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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Citrus and Other Subtropical Products Research » Research » Publications at this Location » Publication #332974

Research Project: Alternatives to Methyl Bromide Soil Fumigation for Vegetable and Floriculture Production

Location: Citrus and Other Subtropical Products Research

Title: Optimizing anaerobic soil disinfestation for Florida fresh-market tomato production

Author
item Di Gioia, Francesco - University Of Florida
item Ozores-hampton, Monica - University Of Florida
item Hong, Jason
item Burelle, Nancy
item Gao, Haichao - University Of Florida
item Zhao, Xin - University Of Florida
item Rosskopf, Erin

Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/1/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary: Anaerobic soil disinfestation (ASD) is a non-chemical alternative to soil fumigation (SF), which exploits the anaerobic decomposition of organic amendment to control a range of soil-borne diseases, plant-parasitic nematodes and weeds. ASD is implemented by saturating irrigation soil mulched with oxygen impermeable film, after its amendment with a readily decomposable carbon (C) source. The selection of a homogeneous, locally available, low cost and easy to apply C source and its application rate are critical for the efficacy of ASD and its acceptance at commercial level. In Florida, molasses, a by-product of the sugarcane industry, and composted poultry litter (CPL) have been selected as effective C source and organic amendment, respectively. However, limited knowledge is available on their dose effect. Lower application rates of organic amendment may require the combined application of an herbicide to assure an adequate weed control. Therefore, there is need to evaluate potential interference of combined application of ASD with an herbicide. Two field studies were conducted to determine the impact of a full-rate of CPL and C and a double rate of C with standard rate of CPL. A second set of studies were conducted to determine if a half rate of both CPL and C could be used and if an herbicide could be included to improve weed control using a half rate. Overall, the results of the two studies suggest that ASD applied using a mixture of CPL and molasses at the rate of 22 Mg ha-1 and 13.9 m3 ha-1, respectively (full rate), can be a sustainable alternative to SF as it provided a good level of weed and root-knot nematodes control, increased marketable yield and assured similar fruit quality of Florida fresh-market tomato. The second study demonstrated that is possible to halve both CPL and molasses rate, however, ASD should be combined with the application of an herbicide to ensure an adequate weed control.

Technical Abstract: Anaerobic soil disinfestation (ASD) is a non-chemical alternative to soil fumigation (SF), which exploits the anaerobic decomposition of organic amendment to control a range of soil-borne diseases, plant-parasitic nematodes and weeds. ASD is implemented by saturating irrigation soil mulched with oxygen impermeable film, after its amendment with a readily decomposable carbon (C) source. The selection of a homogeneous, locally available, low cost and easy to apply C source and its application rate are critical for the efficacy of ASD and its acceptance at commercial level. In Florida, molasses, a by-product of the sugarcane industry, and composted poultry litter (CPL) have been selected as effective C source and organic amendment, respectively. However, limited knowledge is available on their dose effect. Lower application rates of organic amendment may require the combined application of a herbicide to assure an adequate weed control. Therefore, there is need to evaluate potential interferences in case of combined application of ASD with an herbicide. Field studies were conducted at the University of Florida/Institute of Food Science and Agriculture/South West Florida Research and Education Center located in Immokalee, FL, in the spring (Exp-1) and fall-winter (Exp-2) season of 2015, to evaluate and compare the performances of ASD and SF in terms of weed and nematodes control, yield and quality of fresh-market tomato (Solanum lycopersicum L.). In Exp-1, Pic-Clor 60 (1,3-dichloropropene + chloropicrin) was used as a reference SF and compared with two ASD treatments applied using a mix of CPL at the rate of 22 Mg ha-1, and molasses at two rates [13.9 (ASD1) and 27.7 m3 ha-1 (ASD2)]. In Exp-2, Pic-Clor 60 was compared with ASD1 (22 Mg ha-1 of CPL and 13.9 m3 ha-1 of molasses) and ASD0.5 (11 Mg ha-1 of CPL and 6.9 m3 ha-1 of molasses), combined or not with the application of the pre-emergence herbicide Sandea. SF assured a complete weed control, while both ASD treatments assured an adequate, but not complete weed control. Total marketable yield was 49 Mg ha-1 in SF plots, and was 19.7% and 26.7% higher in ASD1 and ASD2 plots, respectively. Fruit quality parameters were not influenced by soil treatments, except the fruit firmness, which was significantly higher in fruits deriving from ASD treated plots, than in those from SF soil. Overall, the results of the two studies suggest that ASD applied using a mixture of CPL and molasses at the rate of 22 Mg ha-1 and 13.9 m3 ha-1, respectively (ASD1), can be a sustainable alternative to SF as it provided a good level of weed and root-knot nematodes control, increased marketable yield and assured similar fruit quality of Florida fresh-market tomato. The second study demonstrated that it is possible to halve both CPL and molasses rate, however, ASD should be combined with the application of an herbicide to ensure an adequate weed control.