Selective chemical control of capeweed in wheat and oats

1972 ◽  
Vol 12 (54) ◽  
pp. 60 ◽  
Author(s):  
TG Reeves ◽  
JM Lumb
Keyword(s):  
Grain Yield ◽  
Chemical Control ◽  
Early Growth ◽  
Crop Damage ◽  
Growth Stages ◽  
North Eastern ◽  
Selective Chemical

In eight experiments conducted in north-eastern Victoria from 1965-1970, a range of herbicides were tested for selective post-emergence control of capeweed (Arctotheca calendula) in wheat and oats. Linuron, diquat, and bromoxynil were the best treatments tested and generally reduced capeweed density when applied in the early growth stages, causing little or no crop damage. Significant grain yield increases from spraying were obtained in each experiment with wheat, but in oats only one significant increase was obtained. Post-tillering treatments with 2,4-D and picloram plus 2,4-D did not increase grain yield.

scholarly journals Effects of simulated hail damage, and foliar-applied recovery treatments, on growth and grain yield of wheat, field pea and dry bean crops

2021 ◽  
Author(s):  
Gurbir Singh Dhillon ◽  
Mike Gretzinger ◽  
Lewis Baarda ◽  
Ralph Lange ◽  
Kabal Singh Gill ◽  
...  
Keyword(s):  
Grain Yield ◽  
Early Growth ◽  
Kernel Weight ◽  
Field Pea ◽  
Crop Damage ◽  
Yield Reduction ◽  
Growth Stages ◽  
Dry Bean ◽  
Hail Damage ◽  
Late Growth

Hailstorms can be responsible for significant economic loss to the agricultural sector in Alberta, Canada. Foliar applications of certain fungicides and nutrient blends have been advocated to promote recovery and yield of hail-damaged crops. Proper understanding of different crop and hail-related factors is required for an accurate assessment of hail damage to crops, and for evaluations of hail-recovery product claims. This study was undertaken at three locations in Alberta during three growing seasons (2016-18) to determine the effects of two levels of simulated hail severity at three different crop developmental stages including early growth (BBCH 30 for wheat; BBCH 14-16 for pulses), mid-growth (BBCH 39 for wheat; BBCH 60 for pulses) and late growth (BBCH 60 for wheat; BBCH 71 for pulses) stages. Plant growth, and yield parameters of wheat (Triticum aestivum L.), field pea (Pisum sativum L.) and dry bean (Phaseolus vulgaris L.) crops were measured. Simulated hail damage led to reductions in height, biomass, NDVI, grain yield and kernel weight of all three crops. Average yield decreased by 24 and 35% for wheat, 17 and 35% for dry beans, and 37 and 45% for field peas for light and heavy hail severity, respectively. Hail timing was a critical factor influencing the extent of crop damage, with hail damage during early growth stage leading to lesser yield reduction compared to hail damage at mid-growth and late growth stages. Fungicides and nutrient blends applications did not significantly improve crop recovery, grain yield or kernel weight for any of the crops in this study.

scholarly journals Water in maize whorl enhances the control of Spodoptera frugiperda with insecticides

2020 ◽  
Vol 50 ◽  
Author(s):  
Adriano Bialozor ◽  
Clérison Régis Perini ◽  
Jonas André Arnemann ◽  
Henrique Pozebon ◽  
Adriano Arrué Melo ◽  
...  
Keyword(s):  
Grain Yield ◽  
Spodoptera Frugiperda ◽  
Insect Pests ◽  
Fall Armyworm ◽  
Early Growth ◽  
Growth Stages ◽  
Bt Maize ◽  
Maize Hybrids ◽  
Cropping Seasons ◽  
And Control

ABSTRACT The fall armyworm Spodoptera frugiperda is among the main insect-pests on maize crops, due to its damaging potential and control issues related to the larval habit of concealing itself within the plant whorl. This study aimed to evaluate the effect of water in the maize whorl, combined with insecticides and spray sets, on the damage caused by S. frugiperda and the grain yield. The experiments were carried out under field conditions, at two cropping seasons, both with Bt-maize hybrids, in a 2 × 2 × 5 + 1 factorial scheme, testing the presence or absence of water inside the plant whorl, two insecticides and five spray sets (combinations of spray volumes, nozzle types, pressures and spraying speed), plus a control without water and insecticide. The presence of water inside the whorl reduced the damage caused by S. frugiperda during the early growth stages, especially in the plants sprayed with the insecticide chlorantraniliprole. The spray sets with 200 L ha1/20.3 psi or 250 L ha1/33.4 psi provided the highest reductions in the percentage of damaged plants and damage scores, regardless of the insecticide. Therefore, the spraying of insecticides, when there is water from irrigation, dew or rainfall inside the maize whorl, improves the control of S. frugiperda in maize crops, especially in Bt-maize.

