| Abstract: | Eleven citrus groves of diverse varieties and ages infected with Tylenchulus semipenetrans growing in differing soils in Florida were treated with three rates of 1,2-dibromo-3-chloropropane (DBCP) applied by various means. Yield, fruit size, and T. semipenetrans populations in the roots were compared between DBCP-treated and untreated trees over a period of I-3 yr. Maximum fruit size and yield were obtained by applying DBCP at 38-58 kg/hectare (ha) (34-52 lb/acre); whereas best nematode control was with a rate of 77 kg/ha (69 lb/acre). Application of chemical emulsion with a special, drilled, low-profile sprinkler irrigation ground pipe was the most suitable method. Effect of DBCP treatment generally lasted for 3 yr. A mean annual I. 1% increase in fruit diameter, 15.2% increase in fruit yield and a 55.7% decrease incitrus nematode populations was found for D BC P-treated trees in contrast to untreated trees. |
