Control of annual grasses by spraytopping and the effect on triticale grain yield

1993 ◽  
Vol 44 (8) ◽  
pp. 1959 ◽  
Author(s):  
PM Dowling ◽  
HI Nicol
Keyword(s):  
Grain Yield ◽  
Seed Set ◽  
Application Rate ◽  
Wetting Agent ◽  
Annual Grass ◽  
Annual Grasses ◽  
Total Seed ◽  
Main Component ◽  
Grass Sward ◽  
Grass Weed

IA range of pre-season management treatments was imposed on a mixed annual grass sward in October 1987, prior to planting triticale into a cultivated and a direct-drilled seedbed in June 1988. The management treatments included three rates of glyphosate: Roundup� (110, 180, 360 g a.i./ha); two rates of paraquat: Gramoxone� (100, 200 g a.i. ha); and one rate of fluazifop-butyl: Fusilade� (53 g a.i./ha � Pulse� wetting agent). All treatments decreased potential grass regeneration, with V. bromozdes being the least affected. Improved control was achieved by increasing application rate, and by adding a wetting agent to fluazifop. Actual grass seedlings emerging within the crop followed a similar pattern to potential grass regeneration. Grass emergence, particularly of V. bromoides and L. rigidum, was always greater on the direct-drilled seedbed. Grain yield was greater on the prepared seedbed. On both seedbeds, yield was inversely related to grass DM 97 days after sowing (DAS) and grass weed seedling numbers 50 DAS. The effectiveness of the herbicides appeared to be related to maturity dates of the target species. The high potential seed-set of the annual grasses present (> 500 000/m2), of which V. bromozdes was the main component, highlights the difficulty of controlling such species. It is suggested that the large apparent decline from total seed-set to potential seedling numbers (14000/m2) resulted from the high stocking pressure by sheep over summer. For a number of annual grasses, a more rapid method for determining seed number based on seed weight and seedhead number is proposed, providing a more informed basis for decision making. We conclude that spraytopping to maximize yield of later sown direct-drilled crops (e.g. triticale) is essential, despite the difficulty in optimizing timing of spraytopping in mixed pasture swards.

Influence of preseason weed management and in-crop treatments in two successive wheat crops 1. Weed seedling numbers and wheat grain yield

1993 ◽  
Vol 33 (2) ◽  
pp. 167 ◽  
Author(s):  
PM Dowling ◽  
PTW Wong
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Seed Set ◽  
Seedling Emergence ◽  
Grass Species ◽  
Wheat Crop ◽  
Annual Grass ◽  
Wheat Grain ◽  
Heavy Grazing ◽  
Annual Grasses

The effect of 5 preseason management treatments on seed set reduction of annual weed grasses and their regeneration in the following autumn was evaluated in a 2-year field experiment commencing at Orange in spring 1986. Preseason (spring) treatments were paraquat, glyphosate (2 rates), unsprayed heavy grazing, and unsprayed control. In the first of 2 successive wheat crops (planted 1987), 3 in-crop weed control treatments [control, chlorsulfuron (both sod-seeded), and trifluralin plus cultivation] were imposed. In 1988, the second wheat crop was sown into a cultivated seedbed or direct-drilled. The preseason treatments reduced potential annual grass regeneration by 91-99% compared with the control, with heavy grazing being the best treatment. For each preseason treatment compared with the control, the pattern of actual seedling emergence within the crop during 1987 was similar to that of potential emergence for each grass species (except Lolium rigidum), but numbers were lower and more variable (7-86% of potential numbers). The proportion of Bromus spp. and Vulpia spp. emerging within the crop declined from the first to the second crop, while L. rigidum increased to an average of 93% of the annual grass population in 1988. Trifluralin plus cultivation increased the control of annual grasses in 1987. In 1988, the 1987 in-crop treatments had little carryover effect on annual grass control; however, wheat grain yield was increased by both chlorsulfuron and trifluralin. Preseason management reduced seed set of annual grass weeds, and this control was maintained under cropping for at least 2 years (except for L. rigidum). Wheat grain yield responded to this control. Long-term control of L. rigidum where soil is disturbed appears difficult because of apparent long-lived seed in the soil.

