Weed seed production, crop planting pattern, and mechanical weeding in wheat

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.

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Influence of crop rotation, tillage, and management inputs on weed seed production

Weed Science ◽

10.1017/s0043174500091591 ◽

1999 ◽

Vol 47 (2) ◽

pp. 175-183 ◽

Cited By ~ 44

Author(s):

George O. Kegode ◽

Frank Forcella ◽

Sharon Clay

Keyword(s):

Seed Production ◽

Crop Rotation ◽

Crop Production ◽

Conservation Tillage ◽

Farming Systems ◽

Crop Rotations ◽

Weed Seed ◽

Weed Species ◽

Weed Seeds ◽

Ridge Tillage

Approaches to crop production that successfully reduce weed seed production can benefit farming systems by reducing management inputs and costs. A 5-yr rotation study was conducted in order to determine the effects that interactions between crop rotation, tillage, and amount of herbicide and fertilizer (management inputs) have on annual grass and broad-leaved weed seed production and fecundity. There were 10 crop rotation and tillage system combinations and three levels of management inputs (high, medium, and low). Green and yellow foxtail were the major weed species, and together they yielded between 76 and 93% of collected weed seeds. From 1990 to 1994, average grass weed seed productions were 7.3 by 103, 3.7 by 1036.1 by 103and 5.7 by 103seeds m−-2, whereas average broad-leaved weed seed productions were 0.4 by 103, 0.4 by 103, 1.4 by 103, and 0.4 by 103seeds m−-2in crop rotations using conventional tillage (moldboard plow), conservation tillage, no tillage, and ridge tillage, respectively. Crop rotations using conventional or ridge tillage consistently produced more grass and broad-leaved weed seeds, especially in low-input plots. There was little difference in weed seed production among input levels for crop rotations using conservation tillage. Comparing rotations that began and ended with a corn crop revealed that by increasing crop diversity within a rotation while simultaneously reducing the amount of tillage, significantly fewer grass and broad-leaved weed seeds were produced. Among the rotations, grass and broad-leaved weed fecundity were highly variable, but fecundity declined from 1990 to 1994 within each rotation, with a concomitant increase in grass and broad-leaved weed density over the same period. Crop rotation in combination with reduced tillage is an effective way of limiting grass and broad-leaved weed seed production, regardless of the level of management input applied.

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THE EFFECT OF TWIN ROW PLANTING PATTERN AND PLANT POPULATION ON YIELD AND YIELD COMPONENTS OF PEANUT (Arachis hypogaea L.) AT MAIN CROP PLANTING IN CUKUROVA REGION OF TURKEY

Turkish Journal Of Field Crops ◽

10.17557/tjfc.301768 ◽

2017 ◽

Cited By ~ 1

Author(s):

Cemal KURT ◽

Halil BAKAL ◽

Leyla GULLUOGLU ◽

Halis ARIOGLU

Keyword(s):

Arachis Hypogaea ◽

Yield Components ◽

Plant Population ◽

Planting Pattern ◽

Main Crop ◽

Arachis Hypogaea L ◽

Yield And Yield Components ◽

Crop Planting

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Crop Planting Pattern Effects on Early Growth and Canopy Shape of Cultivated and Wild Oats (Avena fatua)

Weed Science ◽

10.1017/s0043174500080875 ◽

1995 ◽

Vol 43 (1) ◽

pp. 88-94 ◽

Cited By ~ 14

Author(s):

Emilie E. Regnier ◽

Kufimfutu B. Bakelana

Keyword(s):

Leaf Area ◽

Early Growth ◽

Weed Suppression ◽

Individual Plant ◽

Canopy Closure ◽

Crop Canopy ◽

Planting Pattern ◽

Wild Oats ◽

Canopy Area ◽

Crop Planting

Field studies were conducted to determine the effects of cultivated oats planting pattern on early canopy shape and growth of cultivated oats and wild oats, in part to test the assumption of radial plant canopy expansion on which previous theoretical models of crop-weed interference models have been based. Cultivated oats density was kept constant as the pattern rectangularity was varied, and single wild oats plants were centered within each pattern. Individual plant canopies, photographed from above 31 days after emergence (DAE), were radial for wild oats in all crop planting patterns and for cultivated oats planted in triangular and square planting patterns. Canopy radius perpendicular to the crop row axis in rectangular patterns was similar to canopy radius along the same cardinal axis in equidistant patterns, but was reduced along the crop row axis, resulting in a rectangular canopy shape and decreased canopy area in rectangular compared to equidistant patterns. Cultivated oats dry weight and leaf area at crop flowering (64 DAE) also decreased with increasing rectangularity of crop planting pattern. Reductions in cultivated oats growth in rectangular patterns were associated with earlier intraspecific interference and delayed crop canopy closure in rectangular compared to equidistant patterns. Wild oats leaf area and tiller number 64 DAE decreased with more equidistant crop planting patterns, consistent with reduced canopy area 31 DAE and earlier crop canopy closure in equidistant patterns. The data suggest that individual oats canopy expansion during early growth is essentially radial and also support previous theoretical predictions of crop planting pattern effects on weed suppression.

