Combinations Of Dicamba Research Articles

The herbicide well runs dry

Since the 1980s, crop protection companies have introduced only one herbicide with a new weed-killing mechanism. During this period, many weeds have evolved to survive the modes of action used by existing herbicides, creating huge problems for farmers. In response, crop protection companies are increasing R&D efforts to discover new modes of action. They’re using new tools, often borrowed from the pharmaceutical industry, to speed up that process. But even if new products do emerge, many experts warn that farmers should moderate their use of herbicides to avoid the evolution of resistance going forward. The first herbicide-resistant weeds started showing up on Keith Miller’s farm about 18 years ago. He grows sorghum, wheat, alfalfa, and soybeans on 4,000 hectares in western Kansas. Amaranthus , often called pigweed, is his biggest problem. Spraying weeds with the workhorse herbicide glyphosate does virtually nothing these days, Miller says. A combination of dicamba, 2,4-D,

‘Atlantic’ and ‘Dakota Pearl’ chipping potato responses to glyphosate and dicamba simulated drift

AbstractField trials were conducted to determine the effects of glyphosate and/or dicamba simulated drift rates on chipping potatoes (Solanum tuberosum L.) ‘Atlantic’ and ‘Dakota Pearl.’ Sublethal herbicide rates were applied at the tuber initiation stage and consisted of dicamba at 99 g ae ha−1 or glyphosate at 197 g ae ha−1 applied alone or the combinations of dicamba at 20 or 99 g ae ha−1 and glyphosate at 40 or 197 g ae ha−1, respectively. At 7 days after treatment (DAT), the high spray combination of glyphosate plus dicamba resulted in the greatest plant damage (28%). Plant injury from plants treated with the low combination of glyphosate plus dicamba did not differ from the nontreated control. At 21 DAT, visible injury increased to 40% for plants treated with the high combination of glyphosate plus dicamba. Total yield suggested that dicamba and glyphosate caused similar yield reductions as plants that received glyphosate at 197 g ha−1 or dicamba at 99 g ha−1 had lower total yields compared to the nontreated and plants that received the combination of glyphosate (197 g ha−1) and dicamba (99 g ha−1) had lower total yields compared to plants that received either herbicide alone. However, ‘Dakota Pearl’ plants were more sensitive to glyphosate at 197 g ha−1 than were ‘Atlantic’ plants, causing the interaction for most tuber grades. Tuber specific gravity was lower for plants that received glyphosate at 197 g ha−1, dicamba at 99 g ha−1, or this combination, but this reduction would not prevent chip processing. Results reinforce the need for diligence when applying these herbicides in proximity to a susceptible crop, such as chipping potatoes, and the need to thoroughly clean sprayers before application to a sensitive crop.

Palmer amaranth control, fecundity, and seed viability from soybean herbicides applied at first female inflorescence

AbstractPalmer amaranth is an extremely troublesome weed for soybean growers because of its aggressive growth, adaptability, prolific seed production, and widespread resistance to many herbicides. Studies were initiated to determine the effects of herbicide application at first female inflorescence on Palmer amaranth control, biomass, seed production, cumulative germination, and seed viability. Enlist (2,4-D–resistant) soybean and Xtend (dicamba-resistant) soybean were planted and various combinations of either 2,4-D or dicamba with and without glufosinate and/or glyphosate were applied at first visible female Palmer amaranth inflorescence. Mixtures of 2,4-D + glufosinate and 2,4-D + glufosinate + glyphosate provided the greatest control at 4 wk after treatment in Enlist soybean. Similarly, in Xtend soybean, combinations of dicamba + glufosinate and dicamba + glufosinate + glyphosate provided the greatest control. The greatest reductions in biomass were from combinations of auxin herbicides (2,4-D or dicamba) plus glufosinate with and without glyphosate. Seed production was reduced most by treatments containing at least one effective site of action: an auxin herbicide (2,4-D or dicamba) or glufosinate. In contrast to previous research, cumulative germination and seed viability were not affected by herbicide treatments. This research indicates the efficacy of auxin herbicides or glufosinate alone and in combination to reduce the seed production of Palmer amaranth when applied at first female inflorescence. More research is needed to evaluate the full potential for applications of these herbicides at flower initiation to mitigate the evolution of herbicide resistance.

