Crop Seeding Level: Implications for Weed Management in Sweet Corn

Weed Science ◽  
2013 ◽  
Vol 61 (3) ◽  
pp. 437-442 ◽  
Author(s):  
Martin M. Williams ◽  
Rick A. Boydston
Keyword(s):  
Seed Production ◽  
Weed Management ◽  
Sweet Corn ◽  
Field Studies ◽  
Weed Suppression ◽  
Minor Role ◽  
Proso Millet ◽  
Wide Range ◽  
Variable Population ◽  
A Minor

Sweet corn is seeded under a wide range of population densities; however, the extent to which variable population density influences weed suppression is unknown. Therefore, field studies were undertaken to quantify the influence of sweet corn seeding level on growth, seed production, and post-harvest seed germination of wild-proso millet, one of the most problematic weeds in the crop. As crop seeding level increased, path analysis results indicated the crop canopy became taller and thicker, resulting in less wild-proso millet biomass, seed production, and germinability. However, at the level of individual fields, reductions in wild-proso millet growth and seed production were modest, at best, between a crop population currently used by growers and a higher crop population known to optimize yield of certain hybrids. These results indicate near-future increases in sweet corn seeding levels may play a minor role in improving weed management in individual sweet corn fields. Nonetheless, a reduction in crop populations, via weather- or management-driven phenomenon, increases risk of greater wild-proso millet seed production.

Efficacy and Crop Response to Glufosinate-Based Weed Management in PAT-Transformed Sweet Corn (Zea mays)

1999 ◽  
Vol 13 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Lee R. Van Wychen ◽  
R. Gordon Harvey ◽  
Mark J. Vangessel ◽  
Thomas L. Rabaey ◽  
David J. Bach
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sweet Corn ◽  
Field Studies ◽  
Yield Response ◽  
Crop Response ◽  
Control Efficacy ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Proso Millet

Field studies were conducted at Arlington, WI, in 1996 and 1997 and at Georgetown, DE, and LeSueur, MN, in 1997 to determine weed control efficacy, crop injury, and yield response of PAT-transformed sweet corn to glufosinate-based weed management. Sequential applications of glufosinate 10 to 18 d apart at 0.4 and 0.3 kg ai/ha controlled common lambsquarters, common ragweed, velvetleaf, wild-proso millet, and fall panicum 90% or better at all locations. Weed control varied little among 0.3, 0.4, or 0.3 and 0.3 (sequential) kg/ha glufosinate rates. Glufosinate applied alone, with, or following atrazine controlled velvetleaf 90% or greater but was less consistent on common ragweed and common lambsquarters (73 to 100%). Atrazine plus metolachlor applied preemergence (PRE) and glufosinate applied alone postemergence (POST) provided inconsistent wild-proso millet and fall panicum control (43 to 99%). Metolachlor followed by glufosinate improved consistency of grass control (> 76%). Glufosinate followed by cultivation provided 80% or greater control of velvetleaf and wild-proso millet. Glufosinate did not injure or delay maturity of PAT-transformed sweet corn. Sweet corn treated with glufosinate resulted in yields greater than or equal to the sweet corn that was hand-weeded or received a standard herbicide treatment.

Combining Cultural Practices and Herbicides to Control Wild-Proso Millet (Panicum miliaceum)

1990 ◽  
Vol 4 (2) ◽  
pp. 433-439 ◽  
Author(s):  
R. Gordon Harvey ◽  
Gregory R. McNevin
Keyword(s):  
Sweet Corn ◽  
Cultural Practices ◽  
Field Studies ◽  
Row Spacing ◽  
Panicum Miliaceum ◽  
Proso Millet ◽  
Field Corn ◽  
No Till ◽  
Millet Seed ◽  
Better Than

