Interference of Common Lambsquarters (Chenopodium album) in Transplanted Tomato (Lycopersicon esculentum)

1988 ◽  
Vol 2 (4) ◽  
pp. 505-508 ◽  
Author(s):  
Prasanta C. Bhowmik ◽  
Krishna N. Reddy

Field studies were conducted in 1982 to 1984 to determine the effects of common lambsquarters on growth, yield, and nutrient concentration of transplanted tomato. Common lambsquarters densities ranged from 16 to 64 plants/m tomato row and fresh weight ranged from 26 360 kg/ha at 16 plants/m to 46 000 kg/ha at 64 plants/m row. Common lambsquarters did not affect tomato shoot dry weight at the vegetative stage but decreased the weight at the early fruit stage. Season-long interference of common lambsquarters reduced marketable tomato fruit number and also, marketable fruit weight ranging from 17% at 16 plants/m to 36% to 64 plants/m row. Concentrations of N in tomato leaves were unaltered at vegetative and flowering stages but decreased regardless of common lambsquarters density at early fruit and harvest stages. Weed density did not alter concentrations of P, K, and Ca in tomato leaves.

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 775-778 ◽  
Author(s):  
Prasanta C. Bhowmik ◽  
Krishna N. Reddy

Field studies were conducted to determine the effects of various barnyardgrass populations on growth, yield, and nutrient concentration of transplanted “Jetstar’ tomato. Barnyardgrass densities at 16, 32, and 64 plants/m tomato row were tested in 1982 and 1983. Barnyardgrass shoot fresh weights/unit area increased as density increased. Fresh weight of barnyardgrass shoots ranged from 17 100 kg/ha at 16 plants/m of row to 35 500 kg/ha at 64 plants/m of row. At the vegetative stage, tomato shoot dry weight was unaffected by barnyardgrass. As crop growth progressed, tomato shoot dry weight decreased at all barnyardgrass densities. Season-long interference of barnyardgrass reduced marketable tomato fruit number and fruit weight at all densities compared to weed-free plots. Reductions in marketable fruit weight ranged from 26% to 16 plants/m row to 84% at 64 plants/m row. In 1982, concentrations of N, P, K, Ca, and Mg in tomato shoots were unaffected by season-long interference of barnyardgrass at all densities. However, in 1983, concentrations of N and K decreased and concentration of P increased in tomato leaves as the density of barnyardgrass increased. Concentrations of Ca and Mg in tomato leaves were unaltered by barnyardgrass density.


1988 ◽  
Vol 68 (1) ◽  
pp. 267-276 ◽  
Author(s):  
JOSÉE CHARBONNEAU ◽  
ANDRÉ GOSSELIN ◽  
MARC-J. TRUDEL

Tomato plants (Lycopersicon esculentum Mill. ’Vendor’ and ’Carmelo’) were cultivated under different electric conductivities (2, 4 and 6 mS cm−1) of a continuously or intermittently supplied nutrient solution. The plants were grown in an NFT system, with or without supplementary lighting using high-pressure sodium (HPS) lamps. Raising electric conductivity reduced the shoot dry weight but increased root dry weight. The number of fruit on the first truss and the fruit weight were not affected significantly by electric conductivities. The use of supplementary lighting with an electric conductivity of 6 mS cm−1 increased the number of marketable fruit. High electric conductivity modified the mineral composition of leaf tissue mainly P, Ca and Mg. The vegetative growth was reduced and better yield was obtained with tomato plants grown under supplementary lighting and high electric conductivity.Key words: Tomato, supplementary lighting, nutrient solution, HPS, electric conductivity, salinity


Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 358-364 ◽  
Author(s):  
Teresa M. Crook ◽  
Karen A. Renner

Field studies were conducted in 1987 and 1988 to evaluate the control and competitiveness of common lambsquarters in soybeans when present at four densities and when removed at four time intervals. Common lambsquarters were removed by hand or treated with a postemergence herbicide application of bentazon plus acifluorfen. Common lambsquarters could remain 10 weeks following soybean emergence before a 20% soybean yield reduction occurred when weeds were removed by hand. When treatment was attempted with postemergence herbicides, a 20% yield reduction occurred in 1987 if application was not made prior to 5 weeks after emergence. In 1988, all postemergence herbicide applications failed to control lambsquarters due to drought conditions. The postemergence herbicide's degree of control was reflected in the number of remaining lambsquarters plants. Common lambsquarters seed production and germination was not influenced by postemergence herbicide application. There was a strong correlation between dry weight of uncontrolled common lambsquarters plants and seed produced per plant.