Effects of Imazapic on Target and Nontarget Vegetation during Revegetation

2007 ◽  
Vol 21 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
Roger L. Sheley ◽  
Michael F. Carpinelli ◽  
Kimberly J. Reever Morghan
Keyword(s):  
Prescribed Fire ◽  
Application Rate ◽  
Annual Grass ◽  
Herbicide Application ◽  
Burn Treatment ◽  
Application Rates ◽  
Nontarget Species ◽  
Annual Grasses ◽  
Winter Annual ◽  
Plot Design

Medusahead is an introduced, winter-annual grass covering millions of hectares of the semiarid West. It forms exclusive stands and has a dense thatch cover that resists the establishment of desirable species. Prescribed fire can remove medusahead litter and improve plant establishment. Medusahead control is fundamental to establishing desirable species that will, in turn, resist further invasion. Imazapic is an effective herbicide for control of medusahead, but more information is needed on its effects on desirable species. Our objectives were to test how imazapic application rate and timing affected medusahead, seeded desirable species, and other nontarget vegetation on burned and unburned rangeland in southeast Oregon. We burned existing medusahead infestations at two different sites in June 2003. Following the burn, imazapic was applied at rates of 0, 35, 70, 105, 140, 175, and 210 g ai/ha between July and October of 2003 in a randomized strip-plot design. In November 2003, monocultures of seven desirable species were drill-seeded across the imazapic treated areas. Data on cover and density of medusahead and seeded species were collected in 2004 and 2005. Cover data of nontarget species were collected in the summer of 2005. Medusahead cover was highest in control plots and lowest in plots that received the highest herbicide application rates. Medusahead cover was lower in burned plots. The effect of imazapic on nontarget vegetation was less clear. Seeded species established in the study plots, but their response to herbicide rate showed few consistent patterns; some of the seeded species showed little response to herbicide, whereas others appeared to establish best at different herbicide rates, depending on site and whether the plots were burned or unburned. Site and burn treatment also affected how imazapic rate or application month influenced cover of perennial or annual grasses or forbs.

Effect of pre-season management and in-crop herbicdes on weed seedling numbers and triticale grain yield

1988 ◽  
Vol 39 (5) ◽  
pp. 783 ◽  
Author(s):  
PM Dowling
Keyword(s):  
Crop Yield ◽  
Similar Pattern ◽  
Seed Set ◽  
Crop Yields ◽  
Sowing Time ◽  
Polygonum Aviculare ◽  
Herbicide Treatments ◽  
Annual Grasses ◽  
Grass Weed ◽  
Potential Level

Six pre-season treatments which aimed to reduce seed set of annual grasses were imposed at Orange, N.S.W., during spring 1985. Five in-crop treatments (cultivation plus trifluralin, trifluralin, oryzalin plus trifluralin, chlorsulfuron, nil - all direct-drilled) were superimposed over the pre-season treatments at sowing time. Triticale was sown 8 days after application of glyphosate (0.72 kg a.i. ha-1) in May 1986. All pre-season treatments reduced potential grass seedling numbers (89-94% reduction), with the grazing treatments being less effective then the herbicide treatments. Actual grass seedling numbers (those emerging within the crop) followed a similar pattern to potential seedling numbers, but at 10-20% of the potential level. Species not targeted for pre-season management (legume spp., Polygonum aviculare, Poa annua) tended to he present in larger numbers on those pre-season treatments where reduction of the topped grasses was greater. In-crop herbicides did not consistently reduce grass weed seedling numbers further. Grass weeds were more effectively controlled by the cultivation plus trifluralin treatment. Triticale crop yield was reduced as seedling numbers of topped grasses increased. In the direct-drilled situation, it was concluded that satisfactory crop yields will be obtained only after imposition of some form of pre-season management. For longer term grass control, these treatments would need to be imposed in at least two consecutive years.

Influence of Winter Wheat (Triticum aestivum) Cultivars on Weed Control in Sorghum (Sorghum bicolor)

Weed Science ◽  
1994 ◽  
Vol 42 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Gail A. Wicks ◽  
Paul T. Nordquist ◽  
Gordon E. Hanson ◽  
John W. Schmidt
Keyword(s):  
Winter Wheat ◽  
Grain Sorghum ◽  
Crop Rotations ◽  
Wheat Cultivars ◽  
Annual Grass ◽  
Weed Biomass ◽  
Annual Grasses ◽  
Winter Wheat Cultivars ◽  
Sorghum Grain ◽  
Grass Weed

