Microbial biomass and diversity in roundup-ready corn rhizosphere

Non-Peer ReviewedThe effects of Roundup-Ready (RR) corn, grown in monoculture or in rotation with canola, on microbial biomass and diversity in corn rhizosphere were investigated at Lethbridge from 2002 to 2004. In monoculture, weeds in RR corn or conventional corn were controlled by applying either Roundup or other herbicides. In rotations, RR corn rotated with RR canola or Liberty-Link (LL) canola was compared with conventional corn rotated with conventional canola. Microbiological properties in corn rhizosphere were measured at tasseling stage. In monoculture, RR corn affected microbial biomass only in 2003, when application of Roundup increased microbial biomass in RR corn rhizosphere, but not in conventional corn rhizosphere. The diversity of bacteria in RR corn rhizosphere was greater than that in conventional corn rhizosphere, regardless of Roundup application, only in 2002. RR corn in rotation did not affect microbial biomass or bacterial diversity. Therefore, RR corn affected microbial biomass or diversity in only one of three years when it was grown in monoculture, but there were no effects when corn was grown in rotation with canola. When effects were significant, the rhizosphere of RR corn had greater microbial biomass or diversity that that of conventional corn

Weed suppression with cereal cover crops

Non-Peer ReviewedExperiments were conducted under rain-fed conditions at Lethbridge, Alberta to determine the effect of short-term fall rye (Secale cereale L.), winter wheat (Triticum aestivum L.) and no cover crop treatments in the fallow year on weed growth. Under favorable weather conditions fall rye was as effective as post-harvest plus early spring tillage or herbicides in spring weed control. Winter wheat and fall rye residues, after growth was terminated in June, reduced weed biomass in September by 50% compared to no cover crop in 1993 but had little effect on weeds in 1995. A fall rye cover suppressed annual sow-thistle, flixweed, stinkweed, foxtail barley, Canada thistle and dandelion but not thyme-leaved spurge and downy brome. Wheat initially suppressed weed growth but did not have a long-term effect on as many weed species

Effect of timing of isoxaflutole application on weed control in desi chickpea (Cicer arietinum)

Non-Peer Reviewe

Late glyphosate applications alter yield and yield components in glyphosate-resistant canola (Brassica napus L.)

Non-Peer Reviewe

In search of new herbicide chemistries for the prairies

Non-Peer ReviewedThere are a limited of herbicide groups for use in western Canada so there is a need introduce different modes of action to manage herbicide resistant weeds. In addition, many broadleaf crops such as chickpea have limited broadleaf weed control options. Sulfentrazone, a Group 14 PPO inhibitor has been screened in a number of broadleaf crops. Chickpea has exhibited excellent tolerance to sulfentrazone, while the tolerance of other broadleaf crops can be summarized as follows: sunflower and fababean (fair to good); field pea, and narrow-leaved lupin (fair); dry bean (poor) and lentil (very poor). Isoxaflutole is a Group 27 carotenoid biosynthesis inhibitor that may have potential for use in chickpea, tame buckwheat, and narrow-leaved lupin. Sulfentrazone effectively controls many broadleaf weeds but is weak on cruciferous weeds such as wild mustard. Isoxaflutole also controls a number of broadleaf weeds but does not control wild buckwheat. Both sulfentrazone and isoxaflutole are soil-applied herbicides with potential to carry-over and injure rotational crops. Preliminary results from field trials indicate that combined low rates of sulfentrazone and isoxaflutole can result in excellent broad spectrum weed control in chickpea. Carfentrazone-ethyl, a contact non-residual PPO inhibitor has been shown to be an effective pre-seed burndown partner for glyphosate. This would allow for the control of volunteer Roundup-ready canola prior to the seeding of broadleaf crops

Update on fall dormant seeded canola research

Non-Peer Reviewe

Economics of preceding crops and nitrogen application rates for canola and barley production in western Canada

Non-Peer ReviewedThe objective of this study was to evaluate the economic effects of a range of legume and non-legume preceding crops and N rates on costs and net revenue (NR) of canola (Brassica napus L.), barley (Hordeum vulgare L.) and canola-barley rotation under various environmental conditions. Legumes such as field pea (Pisum sativum L.) and lentil (Lens culinaris Medik.) as preceding crop generated higher net revenues for the following crops canola and barley than when wheat (Triticum aestivum L.) and canola were the preceding crops. Although faba bean (Vicia faba L.) grown as a green manure produced the highest annual net revenues for the following crops canola and barley, this contribution was not enough to compensate for the loss of income during the green manure production year. Therefore, growing faba bean as a green manure was not economical. Response of net revenue to N rates was mainly linear or quadratic, and N was optimal at 60 to 90 kg ha-1 at most sites. The results indicate that growing legumes for seed prior to canola can increase net revenues of canola and subsequent barley

Contribution of legume preceding crops to improve economic and non-renewable energy use efficiency of canola production

Non-Peer Reviewe