• Authors:
    • Shirriff, S.
    • Lozinski, C.
    • Holzgang, G.
    • Hall, L.
    • Brenzil, C.
    • Thomas, A.
    • Leeson, J.
    • Beckie, H.
  • Source: Weed Technology
  • Volume: 22
  • Issue: 3
  • Year: 2008
  • Summary: Weed resistance monitoring has been routinely conducted in the Northern Great Plains of Canada (Prairies) since the mid-1990s. Most recently, random surveys were conducted in Alberta in 2001, Manitoba in 2002, and Saskatchewan in 2003 totaling nearly 800 fields. In addition, nearly 1,300 weed seed samples were submitted by growers across the Prairies between 1996 and 2006 for resistance testing. Collected or submitted samples were screened for group 1 [acetyl-CoA carboxylase (ACCase) inhibitor] and/or group 2 [acetolactate synthase (ALS) inhibitor] resistance. Twenty percent of 565 sampled fields had an herbicide-resistant (HR) wild oat biotype. Most populations exhibited broad cross-resistance across various classes of group 1 or group 2 herbicides. In Manitoba, 22% of 59 fields had group 1-HR green foxtail. Group 2-HR biotypes of kochia were documented in Saskatchewan, common chickweed and spiny sowthistle in Alberta, and green foxtail and redroot pigweed in Manitoba. Across the Prairies, HR weeds are estimated to occur in fields covering an area of nearly 5 million ha. Of 1,067 wild oat seed samples submitted by growers and industry for testing between 1996 and 2006, 725 were group 1 HR, 34 group 2 HR, and 55 groups 1 and 2 HR. Of 80 submitted green foxtail samples, 26 were confirmed group 1 HR; most populations originated from southern Manitoba where the weed is most abundant. Similar to the field surveys, various group 2-HR biotypes were confirmed among submitted samples: kochia, wild mustard, field pennycress, Galium spp., common chickweed, and common hempnettle. Information from grower questionnaires indicates patterns of herbicide usage are related to location, changing with cropping system. Two herbicide modes of action most prone to select resistance, groups 1 and 2, continue to be widely and repeatedly used. There is little evidence that growers are aware of the level of resistance within their fields, but a majority have adopted herbicide rotations to proactively or reactively manage HR weeds.
  • Authors:
    • Bleidere, M.
    • Malecka, S.
    • Belicka, I.
  • Source: Agronomijas Vestis
  • Issue: 10
  • Year: 2008
  • Summary: The aim of experiment was to evaluate and compare grain chemical composition (crude protein, starch, crude fat, crude fibre, crude ash and phosporus) of hulled and hulless cereals. The four hulless barley varieties and lines - 'Gainer' (Canada), 'KM-2084', (the Czech Republic), 'L-302' (Latvia), 'SW-1291' (Sweden), one hulled barley variety - 'Linga' (Latvia), hulless oat line 'L-28156' (Latvia), hulled variety 'Laima' (Latvia) and spring wheat variety 'Vinjett' (Sweden) were included in this study. Field experiments were carried out at the State Stende Cereal Breeding Institute in 2004-2006. All plots received 60 kg ha -1 nitrogen (N). On the average for all hulless varieties, the content of crude protein ranged from 129.7-171.0 g kg -1. The hulled variety 'Linga' contained 140.7 g kg -1 crude protein. The content of crude protein for hulless oat line was 170.9 g kg -1 and it was significantly higher than for covered oat variety (120.9 g kg -1), but spring wheat 'Vinjett' (133.3 g kg -1) took place between hulled barley and hulled oat. In 2006, hot summer temperatures increased the crude protein content in all cereal varieties. There were differences in starch content among cereals. Regarding to starch content the species were ranged in following order: wheat > hulless barley > hulled barley > hulless oat > hulled oat (668, 623-686, 598, 589, 454 g kg -1, respectively). The hulless line L-28156 showed the highest fat content - 91.7 g kg -1. This value exceeded 1.5 to 3.8 fold the content of fat found in hulled oat, hulled and hulless barley and spring wheat. The hulless barley, hulless oat and spring wheat had the lowest crude fibre content 18.3-24.3 g kg -1, 20.3 g kg -1 and 28.5 g kg -1, respectively. The hulled barley and oat contained from 2 to 5 fold more crude fibre than hulless types. Hulled varieties of barley and oat had higher crude ash content (23.0-25.2 g kg -1) than hulless type (17.6-22.2 g kg -1). The results of grain chemical composition suggest that the hulless varieties of barley and oats might awake interest for food and feed producers.
