Cabbage (B. oleracea L.) is an important vegetable crop in Florida. In 2010, Florida ranked third nationally in the production of fresh market cabbage accounting for 12.7% of the U.S. total cabbage production (USDA, 2017a). In 2016, cabbage growers in Florida planted 3439 ha fresh market cabbage and harvested 3197 ha, and the average yield was 36,980 kg·ha−1 (USDA, 2017b). Cabbage produced in Florida is exclusively for fresh market with the late fall, winter, and early spring harvests supplying the northern United States (USDA, 2017b).
In Florida, cabbage is typically grown without a plastic mulch and as a result, weeds are a significant problem in most fields. Weed competition may reduce cabbage growth, quality, and yield by competing for nutrients, sunlight, and soil moisture (Al-Khatib et al., 1995; Bhowmik and McGlew, 1986; Hoyt et al., 1996; Webster, 2010). The most common weeds in Florida cabbage production during the peak production period (December through February) are winter annuals such as cutleaf evening primrose (Oenothera laciniata Hill.) and wild radish (Raphanus raphanistrum L). However, in late fall or near the end of harvest in early spring, summer annual broadleaf weeds, such as common lambsquarters (Chenopodium album L.), and annual grass species, such as crabgrass (Digitaria spp.) and goosegrass [Eleusine indica (L.) Gaertn.], can be problematic. Yellow (Cyperus esculentus L.) and purple (Cyperus rotundus L.) nutsedges are also a serious issue. Because of its small stature, shallow root system, and thin canopy, cabbage seedlings are poor competitors with weeds. Therefore, controlling weeds early in the season is particularly important to maintain crop vigor and yield (Miller and Hopen, 1991; Weaver, 1984).
As with most minor crops, registered herbicides for use in cabbage are limited. Bensulide, clomazone, DCPA, oxyfluorfen, and trifluralin are registered for preplant incorporated application (Zotarelli et al., 2016). Clethodim, clopyralid, DCPA, napropamide, and sethoxydim are registered for over-the-top applications (Zotarelli et al., 2016). S-metolachlor controls annual broadleaf and grass weeds and suppress nutsedge species (Anonymous, 2014; Bellinder et al., 1989; Sikkema et al., 2007). It is registered with a third-party identified label in Florida, and growers need to sign an agreement with the third-party indemnitors. The field half-life of S-metolachlor is generally 15–25 d based on direct bioassay measurements in southern states (Shaner, 2014). Now, most cabbage growers in Florida use a single application of S-metolachlor immediately after transplant for weed control. However, a single application typically does not provide season-long weed control.
There are few published studies evaluating weed control and cabbage tolerance of herbicides applied PRE-T or POST-T over the top. The objectives of this research were to evaluate weed control and cabbage tolerance to multiple herbicide programs.
Anonymous2014Dual II magnum. Syngenta Crop Protection LLC Greensboro NC
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BhowmikP.C.McGlewE.N.1986Effects of oxyfluorfen as a pretransplant treatment on weed control and cabbage yieldJ. Amer. Soc. Hort. Sci.111686689
DasA.C.DebnathA.MukherjeeD.2003Effect of the herbicides oxadiazon and oxyfluorfen on phosphates solubilizing microorganisms and their persistence in rice fieldsChemosphere53217221
HoytG.D.BonannoA.R.ParkerG.C.1996Influence of herbicides and tillage on weed control, yield, and quality of cabbage (Brassica oleracea L. var. capitata)Weed Technol.105054
O’barrJ.H.McCauleyG.N.BoveyR.W.SensemanS.A.ChandlerJ.M.2007Rice response to clomazone as influenced by application rate, soil type, and planting dateWeed Technol.21199205
ShanerD.L.2014Herbicide handbook. 10th ed. p. 110 134 320 406. In: K.S. Lawrence (ed.). Weed Sci. Soc. America Lawrence KS
USDA2017aCabbage statistics United States Department of Agriculture Economics Statistics and Market Information System. 12 June 2017. <http://usda.mannlib.cornell.edu/MannUsda/ viewDocumentInfo.do?documentID=1397>.
USDA2017bCabbage statistics United States Department of Agriculture National Agricultural Statistics Service. 20 May 2017. <https://quickstats.nass.usda.gov>.
WebsterT.2010Weed survey-southern states: cucurbits, fruiting vegetables, cole crops and greens, other vegetables, peaches, apples, fruits and nuts, citrus cropsProc. South Weed Sci. Soc.63250
ZotarelliL.DittmarP.J.Ozores-HamptonM.O.DufaultN.S.StansleyP.SmithH.A.WebbS.E.WangQ.MillerC.2016. Cole crop production. p. 33–51. In: G. Vallad J. Freeman and P. Dittmar (eds.). Vegetable production handbook for Florida 2016–2017. Univ. Florida’s Inst. Food Agr. Sci. Gainesville FL.