Mechanisms of Yield Loss in Maize Caused by Weed Competition

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Diego Cerrudo ◽  
Eric R. Page ◽  
Matthijs Tollenaar ◽  
Greg Stewart ◽  
Clarence J. Swanton
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Yield Loss ◽  
Kernel Weight ◽  
Rapid Decline ◽  
Weed Competition ◽  
Individual Plant ◽  
Rapid Loss ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The physiological process underlying grain yield (GY) loss in maize as a result of weed competition is not understood clearly. We designed an experiment to test the hypotheses that early season stress caused by the presence of neighboring weeds will increase plant-to-plant variability (PPV) of individual plant dry matter (PDM) within the population. This increase in PPV will reduce GY through a reduction in harvest index (HI). Field experiments were conducted in 2008, 2009, and 2010. A glyphosate-resistant maize hybrid was cropped at a density of 7 plants m−2. As a model weed, winter wheat was seeded at the same time as maize and controlled with glyphosate at the 3rd or 10th to 12th leaf-tip stage of maize. Weed competition early in the development of maize decreased PDM and GY. This reduction in PDM, which occurred early in the development of maize, was attributed initially to a delay in rate of leaf appearance. Reductions in PDM were accompanied by an increase in PPV of PDM. This increase in PPV, however, did not reduce HI and did not contribute to the GY reductions created by weed competition, as hypothesized. As weed control was delayed, a reduction in fraction of photosynthetically active radiation (fIPAR) accounted for a further reduction in PDM and notably, a reduction in DMA from 17th leaf-tip stage through to maturity. The rapid loss of PDM and the subsequent inability to accumulate dry matter during maturation accounted for a rapid decline in kernel number (KN) and kernel weight (KW).

Effect of Corn-Induced Shading and Temperature on Rate of Leaf Appearance in Redroot Pigweed (Amaranthus retroflexus L.)

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 590-593 ◽  
Author(s):  
Stephane M. Mclachlan ◽  
Clarence J. Swanton ◽  
Stephan F. Weise ◽  
Matthijs Tollenaar
Keyword(s):  
Field Experiments ◽  
Linear Increase ◽  
Amaranthus Retroflexus ◽  
Planting Date ◽  
Weed Interference ◽  
Redroot Pigweed ◽  
Field Temperature ◽  
Effects Of Temperature ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf development and expansion are important factors in determining the outcome of crop-weed interference. The comparative effects of temperature and corn canopy-induced shading on the rate of leaf appearance (RLA) of redroot pigweed were quantified in this study. Growth cabinet results indicated a linear increase in RLA with increased temperature. Weed RLA was predicted utilizing both this function and field temperature data. The ratio of observed to predicted RLA of redroot pigweed grown in field experiments decreased in 1990 and 1991 as shading increased with increased corn density and delayed weed planting date. Results indicated that RLA is substantially affected by canopy-induced shading in addition to temperature.

Seasonal changes in growth and nodulation of perennial tropical pasture legumes in the field. I. The influence of planting date and grazing and cutting on Desmodium uncinatum and Phaseolus atropurpureus

1970 ◽  
Vol 21 (2) ◽  
pp. 195 ◽  
Author(s):  
PC Whiteman ◽  
A Lulhan
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Planting Date ◽  
Rapid Decline ◽  
Individual Plant ◽  
Dry Matter Yield ◽  
Nodule Number ◽  
Pasture Legumes ◽  
Three Samples ◽  
Made In

Plantings of D. uncinatum and P. atropuvpureus were made in October and December 1965 and February and April 1966, and subsequently the plots were either rotationally grazed by sheep, cut with a mower at 3 inches, or left undefoliated. Monthly samples were taken to determine individual plant dry weight, nodule weight per plant, nodule number, and mean weight per nodule. Three samples for plot dry matter yield were also taken. Individual plant dry weight was higher in the October and December sowings, although by the end of the second growing season dry matter yield per plot was higher in the December and February sowings. Dry matter yield of legume was depressed by April planting. D. uncinatum began regrowth in spring 2 months earlier than P, atropurpureus, when minimum temperatures exceeded 48-50�F compared with 57' for P. atropurpureus. Both species had marked seasonal peaks in nodule and plant dry weight. The rapid decline in nodule weight could not be directly related to the onset of flowering or frosts. Grazing caused a greater reduction than cutting in terms of plant and nodule weight and legume yield. In P. atropurpureus nodule weight per plant was reduced through a decline in mean weight per nodule, while in D. uncinatum grazing and cutting reduced nodule number per plant.

