Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: November 6, 2000
Publication Date: N/A
Technical Abstract: The available commercial chemical alternatives to methyl bromide are 1,3-dichloropropene (1,3-D), chloropicrin (CP), and metam sodium (sodium N-methyldithiocarbamate). The objective of this study was to evaluate growth and yield of strawberry grown in soils fumigated with metam sodium and emulsified formulations of 1,3-D and CP applied through drip irrigation systems. The research was conducted in two major commercial strawberry production areas in CA (Watsonville and Salinas) for three consecutive years (1997-2000). Treatments were randomized in a complete block design with four replicates in Watsonville (10 m long beds) and three replicates at salinas (30 m long beds). At both locations, MeBr-CP (6 7:33) at 365 to 425 kg ha-1 and Telone C35 (61% 1,3-D and 35% CP) at 453 kg ha-1 (374 L ha-1) were shank injected at 25-30 cm depth with two chisels spaced 35 cm apart into soil beds. Metam sodium (Vapam HL, 42%) and emulsified concentrate (EC) formulations of chloropicrin (CP EC, 96%) and Telone C35 (InLine, 58% 1,3-D and 33% CP) were applied through drip irrigation systems. Marketable fruit yields were significantly greater in the chemical treatments than in the untreated plots. In Watsonville, the highest yield was in beds treated with Inline at 393 L ha-1 in the high amount of water (61 mm water). Yields from the metam sodium treated beds were lower than yields from Inline treatments and ranged between 67 to 79% relative to MeBr-CP treatment. At the Salinas site, greatest yields were also in beds treated with Inline. Long-term application of Inline, CP EC, and sequential application of reduced rates of these fumigants with metam sodium to strawberry beds shows promise in controlling soil pathogens and in producing yields nearly comparable to present production with MeBr-CP.