INFLUENCE OF VARIOUS HERBICIDES AND TWEEN 20 ON THE EFFECTIVENESS OF GLYPHOSATE

1980 ◽  
Vol 60 (3) ◽  
pp. 939-945 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN
Keyword(s):  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Initial Reduction ◽  
Annual Grasses ◽  
Excellent Control ◽  
High Degree

Glyphosate (N-phosphonomethyl glycine) at 0.21 kg/ha applied at the 4-leaf stage provided excellent control of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.), and rape (Brassica campestris L.). Tank mixtures of 0.21 kg/ha glyphosate with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba resulted in an initial reduction (antagonism) of glyphosate activity on the grass species at 5 days after treatment. At 34 days after treatment, the early differences had disappeared and grass kill was virtually complete with all treatments containing glyphosate. The early reduction in annual grass control with these mixtures was overcome in most cases by addition of Tween 20. Dicamba at 0.11 kg/ha, applied sequentially at various times in relation to glyphosate at 0.21 kg/ha, provided significantly increased early control of annual grasses over that obtained with glyphosate alone. Glyphosate combinations with bromoxynil/MCPA, bromoxynil, MCPA, 2,4-D, or dicamba were as effective or more effective for rape control than the various broad-leaved herbicides applied alone. Rape showed a high degree of tolerance to dicamba.

INFLUENCE OF SEVERAL HERBICIDES FOR BROAD-LEAVED WEED CONTROL AND TWEEN 20 ON THE PHYTOTOXICITY OF PARAQUAT

1982 ◽  
Vol 62 (2) ◽  
pp. 445-452 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN
Keyword(s):  
Weed Control ◽  
Avena Sativa ◽  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Excellent Control ◽  
Permanent Reduction

Paraquat at 0.28 kg/ha provided excellent control of barley (Hordeum vulgare L.), wheat (Triticum aestivum L.) and oats Avena sativa L.) when applied at the four-leaf stage of growth. Applications of paraquat in tank mixtures with ester formulations of 2,4-D, MCPA, bromoxynil or bromoxynil/MCPA did not affect paraquat activity on the grasses. Tank mixtures of paraquat with dimethylamine formulations of 2,4-D and MCPA resulted in a permanent reduction of paraquat activity on the annual grass species. Sequential applications of 2,4-D amine or MCPA amine in relation to paraquat did not reduce paraquat activity on the annual grass species. Control of rapeseed (Brassica campestris L.) with 0.28 kg/ha paraquat was not acceptable and was variable. However, excellent control of rapeseed was obtained when one of several herbicides for broad-leaved weed control were combined with paraquat.

INFLUENCE OF STAGE OF APPLICATION OF GLYPHOSATE AND PARAQUAT WITH AND WITHOUT TWEEN 20 ON THE CONTROL OF ANNUAL GRASS SPECIES

1983 ◽  
Vol 63 (4) ◽  
pp. 1039-1046 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
J. T. O’DONOVAN ◽  
G. M. WEISS
Keyword(s):  
Triticum Aestivum L ◽  
Confidence Bands ◽  
Acceptable Level ◽  
Grass Species ◽  
Tween 20 ◽  
Annual Grass ◽  
Hordeum Vulgare L ◽  
Sorbitan Monolaurate ◽  
Leaf Stage ◽  
Wild Oats

Experiments were conducted in the field at Lacombe in 1980 and 1981 to determine the influence of leaf stage at application (one to six-leaf) on the effectiveness of glyphosate at 0.21 kg/ha and paraquat at 0.28 kg/ha with or without Tween 20 polyoxyethylene (20) sorbitan monolaurate (Tween is a trademark of ICI Amercas Inc.) for control of three annual grass species. Visual estimates of percent control were taken 3 wk after the last herbicide application. Curvilinear regression analysis of the data using linear plus quadratic effects produced a significant fit (P < 0.01) for determining percent control for a given leaf stage. Ninety percent control was selected as the minimum acceptable level, and the most restrictive leaf stage of application ranges to achieve this level of control over both years were determined. For glyphosate the ranges were 1 to >6-leaf for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) and 3 to >6-leaf for wild oats (Avena fatua L.). For glyphosate plus Tween 20, the ranges were 1 to >6-leaf for barley and wheat and 2 to >6-leaf for wild oats. For paraquat, the leaf stage ranges were 2 to 4.5-leaf for barley and wheat, and 2 to 5-leaf for oats (Avena sativa L.). For paraquat plus Tween 20, the ranges for barley, wheat and oats were 2- to 5-leaf, 2- to 4.5-leaf and 1.5- to 4.5-leaf, respectively. The data are presented so that any acceptable level of control may be selected, confidence bands [Formula: see text] may be included and the leaf stage range to obtain the selected level of control may be determined.Key words: Glyphosate, paraquat, surfactant, leaf stage, zero tillage

