Crescimento, fisiologia e produção de tomateiro cereja sob estresse salino e formas de fertilização.

Abstract

Cherry tomato is occupying their place in the vegetable market with each passing day, due to the growing consumers demand and the greater economic return to the producer. In the Northeastern region of Brazil, due to the low precipitation, irrigation is necessary for most of the year, however, most of the available waters for this purpose have high levels of salts. An important technique that has been studied for mitigating the effects of saline stress on plants is fertilization. Thus, the objective with this work was to evaluate the interaction between salinity and forms of fertilization (mineral and organic) on cherry tomato growing, physiology and production. Two levels of electrical conductivity of irrigation water (0.9 and 4.0 dS m-1) and three fertilizations (control without fertilization; NPK according to the soil analysis data; and with bovine manure) were evaluated in greenhouse, in a randomized block design and 2 x 3 factorial, with four replications and two plants per plot. The analyzed variables were: plant height, stem diameter, number of leaves and relative growth rates, during two periods of the crop cycle; dry matters of shoot, root and total; CO2 assimilation rate, transpiration, stomatal conductance, CO2 internal concentration, instant and intrinsic water use efficiencies, instantaneous efficiency of carboxylation; concentrations of chlorophylls a, b and total, carotenoids, chlorophyll a/b ratio; number of fruits per plant and weight of fruits per plant. Irrigation water with salinity of 4.0 dS m-1 impaired growth, gas exchanges and cherry tomato production; however, mineral (NPK) and organic (with manure) fertilizations attenuated harmful effects of salinity on cherry tomatoes, promoting better growth, better levels of gas exchanges and higher production.