Strawberry Tolerance to Bed-Top and Drip-Applied Preemergence Herbicides

Abstract

Broadleaf weeds and nutsedge are persistent problems with limited management options for strawberry growers in Florida. Experiments were conducted in 2012 to 2013 (year 1) and 2013 to 2014 (year 2) at the Gulf Coast Research and Education Center in Wimauma, FL, to evaluate tolerance of two strawberry cultivars (‘Strawberry Festival' and ‘WinterStar'™) to PRE herbicides applied on the bed top or injected through the drip tape. The bed-top herbicides were applied to formed beds following fumigation but prior to laying the plastic mulch. Herbicides evaluated included two rates of EPTC, fomesafen, halosulfuron, and S-metolachlor as well as tank mixes of EPTC + S-metolachlor, fomesafen + S-metolachlor, and napropamide + oxyfluorfen. Drip-applied herbicides were applied through a single drip tape and strawberries were transplanted 1, 7, 15 and 30 d following application. Drip-applied herbicides included two rates of EPTC and fomesafen as well as two rates of a tank mix of napropamide + oxyfluorfen. None of herbicides applied on the bed top except S-metolachlor 214 g ai ha−1 consistently injured either strawberry cultivar or impacted yields. None of the drip-applied herbicides damaged the strawberry plants or reduced yields at all planting dates. In year 1, EPTC at 229 g ai ha−1 and EPTC at 229 g ha−1 + S-metolachlor at 107 g ha−1 resulted in a 70 to 86% reduction in purple nutsedge density compared to the nontreated control. No differences in nutsedge density among treatments were observed in year 2. The herbicides evaluated are safe for use on strawberry and would provide growers with alternative herbicide options, application timings, and application techniques. Further research is needed to evaluate efficacy.

Weed Control with and Strawberry Tolerance to Herbicides Applied through Drip Irrigation

“…In previous research, Boyd and Reed (2016) reported EPTC at 229 and 458 g ha , fomesafen at 42 and 84 g ha , and oxyfluorfen plus S-metolachlor at 56 + 448 g ha −1 applied through drip irrigation at 1, 7, 15, and 30 d prior to transplanting did not cause significant strawberry injury. Daugovish et al (2008) also found oxyfluorfen applications made 7 d prior to transplanting did not injure strawberry.…”

“…Gilreath et al (2003) reported that napropamide plus oxyfluorfen at 4.5 + 0.57 kg ha −1 resulted in the best grass and broadleaf weed control and also had greater berry numbers and weights than did either herbicide applied alone. Boyd and Reed (2016) reported that EPTC at 458 g ha…”

Evaluation of ethanedinitrile (EDN) as a preplant soil fumigant in Florida strawberry production

“…Strawberry yields in the non‐fumigated control were comparable with the soil fumigated with 1,3‐D + Pic or EDN. This is likely due to insufficient weed or soil‐borne disease pressure to reduce yields …”

“…A number of pre‐emergent (PRE) herbicides have been evaluated for use in strawberry . Previous studies demonstrated strawberry tolerance to PRE applications of S‐ethyl dipropylthiocarbamate (EPTC), fomesafen, pendimethalin, prodiamine, napropamide and oxyfluorfen . However, control of weeds with these PRE herbicides in strawberry has been inadequate or inconsistent .…”

“…For example, Yu and Boyd reported that flumioxazin, fomesafen and halosulfuron suppressed Medicago lupulina emergence to 55%, 52% and 55% of the nontreated control, respectively, whereas none of these herbicides adequately suppressed G. carolinianum . Several authors suggested that post‐transplant herbicide applied in conjunction with a PRE herbicide is required to provide season‐long weed control . However, there are limited post‐emergent (POST) herbicides currently registered for use on strawberry.…”