RE-EVALUATION OF TCA FOR GREEN FOXTAIL CONTROL IN RELATION TO SEED YIELD AND OIL QUALITY OF FLAX

1977 ◽  
Vol 57 (3) ◽  
pp. 969-976
Author(s):  
P. N. P. CHOW ◽  
D. G. DORRELL
Keyword(s):  
Seed Yield ◽  
Chenopodium Album ◽  
Oil Quality ◽  
Good Control ◽  
Amaranthus Retroflexus ◽  
Oil Composition ◽  
Linum Usitatissimum L ◽  
Green Foxtail ◽  
Increase Protein Content ◽  
Lamb’S Quarters

The role of TCA (trichloroacetic acid) in green foxtail (Setaria viridis (L.) Beauv.) control and its effect on seed yield and oil composition of flax (Linum usitatissimum L.) cvs. Noralta, Raja, and Redwood were re-assessed under various weedy conditions from 1972 to 1975. When a mixture of weeds was present, TCA at 2.24 kg/ha controlled green foxtail but failed to control lamb’s-quarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.). However, TCA mixtures which included one or two broad-leaf herbicides gave good control of all weeds and a 40% increase in yield over the untreated check. Under natural infestation conditions where green foxtail was light but the predominant weed, TCA at 2.24–4.48 kg/ha gave partial weed control but did not increase the seed yield of flax. Cultivation consistently produced the highest yields and TCA alone generally produced the lowest yields. While the lower yields experienced with TCA were partially offset by cultivating before or after the application of TCA, in no cases were the yields from these combined treatments ever equal to that of cultivation alone. Plants treated with 3.36 and 4.48 kg/ha of TCA in the greenhouse showed leaf injury and a significant reduction in top weight. It is suggested that this type of injury is one of the factors contributing to the failure of TCA to significantly increase the yield of flax following suppression of green foxtail growth. TCA tended to increase protein content but has little effect on oil content, fatty acid composition, or iodine number.

Floristic composition and relative abundance of weeds in annual crops of Manitoba

1991 ◽  
Vol 71 (3) ◽  
pp. 831-839 ◽  
Author(s):  
A. G. Thomas
Keyword(s):  
Relative Abundance ◽  
Chenopodium Album ◽  
Floristic Composition ◽  
Sampling Procedure ◽  
Amaranthus Retroflexus ◽  
Wild Buckwheat ◽  
Wild Oats ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Lamb’S Quarters

Annual surveys for weeds of fields seeded to spring wheat, barley, oats, flax, and canola in Manitoba were conducted during 1978, 1979, and 1981. Fields were surveyed during July and early August each year using a stratified random sampling procedure. Data for the crops and years were combined for analysis. The frequency, the area infested, and the density of the infestation were determined for each species. These three measures of the abundance of the weed were combined into a single synthetic value called relative abundance. Nine of the 152 species recorded by the surveyors accounted for 77% of the total relative abundance. Ranked in order by relative abundance, these species were green foxtail (Setaria viridis (L.) Beauv.), wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), annual smartweed (Polygonum spp.), Canada thistle (Cirsium arvense (L.) Scop.), lamb's-quarters (Chenopodium album L.), wild mustard (Sinapis arvensis L.), perennial sow-thistle (Sonchus arvensis L.), and redroot pigweed (Amaranthus retroflexus L.). Green foxtail was the predominant weed with an abundance value three times larger than wild oats or wild buckwheat. The pattern of dominance found in Manitoba fields was similar to results from comparable surveys in Saskatchewan and North Dakota. Key words: Relative abundance, weed survey, weed density, green foxtail, wild oats, wild buckwheat

Flax (Linum usitatissimum L.) responses to chilling and heat stress on flowering and seed yield

1997 ◽  
Vol 77 (1) ◽  
pp. 97-99 ◽  
Author(s):  
L. V. Gusta ◽  
B. J. O'Connor ◽  
R. S. Bhatty
Keyword(s):  
Heat Stress ◽  
Seed Yield ◽  
Linum Usitatissimum ◽  
Oil Quality ◽  
Oil Composition ◽  
Flowering Stage ◽  
Linum Usitatissimum L ◽  
Flower Yield ◽  
Delayed Flowering ◽  
Chilling Treatment

