production of fitomassas and leaf area, and increased the content of chlorophyll, with
genotypes 1 (MNC01-649F-2-1), 2 (MNC03-736F-2), 5 (BRS-Marataoa ) and 6 (MNC02-
676F-3) and the most tolerant genotypes 3 (PINGO GOLD-1-2), 4 (BRS-Gurgueia), 7
(MNC02-683F-1), 8 (MNC03-5-737F -4), 9 (MNC03-737F-5-9), 10 (BRS-Tumucumaque)
were the most sensitive to salt stress.