Weed management in irrigated fenugreek grown for forage in rotation with other annual crops

Abstract

) is an annual legume that has potential as a forage crop on the Canadian Prairies. Experiments were established to determine the tolerance of fenugreek to several herbicides and their efficacy on various weeds. Potentially, fenugreek could be grown in conservation tillage systems in rotation with other annual crops. Therefore, additional multi-factor experiments were conducted to determine the effect of herbicides, seeding method, and 11 previous crops on fenugreek yield. Without herbicide application, weeds contributed 37 to 86% to total dry matter production. When imazamox/imazethapyr, or combinations of imazamoz/imazethapyr or imazethapyr with ethalfluralin was applied, weed contents were about 5% of the total dry matter and the herbicides did not reduce fenugreek yield compared to the hand-weeded check. Total forage samples with a low weed content had lower fibre content and higher protein and digestible dry matter content than forages with a high weed content. When imazamox/imazethapyr was used for weed control, fenugreek yields and weed biomass were similar after direct seeding and after cultivation plus seeding. In addition, the effect of previous crop and the previous crop by seeding method interaction was not significant for fenugreek yield and weed biomass. Therefore, irrigated fenugreek can be successfully grown in conservation tillage systems in rotation with several crops provided an effective herbicide is used for weed control. ) est une légu-mineuse annuelle dont on pourrait se servir pour l'affouragement dans les Prairies canadiennes. Des expériences ont permis d'établir la tolérance de cette culture à divers herbicides et l'efficacité de ces derniers sur plusieurs adventices. Le fenugrec pourrait être cultivé dans un système de conservation du sol, en assolement avec d'autres annuelles. Les auteurs ont donc entrepris de nouvelles expériences multifactorielles afin de préciser les effets des désherbants, de la méthode d'ensemencement et de onze cultures antérieures sur le rendement du fenugrec. En l'absence d'herbicides, les adventices représentent de 37 à 86 % de la matière sèche totale produite. Quand on applique de l'imazamox/imazéthapyr ou un mélange d'imazamox/imazéthapyr ou d'imazéthapyr et d'éthalfluraline, elles ne constituent toutefois plus que 5 % du volume total de matière sèche; en outre, les herbicides ne réduisent pas le rendement du fenugrec, quand on le compare au rendement de la parcelle témoin, désherbée à la main. Les échantillons de fourrage renfermant peu d'adventices se caractérisaient par une plus faible teneur en fibres ainsi que par une concentration accrue de protéines et de matière sèche digestible, comparativement aux échantillons contenant beaucoup de mauvaises herbes. Après désherbage chimique à l'imazamox/imazéthapyr, le semis direct de fenugrec donne un rendement et une biomasse d'adventices semblables à ceux obtenus avec l'ensemencement après travail du sol. La culture antérieure et les interactions entre cette dernière et la méthode de semis n'ont pas d'incidenc...

Tolerance of annual forage legumes to herbicides in Alberta

“…The results suggest that either imazethapyr or ethalfluralin at the standard rate could be used for weed control in alfalfa, arrowleaf, balansa, berseem and crimson clover, black lentil, fenugreek, pea, hairy and winter vetch, barrel, snail, and strand medic. These results are in agreement with findings of a recent study in Lethbridge (Moyer et al 2003) that yields of alfalfa and fenugreek treated with imazamox/imazethapyr or trifluralin are usually similar to those from hand-weeded plots. In the study of Moyer et al (2003), the digestibility and protein content of forage was significantly lower in the weedy check than in the imazamox/imazethapyr treatment indicating that weed control in annual legumes is essential.…”

“…These results are in agreement with findings of a recent study in Lethbridge (Moyer et al 2003) that yields of alfalfa and fenugreek treated with imazamox/imazethapyr or trifluralin are usually similar to those from hand-weeded plots. In the study of Moyer et al (2003), the digestibility and protein content of forage was significantly lower in the weedy check than in the imazamox/imazethapyr treatment indicating that weed control in annual legumes is essential. The imazamox/imazethapyr treatments controlled green foxtail, wild oat and redroot pigweed in most years (Moyer et al 2003).…”

“…Alfalfa, balansa clover and black medic showed significant (P < 0.001) treatment differences in both years. Year-to-year variations in crop injury with ethalfluralin and trifluralin have been noted elsewhere for fenugreek (Moyer et al 2003).…”

“…In the study of Moyer et al (2003), the digestibility and protein content of forage was significantly lower in the weedy check than in the imazamox/imazethapyr treatment indicating that weed control in annual legumes is essential. The imazamox/imazethapyr treatments controlled green foxtail, wild oat and redroot pigweed in most years (Moyer et al 2003). Ethalfluralin or imazethapyr can control more than 30 annual weeds that infest Alberta's fields (Anonymous 2000).…”

Fenugreek (Trigonella foenum-graecum L.) as an alternative forage for dairy cows

“…Those studies have revealed the enormous potential of fenugreek as an alternative forage crop for areas with a temperate climate such as that of the Western Canadian prairie. Besides its use for forage production, the annual nature of fenugreek may provide producers an opportunity to use fenugreek as a break crop in crop rotations (Moyer et al, 2003).…”