The effect of a 5 °C chilling treatment at the seedling stage on days to flower, yield and oil quality and quantity was determined for seven cultivars of flax (Linum usitatissimum L.). Three days of chilling delayed flowering in Dufferin, McGregor and NorLin, whereas 5 d of chilling delayed flowering in all cultivars except Andro and Noralta. Seven days of chilling reduced the seed yield of only McGregor, Norlin, NorMan and Vimy. The effect of a 40 °C heat stress at the flowering stage on yield and oil composition was determined for the same seven cultivars. A heat stress of 40 °C for 3 d reduced the seed yield of NorMan, whereas, a 5 d stress reduced the seed yield of all cultivars except McGregor and Noralta. The composition of the oil was not affected by the heat stress. These results suggest genetic variability exists among flax cultivars for tolerance to chilling and heat stresses. Controlled tests can be used to select superior stress tolerant genotypes. Key words: Flax, chilling, heat, flowering, yield

scholarly journals Combined effects of pesticides on weedines and seed yield of soybean crops

2020 ◽  
pp. 41-44
Author(s):  
R. Hutianskyi
Keyword(s):  
Weed Control ◽  
Seed Yield ◽  
Chenopodium Album ◽  
Soybean Seed ◽  
Amaranthus Retroflexus ◽  
Forest Steppe ◽  
Wet Weight ◽  
Soybean Plants ◽  
Lamb’S Quarters ◽  
Sowing Seed

Goal. of my study was to investigate the combined effect of pesticides, including seed dressers, post-emergence herbicides, fungicides, biologicals, and plant growth regulators on weediness and soybean yield in the Eastern Forest-Steppe of Ukraine. Methods. Field, analytical and statistical. Results. The weeds in the soybean crops were represented by 15 species. Cockspur (Echinochloa crusgalli (L.) Roem et Schult.), yellow foxtail (Setaria glaua (L.) Beauv.), lamb’s quarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.) dominated in the soybean crops. In the controls, the dominant position in the soybean crops (in terms of the wet weight of weeds) was occupied by biennial and annual dicotyledonous weeds (56—57% of the total wet weight of weeds). Annual gramineous weeds (37—42%) and perennial dicotyledonous weeds (2—6%) ranked the second and third most spread species. Pre-sowing treatment of seeds increased the competitiveness of soybean plants against weeds. Herbicide composition Tabezon (2.0 l/ ha) + Formula (6 g/ ha) + surfactant Trend 90 (0.2 l/ ha) (primordial leaves) + Lemur (1.5 l/ ha) (biternate/ triternate leaves) significantly reduced the total number of weeds in the soybean crops by 89% and their wet weight by 97%. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical or biological pesticides on the effectiveness of weed control in the soybean crops. Analyzing the soybean seed yield, I revealed that application of herbicides alone in the crops was the most justified. Conclusions. Increased competitiveness of soybean plants against weeds on pre-sowing seed treatment has been demonstrated. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical and biological pesticides on the weed control effectiveness. Monoapplication of herbicides was the most justified.

scholarly journals Differential susceptibility of agricultural weeds to ultraviolet-B radiation

2002 ◽  
Vol 82 (4) ◽  
pp. 789-796 ◽  
Author(s):  
N. H. Furness ◽  
M. K. Upadhyaya
Keyword(s):  
Leaf Area ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Ultraviolet B ◽  
Setaria Viridis ◽  
Stellaria Media ◽  
Redroot Pigweed ◽  
Green Foxtail ◽  
Lamb’S Quarters ◽  
Polygonum Persicaria

