Browsing by Author "Holm, F.A."
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Item Availability of soil nitrogen released from pea and lentil residue to subsequent cereal crops under reduced tillage(1998-02-19) Adderley, D.R.; Schoenau, J.J.; Holm, F.A.The release of N from legume crop residues in the field can potentially be an important nutrient source for succeeding cereal crops, particularly in soils which are N deficient. Field studies were conducted in 1996 on two soils of contrasting textures in the Dark Brown Soil Zone of Saskatchewan, a 1) Sutherland clay loam (Kernen), and a 2) Bradwell sandy loam (Goodale), which were previously cropped to pea and lentil in order to compare the effects of legume stubble type on soil N supply. Spring wheat was direct seeded in 1997 in order to compare yields and crop N uptake on pea and lentil stubble. Pre-seeding soil samples were taken and analyzed for NH, and NO,. Pre-seeding available N amounts were significantly greater at Kernen, corresponding to higher organic matter levels. Supply rates of NO, during the growing season were measured using anion exchange resin membranes (PRS- probes). Higher overall supply rates were measured at Kernen as compared to Goodale, while significantly greater supply rates on pea stubble were observed at Goodale only. Both wheat yield and N uptake were significantly greater at Kernen as a function of higher N availability. Mean N uptake and yields were generally higher under pea stubble than lentil at both sites but not significantly different at the 10% level.Item Broadleaf weed control in chickpea (Cicer arietinum) and lentil (Lens culinaris) with fall application of pursuit(2003-02-18) Sapsford, K.L.; Holm, F.A.; Johnson, E.N.; Gan, Y.Broadleaf weed control options in chickpea and lentil are very limited. Preliminary trials found that spring applied Pursuit at rates from 0.25X to 0.5X resulted in severe injury to chickpea in some years. The objective of these trials was to evaluate fall application of Pursuit in chickpea and lentil, at rates from 0.25X to 0.5X, for both crop tolerance and weed control efficacy. A 4-replicate trial was set up at Saskatoon, Sask. in 2000, 2001 and 2002 and at Scott, Sask. and Swift Current, Sask. in 2002. Pursuit was surface applied, with no incorporation, in the fall, at rates of 0.25X, 0.33X, 0.4X and 0.5X. Edge (2000) or Poast Ultra (2001, 2002) were applied to improve grassy weed control. The trials were direct seeded with low disturbance openers. There was excellent crop tolerance to fall applications of Pursuit in both chickpea and lentil at all location-years. Some visual crop injury was evident at the higher rates of Pursuit; however, yield was not reduced. Broadleaf weed control was inconsistent at the 0.25X rate. Rates higher than 0.33X rates resulted in excellent control of stinkweed (Thlaspi arvense L.), wild mustard (Sinapsis arvensis L.), wild buckwheat (Polygonum convolvulus L.), lamb’s-quarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), Russian thistle (Salsola kali L.) and cleavers (Galium aparine L.) at all location-years. When compared to a post-emergence application of Sencor, fall applied Pursuit at 0.33X to 0.4X rates resulted in similar to 20% higher seed yields in lentil and chickpea, respectively. Fall applied Pursuit at 0.33X to 0.4X rate resulted in consistent broadleaf weed control, low crop injury, and high crop yield.Item Defining optimum herbicide rate and timing for wild oat control in spring wheat(1999-02-25) Holm, F.A.; Kirkland, K.J.; Stevenson, F.C.Field trials were conducted at Scott and Saskatoon, SK from 1994 through 1997 to determine the optimum rate and timing for five post-emergent herbicides used to control wild oat in spring wheat. The herbicides tested were clodinafop-propargyl, fenoxaprop-P, flamprop, imazamethabenz and tralkoxydim. Herbicides were applied at the recommended label rate, 0.67 times or 0.33 times the recommended rate at the 2-, 4- or 6-leaf stages of wild oat. Wild oat infestation was moderate to heavy at Saskatoon and light to moderate at Scott.Item Economics of integrated crop management systems in the Dark Brown Soil Zone(2002-02-20) Zentner, R.P.; Holm, F.A.; Kratchmer, D.; Thomas, A.G.; Blomert, B.J.; Wilson, C.A.Low commodity prices, rising input costs, and increasing concerns about environmental degradation are encouraging producers in western Canada to consider alternative soil tillage and weed management methods that conserve resource inputs. However, little is known about the economic merits of these management changes. This study determines the effects of six integrated soil, cultural, and weed management practices on production costs, economic returns, and riskiness for a Wheat (W)-Canola (C)-Barley (B)-Pea (P) rotation in the Dark Brown Soil Zone of Saskatchewan.Item Effect of application time, carrier pH, carrier volume, and rate on Tralkoxydim activity on wild oat (Averza fatua)(1998-02-19) Kirkland, K.J.; Holm, F.A.; Johnson, E.M.Field studies were conducted from 1994 to 1997 at the Agriculture and Agri-Food Canada Research Farm, Scott, Saskatchewan, and Crop Science Dept., University of Saskatchewan, Saskatoon, Saskatchewan. Tralkoxydim was applied to wild oats in hard red spring wheat (Triticum aestivum) at; two application times, 11:00 a.m. and 9:00 p.m.; two carrier pH levels, 8.0 and 4.0; three water volumes, 100, 50 and 30 litres per hectare and four rates, 100, 75, 50 and 25% of recommended (200 g / ha). Wild oat populations were heavy at Saskatoon in 1994 and 1995 and light to moderate in 1996 and 1997 and light to moderate at Scott in all years. At Scott. 