RESPONSE OF VARIOUS BROAD-LEAVED WEEDS, AND TOLERANCE OF CEREALS, TO SOIL AND FOLIAR APPLICATIONS OF DPX-4189

1982 ◽  
Vol 62 (3) ◽  
pp. 715-724 ◽  
Author(s):  
P. A. O’SULLIVAN
Keyword(s):  
Soil Surface ◽  
Triticum Aestivum L ◽  
Herbicidal Activity ◽  
Weed Species ◽  
Canada Thistle ◽  
Fagopyrum Tataricum ◽  
Hordeum Vulgare L ◽  
Loam Soil ◽  
Excellent Control ◽  
And Control

DPX-4189 (2-chloro-N-[4-methoxy-6-methyl-1,3,5-triazin-2-yl) amino-carbonyl]-benzenesulfonamide), applied at relatively low rates to the soil (40–200 g/ha) or foliage (1–100 g/ha), generally provided excellent control of a variety of broad-leaved weeds, but poor control of green foxtail (Setaria viridis (L.) Beauv.). Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) showed excellent tolerence. At equivalent dosages, foliar applications were more effective than soil applications in the year of application. With foliar applications, herbicidal activity on a variety of annual broad-leaved weed species was reduced with application at later (four to eight) versus earlier (two to four) leaf stages. Preplant incorporated (PPI) treatments were more effective for control of Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) than soil surface (PE) or preemergence incorporated (PEI) treatments. DPX-4189 provided weed control 8 mo after application at 20 g/ha in the greenhouse and 12 mo after application at 40 g/ha in the field. Canada thistle (Cirsium arvense (L.) Scop.) topgrowth control during the year of application, and control of regrowth 1 yr after application of DPX-4189 at 50 g/ha under field conditions was excellent. DPX-4189 may be transported from the leaves to the roots of Canada thistle, but soil residue carryover is probably more important for control during the second year. DPX-4189 was readily leached in a silt-loam soil.

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.

PROPANIL FOR CONTROL OF GREEN FOXTAIL IN WHEAT AND BARLEY

1980 ◽  
Vol 60 (1) ◽  
pp. 177-184 ◽  
Author(s):  
JAMES H. HUNTER
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Growth Period ◽  
Triticum Aestivum L ◽  
Setaria Viridis ◽  
Wheat Grain ◽  
Hordeum Vulgare L ◽  
Crop Tolerance ◽  
Green Foxtail ◽  
Excellent Control

In a series of field and greenhouse experiments, propanil (3′, 4′-dichloropropionalide) as a postemergent herbicide provided excellent control of green foxtail (Setaria viridis (L.) Beauv.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). Although some initial chlorosis occurred, wheat and barley recovered quickly and were considered tolerant to propanil at up to 1 kg/ha applied over a growth period extending from the 2- to 8-leaf stages of the green foxtail. Propanil at rates greater than 1 kg/ha resulted in considerable chlorosis and leaf tip burn, and although grain yields were not reduced, crop tolerance was visually assessed as unsatisfactory. Control of green foxtail was satisfactory with 1 kg/ha at the 2- to 4-leaf stages but not at later stages. Control was significantly better when the spray pressure at application was 310 kPa compared to 207 kPa. Analysis indicated that at the 2 and 4 kg/ha rate of propanil the residues in wheat and barley disappeared very quickly. At harvest, wheat grain contained 0.09 ppm of propanil.

scholarly journals Invasive Grasses Increase Nitrogen Availability in California Grassland Soils

2010 ◽  
Vol 3 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Sophie S. Parker ◽  
Joshua P. Schimel
Keyword(s):  
Nitrogen Availability ◽  
Perennial Grass ◽  
N Cycling ◽  
Rooting Depth ◽  
Grass Species ◽  
Annual Grass ◽  
Annual Grasses ◽  
California Grassland ◽  
Pool Sizes ◽  
Native Perennial Grass