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Cultural Practices Affecting Season-Long Weed Control in Irrigated Corn (Zea mays)

Weed Science ◽

10.1017/s0043174500059348 ◽

1984 ◽

Vol 32 (4) ◽

pp. 460-467 ◽

Cited By ~ 9

Author(s):

Russell S. Moomaw ◽

Alex R. Martin

Keyword(s):

Zea Mays ◽

Weed Control ◽

Seed Production ◽

Field Experiments ◽

Cultural Practices ◽

Fine Sand ◽

Corn Yield ◽

Weed Seed ◽

Weed Growth ◽

Herbicide Use

Season-long weed control has been a goal of some producers of irrigated corn (Zea maysL.) to reduce competition, lessen weed seed production, facilitate crop harvest, improve water efficiency (particularly with furrow irrigation), and improve aesthetic properties of fields. Field experiments were conducted for 3 yr on sprinkler-irrigated corn on a loamy fine sand. Five herbicides applied at layby generally provided season-long control of grass weeds and reduced weed seed production up to 100%. Pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] was particularly effective. Yields of irrigated corn were not increased by layby herbicide application. Use of corn rows spaced 91 cm apart and use of a shorter, early-maturing, horizontal-leaf corn cultivar resulted in greater weed growth and weed seed production than did use of 76-cm rows and a taller, full-season, upright-leaf corn cultivar. After nearly complete weed control with herbicides for 2 yr, withholding herbicide use in the third year allowed weed growth which reduced corn yield. Indications were that weed control efforts need to be continuous in irrigated corn production.

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Management of Avena ludoviciana and Phalaris paradoxa with barley and less herbicide in subtropical Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea01002 ◽

2001 ◽

Vol 41 (8) ◽

pp. 1179 ◽

Cited By ~ 9

Author(s):

S. R. Walker ◽

G. R. Robinson ◽

R. W. Medd

Keyword(s):

Seed Production ◽

Weed Management ◽

Field Experiments ◽

Management Strategies ◽

Maximum Yield ◽

Yield Reduction ◽

Weed Seed ◽

Tiller Density ◽

Weed Emergence ◽

Subtropical Australia

The competitive advantage of barley compared with wheat was quantified for suppressing seed production of Avena ludoviciana Durieu. (wild oats) andPhalaris paradoxa L. (paradoxa grass), and for improving herbicide effectiveness on these major winter grass weeds of the subtropical grain region of Australia. Eight field experiments were broadcast with weed seed before sowing wheat or barley, in which the emerged weeds were then treated with 4 herbicide doses (0, 25, 50, 100% of recommended rates). Yield reduction from untreated weeds was on average 4 times greater in wheat than in barley, with greater losses from A. ludoviciana than P. paradoxa. Barley did not affect weed emergence, but suppressed weed tiller density and, to a lesser extent, the number of weed seeds per tiller. Seed production was, on average, 4340 and 5105 seeds/m2 for A. ludoviciana and P. paradoxa, respectively, in untreated wheat compared with 555 and 50 seeds/m2 in untreated barley. Weed seed production following treatment with 25% herbicide rate in barley was similar or less than that after treatment with 100% herbicide rate in wheat. Overall, 25% herbicide rate was optimal for both conserving yield and minimising weed seed production in barley. For wheat, maximum yield was achieved with 50% herbicide but weed seed production was lowest with 100% herbicide rate. This indicates that weeds can be effectively controlled in barley with considerably less herbicide than required in wheat, highlighting the importance of including barley as a part of weed management strategies that aim to reduce herbicide inputs.

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Late-Season Weed Management to Stop Viable Weed Seed Production

Weed Science ◽

10.1614/ws-d-15-00096.1 ◽

2016 ◽

Vol 64 (1) ◽

pp. 112-118 ◽

Cited By ~ 6

Author(s):

Erin C. Hill ◽

Karen A. Renner ◽

Mark J. VanGessel ◽

Robin R. Bellinder ◽

Barbara A. Scott

Keyword(s):