Field studies evaluated the effects of crop, crop rotation, planting date, row spacing, no-till planting, and herbicides on wild-proso millet control. Benefin and EPTC reduced wild-proso millet biomass in new seedings of alfalfa, and the combination of herbicides and forage harvest prevented wild-proso millet seed production in that crop. Wild-proso millet seedling populations were reduced and corn yields increased when corn followed 1 to 4 yr of alfalfa. Apparent effectiveness of herbicides in corn increased after cropping with alfalfa. Germination of buried wild-proso millet seed decreased approximately 90% after 54 months which is equivalent to 4-yr prior cropping to alfalfa. Wild-proso millet control and field and sweet corn yields increased when the crops were planted late season (May 17) rather than early season (April 27). Planting sweet corn in rows spaced 76 cm rather than 108 cm apart also increased sweet corn yields. EPTC plus dichlormid (EPTC+) plus cyanazine always controlled wild-proso millet equal to or better than EPTC+alone. When field corn was planted no-till into killed alfalfa sod, combinations of pendimethalin plus simazine and pendimethalin plus cyanazine provided the best wild-proso millet control and corn yields. But the following year when corn was no-till planted into corn stubble of the identical plots, wild-proso millet control from the same treatments tended to be lower and corn yields were reduced.

Variation in the recruitment behaviour of seagrass seeds: implications for population dynamics and resource management

1999 ◽  
Vol 5 (4) ◽  
pp. 251 ◽  
Author(s):  
Graeme J. Inglis
Keyword(s):  
Field Studies ◽  
Clonal Plants ◽  
Minor Role ◽  
Spatial And Temporal Scales ◽  
Local Populations ◽  
Seed Supply ◽  
Seed Reserves ◽  
A Minor ◽  
Effective Conservation

Effective conservation of marine organisms requires an understanding of the processes that affect the establishment, persistence and extinction of local populations. Our knowledge of the recruitment of seagrasses comes largely from studies done at small spatial and temporal scales within extant meadows. Descriptions of the demography of local populations, therefore, typically emphasize prolific ramet production and only a minor role for sexual propagules. Recent genetic and field studies, however, have shown greater variation in recruitment behaviour than previously suspected. In this paper, I review what is known about the seeds of seagrasses ? including their dormancy, dispersability and requirements for germination and establishment ? and examine the utility of recent conceptual models, developed for terrestrial clonal plants, to explain the long-term dynamics of seagrass populations. Sizable variation among species in seed size and dispersal strategy appears to be related predictably to variation in life-history and rates of recruitment. Species with small, poorly-dispersed fruits (e.g., Halophila, Halodule) are more likely to form persistent seed reserves and be rapid colonizers of disturbances within established meadows. Genera with large, buoyant fruits, capable of moderate dispersal (e.g., Thalassia, Posidonia), in contrast, appear to recruit rarely within existing meadows of conspecifics. Our ability to model long-term changes in demography and community structure is likely to benefit from a better knowledge of the importance of seed supply and microsite availability to recruitment.

Maize Dwarf Mosaic Can Reduce Weed Suppressive Ability of Sweet Corn

Weed Science ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 577-582 ◽  
Author(s):  
Martin M. Williams ◽  
Jerald K. Pataky
Keyword(s):  
North America ◽  
Sweet Corn ◽  
Field Studies ◽  
Viral Disease ◽  
Population Densities ◽  
Corn Hybrids ◽  
Weed Population ◽  
Proso Millet ◽  
Weed Growth ◽  
Weed Suppressive Ability

Maize dwarf mosaic (MDM) stunts corn growth, delays development, and is the most prevalent viral disease of sweet corn grown in many regions of North America and Europe. Although some weeds escape control in most sweet corn fields, the extent to which MDM influences the weed suppressive ability of the crop is unknown. Field studies were conducted over a 3-yr period to characterize the influence of variable MDM incidence in sweet corn on growth, fecundity, and germinability of wild-proso millet, a common weed in the crop. Treatments included five levels of MDM incidence (0, 25, 50, 75, and 100% of plants infected) in two MDM-susceptible hybrids differing in weed suppressive ability. Previous research showed that hybrid ‘Legacy’ had greater weed suppressive ability than ‘Sugar Buns’. Wild-proso millet biomass and fecundity depended largely on the hybrid in which the weed was growing. Wild-proso millet growing in Sugar Buns weighed 45 to 117% more than wild-proso millet in Legacy. Incidence of MDM in sweet corn affected wild-proso millet biomass and fecundity, but only under high weed population densities. When wild-proso millet was observed at 122 plants m−2, weed biomass increased 9 g m−2 for each additional 10% incidence of MDM of sweet corn. Weed suppressive ability of the competitive and less competitive hybrids were influenced to the same extent by MDM. Coupled with a lack of resistance to MDM in two-thirds of commercial sweet corn hybrids, the disease could be an additional factor perpetuating weed growth and fecundity in sweet corn, particularly in fields with high population densities of wild-proso millet.

