Evaluation of methyl iodide for control of peach replant disorder

Peach replant soils were fumigated with methyl bromide (MB) or methyl iodid e (MI) at rates of 392 to 448 kg/ha. In two trials, peach tree growth in fu migated soil or in untreated soil was evaluated by measuring trunk diameter and weight of branches removed by pruning. In both trials, trunk diameter of trees grown in MB- and MI-fumigated plots was greater than trees in cont rol plots (P less than or equal to 0.01). In both trials, weight of branche s pruned from trees grown in fumigated plots was greater than branch weight s from trees grown in control plots (P less than or equal to 0.01). Plots f umigated with MI did not differ from plots fumigated with MB in trunk growt h, weight of branch prunings, or reductions in population densities of the nematode Paratylenchus. MI and MB appeared to be equally effective in contr olling replant disorder.