Differential morphological sensitivity of weed species to ultraviolet-B (UV-B) radiation (290–320 nm) may alter competitive relationships among weeds and associated crop species as the level of this radiation changes. In order to determine relative sensitivity of common chickweed [Stellaria media (L.) Vill.], green foxtail (Setaria viridis L.), lady's-thumb (Polygonum persicaria L.), lamb's-quarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), and shepherd's-purse (Capsella bursa-pastoris L.) to this radiation, seedlings were grown under 0, 7, and 11 kJ m-2 d-1 of biologically effective UV-B radiation in a greenhouse for 6 wk. The influence of UV-B radiation on seedling growth and morphology was investigated. UV-B radiation reduced shoot height in green foxtail (by up to 41%), lamb's-quarters, and redroot pigweed, and increased tillering in green foxtail seedlings. Leaf area and leaf biomass in common chickweed, green foxtail, lamb's-quarters, and shepherd's-purse, and stalk biomass in common chickweed, green foxtail, lamb's-quarters, redroot pigweed and shepherd's-purse declined in response to UV-B radiation. In common chickweed, leaf area was reduced by 74% at 11 kJ m-2 d-1. Root biomass was reduced by UV-B radiation in all species (up to 68% at 11 kJ m-2 d-1 in common chickweed) except lady's-thumb. Specific leaf weight increased and leaf area ratio declined in response to UV-B radiation in common chickweed and shepherd's-purse. Exposure to UV-B radiation increased the leaf weight ratio in common chickweed. Shoot:root ratios increased in response to UV-B radiation in common chickweed and redroot pigweed. Scanning electron microscopy revealed collapsed epidermal cells in occasional necrotic regions on adaxial leaf surfaces of redroot pigweed grown under 11 kJ m-2 d-1 UV-B radiation. Morphology and growth of lady's-thumb were not affected by UV-B radiation. This study suggests that common agricultural weeds have differential morphological and growth responses to UV-B-enhanced environments. Sensitivity to UV-B radiation was greatest for common chickweed and least for lady's-thumb and redroot pigweed. Key words: ultraviolet-B, Amaranthus retroflexus, Capsella bursa-pastoris, Chenopodium album, Polygonum persicaria, Setaria viridis, Stellaria media

A COMPARISON OF MCP AND 2,4-D FOR THE CONTROL OF ANNUAL WEEDS IN GRAIN CROPS

1957 ◽  
Vol 37 (1) ◽  
pp. 69-83 ◽  
Author(s):  
H. A. Friesen ◽  
D. R. Walker
Keyword(s):  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Seedling Stage ◽  
Dichlorophenoxyacetic Acid ◽  
Growth Stages ◽  
Thlaspi Arvense ◽  
Wild Mustard ◽  
The Difference ◽  
Lamb’S Quarters ◽  
2,4 Dichlorophenoxyacetic Acid

Oats, flax and barley were sprayed with various formulations of MCP (2-methyl-4-chlorophenoxyacetic acid) and 2,4-D (2,4-dichlorophenoxyacetic acid) at a number of Experimental Farms in Western Canada in 1954 and 1955. Each formulation was applied at 4 and 8 ounces of acid equivalent per acre at each of two dates, viz., Date 1, when the weeds were in the seedling stage less than 3 inches in height; and Date 2, at a stage coinciding with the first appearance of buds on the major weed species.Stinkweed (Thlaspi arvense, L.), wild mustard (Brassica kaber (DC.) L.C. Wheeler var. pinnatifida (Stokes) L.C. Wheeler), lamb's quarters (Chenopodium album L.), Russian pigweed (Axyris amarantoides L.), and ball mustard (Neslia paniculata L.), were effectively controlled by each of the MCP and 2,4-D formulations used. Russian thistle (Salsola kali L.), and red-root pigweed (Amaranthus retroflexus L.), were not satisfactorily controlled by MCP, whereas hemp nettle (Galeopsis tetrahit L.) was not controlled by 2,4-D. Wild buckwheat (Polygonum convolvulus L.) was not controlled by any of the treatments. Each treatment was more effective when applied during the seedling stage of the weeds.On the basis of wood control and yield of grain the results of this study favour the use of MCP over 2,4-D with either oats or flax. Oats was significantly more tolerant to MCP, particularly if treated during the early growth stages when weed competition was most critical. With flax, the difference in tolerance was most pronounced in favour of MCP at the later date of treatment. The 2,4-D ester and low volatile ester resulted in a preponderance of plant deformities, lowered the yields of both oats and flax and delayed the maturity of flax significantly. Barley yields in this study were not adversely affected by any of the treatments.

