scholarly journals Weed Interference Affects Dry Bean Yield and Growth

2012 ◽  
Vol 4 (3) ◽  
pp. 70-75 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.

2013 ◽  
Vol 5 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND

In production agriculture, weed plants play an important role in yield reduction. Analysis of crop growth can reveal underlying processes of yield loss under weed interference conditions. Therefore, an experiment was conducted in 2011 in order to assess the effect of weed competition on different aspects of dry bean growth. The experiment was a randomized complete block design with 3 replications. Treatments included weed-infested and weed-free periods until 0, 10, 20, 30, 40 and 50 days after crop emergence. Aboveground dry matter and leaf area were measured every two weeks. The functional approach to growth analysis was used to examine temporal patterns in crop growth in weed interference conditions. A negative relationship between weed biomass and dry bean growth indexes was observed. In all treatments, crop biomass had a similar trend and progressively increased over the crop cycle, then after reaching the maximum amount, gradually decreased. The lowest crop biomass (676.60 g m-2) was observed in season-long weed-infested treatment, while the maximum one (1238.82 g m-2) was recorded in season-long weed-free treatment. Relative growth rate (RGR) and net assimilation rate (NAR) had a declining trend during the growing season. Increase in weed-infested periods intensified decrease of them. Effect of weed competition on crop growth was trifle at the early of growing season. Since NAR and RGR represent photosynthesis potential and dry matter accumulation of the crop, their reduction can be the main cause of yield loss.


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


2013 ◽  
Vol 5 (1) ◽  
pp. 74-78
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND

Field study was carried out in 2011 in west of Iran to assess responses of dry bean (Phaseolus vulgaris L.) morpho-physiological traits to gradual weed biomass accumulation. The treatments consisted of two different periods of weed interference, which weeds either infested the plots or removed for an increasing duration of time (0, 10, 20, 30, 40, 50 days) after crop emergence. Relative dominance and relative importance of weed species fluctuated over the crop cycle. As the duration of weed interference was increased, a declining trend of crop growth rate (CGR) was observed. When weeds were allowed to compete with crop throughout the crop cycle, maximum value of CGR was decreased from 25.57 g m-2 days in full season weed free treatment to 16.78 g m-2 days in full season weed infested treatment. Effect of treatments on leaf area index (LAI) was significant. Weed removal increased LAI but it could not significantly affect this trait, at the early of growing season. Weed interference caused a significant reduction on number of branches. The minimum number of branches was registered in full season weed infested treatment (2.58 branches per plant), while the maximum one was observed in the full season weed free treatment (4.25 branches per plant). Weed competition severely reduced crop yield. At 10 and 20 days after crop emergence, weed infestation could not significantly affect the yield. A negative relationship between weeds’ dry matter accumulation and LAI as well as number of branches was observed which signify the vulnerability of these morpho-physiological traits to weed competition.


Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 7-10 ◽  
Author(s):  
R. B. Taylorson

AbstractGermination of seeds of 10 grass and 33 broadleaved weed species was examined for response to ethylene. Germination was promoted in nine species, inhibited in two, and not affected in the remainder. Of the species promoted, common purslane (Portulaca oleraceaL.), common lambsquarters (Chenopodium albumL.), and several Amaranths, including redroot pigweed (Amaranthus retroflexusL.), were affected most. Transformation of phytochrome to the active form (Pfr) gave interactions that ranged from none to syntergistic with the applied ethylene. In subsequent tests seeds of purslane, redroot pigweed, and giant foxtail (Setaria faberiHerrm.), a species not responsive to ethylene, were examined for germination response to 14 low molecular weight hydrocarbon gases other than ethylene. Some stimulation by the olefins propylene and propadiene was found for purslane and pigweed. Propionaldehyde and butyraldehyde were slightly stimulatory to purslane only.


