Anaerobic Soil Disinfestation Effects on Weed and Nematode Control, Plant Growth, Fruit Yield and Quality of Fresh-market Tomato

Anaerobic soil disinfestation (ASD) represents a promising non-chemical alternative to soil fumigation (SF), demonstrated to be effective against soil-borne diseases, plant-parasitic nematodes, and weeds in several crop production systems. However, limited knowledge is available on the effects of ASD on plant growth, yield, and quality. Therefore, a field experiment was conducted in the spring of 2015, at the University of Florida/Institute of Food Science and Agriculture/South West Florida Research and Education Center located in Immokalee, FL, to evaluate and compare the performances of ASD and SF on weed and nematode control, plant growth, yield, and quality of fresh-market tomato (Solanum lycopersicum L.). Pic-Clor 60 (1,3-dichloropropene + chloropicrin) was used as a SF and compared with two ASD treatments applied using a mix of composted poultry litter (CPL) at the rate of 22 Mg ha^-1, and two rates of molasses [13.9 (ASD1) and 27.7 m³ ha^-1 (ASD2)] as a carbon source. ASD plots reached high anaerobic conditions, and cumulative redox potential was 167% higher in ASD2 plots than in ASD1 plots. Soil treatments showed no significant effect on leaf, stem, fruit, and total plant biomass either on fresh or dry weight basis. SF assured the best weed control; however ASD treatments ensured an adequate level of weed control, enough to prevent yield reduction. The application of ASD at both rates assured equivalent or higher level of control of root-knot nematode (Meloidogyne spp.) as compared to SF. Total marketable yield was 49 Mg ha^-1 in SF plots, and 19.7% and 26.7% higher in ASD1 and ASD2 plots, respectively. Postharvest fruit quality parameters were not influenced by soil treatments, except fruit firmness, which was significantly higher in fruits from ASD treated plots, than in those from the SF treatment. Fruit produced in ASD treatment showed on average 15.6%, 14.6%, and 7.7% higher potassium, calcium, and magnesium and 23.2% lower manganese than those obtained from SF, respectively. Using a mixture of CPL and molasses, ASD can be a sustainable alternative to SF as it provided an adequate level of weed and root-knot nematode control, and it may improve marketable yield and fruit quality of Florida fresh-market tomato.