AbstractAs Europeans colonized California, they introduced annual grasses from the Mediterranean Basin. These exotic annual grasses eventually invaded grasslands throughout the state, some of which were once dominated by native perennial grass species. Annual grasses differ from perennials in their phenology, longevity, rooting depth, litter chemistry, and interaction with the microbial community. As these traits may influence plant nitrogen (N) use, it is likely that the invasion by annual species resulted in changes in the availability and cycling of N in California grassland systems. We addressed the question of how invasive annual grasses influence rates of N cycling by measuring N pool sizes and rates of net and gross mineralization and nitrification, gross immobilization, and the denitrification potential of soils from experimentally planted annual and perennial-dominated grasslands. With an increase in annual grass cover, we saw increases in ammonium (NH4+) pool sizes and rates of N mineralization, nitrification, and denitrification in soils. These differences in N status suggest that N cycling in California grasslands was altered at sites where native perennial bunchgrasses were invaded by nonnative annual grasses. One consequence of annual grass invasion may be a legacy of NH4+-enriched soils that hinder the reestablishment of native perennial grass species.

ANNUAL WEED CONTROL WITH PARAQUAT IN COMBINATION WITH OTHER HERBICIDES

1986 ◽  
Vol 66 (1) ◽  
pp. 153-160 ◽  
Author(s):  
J. T. O’DONOVAN ◽  
P. A. O’SULLIVAN
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Weed Control ◽  
Avena Sativa ◽  
Brassica Campestris ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Zero Tillage ◽  
Hordeum Vulgare L ◽  
Key Words Wheat

Paraquat at 0.28 kg/ha effectively controlled barley (Hordeum vulgare L. ’Galt’), wheat (Triticum aestivum L. ’Neepawa’) and oat (Avena sativa L. ’Random’) in field trials conducted during 1982 and 1983. Grass control was excellent with paraquat and its activity was unaffected when it was applied in combination with either clopyralid, picloram, metribuzin, linuron, or chlorsulfuron. Slight reductions in paraquat phytotoxicity occurred in some instances when paraquat was applied in combination with commercially formulated mixtured of clopyralid plus 2,4-D, clopyralid plus MCPA or picloram plus 2,4-D, but grass control was still acceptable (90% or greater). However, a commercially formulated mixture of cyanazine plus MCPA consistently reduced the phytotoxicity of paraquat and rendered grass control unacceptable. Control of rapeseed (Brassica campestris L. ’Candle’) with paraquat and most paraquat mixtures was excellent in 1982 but was poor and variable in 1983.Key words: Wheat, barley, oat, rapeseed, zero tillage, chemical summerfallow

Preemergence Herbicides Followed by Trifloxysulfuron Postemergence in Cotton

2007 ◽  
Vol 21 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Robert J. Richardson ◽  
Henry P. Wilson ◽  
Thomas E. Hines
Keyword(s):  
Weed Control ◽  
Field Studies ◽  
Grass Species ◽  
Annual Grass ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Pitted Morningglory ◽  
Annual Grasses ◽  
Preemergence Herbicides ◽  
Smooth Pigweed

Field studies were conducted in 1999, 2000, and 2001 to evaluate weed control and cotton response from PRE herbicides followed by (fb) trifloxysulfuron POST. In the first study, trifloxysulfuron at 3.8, 7.5, or 15 gai/ha was applied POST with or without pendimethalin at 690 gai/ha applied PRE in a factorial treatment arrangement. Visible crop injury occurred after all trifloxysulfuron applications, but injury was not affected by application of pendimethalin PRE. Cotton injury was 19 to 22% 7 d after POST treatment (DAT) from trifloxysulfuron at 3.8 to 15 g/ha but was 5 to 12% 28 DAT. Trifloxysulfuron controlled smooth pigweed, common ragweed, and common cocklebur, but spurred anoda, large crabgrass, goosegrass, and stinkgrass were not controlled by trifloxysulfuron. Morningglory species (tall morningglory, ivyleaf morningglory, and pitted morningglory) control with trifloxysulfuron at 7.5 and 15 g/ha was at least 79%, whereas velvetleaf was controlled 66% over all years. In a second study, clomazone, pendimethalin, pendimethalin plus fluometuron, pyrithiobac, or flumioxazin were applied PRE fb 7.5 g/ha trifloxysulfuron POST. Cotton injury from PRE herbicides fb trifloxysulfuron was 13 to 39% 7 DAT. Spurred anoda control exceeded 54% only with treatments that included flumioxazin or pyrithiobac PRE. Common lambsquarters, common cocklebur, and morningglory species were controlled at least 75% with all treatments that included trifloxysulfuron POST, whereas pendimethalin and clomazone usually controlled annual grasses. In both studies, the application of pendimethalin PRE controlled annual grass species and improved control of smooth pigweed and common lambsquarters over that controlled by trifloxysulfuron POST without a PRE herbicide.