  • Authors:
    • Blackshaw, R. E.
  • Source: Crop Protection
  • Volume: 27
  • Issue: 2
  • Year: 2008
  • Summary: Cover crops may have a valuable role to play in developing improved dry bean production systems. A field experiment was conducted to determine the agronomic benefits of including various fall-seeded and spring-seeded cereal cover crops with and without in-crop herbicides in dry bean. Main plot treatments included fall-seeded winter rye, barley, oat, and spring rye; spring-seeded barley, oat, and spring rye; and a no-cover crop control. Subplot treatments consisted of in-crop sethoxydim/bentazon and an untreated control. Fall-seeded cover crops were often superior to spring-seeded cover crops in terms of providing sufficient ground cover to reduce the risk of soil erosion and reducing weed emergence and growth. Among the fall-seeded cover crops, winter rye provided the greatest ground cover and often resulted in the greatest weed suppression. Dry bean density was not affected by any of the cover crops, but fall-seeded cover crops delayed emergence by up to 5 days and delayed maturity by up to 4 days. Cover crop effects on dry bean yield were most evident in the absence of in-crop herbicides, where fall-seeded cover crops increased dry bean yield by 20-90%. Cover crops also increased dry bean yield in 2 of 3 years when in-crop herbicides were used but yield increases were much smaller, ranging from 5% to 13%. These yield increases occurred with fall-seed cover crops that aided in weed management but also with spring-seeded cover crops where weed suppression was not evident, suggesting that cover crops provided additional benefits beyond weed management. Information gained in this study will be utilized to advise farmers on the most suitable use of cover crops in sustainable dry bean production systems.
  • Authors:
    • Butkuviene, E.
  • Source: Biodiversity and animal feed: future challenges for grassland production. Proceedings of the 22nd General Meeting of the European Grassland Federation, Uppsala, Sweden, 9-12 June 2008
  • Year: 2008
  • Summary: Pasture sward improvement investigations were conducted during the period 1980-2003 at the Vezaiciai Branch of the Lithuanian Institute of Agriculture. The focus was on the effects of pasture turf cultivation and resowing time, different cover and catch crops, and herbicide use in combination with pasture resowing. Cover crops, catch crops and pasture resowing time all affected dry matter (DM) yield. The most suitable time for turf cultivation was August-September and spring was most suitable for grass sowing. The best cover crops were barley for grain and oat-vetch mixture for green forage/silage. Potato and cereals were the best catch crops for pasture resowing. DM yield of resown pasture increased by 0.04-2.181 ha -1 compared with old untreated pasture. Resowing led to increased proportions of legumes in the sward by 1.1-9.2%, while the proportions of forbs decreased by 9.1-14.9%.
  • Authors:
    • Barth, G.
    • Garbuio, F.
