Altai wild ryegrass yield response to herbicides applied during establishment

1991 ◽  
Vol 71 (1) ◽  
pp. 115-125 ◽  
Author(s):  
N. Malik

The effects on productivity of Altai wild ryegrass (Leymus angustus (Trin.) Pilger) of 14 herbicide treatments applied during establishment were investigated in two field experiments at Melfort, Saskatchewan. Weed control achieved with metsulfuron, chlorsulfuron, thifensulfuron and tank-mixed applications of bromoxynil with diclofop or fenoxaprop during the establishment year ensured satisfactory forage establishment which in turn caused a "residual effect" for 1–3 yr increasing individual cut as well as cummulative forage dry matter yields significantly. When established with a heavy broadleaf weed infestation (138 m−2) dominated by stinkweed (Thlaspi arvense L.) in 1985, bromoxynil plus diclofop increased yield 359% over a 3-yr period. Sulfonylurea herbicides increased yield 221–346%. Bentazon and MCPA/mecoprop/dicamba increased yields 85%. With a moderate weed infestation (40 m−2) dominated by lamb's-quarters (Chenopodium album L.) in 1986, sulfonylurea herbicides and bromoxynil plus the graminicides increased cummulative yields only 37–59%. Sethoxydim and fenoxaprop, tested alone, caused significant crop injury in both experiments. Key words: Altai wild ryegrass, Leymus angustus (Trin.) Pilger, herbicide, weed control, forage yield

1990 ◽  
Vol 4 (3) ◽  
pp. 598-605 ◽  
Author(s):  
Najib Malik

The effects of 14 herbicide treatments, tested in the establishment phase, were investigated on timothy productivity in two field experiments conducted at Melfort, Saskatchewan. Satisfactory weed control achieved with chlorsulfuron, metsulfuron, thifensulfuron, bentazon, diclofop plus bromoxynil, and MCPA/mecoprop/dicamba during the establishment year ensured good forage establishment which in turn caused a ‘residual effect’ for 1 to 3 yr increasing individual cut as well as cumulative forage dry matter yields significantly. In the stand established in 1985, when field pennycress (97 m-2) was the dominant weed in the seedling stage, these treatments increased yields 29 to 52% over a 3-yr period. In the stand established in 1986, when common lambsquarters (27 m-2) was the dominant weed, these treatments increased cumulative yields 24 to 44%. Sethoxydim and fenoxaprop, tested alone, caused significant crop injury in both experiments.


1990 ◽  
Vol 70 (4) ◽  
pp. 1215-1221 ◽  
Author(s):  
IRIS BITTERLICH ◽  
MAHESH K. UPADHYAYA

Field experiments were conducted in 1987 and 1988 to study the effect of lamb’s-quarters (Chenopodium album L.) interference on broccoli (Brassica oleracea L. var. botrytis ’Emperor’) growth and yield. Broccoli growth was initially affected by weed interference at 28–36 d after seeding. Generally, the negative effect of weed interference on broccoli growth increased with increasing weed density and time after seeding. Interference by 15 lamb’s-quarters plants m−2 reduced the biomass of broccoli plants by 71–73% compared to the weed-free control at 57–58 d after seeding. Weed density-crop yield relationship curves showed that one lamb’s-quarters plant m−2 decreased total yield by 18–20% and marketable yield by 22–37%. Lamb’s-quarters reduced the total yield per plot by decreasing the average head weight of broccoli. The number of heads per plot was not affected. Weed interference also reduced the weight of heads classified as marketable (> 10 cm across). However, in 1987 more heads failed to reach a marketable size which resulted in a much smaller marketable yield than in 1988.Key words: Brassica oleracea var. botrytis, broccoli, Chenopodium album L., weed density, weed interference, cole crop


2004 ◽  
Vol 52 (2) ◽  
pp. 199-203 ◽  
Author(s):  
G. Singh ◽  
R. S. Jolly

Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.


1957 ◽  
Vol 37 (1) ◽  
pp. 69-83 ◽  
Author(s):  
H. A. Friesen ◽  
D. R. Walker

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.


1977 ◽  
Vol 57 (1) ◽  
pp. 243-249 ◽  
Author(s):  
RUSSELL TKACHUK ◽  
V. JEAN MELLISH

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kelly A. Nelson ◽  
Peter P. Motavalli ◽  
William E. Stevens ◽  
John A. Kendig ◽  
David Dunn ◽  
...  

Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S), 0-0-25-17, 3-18-18-0, and 5-0-20-13) and additive rates (2.2, 8.8, and 17.6 kg K ha−1) on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1in a low-yield year (2005) depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K(P=0.03), S(P=0.03), B(P=0.0001), and Cu(P=0.008)concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.


1982 ◽  
Vol 62 (2) ◽  
pp. 607-616 ◽  
Author(s):  
S. P. ROSE ◽  
J. M. BELL

Three samples of defatted fine rapeseed screenings meals and defatted stinkweed (Thlaspi arvense) seed meal were used at 5 and 15% (wt/wt) to contaminate low glucosinolate rapeseed meal (LG-RSM). Defatted lamb's-quarters (Chenopodium album) and smartweed (Polygonum spp.) seed meals were also used, at levels of 1.7 and 5% (wt/wt) contamination. The contaminated LG-RSM was included at 15% (wt/wt) in diets fed to female adult mice during a 2-wk preliminary period, pregnancy, lactation and the first 18 days of the second pregnancy. There was a nonsignificant trend (P > 0.05) for the female mice fed stinkweed meal to have the lowest body weight throughout the two pregnancies, although those fed the six contaminants, and the uncontaminated LG-RSM control diet had an equivalent number of offspring born in the two pregnancies and surviving to weaning. Male offspring of mice fed the higher levels of contaminants tended to have a lower (P > 0.05) body weight during the early part of the lactation period. A decreased availability of protein and energy in these diets possibly resulted in decreased milk production. The numbers of blastocysts implanted, embryos resorbed, fetal deaths and malformed fetuses were similar among the dietary treatments. Key words: Rapeseed meal, weed seeds, glucosinolates, mice, reproduction


2016 ◽  
Vol 96 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Zhenyi Li ◽  
Rene Van Acker ◽  
Darren E. Robinson ◽  
Nader Soltani ◽  
Peter H. Sikkema

Six field experiments were conducted over a two-year period (2013 and 2014) to evaluate the tolerance of white bean and spectrum of weeds controlled with halosulfuron applied preplant incorporated (PPI) alone or tankmixed with trifluralin, pendimethalin, EPTC, dimethenamid-P, or S-metolachlor. Halosulfuron applied alone or in tankmix with trifluralin, pendimethalin, EPTC, dimethenamid-P, or S-metolachlor caused 2% or less visible injury 1 and 4 weeks after emergence (WAE). Halosulfuron applied PPI controlled common lamb's-quarters, wild mustard, redroot pigweed, and common ragweed greater than 90% and green foxtail less than 60% 4 and 8 WAE. Weed biomass and density followed a similar pattern. White bean yield with halosulfuron applied alone or in tankmix with the same herbicides was equivalent to the weed-free control.


2020 ◽  
pp. 41-44
Author(s):  
R. Hutianskyi

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.


HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1302-1304 ◽  
Author(s):  
Mathieu Ngouajio ◽  
Jeremy Ernest

Weed control is one of the benefits associated with the use of plastic mulches used for vegetable production. The mulches decrease light transmission and prevent development of most weed species. Plastics chemistry has developed films varying in their ability to reflect, absorb, and transmit light. Laboratory and field experiments were conducted to 1) measure light transmitted through colored mulches, 2) evaluate weed populations under each mulch type, and 3) determine if light transmission could be used as an indicator for weed populations in the field. The polyethylene mulches were black, gray, infrared transmitting brown (IRT-brown), IRT-green, white, and white-on-black (co-extruded white/black). On average, 1%, 2%, 17%, 26%, 42%, and 45% light in the 400 to 1100 nm range was transmitted through the black, white/black, gray, IRT-brown, IRT-green, and white mulches, respectively. In field experiments, density and dry biomass of weeds growing under the mulches were evaluated. The white mulch had the highest weed density with an average of 39.6 and 155.9 plants/m2 in 2001 and 2002, respectively. This was followed by the gray mulch, with 10.4 and 44.1 weed seedlings/m2 in 2001 and 2002, respectively. Weed density was <25 plants/m2 with the other mulches in both years. Weed infestation was correlated with average light transmission for white, black, white/black, and gray mulches. However, both light quantity and quality were necessary to predict weed infestations with the IRT mulches. Weed infestation under the IRT mulches was better estimated when only wave lengths in the photosynthetically active radiation range (PAR; 400 to 700 nm) were considered. Low weed pressure and high light transmission with the IRT mulches would make them appropriate for use in areas where both weed control and soil warming are important factors.


Sign in / Sign up

Export Citation Format

Share Document