1997 ◽  
Vol 11 (2) ◽  
pp. 324-328 ◽  
Author(s):  
John A. Ackley ◽  
Henry P. Wilson ◽  
Thomas E. Hines

In field studies in 1991, 1992, and 1993, rimsulfuron at 26 and 35 g ai/ha, sequentially at 26 g/ha, at 26 g/ha plus metribuzin at 280 g ai/ha, and metribuzin at 280 g/ha were evaluated POST for weed control in transplanted ‘Agriset’ tomato. Common lambsquarters was controlled by rimsulfuron at 35 g/ha. Rimsulfuron plus metribuzin gave consistent control of common ragweed, but jimsonweed control was inconsistent and goosegrass control was generally low. Rimsulfuron treatments caused slight (< 12%) temporary injury to new terminal growth of tomato. Yield of tomato fruit was consistently high in the metribuzin, metribuzin plus rimsulfuron, and rimsulfuron sequential treatments. In greenhouse studies, giant foxtail and large crabgrass control by rimsulfuron was above 95 and 85%, respectively, but goosegrass was not controlled. Height of four tomato cultivars was not reduced, but dry weight of ‘Floradade’ and ‘Sunbeam’ was reduced by rimsulfuron.


2013 ◽  
Vol 27 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Paul V. Garvey ◽  
Stephen L. Meyers ◽  
David W. Monks ◽  
Harold D. Coble

Field studies were conducted in 1996, 1997, and 1998 at Clinton, NC, to determine the influence of Palmer amaranth establishment and removal periods on the yield and quality of plasticulture-grown ‘Mountain Spring' fresh market tomato. Treatments consisted of 14 Palmer amaranth establishment and removal periods. Half of the treatments were weed removal treatments (REM), in which Palmer amaranth was sowed at the time tomato transplanting and allowed to remain in the field for 0 (weed-free all season), 2, 3, 4, 6, 8, or 10 wk after transplanting (WAT). The second set of the treatments, weed establishment treatments (EST), consisted of sowing Palmer amaranth 0 (weedy all season), 2, 3, 4, 6, 8, or 10 WAT and allowing it to grow in competition with tomato the remainder of the season. Tomato shoot dry weight was reduced 23, 7, and 11 g plant−1for each week Palmer amaranth removal was delayed from 0 to 10 WAT in 1996, 1997, and 1998, respectively. Marketable tomato yield ranged from 87,000 to 41,000 kg ha−1for REM of 0 to 10 WAT and 28,000 to 88,000 kg ha−1for EST of 0 to 6 WAT. Percentage of jumbo, large, medium, and cull tomato yields ranged from 49 to 33%, 22 to 31%, 2 to 6%, and 9 to 11%, respectively, for REM of 0 to 10 WAT and 30 to 49%, 38 to 22%, 3 to 2%, and 12 to 9%, respectively, for EST of 0 to 6 WAT. To avoid losses of marketable tomato yield and percentage of jumbo tomato fruit yield, tomato plots must remain free of Palmer amaranth between 3 and 6 WAT. Observed reduction in marketable tomato yield was likely due to competition for light as Palmer amaranth plants exceeded the tomato plant canopy 6 WAT and remained taller than tomato plants for the remainder of the growing season.


Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. Kent Harrison

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.