The phenology and seed production of Cucumis melo as an invasive weed in northern Iran

2016 ◽  
Vol 64 (3) ◽  
pp. 227 ◽  
Author(s):  
Sima Sohrabi ◽  
Javid Gherekhloo ◽  
Behnam Kamkar ◽  
Ali Ghanbari ◽  
Mohammad Hassan Rashed Mohassel
Keyword(s):  
Seed Production ◽  
Weed Management ◽  
Cucumis Melo ◽  
Sowing Date ◽  
Growth Cycle ◽  
Future Research ◽  
Degree Days ◽  
Northern Iran ◽  
Invasive Weed ◽  
Wide Range

Accurately representing plant development is essential for applying phenology knowledgement to investigate the effects of climate on weed management. Development in wild melon (Cucumis melo L.) is driven by temperature; thus, it could be simulated by thermal-time (TT) accumulation using limited accumulation when a lower optimum temperature (Topt) is exceeded. Experiments were conducted to investigate wild melon phenology (development rate) and seed production in soybean (Glycine max L.) at seven different sowing dates (April to August) in a completely randomised design (CRD) at Research Farm of Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2012. Results indicated that a slight shift in developmental rates occurs among plantings dates, except for those plants sown in August. The estimated TT for April–August planting dates were ~411 Celcius degree days, 448 Celcius degree days, 733 Celcius degree days, 672 Celcius degree days, 604 Celcius degree days, 558 Celcius degree days and 251 Celcius degree days respectively. Depending on planting date, weed emergence occurred at 5–20 days after planting. During the 79, 75, 92, 81, 71, 67 and 61 days of wild-melon growth, the mean number of fruits per plant and seeds per fruit were significantly different at each sowing date. Wild melon could produce a lot of fruits and seeds (up to 5000) within a growth cycle (average in 75 days) and also weed management is needed during the May and June because of the highest seed production of wild melons that emerged during May. The results attained here suggest that temperature alone could not reflect the effect of environment on C. melo development at each given growth stage. Thus, other environmental factors, such as daylength, maybe needed to better estimate weed development. Future research may use multiplicative models to clarify this claim. These results highlighted the value of testing a model over a wide range of environments.

scholarly journals The UK Smoke Constituents Testing Study. Summary of Results and Comparison with Other Studies

2004 ◽  
Vol 21 (2) ◽  
pp. 117-138 ◽  
Author(s):  
E Gregg ◽  
C Hill ◽  
M Hollywood ◽  
M Kearney ◽  
D McLaughlin ◽  
...  
Keyword(s):  
Yield Variability ◽  
Analytical Determination ◽  
Minor Role ◽  
Department Of Health ◽  
Routine Measurement ◽  
Wide Range ◽  
The Uk ◽  
A Minor ◽  
Analytical Variation

AbstractAt the request of the UK Department of Health, samples of 25 commercial UK cigarette brands were provided to LGC Ltd a for smoke analysis. The brands reflected a high market share (58% in July 2001) and included a wide range of blend and product styles manufactured and imported into the UK.= 0.76), suggesting a minor role of other design features on constituents yield variability. This was confirmed by the application of multiple regression analysis to the data. A subset of five brands, retested at another laboratory, gave between-laboratory differences in mean constituent yields of as much as 2.5-fold. Consideration of these results, other likely sources of analytical variation in this study and a review of other studies, clearly indicates that any tolerance values to be associated with individual smoke constituent measurements will be greater than those for NFDPM, and in some cases, much greater. Consistent with the reported results from other large studies it is concluded that, under ISO smoking conditions, smoke constituent yields are largely predictable, if NFDPM and CO yields are known, for a standard cigarette. Given these observations and the likely limitations of analytical determination, the need for routine measurement of smoke constituent yields, other than NFDPM, nicotine or CO, on standard cigarettes, is questionable.