    • Caires, E.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 39
  • Issue: 13/14
  • Year: 2008
  • Summary: Crop residues that are left on the soil surface to serve as mulch can diminish the soybean response to surface application of lime under no-till management by ameliorating soil chemical and physical attributes and the plant nutrition. A field experiment was performed in the period from 2000 through 2003 in Parana State, Brazil, on a clayey-sandy Rhodic Hapludox. Soil chemical attributes and soybean [ Glycine max (L.) Merrill] nutrition, grain yield, and quality were evaluated after surface application of lime and covering with crop residues of black oat ( Avena strigosa Schreb) and corn ( Zea mays L.) under a no-till system. Dolomitic lime was surface applied at the rates of 0, 2.5, 5.0, and 7.5 t ha -1 on the main plots, and three treatments with vegetable covering were applied on the subplots: (i) without covering, (ii) with covering of corn straw, and (iii) with covering of corn straw and black oat residue (oat-corn-oat). After 30 months, surface-applied lime increased soil pH and the exchangeable calcium (Ca 2+) and magnesium (Mg 2+) levels down to a 10-cm depth, independent of the vegetable covering treatments. The black oat and corn residues on the soil surface increased the soil exchangeable K + level at the 5- to 10-cm depth. Liming increased leaf potassium (K) content and phosphorus (P) content in the soybean grain and reduced leaf zinc (Zn) content and manganese (Mn) content in the soybean leaf and grain. There was no effect of liming on soybean grain, oil, or protein yields, independent of the vegetable residues kept on the soil surface. The treatment with black oat covering and corn straw increased leaf N content, P content in the leaf and grain, and the contents of K, Mg, copper (Cu), and Zn in the soybean grain. It also increased soybean grain and protein yields. The corn straw left at the surface after harvesting was very important to the performance of the no-till soybean.
  • Authors:
    • Zardo Filho, R.
    • Pereira Filho, P.
    • Caires, E.
    • Feldhaus, I.
  • Source: Soil Use and Management
  • Volume: 24
  • Issue: 3
  • Year: 2008
  • Summary: A 3-year field trial examined in a long-term no-till system the effects of surface-applied lime and cover black oat ( Avena strigosa Schreb) residues on soil chemical attributes, root growth and grain yield of corn ( Zea mays L.) and soybean ( Glycine max L. Merrill) on a loamy, kaolinitic, thermic Typic Hapludox in Parana State, Brazil. The treatments consisted of dolomitic lime broadcast on the soil surface at 0 or 12 t/ha, with and without cover of black oat residues. Corn and soybeans were grown without rainfall limitation. Applying lime on the surface improved soil acidity and decreased aluminium (Al) toxicity to a 10-cm depth 1 year after application. Surface liming increased pH and the content of exchangeable Ca 2+ to a 20-cm depth, and decreased Al toxicity to a 40- to 60-cm depth, 3 years after application, indicating that the surface-applied lime moved deeper. Cover black oat residues did not favour the mobility of surface-applied lime to alleviate subsoil acidity and an increase in the Al 3+ saturation level at the soil surface was found in unlimed plots with black oat residues. Root growth and grain yields of corn and soybean were not influenced by surface liming with or without cover black oat residue. Despite the soil acidity level, root length of corn and soybean ranged from 55 to 60% at 0- to 10-cm depth. The results suggest that Al toxicity is low in no-till systems during cropping seasons with adequate and well-distributed rainfall, but this effect is not related to the presence of cover oat residues.
  • Authors:
    • Mbuya, O.
    • Chase, C.
  • Source: Weed Technology
  • Volume: 22
  • Issue: 2
  • Year: 2008
  • Summary: Twelve winter cover crops were planted in Citra and Live Oak, FL, in 2004, to evaluate their potential for use as living mulches in organic vegetable production: black oat, rye, annual ryegrass, hard fescue, two cultivars of white clover, berseem clover, crimson clover, subterranean clover, arrowleaf clover, barrel medic, and a hybrid disc * strand medic cultivar. The best canopy development and weed suppression occurred with black oat, rye, and annual ryegrass. In 2005, black oat, two rye cultivars, and annual ryegrass were evaluated as living mulches in broccoli at Citra and Live Oak, using organic production methods. 'Florida 401' (FL 401) rye was tallest, black oat was intermediate, and 'Wrens Abruzzi' (WA) rye and 'Gulf' ryegrass were of similar height and were the shortest living mulches. Biomass harvested at 12 and 13 wk after planting at Citra and Live Oak, respectively, was greatest with FL 401 rye. At Live Oak, the three other mulches had similar amounts of biomass; however, at Citra, black oat biomass was greater than that of WA rye, and biomass of ryegrass was lowest. The greatest weed infestation occurred with the weedy control. Weed biomass was highest with the weedy control, intermediate with ryegrass, and lowest with rye and black oat. However, the biomass of the weedy control was lower than that of the living mulches plus any associated weeds. Marketable broccoli yield was highest with the weed-free control. Yields with black oat, WA rye, and ryegrass were similar to that of the weedy control, whereas yield with the FL 401 rye was lower than with the weedy control. Suppression of living mulches by mowing at 3 and 7 wk after planting had no effect on broccoli growth or yield.