Response of ‘Russet Burbank’ Seed Tubers Containing Dicamba and Glyphosate

AbstractIncreased use of dicamba and/or glyphosate in dicamba/glyphosate-tolerant soybean might affect many sensitive crops, including potato. The objective of this study was to determine the growth and yield of ‘Russet Burbank’ potato grown from seed tubers (generation 2) from mother plants (generation 1) treated with dicamba (4, 20, and 99 g ae ha−1), glyphosate (8, 40, and 197 g ae ha−1), or a combination of dicamba and glyphosate during tuber initiation. Generation 2 tubers were planted near Oakes and Inkster, ND, in 2016 and 2017, at the same research farm where the generation 1 tubers were grown the previous year. Treatment with 99 g ha−1dicamba, 197 g ha−1glyphosate, or 99 g ha−1dicamba + 197 g ha−1glyphosate caused emergence of generation 2 plants to be reduced by up to 84%, 86%, and 87%, respectively, at 5 wk after planting. Total tuber yield of generation 2 was reduced up to 67%, 55%, and 68% when 99 g ha−1dicamba, 197 g ha−1glyphosate, or 99 g ha−1dicamba + 197 g ha−1glyphosate was applied to generation 1 plants, respectively. At each site year, 197 g ha−1glyphosate reduced total yield and marketable yield, while 99 g ha−1dicamba reduced total yield and marketable yield in some site-years. This study confirms that exposure to glyphosate and dicamba of potato grown for potato seed tubers can negatively affect the growth and yield potential of the subsequently grown daughter generation.

Evaluation of Postemergence Herbicide Combinations for Long-Term Trumpetcreeper (Campsis radicans) Control in Corn (Zea mays)1

Field trials were conducted in Virginia during 2000 and 2001 to evaluate long-term trumpetcreeper control in corn with dicamba, BAS 654 plus dicamba, 2,4-D, CGA 152005 plus primisulfuron, halosulfuron, primisulfuron, and mesotrione. Each of these herbicides was applied alone as a single postemergence (POST) treatment or as a component of a POST herbicide combination. Trumpetcreeper suppression ratings 3 mo after treatment (MAT) revealed a general trend toward higher levels of suppression with combinations of dicamba, BAS 654 plus dicamba, or 2,4-D with any of the sulfonylurea herbicides and lower levels of suppression with applications of any of the sulfonylurea herbicides alone. Combinations of dicamba, BAS 654 plus dicamba, or 2,4-D with mesotrione also provided some of the highest levels of trumpetcreeper suppression 3 MAT in both years. At 1 yr after treatment (YAT), 2,4-D alone, BAS 654 plus dicamba, CGA 152005 plus primisulfuron plus 280 g ai/ha dicamba, primisulfuron plus 280 g/ha dicamba, primisul...

Mesotrione Combinations for Postemergence Control of Horsenettle (Solanum carolinense) in Corn (Zea mays)1

Field and greenhouse studies were conducted near Painter, VA, in 1999, 2000, and 2001 to evaluate mesotrione postemergence for control of horsenettle in corn. Mesotrione at 105 g ai/ha controlled horsenettle at least 80% in all studies, and in 2001, after two consecutive annual applications, mesotrione controlled horsenettle up to 91%. Additions of primisulfuron, dicamba, and 2,4-D to mesotrione did not increase horsenettle control. Occasionally, combinations of dicamba with mesotrione controlled horsenettle less than did mesotrione alone, and primisulfuron combinations with mesotrione delayed or reduced development of bleaching symptoms associated with mesotrione. Initial horsenettle response to mesotrione was increased by addition of 280 g ai/ha atrazine; however, late-season horsenettle control was not improved by atrazine. Two consecutive annual applications of mesotrione alone decreased horsenettle biomass > 89%. Treatments of primisulfuron plus dicamba, primisulfuron plus CGA 152005 plus dicamba, an...