Row Width Affects Weed Management in Type II Black Bean

2013 ◽  
Vol 27 (3) ◽  
pp. 538-546 ◽  
Author(s):  
Ryan C. Holmes ◽  
Christy L. Sprague
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Control Strategies ◽  
Field Studies ◽  
Weed Suppression ◽  
Type Ii ◽  
Weed Biomass ◽  
Black Bean ◽  
Crop Injury ◽  
Row Width

Field studies were conducted in 2010 and 2011 at two locations in Michigan to examine the effect of row width and herbicide combination on weed suppression and yield in the new Type II black bean variety ‘Zorro.' Black bean was planted in 38- and 76-cm rows. Six weed control strategies were examined:S-metolachlor + halosulfuron (PRE),S-metolachlor (PRE) followed by (fb) bentazon + fomesafen (POST), halosulfuron (PRE) fb clethodim (+ fomesafen at one site in one year) (POST), imazamox + bentazon (POST), a weed-free control, and a nontreated control. Weed control and crop injury were evaluated throughout the growing season. In addition, weeds were counted by species in late July, and weed biomass was harvested and weighed at the end of the season. Black bean yield was obtained by direct harvest. Narrow rows reduced weed populations in two of the four site–year combinations (referred to hereafter as site–years), reduced weed biomass in three of the four site–years, and often improved control of upright broadleaf weeds. All herbicide combinations generally reduced weed populations and biomass, but control of specific weeds was variable. Crop injury was generally slight and transient. Yield was greater in narrow rows in two of the four site–years. All herbicide combinations increased yield compared with the nontreated control and resulted in similar yields to one another. Yield and weed suppression was often maximized in narrow rows, while herbicide performance varied by year and weed spectrum.

Growth and chemical composition of Townsville lucerne (Stylosanthes humilis). 1. Dry matter yield and nitrogen content in response to superphosphate

1966 ◽  
Vol 6 (21) ◽  
pp. 150 ◽  
Author(s):  
NH Shaw ◽  
CT Gates ◽  
JR Wilson
Keyword(s):  
Nitrogen Content ◽  
Dry Matter ◽  
Nutrient Deficiency ◽  
Dry Weight ◽  
Pot Experiment ◽  
Minor Role ◽  
Dry Matter Yield ◽  
Nutritional Conditions ◽  
Wide Range ◽  
A Minor

In a field experiment on a solodic soil, applications of superphosphate, in the presence of molybdenum, increased the dry matter yield of S. humilis H.B.K. from 2,450 to 5,800 lb an acre, and increased the relative nitrogen content from 2.36 to 3.28 per cent. When this result was examined under more closely controlled conditions in a pot experiment, using the constituent elements of molybdenized superphosphate, it was found that the combination of phosphorus and sulphur produced the greatest dry weight and nitrogen responses. Nevertheless, substantial increases in dry weight of plant tops were obtained with added phosphorus in the absence of sulphur, although the relative nitrogen content of this dry matter was low unless sulphur was also present. There was a small response to molybdenum in this experiment, but calcium played only a minor role. In the pot experiment three replicates were placed in a glasshouse, and one under a light bank in a growth room. Plants grew faster and gave higher dry matter and nitrogen yields under the light bank than in the glasshouse. Attention is drawn to the adaptability that S. humilis displays to a wide range of nutritional conditions, and it is suggested that both the yield and nitrogen content of this legume are probably being limited by nutrient deficiency in most areas of northern Australia where it is being grown.