Weed Science ◽  
1979 ◽  
Vol 27 (4) ◽  
pp. 401-415 ◽  
Author(s):  
Robert N. Andersen ◽  
Willard L. Koukkari

In growth chamber studies, we measured the movement of cotyledons and leaves or leaflets in seedlings of nine weed species to determine: the magnitude of movement, whether movements followed a rhythmic pattern, and if rhythmic movements were endogenously controlled. Seedlings were always entrained under a 15-h light:9-h dark regime. Measurements were made at 3-h intervals for 3 to 4 days under four light regimes: alternating 15-h light:9-h dark; continuous light; one 15-h light:9-h dark span, followed by continuous light; and a 15-h light:9-h dark regime, in which the dark span was advanced 9 h (phase shift) when measurements were begun. No clearly defined pattern of leaf movement was found in wild mustard [Brassica kaber(DC.) L. C. Wheeler var.pinnatifida(Stokes) L. C. Wheeler]. Daily rhythmic leaf movements that did not appear to be endogenously controlled were found in redroot pigweed (Amaranthus retroflexusL.) and black nightshade (Solanum nigrumL.). Circadian rhythmic leaf movements that appeared to be under endogenous control were found in jimson-weed (Datura stramoniumL.), common lambsquarters (Chenopodium albumL.), common cocklebur (Xanthium pensylvanicumWallr.), prickly sida (Sida spinosaL.), sicklepod (Cassia obtusifoliaL.), and coffee senna (Cassia occidentalisL.).


HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1492-1494 ◽  
Author(s):  
Darren E. Robinson ◽  
Kristen McNaughton ◽  
Nader Soltani

Pepper growers currently have limited access to many effective broadleaf herbicides. Field trials were conducted over a 3-year period in Ontario to study the effect of tank mixtures of sulfentrazone (100 or 200 g·ha−1 a.i.) with either s-metolachlor (1200 or 2400 g·ha−1 a.i.) or dimethenamid-p (750 or 1500 g·ha−1 a.i.) on transplanted bell pepper. Under weed-free conditions, there was no visual injury or reduction in plant height, fruit number, fruit size, or marketable yield of transplanted pepper with pretransplant applications of sulfentrazone applied in tank mixtures with s-metolachlor or dimethenamid-p. The tank mixture of sulfentrazone + s-metolachlor gave greater than 85% control of redroot pigweed (Amaranthus retroflexus) and eastern black nightshade (Solanum ptycanthum), but only 70% to 76% control of velvetleaf (Abutilon theophrasti), common ragweed (Ambrosia artemisiifolia), and common lambsquarters (Chenopodium album). The combination of sulfentrazone + dimethenamid-p provided good to excellent control of all weed species except velvetleaf. Based on this study, sulfentrazone and dimethenamid-p have potential for minor use registration in pepper.


Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 128-133 ◽  
Author(s):  
E. E. Schweizer

Interference within a mixture of equal densities of common lambsquarters (Chenopodium albumL.), kochia [Kochia scoparia(L.) Schrad.], and redroot pigweed (Amaranthus retroflexusL.) in sugarbeets (Beta vulgarisL. ‘Mono Hy D2’) was determined in a 3-yr field study. Yield of sugarbeet roots and sucrose per hectare decreased as intensity of competition from equal populations of these three weeds increased. At densities of 6, 12, 18, and 24 broadleaf weeds per 30 m of row, root yields were reduced 13, 24, 33, and 39%, respectively. Sucrose yields were reduced similarly. Fewer than three weeds per 30 m of row did not significantly reduce root yield. Reduction in root yield (Y) of sugarbeets caused by specific densities (X) of the three broadleaf weeds was predicted by using the linear equation Y = 1.64 + 1.88 X. The actual reductions in yield were always less than the predicted reductions when this equation was tested against 36 weed control systems because the competitive ability of broadleaf weeds that were treated with herbicides, but not killed, was suppressed during the growing season. By harvest, broadleaf weeds present in weed-control-system plots weighed an average of 75 to 85% less than broadleaf weeds present in nontreated plots.