Weed Science ◽  
1974 ◽  
Vol 22 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Robert N. Andersen ◽  
William E. Lueschen ◽  
Dennis D. Warnes ◽  
Wallace W. Nelson

In field studies, bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide] was applied as postemergence sprays over the top of weeds and soybeans[Glycine max(L.) Merr.]. Bentazon at 0.84 to 1.68 kg/ha applied as an early postemergence treatment controlled wild mustard[Brassica kaber(DC.) L.C. Wheeler var.pinnatifida(Stokes) L.C. Wheeler], common ragweed (Ambrosia artemisiifoliaL.), velvetleaf (Abutilon theophrastiMedic.), Pennsylvania smartweed, (Polygonum pensylvanicumL.), common cocklebur (Xanthium pensylvanicumWallr.), and wild common sunflower (Helianthus annuusL.). Pigweeds (Amaranthussp.) were controlled by applications in the three true-leaf stage but became more resistant at later stages. Control of common lambsquarters (Chenopodium albumL.) was erratic. The optimum time for controlling weeds with bentazon was around the first trifoliolate stage of soybeans. Rainfall within several hours after treatment reduced weed control. Eight yield studies, two of which included eight cultivars, were conducted on weed-free soybeans. In none were yields reduced significantly by bentazon at 3.36 kg/ha (the highest rate studied). Eight yield studies were conducted on soybeans infested with common cocklebur or velvetleaf. Weed control was generally excellent with 0.84 kg/ha of bentazon. Where infestations were sufficient to reduce yields, bentazon treatments increased the yields to levels generally comparable with those of the handweeded checks. One exception was an application of bentazon to soybeans growing in a low area that was periodically flooded by heavy rains. In that experiment the benefit of controlling common cocklebur was offset by bentazon injury to the soybeans, and yields from the treated plots were about the same as those of the weedy check.


1995 ◽  
Vol 9 (2) ◽  
pp. 352-355 ◽  
Author(s):  
Sharon A. Clay ◽  
Jim F. Gaffney ◽  
Leon J. Wrage

Trifluralin is used for weed control in wheat but may reduce vegetative growth and yield. Postemergence (POST) herbicides may cause additional plant stress to trifluralin-stressed wheat. Field studies at Groton, SD in 1991 and 1992 and at Highmore, SD in 1992 evaluated the effects of 2,4-D-amine, difenzoquat, metsulfuron, and a combination of fenoxaprop-ethyl + 2,4-D-ester + MCPA-ester on hard red spring wheat cultivars ‘2375,’ ‘Prospect,’ and ‘Butte 86’ seeded in areas treated with preplant incorporated trifluralin either in the spring before seeding (0.56 kg ai/ha) or the previous year (1.12 or 2.24 kg ai/ha). Trifluralin applied alone in the spring, and followed by some POST herbicides, reduced shoot dry weight and grain yield. Trifluralin reduced the yield of Prospect the most and the yield of 2375 the least. Yields of trifluralin-treated wheat were reduced 23% by metsulfuron and 14% by fenoxaprop-ethyl + 2,4-D + MCPA compared to yields of wheat treated with only the respective POST herbicide. Yields were not reduced with any trifluralin-POST herbicide combination when trifluralin was applied a year prior to seeding wheat.


2009 ◽  
Vol 44 (12) ◽  
pp. 1673-1681 ◽  
Author(s):  
Sebahattin Çürük ◽  
H. Yıldız Dasgan ◽  
Sedat Mansuroğlu ◽  
Şener Kurt ◽  
Meltem Mazmanoğlu ◽  
...  

The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw.) on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L.) cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis) is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala). Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.


Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 455-459 ◽  
Author(s):  
Richard D. Comes ◽  
Louis Y. Marquis ◽  
Allen D. Kelley

In field studies 0.1 ppmw ae or less 2,4-D [(2,4-dichlorophenoxy)acetic acid] applied by sprinklers in 5.1 cm of water over 8 h did not affect the number or dry weight of leaves or length of canes of 1-yr-old Concord grape plants (Vitis labruscaL.). A second application at 0.01 ppmw or higher to the same plants 1 yr later reduced growth of leaves, canes, and trunk. Combined effects of root pruning (required to position plants for treatment the second year) and 2,4-D probably account for this apparent anomaly. When 2,4-D was applied annually at 1.0 ppmw or less to established plants for three consecutive years, growth, yield, and fruit quality were not affected. No residues of 2,4-D were detected in the fruit at harvest (detection limit 0.05 ppmw). Grapes treated with 1.0 ppmw 2,4-D developed moderate injury symptoms.


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