Weed management in common buckwheat (Fagopyrum esculentum)

Abstract

Wall, D. A. and Smith, M. A. H. 1999. Weed management in common buckwheat (Fagopyrum esculentum). Can. J. Plant Sci. 79: 455-461. There are currently no broadleaf herbicides registered in Canada for use in common buckwheat (Fagopyrum escu-lentum Moench.). Greenhouse and field studies were conducted from 1994 to 1997 at Morden and Brandon, Manitoba, to investigate potential herbicide treatments for buckwheat when cultural methods fail to control broadleaf weeds. Dose-response studies conducted in the greenhouse showed that buckwheat tolerance to desmedipham was three to five times greater than that of volunteer canola (Brassica napus L. and B. rapa L.), lamb's-quarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.). A separate experiment showed that buckwheat cultivars did not differ in tolerance to desmedipham. Another greenhouse study demonstrated that low dosages of bentazon caused severe injury in buck-wheat. In field studies, 500 to 700 g a.i. ha-1 of desmedipham effectively suppressed the annual broadleaf weed biomass in buck-wheat without reducing seed yields. At a low dosage of 300 g a.i. ha-1 of desmedipham there were no yield losses even though no weed biomass reduction was evident. Imazamethabenz at 150 to 250 g a.i. ha-1 and metribuzin at 140 and 210 g a.i. ha-1 severely injured buckwheat and usually reduced yields. 2,4-D at 140 g a.i. ha-1 suppressed weed biomass, but caused severe injury and often reduced buckwheat yield. At 70 g a.i. ha-1 , 2,4-D suppressed weed growth as effectively as the higher dosage with less visual injury, but sometimes reduced buckwheat yields. Thus, desmedipham is the most promising postemergence broadleaf herbicide for use in common buckwheat. Wall, D. A. et Smith, M. A. H. 1999. Maîtrise des mauvaises herbes dans les cultures de sarrasin (Fagopyrum esculentum). Can. J. Plant Sci. 79: 455-461. Il n'existe actuellement aucun herbicide antidicotylédones homologué pour le désherbage du sar-rasin (Fagopyrum esculentum Moench.). Des expériences en serre et au champ ont été réalisées à Morden (Manitoba) de 1994 à 1997 pour examiner divers traitements herbicides pour cette culture advenant l'échec des méthodes culturales contre les mauvais-es herbes dicotylédones. Des études dose-réponse menées en serre ont montré que la tolérance du sarrasin au desmédiphame était 3 à 5 fois plus forte que celle des repousses de canola (Brassica napus L. et B. rapa L.), du chénopode blanc (Chenopodium album L.), de l'amarante à racine rouge (Amaranthus retroflexus L.) et de la moutarde des champs (Sinapis arvensis L.). Une expérience distincte a permis de constater que les cultivars de sarrazin ne différaient pas quant au degré de tolérance au desmédiphame. Dans une autre expérience en serre, on a constaté que même à faible dose, le bentazone endommageait gravement le sarrasin. Dans les expériences au champ, le desmédiphame aux doses de 500 à 700 g m.a. ha-1 était efficace contre les dicotylédones annuelles dans le sarrasin, sans réduire...

Tolerance of common buckwheat (Fagopyrum esculentum) to low rates of 2,4-D and MCPA

“…In another study, 2,4-D amine at 140 g a.i. ha -1 suppressed weed biomass in common buckwheat when weed densities were moderate to heavy (Wall and Smith 1999). Weather during the growing season, especially just before and after herbicide application, appears to be an important factor in the ability of common buckwheat to recover from injury without yield loss.…”

Early Season Weed Suppression in Buckwheat Using Clopyralid

“…For example, grass herbicides in trials have included the PRE herbicides alachlor (Rana et al 2004), pendimethalin, acetochlor, metolachlor (Salna and Kavoliunaite 2001), and the POST herbicide fenoxaprop ( Jakubiak and Adamczewski 2006). Broadleaf weed control also has been attempted with PRE herbicides such as pyrazon (Kavoliunaite and Salna 2003a), and POST herbicides with varying rates and application timings of desmedipham (Kavoliunaite and Salna 2003b;Wall and Smith 1999), napropamide (Kozaczenko 1988), 2, 4-D, and MCPA (Salna et al 1998;Wall and Smith 2000). In some cases, mixtures of grass and broadleaf herbicides have been studied (Knezevic and Baketa 1992).…”

Buckwheat: A Cool-Season Cover Crop for Florida Vegetable Systems

“…Often, thick stands are planted to out compete weeds, but that can interfere with mechanical cultivation. In Canada, only diclofop methyl is registered for control of some annual grasses in buckwheat, and no labels exist for broadleaf weed control (Wall and Smith, 1999). Buckwheat is sensitive to broadleaf herbicides, and germination may be hindered by residues of atrazine, trifluralin, and sulfonylurea herbicides.…”