9:00 p.m. application compared to 11:00 a.m. reduced wild oat biomass significantly in all years with reductions ranging from 26 to 80%. This suggests that the high intensity of UV light present at midday may reduce the effectiveness of tralkoxydim. Reducing carrier pH from 8.0 to 4.0 produced reductions in wild oat biomass in three of 4 years with reductions ranging from 40 to 76%. The interaction, time X carrier pH was significant for wild oat biomass in all years and wheat yields in one year. Late evening application combined with reduced carrier pH was the most effective. At Saskatoon, time of application and carrier pH had no influence on wild oat biomass or wheat yields although trends toward a reduction in total biomass with reduced carrier pH were noted in all years. Reduced carrier volume decreased efficacy in seven of 8 site years and was particularly evident when carrier volume was reduced to 30 l/ha. Wheat yields declined nine and 14% at Scott and Saskatoon, respectively when tralkoxydim carrier volume was reduced from 100 to 30 l/ha. Reducing the tralkoxydim rate to 75% of recommended had no effect on wild oat biomass in seven of 8 site years. Further reductions to 50 or 25% of recommended resulted in significant increases in wild oat biomass and reductions in wheat yields.Item The effect of dilution water quality on herbicide efficacy(1991-02-21) Holm, F.A.; Henry, J.L.The antagonistic effect of Ca2+ and Mg2+ ions on the efficacy of glyphosate (Roundup) has been well documented for some time but there is relatively little information available on the effect of other ions on glyphosate or other herbicides. Field trials were conducted at Saskatoon in 1989 and 1990 to determine the effect of dilution water ion content on the efficacy of several herbicides. Water sources examined were: Saskatoon (surface, fresh, low mineralization), Goodale (artesian well, hard, high Ca2+ and Mg2+), Zelma (well, hard, high Fe3+), Outlook (well, soft, high Na+), Unity (well, soft, medium HCO3-), Maple Creek (well, soft, high HCO3-) Recommended and less than recommended rates of selected herbicides were applied in four replicate field trials using standard flat fan nozzles that delivered 130 L/ha (1989) or 110 L/ha (1990) of spray mixture. Herbicide X water combinations that have resulted in reduced weed control as compared to Saskatoon water as the check are: glyphosate (Roundup) X Goodale or Zelma, sethoxydim (Poast) X Unity or Maple Creek, clethodim (Select) X Unity or Maple Creek, 2,4-D amine X Goodale, Outlook or Unity. Imazamethabenz (Assert) was not affected initially but plants treated with water from Unity or Maple Creek recovered more rapidly than those treated with Saskatoon water. Fenoxaprop-ethyl (Excel), 2,4-D ester, and glufosinate ammonium (Ignite, Harvest) were not affected by water source.Item The effect of seeding depth and soil incorporated herbicides on spring wheat(1988-02-19) Lyimo, S.D.; Holm, F.A.Item Effect of timing of isoxaflutole application on weed control in desi chickpea (Cicer arietinum)(2007-03-01) Johnson, E.N.; Ulrich, D.J.; Blackshaw, R.E.; Sapsford, K.L.; Holm, F.A.Item Energy efficiency of integrated crop management systems in the Dark Brown Soil Zone(2002-02-20) Blomert, B.J.; Zentner, R.P.; Thomas, A.G.; Holm, F.A.; Kratchmer, D.; Wall, D.D.Item Field pea seed residues: the potential for low cost weed control(2010-02-24) Marles, M.A.S.; Holm, F.A.; Warkentin, T.D.Plant growth suppression trials were undertaken with soil sampled 18 mo apart (2008, 2009) from two locations affected by field pea seed residues. Test plant species were grown in the residue-affected soil and compared to residue-unaffected soils, sampled from nearby fields. Germination was either fully inhibited or emergence delayed by more than one week in residue-affected soil. Dry matter accumulation of test species grown in residue-affected soil was significantly reduced compared to dry matter of these species grown in unaffected soil (P <0.0001). Canola and field pea were inhibited more than wheat and green foxtail over both years. Greenhouse trials also revealed that germination of wild oats was inhibited in the residue-affected soils, although overall, wheat and grassy weeds were less affected than dicots. Significant reductions of weed species diversity and abundance were correlated to residue-affected soils (P <0.0001) when compared to control soils using multi-response permutations procedures. In bioassays in sterile media, germination of wheat and canola seed was inhibited, using aqueous extracts of weathered pea seeds or extracts of the residue-affected soil. An allelopathic response was proposed to explain these results.Item Field performance of a transgenic flax line resistant to sulfonylurea herbicides(1995-02-23) Holm, F.A.; McHughen, A.Item From high herbicide/no tillage to no herbicide/high tillage: how do crops respond?