scholarly journals AMINO ACID AND PROXIMATE ANALYSES OF WEED SEEDS

1977 ◽  
Vol 57 (1) ◽  
pp. 243-249 ◽  
Author(s):  
RUSSELL TKACHUK ◽  
V. JEAN MELLISH
Keyword(s):  
Amino Acid ◽  
Chenopodium Album ◽  
Essential Amino Acids ◽  
Amaranthus Retroflexus ◽  
Thlaspi Arvense ◽  
Wild Mustard ◽  
Acid Protein ◽  
Weed Seeds ◽  
Lamb’S Quarters ◽  
Amino Acid Balance

Weed seeds commonly found in Western Canadian cereals and oil seeds as dockage were examined for their amino acid, protein, oil and fiber contents. The weeds analyzed were Sinapis arvenis L.(wild mustard), Thlaspi arvense L. (stinkweed), Descurainia sophia (L.) Webb (flixweed), Polygonum convolvulus L. (wild buckwheat), Rumex pseudonatronatus L. (field dock), Avena fatua L. (wild oats), Setaria viridis (L.) Beauv. (green foxtail), Iva xanthifolia Nutt. (false ragweed), Chenopodium album L. (lamb’s-quarters), and Amaranthus retroflexus L. (redroot pigweed). Composite analysis showed that some of the weed seeds are high in protein and oil content. Amino acid analysis showed that many weeds have an excellent essential amino acid balance, and also a higher content of essential amino acids than do the commonly grown cereals. These results suggest that some weed seeds could be excellent sources of protein and oil for feed or food purposes.

A survey of the occurrence of seedling weeds in spring annual crops in Manitoba

1991 ◽  
Vol 71 (3) ◽  
pp. 811-820 ◽  
Author(s):  
A. G. Thomas ◽  
D. I. Donaghy
Keyword(s):  
Chenopodium Album ◽  
Abundant Species ◽  
Amaranthus Retroflexus ◽  
Canada Thistle ◽  
Perennial Weed ◽  
Wild Buckwheat ◽  
Annual Crops ◽  
Wild Oats ◽  
Wild Mustard ◽  
Green Foxtail

A floristic survey for weeds in spring annual crops throughout Manitoba from 1975 to 1978 indicated the occurrence of a total of 83 species in 654 fields. Field counts were done during June when the crop and weeds were in the seedling stage. In terms of total abundance, the 28 annual dicotyledonous weeds were found to be the most important group among the 50 species occurring in more than 1% of the fields. Wild buckwheat (Polygonum convolvulus L.), wild mustard (Sinapis arvensis L.), redroot pigweed (Amaranthus retroflexus L.), and lamb's-quarters (Chenopodium album L.) were the most widespread and abundant species in this group with mean densities from 9.6 to 16.2 plants m−2. The combined abundance of green foxtail (Setaria viridis L.), wild oats (Avena fatua L.), and barnyard grass (Echinochloa crusgalli (L.) Beauv.), the three major annual monocotyledonous weeds, was nearly equal to that of the annual dicotyledonous weed group. Green foxtail was the most abundant weed, occurring in 89% of the fields at mean densities of 270.5 plants m−2. Canada thistle (Cirsium arvense (L.) Scop.) and perennial sow-thistle (Sonchus arvensis L.) were the most abundant species in the biennial and perennial weed group and had mean densities of 4.4–4.8 plants m−2 in infested fields. Key words: Weed survey, green foxtail, wild oats, wild buckwheat, wild mustard, Canada thistle

BENAZOLIN FOR SELECTIVE WEED CONTROL IN WHEAT AND OILSEED CROPS

1971 ◽  
Vol 51 (5) ◽  
pp. 371-376 ◽  
Author(s):  
E. S. MOLBERG ◽  
M. A. ASHRAFF
Keyword(s):  
Crop Yields ◽  
Field Tests ◽  
Good Control ◽  
Triticum Aestivum L ◽  
Amaranthus Retroflexus ◽  
Visible Injury ◽  
Oilseed Crops ◽  
Linum Usitatissimum L ◽  
Wild Mustard ◽  
Growing Conditions

