Effect of liming and potassium on the nematode Heterodera glycines (Ichinohe 1952)

Abstract

With the puropose to evaluate the effect of liming and Potassium fertilization on Heterodera glycines population, the present study was conducted in a complete randomized design, in a 4 x 2 x 3 factorial scheme, with 4 replications. Four doses of Potassium (0, 30, 60 and 120 kg of K₂ O.ha^-1) two levels of liming (0 and 1.35 t.ha^-1) and 3 periods of evaluation based on the plant development stage (blossoming, grain-filling and late season) were tested. Susceptible soybean cultivar FT-Cristalina was planted in pots and artificially inoculated with 4,000 eggs of H. glycines/pot. Number of H. glycines females on the roots, number of cysts/100cm³ of soil and number of eggs/cyst were evaluated. Number of females and cysts were higher at the grain-filling plant stage. During this stage the liming increased the number of females in comparison to the treatment with no lime. Increasing doses of Potassium up to 106 and 90 kg of K₂ O.ha^-1 reduced the number of females and cysts, respectivelly. Number of eggs/cyst was higher at the grainfilling stage.