Effect of rate and timing of indaziflam on ‘Sunbelt’ and muscadine grape

Abstract

Studies were conducted at six locations across North Carolina to determine tolerance of ‘Sunbelt’ grape (bunch grape) and muscadine grape (‘Carlos’, ‘Triumph’, ‘Summit’) to indaziflam herbicide. Treatments included indaziflam (0, 50, 73 g ai ha–1) or flumioxazin (213 g ai ha–1) applied alone in April, and sequential applications of indaziflam (36, 50, 73 g ai ha–1) or flumioxazin (213 g ai ha–1) applied in April followed by the same rate applied in June. No crop injury was observed across locations. Muscadine yield was not affected by herbicide treatments. Yield of ‘Sunbelt’ grape increased with sequential applications of indaziflam at 73 g ha–1 when compared to a single application of indaziflam at 50 g ha–1 or flumioxazin at 213 g ha–1 in 2015. Sequential applications of flumioxazin at 213 g ha–1 reduced ‘Sunbelt’ yield compared to a single application of indaziflam at 73 g ha–1 in 2016. Trunk cross-sectional area was unaffected by herbicide treatments. Fruit quality (soluble solids concentration, titratable acidity, and pH) for muscadine and bunch grape was not affected by herbicide treatments. Indaziflam was safe to use at registered rates and could be integrated into weed management programs for southern US vineyards.

Blueberry and blackberry are tolerant to repeated indaziflam applications

“…Blueberry and blackberry production regions in the southeastern U.S. typically have acidic soils (pH 3.6 to 5.5) and use overhead or drip irrigation, therefore reducing potential indaziflam mobility. This was also noted by Basinger et al (2019), who noted no crop injury on grape and muscadine varieties up to and exceeding labeled rates in single and sequential applications. It was also noted that yield and yield components (berries per cluster, berry weight, cluster number per meter cordon) were not different than weed-free controls.…”

“…Blackberry primocanes and floricanes exhibited no visual injury to any herbicide treatment (data not shown). As previously noted, there are many reports of little to no visual injury for indaziflam applied to perennial crops (Basinger et al 2019;González-Delgado et al 2017;Grey et al 2018Grey et al , 2016Hurdle et al 2019).…”

“…This was always transient and no longer noted 8 wk after treatment. Many reports of little to no visual injury have been made for indaziflam applied to perennial crops (Basinger et al 2019;González-Delgado et al 2017;Grey et al 2018Grey et al , 2016Hurdle et al 2019).…”

“…Indaziflam is a Weed Science Society of America (WSSA) Group 29 cellulose biosynthesis-inhibitor herbicide belonging to the alkylazine family (Brabham et al 2014). As a PRE herbicide, it is used in numerous crop settings and has shown to be safe to perennial crops including grapes (Vitis vinifera L.; Basinger et al 2019), olive (Olea europaea L.; Grey et al 2016), pecan (Carya Illinoinensis Wangenh. ; Grey et al 2018), bermudagrass forage (Cynodon dactylon L.; Hurdle et al 2019), turf (McCullough et al 2013, and citrus (Jhala et al 2013).…”

Influence of Some Herbicides on the Chemical Composition of Cabernet Sauvignon Grapes and Wine

“…Applied in the soil, the same herbicide led to stress reduction in leaf carbohydrates, a decrease in free amino acids, which could affect the vine vitality for a long-term (Saladin et al, 2003). On the other hand, a study of the effect of indaziflam and flumioxazin on the varieties Sunbelt, Carlos, Triumph, Summit found that the quality of grapes (extract, titratable acidity and pH) was not affected by the application of these herbicides (Basinger et al, 2019).…”