Somatic Embryogenesis of Rosa Hybrida L.

ABSTRACTWe present two regeneration protocols via somatic embryogenesis in three cut roses—Rosa hybrida cvs. “Anny”, “Trimontsium” and “Saltze Gold”. The first regeneration protocols are based on regeneration via somatic embryogenesis in callus from leaf and petiole segments of Rosa hybrida cvs. “Trimontsium” and “Saltze Gold”. The other protocol is via somatic embryogenesis in callus culture from petals of Rosa hybrida cv. “Anny”. Both regeneration protocols were developed on solid medium under subculturing on every 35–40 days. MS-medium including MS (1962—Murashige & Skoog) or QL (Quorin & Lepoivre) vitamins were used. For the embryo induction of callus derived from leaf and petiole explants were used BAP, NAA and kinetin, while for the combination of dicamba, kinetin and 2-ip are the most efficient for the embryo induction of callus derived from petals. A part of these embryos was converted to intact plants and an other part had been multiplicated and maintained in vitro for two years in order to check their regeneration capacity. All the regenerants that had been obtained from the three cut roses were adapted under in vitro conditions and cultivated in a greenhouse. Regenerated plantlets were morphologically true to the type of the initial donor-genotype.

Response of an acetolactate synthase (ALS)‐resistant biotype of Amaranthus rudis to selected ALS‐inhibiting and alternative herbicides

SummaryAn Amaranthus rudis Saner (common water‐hemp) biotype from a field treated for two consecutive years with a mixture of chlorimuron and metribuzin was tested in greenhouse and laboratory studies to assess resistance and cross‐resistance to four acetolactale synthase (ALS)‐inhibiting herbicides. The biotype demonstrated >1920‐fold resistance at the whole plant level, and >850‐fold resistance at the ALS enzyme to chlorimuron, compared with a susceptible biotype. This chlorimuron‐resistant biotype was also cross‐resistant to primisuifu‐ron, haiosulfuron and imazethapyr. In greenhouse studies, atrazine alone or in combination with ALS‐inhibiting herbicides provided excellent control of the resistant biotype of A. rudis. Combinations of dicamba and ALS‐inhibitors also provided adequate control. Additionally, premixtures of flumetsulam and metolachlor and of dicamba and atrazine furnished excellent control of this chlorimuron‐resistant A. rudis biotype.

Influence of dicamba and casein hydrolysate on somatic embryo number and culture quality in cell suspensions of Dactylis glomerata (Gramineae)

The effects of various concentrations and combinations of dicamba (3,6-dichloro-o-anisic acid) and casein hydrolysate on growth, mucilage accumulation, somatic embryo and root development in suspension cultures of Dactylis glomerata L. (orchardgrass) were examined. Fresh weight of culture tissue was increased with 20 μM but not with 80 or 160 μM dicamba in treatments with 1–4 g/l casein hydrolysate. Different casein hydrolysate concentrations did not alter the amount of mucilage (measured by viscosity) in the supernatant in the absence of dicamba. However, the addition of dicamba increased viscosity with 80 μM giving the maximum response. Casein hydrolysate produced the greatest viscosity at 1–3 g/l in treatments where dicamba was present. Both dicamba and casein hydrolysate were required for development of somatic embryos. Dicamba at 40 μM with 3–4 g/l casein hydrolysate produced approximately 2000 embryos/35 ml of suspension. Root development was inhibited by dicamba and stimulated by the presence of casein hydrolysate. The usefulness of medium component manipulations for influencing somatic embryogenesis and culture quality is discussed.

Herbicide Interactions in Control of Sand Shinnery Oak

Silvex was the most effective herbicide for reducing sand shinnery oak (Quercus havardii Rydb.) density and increasing grass production in the Rolling Plains of Texas. Combinations of silvex or 2,4,5-T with picloram controlled more sand shinnery oak than expected (synergistic) and substantially increased grass production. Picloram and 2,4-D (1:1) at 0.5 lb./acre total were additive and less effective than other phenoxy:picloram combinations. Combinations of dicamba with 2,4,5-T or silvex were usually additive.