|GUO, HAICHAO - University Of Florida|
|DI GIOIA, FRANCESCO - University Of Florida|
|ZHAO, XIN - University Of Florida|
|OZORES-HAMPTON, MONICA - University Of Florida|
|SWISHER, MARILYN - University Of Florida|
|DE LONG, ALIA - University Of Florida|
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/7/2017
Publication Date: 4/14/2017
Citation: Guo, H., Di Gioia, F., Zhao, X., Ozores-Hampton, M., Swisher, M., Hong, J.C., Burelle, N.K., De Long, A., Rosskopf, E.N. 2017. Optimizing anaerobic soil disinfestation for fresh market tomato production: Nematode and weed control, yield, and fruit quality. Scientia Horticulturae. 218:105-116. https://doi.org/10.1016/j.scienta.2017.01.054.
Interpretive Summary: Anaerobic soil disinfestation (ASD) is a non-chemical method proposed as an alternative to chemical soil fumigation. Many studies have been conducted on pest control and vegetable production using various amendments and approaches to ASD. Two principal limitations to the use of ASD in commercial agriculture are a lack of efficacy against nutsedge species, important weeds in tomato production, and the large quantity of organic amendments needed to achieve the anaerobic conditions needed for successful implementation of the method. In a recent set of experiments conducted in two locations in Florida, ASD was tested using half the rate of organic amendments previously suggested compared to a standard ASD treatment and chemical soil fumigation. Each soil disinfestation treatment plot was split to include a pre-emergent herbicide application or no herbicide applied. The herbicide halosulfuron-methyl was selected due to the potential to cause phytotoxicity in the presence of excessive amounts of water at application in order to test the potential of negative impact of the irrigation water applied for ASD. Herbicide application improved nutsedge control and had no negative impact on the development of anaerobicity in ASD-treated plots, while total marketable yield and fruit quality were not impacted by herbicide treatment in either location. Tomato yields from ASD-treated plots were equal or higher than yields achieved using chemical soil fumigation, regardless of the reduction in the rate of organic amendments.
Technical Abstract: Anaerobic soil disinfestation (ASD) has potential as an alternative to chemical-fumigation for controlling soilborne pathogens and pests. Previously, control of nutsedge was sub-optimal and the quantity of inputs for commercial production was an impediment to adoption. Field studies were conducted in Citra and Immokalee, Florida to assess the effects of ASD with reduced amendments and inclusion of a pre-emergent herbicide on weed and nematode populations, tomato yield, and fruit quality. Pre-plant soil treatments included ASD with 6.9 m3 ha-1 of molasses and 11 Mg ha-1 of composted poultry litter (CPL) (ASD0.5), ASD with 13.9 m3 ha-1 of molasses and 22 Mg ha-1 of CPL (ASD1.0), and chemical soil fumigation using Pic-Clor 60 (CSF). Subplot treatments were halosulfuron-methyl (Sandea®) herbicide and no herbicide application. ASD0.5 reached high and equivalent accumulation of anaerobic conditions as ASD1.0 during the three-week soil treatment in both locations. Root galling and plant-parasitic nematode population at harvest in ASD treatments were similar in nematode suppression to CSF in both locations, while ASD1.0 resulted in higher non-parasitic nematode populations in soil compared to CSF in Citra. In Citra, ASD treatments did not differ from CSF in total marketable fruit yield; however, ASD0.5 resulted in higher total yield of extra-large fruit than CSF and ASD1.0 by 95.1% and 112.5%, respectively. ASD1.0 exhibited 25.3% and 30.6% higher total cull fruit yield compared with CSF and ASD0.5, respectively. In Immokalee, no difference was observed in total marketable yield between ASD0.5 and CSF, whereas ASD1.0 produced 26.3% and 20.4% higher total marketable yield and 54.8% and 19.3% higher total yield of extra-large fruit than that of CSF and ASD0.5, respectively. ASD treatments had no impact on fruit quality attributes including color, firmness, pH, total soluble solids, and dry matter content. Herbicide application improved nutsedge control and had no negative impact on the development of anaerobicity in ASD-treated plots, while total marketable yield and fruit quality were not impacted by herbicide treatment in either location. Despite some variations between the two locations, reduced application rates of CPL and molasses pro duced results similar to the full rates of amendment as well as the fumigation treatment. Combining ASD with an herbicide had no negative impacts on crop production and resulted in improved weed control.