GROWTH AND ELEMENTAL COMPOSITION OF TOMATO AS AFFECTED BY FUNGICIDES AND NITROGEN-SOURCES

Tomato (Lycopersicon esculentum Mill.) plant growth and elemental composition were evaluated using three NH4-N:N03-N form ratios with or without the fungicide benomyl, captan, lime-sulfur, nitrapyrin, or terrazole in a greenhouse soil culture study. Nitrogen was applied weekly for 5 weeks providing a total of 115 mg N/kg. Each fungicide was applied at 0.25 mg/kg 3 days before transplanting, followed by 3 weekly applications with each N treatment. The largest shoot and root dry weights were obtained with 1:1 N form ratio. With 1:1 N ratio treatment, all chemicals significantly increased plant growth resulting in lower element concentrations relative to the untreated control. However, growth of plants receiving either 1:0 or 0:1 N ratio treatment was not affected by nitrapyrin and terrazole, but was restricted by benomyl, captan, or lime-sulfur. Overall, elemental concentrations in the tissues of plants receiving either N form was related to the fungicide treatment. © 1990, Taylor & Francis Group, LLC. All rights reserved.