scholarly journals Growth Analysis of Dry Bean (Phaseolus vulgaris L.) in Different Weed Interference Situations

2013 ◽  
Vol 5 (3) ◽  
pp. 394-399 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Dry Matter ◽  
Growth Analysis ◽  
Yield Loss ◽  
Growing Season ◽  
Crop Growth ◽  
Weed Competition ◽  
Dry Matter Accumulation ◽  
Dry Bean ◽  
Weed Interference ◽  
Crop Biomass

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.

scholarly journals Tillering does not interfere on white oat grain yield response to plant density

2003 ◽  
Vol 60 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Milton Luiz de Almeida ◽  
Luís Sangoi ◽  
Márcio Ender ◽  
Anderson Fernando Wamser
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Plant Density ◽  
Dry Mass ◽  
Main Stem ◽  
Yield Response ◽  
Individual Plant ◽  
Growing Seasons ◽  
Plant Densities

Plant density is one of the cropping practices that has the largest impact on individual plant growth. This work was conducted to evaluate the response of white oat (Avena sativa) cultivars with contrasting tillering patterns to variations in plant density. Two field experiments were carried out in Lages, SC, Brazil, during the 1998 and 1999 growing seasons. A split plot experimental design was used. Four oat cultivars were tested in the main plots: UFRGS 14, UFRGS 18, UPF 16 and UPF 17 using five plant densities split plots: 50, 185, 320, 455 and 550 plants m-2. Five plant samples were taken 25, 34, 48, 58 and 70 days after plant emergence to assess the treatment effects on dry matter partition between main stem and tillers. UFRGS 18 promoted dry matter allocation to tillers whereas UPF 17 directed dry mass mostly to the main stem. Differences in dry mass allocation between the main stem and tillers had no impact on grain yield, UPF 16 presenting the highest values for both growing seasons. The lack of interaction between population density and cultivar and the small effect of plant population on grain yield indicates that the oat tillering ability is not fundamental to define its grain yield.

Parameterization of the Phenological Development of Select Annual Weeds Under Noncropped Field Conditions

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 446-454 ◽  
Author(s):  
Anil Shrestha ◽  
Clarence J. Swanton
Keyword(s):  
Field Conditions ◽  
Weed Competition ◽  
Controlled Environment ◽  
Weed Species ◽  
Planting Dates ◽  
Common Lambsquarters ◽  
Wild Mustard ◽  
Competition Models ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Barnyardgrass, common lambsquarters, redroot pigweed, and wild mustard are among the most common weeds in cropping systems throughout North America. Crop and weed competition models that predict phenological development across environments are useful research tools for advancing our knowledge of population dynamics or crop and weed competition. Phenological parameter estimates for such models require verification under field conditions. Field studies were conducted in 1999 and 2000 to determine growth and phenological development of these species under noncropped conditions to compare parameters developed previously from controlled environment studies. Weeds were planted on three separate planting dates in each year. Growth and phenological development were recorded. Number of leaves on the mainstem of all weed species, except common lambsquarters, was not affected by planting dates. Rate of leaf appearance described as a function of days after emergence ranged from 0.48 to 0.89, 0.10 to 0.31, 0.33 to 0.65, and 0.24 to 0.29 leaves d−1 for common lambsquarters, barnyardgrass, redroot pigweed, and wild mustard, respectively. When expressed as a function of growing degree days (GDD), rate of leaf appearance for these species ranged from 0.04 to 0.05, 0.01 to 0.02, 0.04 to 0.07, and 0.02 to 0.03 leaves GDD−1, respectively. Planting date had differential effects on the rate of stem elongation and final plant height of each species in the 2 yr. Final plant biomass was also influenced by the time of planting; in general, weeds planted by mid-May had more biomass than those planted later. Parameters developed to describe phenological development under field conditions were comparable to those reported previously from controlled environment studies. We conclude that phenological parameters quantified under controlled environmental studies were comparable to those developed under field conditions for these weed species. Thus, either experimental method can be used to parameterize weed phenological development to initialize crop and weed competition models with reasonable confidence.