  • Authors:
    • Wolfe, M.
    • Boyd, H.
    • Haigh, Z.
    • Jones, H.
    • Clarke, S.
  • Source: Cultivating the future based on science. Volume 1: Organic Crop Production. Proceedings of the Second Scientific Conference of the International Society of Organic Agriculture Research (ISOFAR), held at the 16th IFOAM Organic World Conference in Cooperatio
  • Year: 2008
  • Summary: Two seasons (2005/06 and 2006/07) of field experiments which aimed to study the suitability of new and established husked oat varieties, variety mixtures and a husked oat population for organic systems were established at two sites in the west and east of the UK. The ground cover and leaf area indices of the varieties had significant effects on final yields in the 2005/06. Mixtures generally yielded similarly to the means of component varieties but the mixtures in 2005/06 and 2006/07 had 25% and 18% less disease, respectively, than the average of the component varieties at one site.
  • Authors:
    • Souza, J.
    • Finger, J.
    • Gobbi, F.
    • Vanin, J.
    • Fey, E.
    • Conti, C.
  • Source: Central theme, technology for all: sharing the knowledge for development. Proceedings of the International Conference of Agricultural Engineering, XXXVII Brazilian Congress of Agricultural Engineering, International Livestock Environment Symposium
  • Year: 2008
  • Summary: The cassava has great ability to adapt and better develop in deep soils without compaction and aeration well. To achieve these characteristics, this work was carried out by subjecting the culture to eight formats furrows and three separate roofs of soil under the tillage system. The work was conducted in a farm located in the district of Pearl Independent municipality of Maripa - Parana - Brazil, which has Latosol red eutrophic. The experiment went installed in randomized blocks with split plot, in the plots main the different furrow in the subplots the coverages. Effectuate up assessments of moisture, penetrometro of impact, breakup of soil in the furrow, depth of maniva and groove, population of plants, stalks per plant and percentage of plants fallings. The coverages of forage turnip and oats had higher humidity and lower resistance to penetration in the layer of up to 8.75 cm. For sulcadores are obtained different breakup of soil, influencing the depth of furrow and maniva. The coverage of oats presented grooves and manivas most deeper, lower breakup soil, providing conditions for less plants fallings.
  • Authors:
    • Lima, E. do V.
    • Moro, E.
    • Crusciol, C. A. C.
    • Andreotti, M.
  • Source: Bragantia
  • Volume: 67
  • Issue: 2
  • Year: 2008
  • Summary: The objective of this research work was to evaluate black oat decomposition and release of nutrients. The experiment was carried out during the 1998 cropping season in an experimental area located in Marechal Candido Rondon, Parana State, Brazil. A randomized block design with four replications was used. The cover crop was rolled over thirty days after emergence. The persistence and release of nutrients were evaluated at 0, 13, 35 and, 53 days after rolling and desiccation. The decomposition rate of oat residue was constant during this period (remaining 34% of the initial amount) and inversely proportional to the C:N ratio that showed an initial value of 34 and a final value of 50. Most K was released soon after oat management, remaining only 2% of the initial content in the last sampling time. N, P, Ca and S were gradually released, and in the last evaluation the remaining amount of these nutrients was 55, 42, 48, and 47% of the total accumulated amount, respectively. Compared to other plant nutrients, K followed by N were the nutrients available in higher amount in the soil, reaching maximum release speed between 10 and 20 days after rolling and dessication of black oat.