In field tests conducted between 1963 and 1969, wheat, Triticum aestivum L., flax, Linum usitatissimum L., Argentine rape, B. assica napus L., and Polish rape, B. campestris L., were tolerant to benazolin (4-chloro-2-oxo-3-benzothiazolineacetic acid). Wild mustard, Sinapia arvensis L., and redroot pigweed, Amaranthus retroflexus L., were controlled. Control of other weeds encountered in these tests was usually unsatisfactory. There was sufficient difference in tolerance of wild mustard and both species of rape to make selective control possible. In years when growing conditions were favorable, benazolin gave good control of wild mustard in rape at 0.56 kg/ha. When crop stands were poor due to dry, unfavorable weather a rate of 0.84 kg/ha was required. This sometimes caused light but visible injury to the rape, although crop yields were not significantly reduced. The selective properties of benazolin may make it possible to grow rape on land infested with wild mustard.

EFFECTS OF GREEN FOXTAIL AND LAMB’S-QUARTERS INTERFERENCE IN FIELD CORN

1980 ◽  
Vol 60 (4) ◽  
pp. 1419-1425 ◽  
Author(s):  
K. P. SIBUGA ◽  
J. D. BANDEEN
Keyword(s):  
Seed Size ◽  
Field Experiments ◽  
Chenopodium Album ◽  
Corn Yield ◽  
Setaria Viridis ◽  
Competitive Effects ◽  
Field Corn ◽  
Green Foxtail ◽  
Lamb’S Quarters

Field experiments were conducted to study the effects of full season interference of various densities of green foxtail (Setaria viridis (L) Beauv.) and lamb’s-quarters (Chenopodium album L.) on the yield of field corn. Green foxtail interference was studied at densities of 0, 29, 56, 89 and 129 plants/m2 in 1976 and 0, 20, 40, 62, 84 and 119 plants/m2 in 1977. Non-significant (P = 0.05) corn yield reductions were obtained at densities of 56 and 20 plants/m2 in 1976 and 1977, respectively. Increased green foxtail density reduced corn yields by 5.8–17.6% in 1976 and 5.6–16% in 1977. Lamb’s-quarters interference was tested at densities of 0, 46, 83, 112, 167 and 221 plants/m2 in 1976 and 0, 54, 109, 172, 208 and 277 plants/m2 in 1977. Corn yields were not reduced significantly at lamb’s-quarters densities of 46 and 109 plants/m2 in 1976 and 1977, respectively, compared to weed-free treatments. Yield reductions\ranged from 12.3–37.9% in 1976 and 6–58% in 1977. The competitive effects of green foxtail and lamb’s-quarters on corn yield differed mainly on the ability of the latter to reduce ear and seed size.

Eliminating soil disturbance reduces post-alfalfa summer annual weed populations

2001 ◽  
Vol 81 (4) ◽  
pp. 881-884 ◽  
Author(s):  
P. D. Ominski ◽  
M. H. Entz
Keyword(s):  
Cropping Systems ◽  
Chenopodium Album ◽  
Soil Disturbance ◽  
Amaranthus Retroflexus ◽  
Weed Ecology ◽  
Wild Mustard ◽  
No Till ◽  
Lamb’S Quarters ◽  
Time Of Year ◽  
Brassica Kaber

The influence of method (tillage vs. no-till) and time of year of alfalfa (Medicago sativa L.) termination on the population of naturally occurring weeds was assessed over three site-years in southern Manitoba. Termination method was found to be more important than timing. Populations of weeds such as green foxtail [Setaria viridis (L.) Beauv.], redroot pigweed (Amaranthus retroflexus L.), wild mustard [Brassica kaber (DC) L.C. Wheeler] and lamb’s quarters (Chenopodium album L.) were usually lower (P < 0.05) in the undisturbed (i.e., no-till) system, compared to where tillage was used. It was concluded that the combination of alfalfa in rotation and no-till management can provide significant weed control benefits to cropping systems. Key words: Weed ecology, no-till cropping, forages

Sign in / Sign up

Export Citation Format

Share Document