(2002-02-20) Sapsford, K.L.; Holm, F.A.; Thomas, A.G.; Kratchmer, D.In general, zero-till systems resulted in higher yields and yields declined as the intensity of tillage was increased. The High Herbicide/Zero Tillage system always resulted in the highest yield. The Medium Herbicide/Zero Tillage, Low Herbicide/Zero Tillage and Medium Herbicide/Medium Tillage systems always resulted in similar yields just slightly lower than the HH/ZT system. Canola yields declined the most and barley and pea yields the least when herbicide inputs were reduced. Management system had little or no effect on crop quality characteristics and weed biomass tended to be greatest when herbicides were not used. As herbicide intensity decreased, weed biomass increased and yield decreased in all crops. Application of fungicide generally increased seed yield of barley, wheat and field pea with the greatest increases occurring in barley. In most cases where yield responses were significant, the magnitude of the increase was relatively small and so the economic impact of fungicide application was often not positive. The greatest response to fungicide occurred in the wetter years of 1999 and 2000. Fungicide application increased seed weight of all crops except for canola, tended to reduce protein concentration of cereals and field pea and increased barley plumpness.Item ICM experiments with barley in Saskatchewan(1987-02-19) Partyka, E.F.; Holm, F.A.Item In search of new herbicide chemistries for the prairies(2006-03-02) Johnson, E.N.; Ulrich, D.A.; Blackshaw, R.E.; May, W.E.; Sapsford, K.L.; Holm, F.A.There 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.Item Integrated management of cropland pests (IMCP)(1998-02-19) Holm, F.A.; Kratchmer, D.J.; Thomas, A.G.Item Integrated pest management systems: rationale, objectives, and design(2002-02-20) Thomas, A.G.; Sapsford, K.; Holm, F.A.; Kratchmer, D.The objective of the project was to develop integrated crop management systems for weed, insect and disease populations and evaluate the efficacy and cost/benefit of the various management practices. The strategy of integrated management of crop pests seeks to understand the factors that influence changes in pest populations and to utilize these factors to regulate population levels. Field experiments were established in the fall of 1996 on the Kernen Crop Research Farm at the University of Saskatchewan and on the Agricultural Research and Development Farm of Saskatchewan Wheat Pool at Watrous. Six systems were based on combinations of tillage and herbicide inputs. A four-year crop rotation of wheat, canola, barley and field pea was used from 1997 to 2000. Agronomic and pest population data were collected yearly. The economics and energy efficiency of the six systems were compared. Carabid beetle diversity was used as an assessment of soil health.Item Interactions of soil residual ALS inhibiting herbicides(2006-03-02) Geisel, B.G.L.; Schoenau, J.J.; Johnson, E.N.; Sapsford, K.L.; Holm, F.A.ALS inhibiting herbicides exhibit high bioactivity at low concentrations and may persist in the soil. To examine possible interactions between two different residues present together in the soil, field and lab tests were performed in three contrasting Saskatchewan soils. Field plots using Roundup Ready canola were used to assess residual effects of combinations of ALS inhibiting herbicides applied to peas and wheat in the previous two years. A root length inhibition bioassay based on oriental mustard was used to test for residual herbicide phytotoxicity in samples of soil from field and lab-spiked soils from the three study sites. The field plots were sprayed initially with imazamox/imazethapyr, and followed by imazamethabenz, flucarbazone-sodium, sulfosulfuron, or florasulam in the second growing season. Soil samples were taken from the plots after the second growing season for the bioassay test. To determine the interactions (antagonistic, additive, or synergistic) between the herbicides investigated, Colby’s equation was applied to the bioassay results. In field samples, the results to date have indicated additive and potential synergistic interactions for the same herbicide combinations in different soils.Item Mechanical weed control in pulse crops(2000-02-22) Johnson, E.N.; Holm, F.A.; Kirkland, K.J.Item Pre-emergence tillage in field pea effective, but timing critical(2001-02-22) Johnson, E.N.; Nielsen, M.E.; Holm, F.A.On the semi-arid prairies, it is generally recommended to seed field pea early and at a depth of 4 to 7.5 cm. Crops that emerge before weed emergence are more competitive than crops emerging at the same time or after weed emergence. Delayed seeding to control late-emerging weeds and seeding at shallower depths to promote rapid emergence may be an alternative weed management strategy. The objective of this experiment was to identify combinations of seed date, seed depth, and pre-emergent weed control to optimize yield of field pea grown without the use of herbicides.Item Response of barley cultivars to plant growth regulators(1988-02-19) Holm, F.A.; Partyka, E.F.