Using Reduced Tillage and Cover Crop Residue to Manage Weeds in Organic Vegetable Production

2017 ◽  
Vol 31 (4) ◽  
pp. 557-573 ◽  
Author(s):  
Guihua Chen ◽  
Lauren Kolb ◽  
Alan Leslie ◽  
Cerruti R. R. Hooks
Keyword(s):  
Weed Management ◽  
Cover Crop ◽  
Sweet Corn ◽  
Conservation Tillage ◽  
Weed Suppression ◽  
Vegetable Production ◽  
Organic Vegetable Production ◽  
Hand Weeding ◽  
Strip Tillage ◽  
Time Required

Adoption of conservation tillage practices has been slow in organic vegetable production, partially due to producers’ concerns regarding weed management. Integrating cover crops into a conservation tillage program may provide organic producers a viable weed management option enabling growers to practice conservation tillage. A four-year study was conducted to evaluate the influence of different tillage methods (two conventional and two conservation practices) jointly with a mixed winter cover crop for weed suppression, time required for hand weeding, and crop yield in organically managed eggplant (2012 and 2014) and sweet corn (2013 and 2015) production systems. Tillage treatments were conventional tillage without surface mulch (CT-BG) and with black polyethylene (plastic) mulch (CT-BP), strip-tillage (ST), and no-tillage (NT) with cover crop residue. At 2 and 7 WAT/P (weeks after transplanting/planting), intra-row weed density was higher in CT-BG and ST, and inter-row weed density was higher in CT-BG and CT-BP treatments. Time required for hand-weeding was greatest in CT-BG and least in CT-BP and NT treatments. Eggplant yield was lowest in NT treatment in 2012 but similar among treatments in 2014. Sweet corn yield was similar among treatments in 2013 but highest in ST in 2015. Though both CT-BP and NT treatments showed greater potential for weed suppression, production input was highest in CT-BP but least in NT. Implications of these findings suggest that there is a potential to use strip tillage integrating with stale seedbed tactic for weed management in organic vegetables, which reduces herbicide use, hand-labor, and overall weed management cost while maintaining high yield potential.

Effect of a Living Mulch on Weed Seed Banks in Tomato

2011 ◽  
Vol 25 (2) ◽  
pp. 245-251 ◽  
Author(s):  
Kevin D. Gibson ◽  
John Mcmillan ◽  
Stephen G. Hallett ◽  
Thomas Jordan ◽  
Stephen C. Weller
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
Critical Period ◽  
Field Studies ◽  
Seed Banks ◽  
Weed Suppression ◽  
Weed Seed ◽  
Fresh Market ◽  
Living Mulch ◽  
Seed Rate

Weeds that emerge between rows in fresh market tomatoes after the critical period of competition are not suppressed by the crop and can produce large quantities of seed. A living mulch planted between rows might limit weed seed production. Buckwheat was seeded between tomato rows after the critical period in 2007 and 2008 in field studies near Lafayette, IN. Weeds were allowed to emerge after the critical period (CP), controlled throughout the growing season (no seed threshold [NST]), or mowed to limit seed production (MOW). Buckwheat and MOW plots were mowed twice after the critical period in 2007 and once in 2008. Seed banks were sampled after the critical period and in the following spring. Tomato yields were not reduced by growing buckwheat between rows. Seed bank densities for common purslane and carpetweed, which escaped mowing due to their prostrate habits, increased in all treatments. Germinable seed bank densities were 306 seeds m−2or less in the NST and buckwheat treatments but 755 seeds m−2or more in the CP treatments for species with erect habits in both years. Seed bank densities were lower in the MOW treatment than in the CP treatments in 2007 but not in 2008. In a parallel experiment conducted in adjacent plots, buckwheat was seeded at five rates (0, 56, 112, 168, and 224 kg seed ha−1). Plots were mowed and emergent weeds sampled as described for the intercrop experiment. Weed densities before mowing decreased linearly with buckwheat seed rate. After mowing, no relationship was detected between seed rate and weed densities. This study supports the hypothesis that a living mulch planted after the critical period can be used to limit seed bank growth without reducing tomato yields, but additional research is needed to better understand the effect of mowing on living mulch growth and weed suppression.

Sign in / Sign up

Export Citation Format

Share Document