2012 ◽  
Vol 60 (3) ◽  
pp. 257-264 ◽  
Author(s):  
F. Takim

Field studies were conducted in 2010 and 2011 at the Teaching and Research Farm of the University of Ilorin, Nigeria (9°29′ N, 4°35′ E) to evaluate the effect of early weed competition on the growth and yield of maize. The experiment was designed as a randomized complete block (RCBD) with a split-plot arrangement and three replications. The main plots consisted of three weed control treatments included weedy (no herbicide), grass weeds (pre-emergence atrazine) and broadleaf weeds (pre-emergence metolachlor), while the sub-plots consisted of six durations of weed infestation (3, 4, 5, 6, 7 and 8 weeks after emergence). The pre-emergence herbicides had a greater effect on weed density and weed dry weight. Weed seedling emergence and weed dry weight increased significantly with an increase in the duration of weed interference. The grasses and broadleaf weeds had a similar influence on the growth and grain yield of maize. Three to five weeks of weed interference gave similar grain yields, which were significantly higher than those obtained in plots that had 6-8 weeks of weed interference. These results suggest that the maize crop must be kept free of weeds for 6-8 weeks after the application of pre-emergence herbicide to minimize weed-crop competition and harvest a good grain yield.


Weed Science ◽  
1970 ◽  
Vol 18 (2) ◽  
pp. 206-214 ◽  
Author(s):  
R. P. Upchurch ◽  
F. L. Selman ◽  
H. L. Webster

Relatively pure stands of eight weed species were maintained under field conditions on a Goldsboro loamy sand at Lewiston, North Carolina, for all or part of a 6-year period. Herbicides evaluated as preemergence surface treatments for these species were 2-sec-butyl-4,6-dinitrophenol (dinoseb), isopropyl m-chlorocarbanilate (chloropropham), 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (diuron), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), and 3-amino-2,5-dichlorobenzoic acid (amiben). S-ethyl dipropylthiocarbamate (EPTC) and a,a,a-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) were evaluated as preemergence incorporated treatments. The first four herbicides were evaluated in 1961, 1964, and 1966 while the last three were evaluated in 1962, 1963, and 1965. A series of rates was used for each chemical with three replications. With the exception of diuron which failed to control goosegrass (Eleusine indica (L.) Gaertn.), all of the herbicides provided at least a moderate degree of control of goosegrass, smooth crabgrass (Digitaria ischaemum (Schreb.) Muhl.), and redroot pigweed (Amaranthus retroflexus L.) at the respective typical field use rates. In general, trifluralin and amiben gave the best grass control and dinoseb the poorest. None of the herbicides effectively controlled common cocklebur (Xanthium pensylvanicum Wallr.) or ivyleaf morningglory (Ipomoea hederacea (L.) Jacq.). Trifluralin and EPTC did not control Pennsylvania smartweed (Polygonum pensylvanicum L.), common ragweed (Ambrosia artemisiifolia L.), and common lambsquarters (Chenopodium album L.). Chloropropham was ineffective on common ragweed. Simazine, chloropropham, and amiben controlled Pennsylvania smartweed while diuron, simazine, dinoseb, and amiben were especially effective on common lambsquarters. Distinctive patterns of nematode infestations were observed as a function of weed species.


Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 612-615 ◽  
Author(s):  
J.F. da Silva ◽  
G.F. Warren

Six species of Solanaceae including tomato (Lycopersicon esculentumMill ‘Campbell 28′) were sprayed in the greenhouse at weekly intervals for 4 weeks starting when tomato plants had one true leaf. All species gained tolerance to metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] with age but tomato and black nightshade (Solarium nigrumL.) were the most tolerant and gained tolerance fastest with age. Jimsonweed (Datura stramoniumL.) and eggplant (Solanum melongenaL. ‘Black Beauty’) were the most susceptible species and the ones that gained least tolerance with age. Potato (Solanum tuberosumL.) from true seeds and pepper (Capsicum annuumL. ‘Yolo wonder’) were intermediate in tolerance. In the field, tomato and nine weed species planted in separate plots and kept free from competition were sprayed at weekly intervals starting when tomato plants had one true leaf. Tomato, large crabgrass (Digitaria sanguinales(L.) Scop.), ivyleaf morningglory (Ipomoea hederaceae(L.) Jacq.) and yellow foxtail (Setaria glauca(L.) Beauv.) were the most resistant species to metribuzin and the ones that gained tolerance fastest with age. The most susceptible weeds were velvetleaf (Abutilon theophrastiMedic), common purslane (Portulaca oleraceaL.), pale smartweed (Polygonum lapathifoliumL.), redroot pigweed (Amaranthus retroflexusL.), common lambsquarters (Chenopodium albumL.), and jimsonweed. Low amounts of sunlight during the 3 days before spraying greatly reduced the resistance of tomato to metribuzin.


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