Effect of Bromide from a Soil Fumigant and from CaBr2 on Growth and Chemical Composition of Citrus Plants

Abstract

Abstract A study was made to determine the influence of soil Br from CaBr 2 treatments or from preplanting fumigation of soil with ethylene dibromide on growth and chemical composition of citrus plants. The treatments did not affect the percentages of Ca, Mg, K, Na, or P in the plants. Preplanting fumigation with ethylene dibromide or treatment with CaBr 2 reduced growth of citrus seedlings, whereas fumigation with ethylene dichloride or treatment with CaCl 2 exerted little or no influence. In one soil, citrus leaf Br concentrations of 0.17, 0.33, 0.40, 1.3, and 1.8% were associated with 12, 22, 31, 57, and 90% reduction in growth, respectively. In two soils certain citrus leaf Br concentrations originating either from soil CaBr 2 applications or pretreatment of the soil with ethylene dibromide fumigant were associated with comparable growth retardation. Carrot and lima bean plants grown for comparison were much more tolerant to Br than were citrus plants. A leaf concentration of 2.5% Br did not reduce growth of carrots. Lima beans tolerated 1.5% or more leaf Br, while 0.2% was sufficient to reduce growth of citrus plants.