Placement of supplemental fumigants within soil management zones for enhanced pest management

N.S. Boyd, G.E. Vallad, J. Noling, J.H. Freeman, F. Wu, Z. Guan
Vegetable growers in Florida adopted a range of alternative fumigants following the phase-out of methyl bromide. The most common fumigants include 1,3-dichloropropene (1,3-D), chloropicrin (Pic), dimethyl disulfide (DMDS) and metam potassium. All of the alternative fumigants have a much lower vapor pressure than methyl bromide and as a result they do not move as extensively through the soil. In many situations, the lack of fumigant efficacy is not due to the products inability to kill the pest but a result of the fumigants not coming in contact with the pest. Improved pest control may be obtained when fumigants are applied to the soil management zone where the pest occurs. The concept of soil management zones for improved pest management has proven successful in a variety of scenarios. For example, the application of supplemental chloropicrin to previously untreated soil on the edges of raised beds covered in plastic mulch reduces Fusarium infection of tomato roots. Placement of fumigants below the soil compaction zone, which tends to be impermeable to fumigants, improves nematode management. A variety of experiments conducted over many years has also proven that the concept of soil management zones can improve weed management in commercial vegetable fields as well. A variety of trials were conducted to evaluate fumigant combinations and placement for weed control. DMDS is an effective nutsedge management tool and control levels generally increase when supplemental applications of metam potassium are applied in conjunction with DMDS. In multiple studies, the combination of DMDS plus metam potassium tended to be the most effective management option over time when compared with other commercial fumigants. The use of metam potassium as a supplemental fumigant for weed control will increase production costs but it is an economically viable option where weed control is a concern.
Boyd, N.S., Vallad, G.E., Noling, J., Freeman, J.H., Wu, F. and Guan, Z. (2020). Placement of supplemental fumigants within soil management zones for enhanced pest management. Acta Hortic. 1270, 193-196
DOI: 10.17660/ActaHortic.2020.1270.22
metam potassium, dimethyl disulfide, chloropicrin, 1,3-dichloropropene

Acta Horticulturae