Tolerance of Cucurbits to the Herbicides Clomazone, Ethalfluralin and Pendimethalin. II. Watermelon

Abstract

<jats:p>Field studies were conducted in 1993, 1994, and 1995 to determine tolerance of seeded and transplanted watermelon [<jats:italic>Citrullus lanatus</jats:italic> (Thunb.) Matsum and Nak.] to clomazone, ethalfluralin, and pendimethalin using method of stand establishment (directseeded vs. transplanted) and time of herbicide application [preplant soil incorporated (PPI), preplant to the surface (PP), or postplant to the surface (POP)] as variables. Yield and average fruit weight in plots with clomazone were equal to or greater than those in control plots for the 3-year study regardless of method of application. Bleaching and stunting were evident with clomazone in early-season ratings, but injury was transient and did not affect quality or yield. Of the three herbicides, ethalfluralin PPI resulted in the greatest injury, stand reduction, and yield reduction of the three herbicides. Pendimethalin (PPI, PP, or POP) reduced yield of direct-seeded but not of transplanted watermelon. Chemical names used: 2-[(-2-chlorophenyl)methyl]-4, 4-dimethyl-3-isoxazolidinone (clomazone); <jats:italic>N</jats:italic>-ethyl-<jats:italic>N</jats:italic>-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine (ethalfluralin); <jats:italic>N</jats:italic>-(1-ethylopropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin).</jats:p>

Bottle Gourd Genotypes Vary in Clomazone Tolerance

“…Even though growth rates varied greatly between the experiments, the relative difference in clomazone response between genotypes was similar in both environments (Table 3). Variability of tolerance as affected by cucurbit variety compliments previous studies (Boyhan et al, 1995;Cohen et al, 2008;Grey et al, 2000).…”

“…Boyhan et al (1995) reported that watermelon yields were reduced by clomazone applied PRE at 1.1 kg · ha -1 to direct seeded watermelon. Grey et al (2000) reported that clomazone applied preplant incorporated at 0.84 kg · ha -1 , preplant to the soil surface, and posttransplant to the soil surface caused minor foliar bleaching (14% injury or less), but did not reduce the yields of seeded or transplanted 'Royal Sweet' watermelon. Cohen et al (2008) concluded from a greenhouse study that clomazone applied at 1.0 and 2.0 kg · ha -1 was too injurious to grafted and nongrafted watermelons.…”

“…The recommended use rates for watermelon are 0.17-0.28 kg · ha -1 depending on the soil type. Clomazone can cause moderate injury to young plants that is expressed as chlorosis of leaves and growing tips (Grey et al, 2000). A study performed at the University of Florida demonstrated that preemergence (PRE) applications of clomazone at 0.28 kg · ha -1 to transplanted watermelon grafted to bottle gourd resulted in 8% injury (Adkins, 2011).…”

Efeitos Da Aplicação De Herbicidas Em Pré-Transplantio No Crescimento Inicial De Plantas De Melão Pele-De-Sapo

“…Há apenas dois produtos registrados:fenoxaprope-P-etílico e a mistura carfentrazona-etilica + clomazona,que controlam exclusivamente gramíneas (AGROFIT, 2017).Alguns estudos em diversos países mostraram que herbicidas como linuron, trifluralin, butilaty são seletivos para cultura do melão (CANTAMUTO, et al, 1996). E que oclomazonee oxyfluorfen tem potencial de uso no melão (GREY et al, 2000;BELLINDER, et al, 1993).…”

Identification of Citrullus lanatus Germplasm Accessions Tolerant to Clomazone Herbicide

“…Boyhan et al (1995) reported that watermelon yields were reduced by clomazone applied pre-emergence at 1.1 and 1.7 kgÁha -1 to direct seeded watermelon. Grey et al (2000) reported that clomazone at 0.84 kgÁha -1 applied preplant-incorporated, preplant to the soil sur-face, and post-transplant to the soil surface caused minor foliar bleaching (14% injury or less) but did not reduce the yields of seeded or transplanted 'Royal Sweet' watermelon. Cohen et al (2008) concluded from a greenhouse study that clomazone at 1.0 and 2.0 kgÁha -1 was too injurious to grafted and non-grafted watermelons to be used safely.…”