Seed Production ◽

Weed Management ◽

Viable Seed ◽

Weed Seed ◽

Common Ragweed ◽

Common Lambsquarters ◽

Late Season ◽

Giant Foxtail ◽

Immature Seeds ◽

Mature Seeds

Integrated weed management (IWM) for agronomic and vegetable production systems utilizes all available options to effectively manage weeds. Late-season weed control measures are often needed to improve crop harvest and stop additions to the weed seed bank. Eliminating the production of viable weed seeds is one of the key IWM practices. The objective of this research was to determine how termination method and timing influence viable weed seed production of late-season weed infestations. Research was conducted in Delaware, Michigan, and New York over a 2-yr period. The weeds studied included: common lambsquarters, common ragweed, giant foxtail, jimsonweed, and velvetleaf. Three termination methods were imposed: cutting at the plant base (simulating hand hoeing), chopping (simulating mowing), and applying glyphosate. The three termination timings were flowering, immature seeds present, and mature seeds present. Following termination, plants were stored in the field in mesh bags until mid-Fall when seeds were counted and tested for viability. Termination timing influenced viable seed development; however, termination method did not. Common ragweed and giant foxtail produced viable seeds when terminated at the time of flowering. All species produced some viable seed when immature seeds were present at the time of termination. The time of viable seed formation varied based on species and site-year, ranging from plants terminated the day of flowering to 1,337 growing degree d after flowering (base 10, 0 to 57 calendar d). Viable seed production was reduced by 64 to 100% when common lambsquarters, giant foxtail, jimsonweed, and velvetleaf were terminated with immature seeds present, compared to when plants were terminated with some mature seeds present. Our results suggest that terminating common lambsquarters, common ragweed, and giant foxtail prior to flowering, and velvetleaf and jimsonweed less than 2 and 3 wk after flowering, respectively, greatly reduces weed seed bank inputs.

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A “Stressed” Alfalfa-Based Cropping System Leads to the Selection of Quizalofop-Resistant Italian Ryegrass (Lolium perennessp.multiflorum)

Weed Science ◽

10.1614/ws-d-15-00193.1 ◽

2016 ◽

Vol 64 (4) ◽

pp. 683-694 ◽

Cited By ~ 1

Author(s):

Alberto Collavo ◽

Silvia Panozzo ◽

Antonio Allegri ◽

Maurizio Sattin

Keyword(s):

Ethyl Ester ◽

Seed Production ◽

Weed Management ◽

Cropping System ◽

Italian Ryegrass ◽

Integrated Weed Management ◽

Forage Production ◽

Weed Seed ◽

Quizalofop Ethyl ◽

Selection Of

Italian ryegrass populations investigated in this study were harvested in an alfalfa-based cropping system. In that system, the agronomic practices and chemical weed management, based on the use of aryloxyphenoxy-propionates herbicides (i.e., quizalofop ethyl ester), were optimized to obtain a dual seed–forage production. Five of seven populations tested were confirmed resistant to quizalofop ethyl ester with resistance indexes ranging from 4.5 to >209. Both target- and nontarget-site resistance mechanisms were most likely involved. Three allelic variants were detected (Ile-1781–Leu, Trp-2027–Cys, and Ile-2041–Asn) in four resistant populations, whereas no known mutations were found in one resistant population. The herbicide treatment on Italian ryegrass plants at different phenological stages suggested that to control regrowth, it is necessary to use two to fives times the herbicide dose suitable for younger plants. This situation is encountered in fields when Italian ryegrass plants need to be controlled to maximize the alfalfa seed production, and it is comparable to using a sublethal herbicide dose, leading to the selection of herbicide-resistant biotypes. In such a situation, the cropping system is not sustainable, and integrated weed management should be implemented to deplete the soil weed seed bank and prevent new weed seed production.

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Planting Date and Preplant Weed Management Influence Yield, Water Use, and Weed Seed Production in Herbicide-Free Forage Barley

Weed Technology ◽

10.1614/wt-08-009.1 ◽

2008 ◽

Vol 22 (3) ◽

pp. 486-492 ◽

Cited By ~ 14

Author(s):

Andrew W. Lenssen

Keyword(s):

Seed Production ◽

Water Use ◽

Great Plains ◽

Weed Management ◽

Planting Date ◽

Management Systems ◽

Northern Great Plains ◽

Zero Tillage ◽

Weed Seed ◽

Early Planting

In the semiarid northern Great Plains, the adoption of zero tillage improves soil water conservation, allowing for increased crop intensification and diversification. Zero-tillage crop production relies heavily on herbicides for weed management, particularly the herbicide glyphosate, increasing selection pressure for herbicide-resistant weeds. Barley is well adapted to the northern Great Plains, and may be a suitable herbicide-free forage crop in zero-tillage systems. A 2-yr field study was conducted to determine if planting date influenced crop and weed biomass, water use (WU), and water-use efficiency (WUE) of barley and weed seed production in three preplant weed management systems: (1) conventional preplant tillage with a field cultivator (TILL); (2) zero tillage with preemergence glyphosate application (ZTPRE); and (3) zero tillage without preemergence glyphosate (ZT). None of the systems included an in-crop herbicide. Planting dates were mid-April (early), late May (mid), and mid-June (delayed). Early planting of ZT barley resulted in excellent forage yields (7,228 kg/ha), similar to those from TILL and ZTPRE. Early planting resulted in a small accumulation of weed biomass, averaging 76 kg/ha, and no weed seed production regardless of preplant weed management system. Early planting resulted in higher WU than delayed planting, averaging 289 and 221 mm, respectively, across management systems and years. The WUE of crop and total biomass did not differ among preplant weed management systems at harvest from the early planting date. Delayed planting resulted in decreased forage yield with high amounts of weed biomass and seed production, especially in ZT. A pre-emergence glyphosate application was not necessary for early-planted ZT forage barley. Early planting of herbicide-free barley for forage can be an excellent addition to northern Great Plains cropping systems as part of a multitactic approach for improved weed and water management.

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