Appearance and growth of individual leaves in the canopies of several potato cultivars

1995 ◽  
Vol 125 (3) ◽  
pp. 379-394 ◽  
Author(s):  
D. M. Firman ◽  
P. J. O'Brien ◽  
E. J. Allen
Keyword(s):  
Air Temperature ◽  
Field Experiments ◽  
Strong Dependence ◽  
N Fertilizer ◽  
Potato Cultivars ◽  
Main Stem ◽  
Planting Dates ◽  
Wide Range ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

SUMMARYLeaf appearance of contrasting potato cultivars was examined in field experiments at Cambridge, UK, between 1985 and 1990. Three experiments examined the effects of N fertilizer on the appearance and growth of leaves. Four experiments examined leaf appearance over a wide range of planting dates and in two of these experiments different physiological ages of seed were compared.Linear regression of rate of appearance of main-stem leaves on air temperature indicated a strong dependence of rate of leaf appearance on temperature in the cultivar Maris Piper with a phyllochron of c. 31 K d/leaf but in Estima variation in rate of leaf appearance was only partly explained by differences in air temperature. The phyllochron of main-stem leaves in Estima and Home Guard was shorter for old seed than young seed but there was little effect of seed age in four other cultivars. The phyllochron of main-stem leaves was longer without N fertilizer than with N but the difference in the phyllochron between rates of applied N was small. Leaf appearance on sympodial branches was slower and more variable than on the main-stem. Growth of branches differed between cultivars, particularly with no N fertilizer. In the determinate cultivars Estima and Diana there was restricted growth of branches but in the indeterminate cultivar Cara, significant leaf area was contributed by branches. The duration of leaf appearance and longevity of individual leaves is discussed in relation to N, temperature and cultivar.

SELECTION FOR DRY MATTER YIELD IN LOLIUM PERENNE L. II. CORRELATED RESPONSES UNDER TWO CUTTING REGIMES

1980 ◽  
Vol 60 (2) ◽  
pp. 501-508 ◽  
Author(s):  
S. CECCARELLI ◽  
M. FALCINELLI ◽  
F. DAMIANI
Keyword(s):  
Lolium Perenne ◽  
Dry Matter ◽  
Leaf Size ◽  
Dry Matter Yield ◽  
Correlated Responses ◽  
Lolium Perenne L ◽  
Selection For ◽  
Cutting Regimes ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The correlated responses to divergent selection for dry matter yield within an ecotype of Lolium perenne L. were evaluated in two experiments under different cutting regimes. Both experiments showed that selection for dry matter yield did not affect leaf size and caused asymmetrical correlated responses on the rate of tiller production and the rate of leaf appearance. Selection for high dry matter yield resulted in an increased rate of tiller production without change in the rate of leaf appearance. Selection for low dry matter yield did reduce both the rate of leaf appearance and the rate of tiller production.

Efficacy of Pre and Post Emergence Application of Imazethapyr and its Ready Mix Herbicides on Growth, Weed Dynamics and Productivity of Chickpea (Cicer arietinum L.)

2021 ◽  
Author(s):  
Sheela Barla ◽  
R.R. Upasani
Keyword(s):  
Weed Management ◽  
Dry Matter ◽  
Yield Loss ◽  
Weed Competition ◽  
Maturity Stage ◽  
Dry Matter Accumulation ◽  
Initial Growth ◽  
Cicer Arietinum L ◽  
Weed Control Efficiency ◽  
Weed Dynamics