Winter wheat cultivars that are competitive with weeds help control weeds in crop rotations. Ten winter wheat cultivars were evaluated for interference with summer annual grasses in the wheat and the subsequent grain sorghum crop in a winter wheat-ecofallow sorghum-fallow rotation in which there are two 10–mo fallow periods and two crops in 3 yr during 1983 to 1987. The medium–tall (100 to 109 cm tall) and medium–statured (90 to 99 cm tall) winter wheat cultivars (‘Buckskin’, ‘Siouxland’, ‘Lancota’, ‘Centurk 78’, and ‘Brule’) were more competitive than medium-short (80 to 89 cm tall) and short (68 to 79 cm tall) cultivars (‘Eagle’, ‘Homestead’, ‘Colt’, ‘Vona’, and ‘TAM 101’). Atrazine plus paraquat was applied to all cultivars 30 d after wheat harvest. When grain sorghum was planted in areas previously seeded with medium–tall and medium-statured winter wheat, summer annual grass weed biomass in sorghum was 61% less than in grain sorghum seeded into areas previously planted with medium-short and short wheat cultivars. Use of pendimethalin plus 2,4–D in winter wheat and glyphosate plus alachlor in grain sorghum eliminated differences in summer annual grass weed density and weed biomass among wheat cultivars. Sorghum grain yields were improved 7% when herbicides were used in the winter wheat and sorghum but value of the increase was less than cost of herbicides. Substituting less costly herbicides for herbicides used in this study still would not have been enough to pay for cost of herbicides for five cultivars. Grain sorghum grown on weed–free stubble of medium–tall and medium–statured winter wheat produced more grain than grain sorghum grown after medium–short and short-statured winter wheat by 5%. Volunteer wheat density during the fallow period following grain sorghum was lower in areas originally seeded to Centurk 78 and Siouxland wheat while volunteer wheat density was higher in areas planted to Homestead and Vona.

Interference of Three Annual Grasses with Grain Sorghum (Sorghum bicolor)

1990 ◽  
Vol 4 (2) ◽  
pp. 245-249 ◽  
Author(s):  
Brenda S. Smith ◽  
Don S. Murray ◽  
J. D. Green ◽  
Wan M. Wanyahaya ◽  
David L. Weeks
Keyword(s):  
Linear Regression ◽  
Grain Yield ◽  
Field Experiments ◽  
Grain Sorghum ◽  
Grass Species ◽  
Row Spacing ◽  
Yield Data ◽  
Weed Density ◽  
Annual Grasses ◽  
Wide Row Spacing

Barnyardgrass, large crabgrass, and Texas panicum were evaluated in field experiments over 3 yr to measure their duration of interference and density on grain sorghum yield. When grain yield data were converted to a percentage of the weed-free control, linear regression predicted a 3.6% yield loss for each week of weed interference regardless of year or grass species. Grain sorghum grown in a narrow (61-cm) row spacing was affected little by full-season interference; however, in wide (91-cm) rows, interference increased as grass density increased. Data from the wide-row spacing were described by linear regression following conversion of grain yield to percentages and weed density to log10. A separate nonlinear model also was derived which could predict the effect of weed density on grain sorghum yield.

Herbicides for Postemergence Control of Annual Grass Weeds in Seedling Forage Grasses

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 375-379 ◽  
Author(s):  
Thomas J. Peters ◽  
Russell S. Moomaw ◽  
Alex R. Martin
Keyword(s):  
Warm Season ◽  
Big Bluestem ◽  
Forage Grasses ◽  
Annual Grass ◽  
Cool Season ◽  
Intermediate Wheatgrass ◽  
Green Foxtail ◽  
Annual Grasses ◽  
Large Crabgrass ◽  
Warm Season Grasses

The control of three summer annual grass weeds with herbicides during establishment of forage grasses was studied near Concord and Mead, NE, in 1984, 1985, and 1986. Three cool-season forage grasses, intermediate wheatgrass, tall fescue, and smooth bromegrass, and two warm-season grasses, big bluestem and switchgrass, were included. The control of three major summer annual grasses, green foxtail, barnyardgrass, and large crabgrass, was excellent with fenoxaprop at 0.22 kg ai/ha. Slight to moderate injury to cool-season forage grasses and severe injury to warm-season grasses were evident. Sethoxydim at 0.22 kg ai/ha and haloxyfop at 0.11 kg ai/ha controlled green foxtail and large crabgrass, but not barnyardgrass. Sulfometuron-treated big bluestem and switchgrass plots had the best forage stand frequencies and yields and, at the rate used, sulfometuron satisfactorily controlled green foxtail but only marginally controlled barnyardgrass and large crabgrass.

