Application of an emulsifiable mixture of 1,3-dichloropropene and chloropicrin against root knot nematodes and soilborne fungi for greenhouse tomatoes in Italy

A mixture of 1,3-dicloropropene 60.5% w/w and chloropicrin 33.3% w/w (Telone C35 EC) may be registered in Italy for soil drip fumigation. Five experiments on greenhouse tomatoes in Northern, Central and Southern Italy compared the effectiveness of this mixture in comparison with methyl bromide to find the optimum application rate in soils infested by Fusarium oxysporum f.sp. lycopersici, F. oxysporum f.sp. radicis lycopersici, Sclerotium rolfsii, Meloidogyne javanica and M. incognita. Its efficacy against F. oxysporum f.sp. radicis lycopersici and M. incognita was confirmed when applied to soils at 100, 200, 300 and 400 l ha−1 (132.4, 268.4, 402.6 and 536.8 kg ha−1) under gas-tight films with 15–45 mm of application water (900–1200 mg Telone C35 EC l−1). In sandy soils, with slight F. radicis lycopersici infections and with heavy nematode (M. incognita) attacks, the mixture, drip applied at 900 mg l−1 during late summer (fumigation: late summer; transplant: late-summer/autumn; last harvest: early spring), performed well up to 132.4 kg ha−1 (100 l ha−1). In sandy loam soils with slight F. radicis lycopersici infections and severe infections of F. lycopersici and galling nematodes (M. javanica), 268.4 kg ha−1 (200 l ha−1) of the mixture applied at 900 mg l−1 as a drip provided yields similar to those of methyl bromide treated plots both in spring and summer cycles. In sandy loam soils, the diseases (F. lycopersici, F. radicis lycopersici) were controlled at rates ⩾268.4 kg ha−1 (containing 90 kg ha−1 of chloropicrin), but the mixture was ineffective against Sclerotium rolfsii occasionally observed in sandy loam soils. In both sandy and sandy loam soils, no significant relationships were found between the rates of mixture applied (132.4, 268.4, 402.6 and 536.8 kg ha−1) and the degree of nematode infestation.