Background: Weeds are major constraints in chickpea production. This crop is highly susceptible to weed competition owing to slow initial growth thus weeds cause up to 75% yield loss. Methods: Treatments comprised of imazethapyr 50 g/ha as PE (pre emergence), imazethapyr 70 g/ha as PE, imazethapyr 50 g/ha as PoE (post emergence), imazethapyr 70g/ha as PoE, imazethapyr + imazamox ready mix (RM) 50 g/ha as PE, imazethapyr + imazamox (RM) 70 g/ha as PE, imazethapyr + imazamox (RM) 50 g/ha as PoE, imazethapyr + imazamox (RM)70 g/ha as PoE, pendimethalin 1 kg/ha PE, imazethapyr + pendimethalin (RM) 1 kg/ha PE, hoeing at 20 and 40 DAS and weedy check. Result: Application of imazethapyr + pendimethalin (RM) 1 kg/ha as pre emergence recorded maximum plant dry matter accumulation at 60, 90, 120 DAS and at maturity stage and also higher CGR at 60-90, 90-120 and120 DAS - maturity of crop. Application of imazethapyr + pendimethalin (RM) 1 kg/ha as pre emergence was most effective in producing higher seed yield (1749 kg/ha), weed control efficiency (87.28%), net return (` 77,136), reduced weed management index 5.15 and 3.90 at 30 and 60 DAS respectively.

An examination of the effects of water stress on leaf growth of crops of field beans (Viciafaba L.):1. Crop growth and yield

1981 ◽  
Vol 96 (2) ◽  
pp. 327-336 ◽  
Author(s):  
S. M. Farah
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Leaf Growth ◽  
Water Shortage ◽  
Growth And Yield ◽  
Natural Rainfall ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Field Beans ◽  
Number Of Cells

SUMMARYField beans (Vicia faba L.) were given three irrigation treatments in the field during two seasons to examine reduction in leaf area by water shortage, through effects on number of cells, cell volume and cell arrangement.The two crops behaved differently in the two seasons, presumably because of differences in environmental conditions. Season 1976 was brighter, warmer and drier than 1977. Water shortage reduced leaf area, dry matter and economic yield. The rate of leaf appearance and leaf longevity were also decreased by water shortage. The greatest biological and economic yields were produced by the wet treatment, followed by the medium and dry treatments. The treatment open to natural rainfall yielded least in 1976, but the second most in 1977. The yields of 1976 were considerably less than those of 1977.

scholarly journals Influence of Weed Competition on Potato Growth, Production and Radiation Use Efficiency

2011 ◽  
Vol 3 (3) ◽  
pp. 42-52 ◽  
Author(s):  
Farzad MONDANI ◽  
Farid GOLZARDI ◽  
Godarz AHMADVAND ◽  
Reza GHORBANI ◽  
Rooholla MORADI
Keyword(s):  
Leaf Area Index ◽  
Weed Control ◽  
Dry Matter ◽  
Yield Loss ◽  
Potato Yield ◽  
Weed Competition ◽  
Area Index ◽  
Use Efficiency ◽  
Radiation Use ◽  
Loss Level

Weed management in potato production is one of the main cost and time consuming practices. Understanding the most effective time of weed control could reduce the costs and increase potato yield. Field study was conducted in the west region of Iran during 2006 to evaluate the effect of weeds damage in potato fields. Twelve treatments used consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 10, 20, 30, 40 and 50 days after crop emergence (DAE), and then weeds were allowed to grow until harvest, and six initial weed-infested periods in which, weeds were allowed to grow for 0, 10, 20, 30, 40 and 50 DAE, then the plots were kept free of weeds until harvest. Experiment was arranged as a randomized complete block design with three replications. The results showed effect of weed competition on crop dry matter started about 40 DAE and about 90 DAE reached its maximum. The weeds competition decreased dry matter accumulation, leaf area index, crop growth rate, leaf area index duration, light absorption, light extinction coefficient and radiation use efficiency (RUE) of potato. Weeds reduced the potato yield 54.8 percent. The beginning and the end of the critical period of weed control in potato (CPWC) was based on 5% and 10% tuber yield loss. The onset of the CPWC ranged from 486 to 572 GDD, at 5% and 10% yield loss level corresponding to 11 and 19 days after crop emergence, respectively. The end of the CPWC varied from 1372 to 1164 GDD, at 5% and 10% yield loss level corresponding to 65 and 51 days after crop emergence, respectively. RUE in the weed infestation treatment in comparison to the weed free treatment, reduced 11.8 percent.

Sign in / Sign up

Export Citation Format

Share Document