Effects of management on soil fertility under pasture. 1. Influence of experimental grazing and fertilizer systems on growth, composition and nutrient status of the pasture

1974 ◽  
Vol 14 (69) ◽  
pp. 470 ◽  
Author(s):  
JR Simpson ◽  
SM Bromfield ◽  
GT McKinney
Keyword(s):  
Nitrogen Availability ◽  
Subterranean Clover ◽  
Nutrient Status ◽  
Grazing Pressure ◽  
Grass Species ◽  
Botanical Composition ◽  
Annual Grass ◽  
Growth And Nutrition ◽  
Animal Excreta ◽  
Annual Grasses

Pasture plots containing phalaris, subterranean clover and annual grass species were fertilized annually at suboptimal (P1), adequate (P2) or a 'luxury' rate (P3) of superphosphate. A fourth treatment combined rate P3 with fertilizer nitrogen (P3N). Each pasture was grazed during five years at a high (H) or a low (L) grazing pressure in such a way that there was little feed left on the H plots and a large amount on the L plots at the end of summer. In this way eight pasture situations were created which differed in botanical composition, nutrient availability, herbage production and the amount of nutrients returned as animal excreta. The plots were used to investigate the effects of fertilizer input and grazing pressure on the growth and nutrition of the different pasture components. Protected microplots during the fourth and fifth years showed that the P1 plots remained responsive to phosphate. The yields of annual grasses on the microplots were increased by H treatment but the proportion of phalaris to annual grasses was reduced, particularly at P1. Clover yields and total pasture yields were affected by previous grazing pressure only in the drier fourth year. At high levels of superphosphate and grazing (P3H), the greater grass-clover ratio and higher grass nitrogen uptake indicated greater nitrogen availability in this treatment.

The effect of time and rate of N application on the yield and N uptake of wheat, barley, flax and four cultivars of rapeseed

1991 ◽  
Vol 71 (2) ◽  
pp. 227-238 ◽  
Author(s):  
W. F. Nuttall ◽  
S. S. Malhi
Keyword(s):  
Field Experiments ◽  
Brassica Campestris ◽  
N Uptake ◽  
Triticum Aestivum L ◽  
Yield Response ◽  
Hordeum Vulgare L ◽  
Brassica Napus L ◽  
N Application ◽  
Linum Usitatissimum L ◽  
Nitrate Fertilizer

Field experiments were conducted for 3 yr on a Black Chernozemic soil at Melfort in northeastern Saskatchewan to determine the yield response and N uptake of seven crop/cultivars to autumn and spring applied N. The crop/cultivars were, rapeseed (Brassica napus L. 'Midas' and 'Target'; Brassica campestris L. 'Torch' and 'Echo'); wheat (Triticum aestivum L. 'Manitou'); barley (Hordeum vulgare L. 'Conquest') and flax (Linum usitatissimum L. 'Noralta') (main plots). Ammonium nitrate fertilizer treatments consisted of three rates of autumn broadcast N, 0, 34 and 67 kg N ha−1 (subplots), combined with N at 0, 11, 22, 45, 67 and 134 kg N ha−1 side-banded with seed in the spring (subsubplots). At the 67 kg N ha−1 rate, autumn application was inferior to spring application in increasing grain yield and N uptake for three of the seven crops (Torch and Echo rapeseed and Manitou wheat). Nitrogen fertilizer applied at 134 kg N ha−1 in spring produced grain yields that were not significantly higher than the split application of 67 kg N ha−1 applied in autumn and 67 kg N ha−1 applied in spring. All crops responded to spring applied N and continued to increase in yield up to the high rates of 67 or 134 kg N ha−1. Key words: Time of N application, N, crops, cultivars

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