Annual Grass Control in Alfalfa (Medicago sativa) with Postemergence Graminicides

1992 ◽  
Vol 6 (4) ◽  
pp. 938-948 ◽  
Author(s):  
Chester L. Foy ◽  
Harold L. Witt
Keyword(s):  
Medicago Sativa ◽  
Field Experiments ◽  
Annual Grass ◽  
Giant Foxtail ◽  
Herbicide Treatments ◽  
Highly Effective ◽  
Annual Grasses ◽  
Large Crabgrass

Field experiments were conducted during 1982 to 1988 in Virginia to evaluate BAS 517, CGA 82725, clethodim, cloproxydim, fenoxaprop, fluazifop, fluazifop-P, haloxyfop, paraquat, quizalofop, SC-1084, sethoxydim, sethoxydim plus thifensulfuron, and terbacil for control of annual grasses in alfalfa. Herbicides were applied to alfalfa and grasses 2 to 30 cm in height after the first and/or second cuttings. Overall, the herbicides were highly effective in controlling fall panicum, giant foxtail, barnyardgrass, and large crabgrass. Alfalfa yields were not increased with herbicide treatments in several experiments. Only paraquat, applied later than recommended after cutting in one experiment, and sethoxydim plus thifensulfuron at one location reduced alfalfa yields.

scholarly journals Genotype selection and addition of fertilizer increases grain yield in upland rice in Suriname

2017 ◽  
Vol 47 (3) ◽  
pp. 185-194 ◽  
Author(s):  
Adriano Stephan NASCENTE ◽  
Ruby KROMOCARDI
Keyword(s):  
Grain Yield ◽  
Management Practices ◽  
Upland Rice ◽  
Block Design ◽  
Field Trials ◽  
Application Rate ◽  
Rice Grain ◽  
Rice Varieties ◽  
Local Conditions ◽  
Randomized Block Design

ABSTRACT The upland rice farmers in Suriname use local varieties and low level technologies in the field. As a result, the upland rice grain yield is low, at about 1 000 kg ha-1. Our objective was to evaluate the use of upland rice cultivars from Suriname and Brazil, and the effect of nitrogen, N, phosphorus, P, and potassium, K, fertilizers on cultivation variables. We undertook four field trials in the Victoria Area, in the Brokopondo District, using a randomized block design each with four replications. The most productive rice varieties were BRS Esmeralda (grain yield 2 903 kg ha-1) and BRS Sertaneja (2 802 kg ha-1). The highest grain yield of 2 620 kg ha-1 was achieved with a top dressing application of 76.41 kg N ha-1 20 days after sowing. For P, the highest grain yield of 3 085 kg ha-1 was achieved with application of 98.06 kg ha-1 P2O5 applied at sowing. An application rate of 31.45 kg ha-1 of K2O at sowing achieved the highest grain yield of 2 952 kg ha-1. Together, these application rates of N, P and K resulted in rice grain yield of about 3 000 kg ha-1, which is three times greater than the national average for upland rice. We demonstrate that the use of improved rice varieties matched to the local conditions, and application of appropriate fertilizers, are management practices that can result in significant increases in rice grain yield in Suriname.

Effect of Spray Components on Glyphosate Toxicity to Annual Grasses

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Douglas D. Buhler ◽  
Orvin C. Burnside
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Plant Growth ◽  
Surfactant Concentration ◽  
Growth Stage ◽  
Annual Grass ◽  
Spray Solution ◽  
Annual Grasses ◽  
Small Grains ◽  
Carrier Volume

Field and greenhouse research was conducted during 1980 and 1981 to evaluate the effects of carrier volume, surfactant concentration, and treatment date on glyphosate [N- (phosphonomethyl)glycine] toxicity to annual-grass weeds and volunteer small grains. Glyphosate phytotoxicity increased as carrier volume was decreased from 190 to 24 L/ha. The presence of a surfactant in the spray solution did not influence grass control when glyphosate was applied in a carrier volume of 24 L/ha. When glyphosate was applied in 48 or 95 L/ha, the presence of surfactant resulted in better grass control than glyphosate without surfactant. When applied in 190 L/ha, glyphosate with 0.5% (v/v) surfactant gave better grass control than glyphosate alone or commercially formulated glyphosate. When glyphosate was applied to plants under water stress, little control was achieved regardless of plant growth stage. Glyphosate application to grass after head initiation also resulted in reduced control. Maximum weed control with glyphosate was attained when applications were made to seedlings growing actively because of adequate soil moisture and favorable temperatures.

Sign in / Sign up

Export Citation Format

Share Document