Tolerance and Selectivity of Cereal Species and Cultivars to Postemergence Weed Harrowing

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Jesper Rasmussen ◽  
Helle H. Nielsen ◽  
Hanne Gundersen
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Soil Cover ◽  
Crop Damage ◽  
Growth Stages ◽  
Crop Tolerance ◽  
Barley Cultivars ◽  
Cereal Species

POST weed harrowing and other cultivation methods to control weeds in early crop growth stages may result in crop damage due to low selectivity between crop and weeds. Crop tolerance to cultivation plays an important role but it has not been clearly defined and analyzed. We introduce a procedure for analyzing crop tolerance on the basis of digital image analysis. Crop tolerance is defined as the ability of the crop to avoid yield loss from cultivation in the absence of weeds, and it has two components: resistance and recovery. Resistance is the ability of the crop to resist soil covering and recovery is the ability to recover from it. Soil covering is the percentage of the crop that has been buried because of cultivation. We analyzed data from six field experiments, four experiments with species of small grains, barley, oat, wheat, and triticale, and two experiments with barley cultivars with different abilities to suppress weeds. The order of species' tolerance to weed harrowing was triticale > wheat > barley > oat and the differences were mainly caused by different abilities to recover from soil covering. At 25% soil covering, grain yield loss in triticale was 0.5%, in wheat 2.5%, in barley 3.7%, and in oat 6.5%. Tolerance, resistance, and recovery, however, were influenced by year, especially for oat and barley. There was no evidence of differences between barley cultivars in terms of tolerance indicating that differences among species are more important than differences among cultivars. Selectivity analysis made it possible to calculate the crop yield loss due to crop damage associated with a certain percentage of weed control. In triticale, 80% weed control was associated with 22% crop soil cover on average, which reduced grain yield 0.4% on average in the absence of weeds. Corresponding values for wheat, barley, and oat were 23, 21, and 20% crop soil cover and 2.3, 3.6, and 5.1% grain yield loss.

ECONOMIC THRESHOLDS AND ECONOMIC INJURY LEVELS OF CEREAL APHIDS ON BARLEY IN SOUTHWESTERN QUEBEC

1980 ◽  
Vol 112 (8) ◽  
pp. 759-764 ◽  
Author(s):  
S. A. Ba-Angood ◽  
R. K. Stewart
Keyword(s):  
Grain Yield ◽  
Chemical Control ◽  
Growth Stages ◽  
Cereal Aphids ◽  
Economic Thresholds ◽  
Rate Of Increase ◽  
Economic Injury ◽  
Ripe Stage ◽  
Different Growth Stages ◽  
Percentage Protein

AbstractArtificial infestations of cereal aphids in caged plants were made at different growth stages of barley in the field in 1978 and 1979. Forty, 80, 160, and 200 aphids/tiller reduced grain yield significantly (P < 0.01) when introduced into caged plants at flowering and milky stages for 2 weeks. Only the 150 and 200 aphids/tiller-treatments gave significant reductions in yield when introduction was at the mealy ripe stage. Twenty aphids/tiller gave a significant reduction in yield only when they were introduced at the beginning of ear emergence and flowering, but not at the milky ripe stage. Significant reduction in percentage protein was obtained only when 160 and 200 aphids/tiller were introduced at flowering and milky ripe stages. The economic injury and threshold levels were calculated as 10–18 and 8–16 aphids/tiller, respectively, depending on rate of increase of aphids, costs of chemical control, and the value of the crop in 1978 and 1979.

The selective chemical control of Wimmera ryegrass in wheat with di-allate and tri-allate

1972 ◽  
Vol 12 (54) ◽  
pp. 55 ◽  
Author(s):  
TG Reeves ◽  
CL Tuohey
Keyword(s):  
Chemical Control ◽  
Crop Damage ◽  
Lolium Rigidum ◽  
Grain Yields ◽  
Economic Basis ◽  
Wimmera Ryegrass ◽  
Selective Chemical

Two herbicides, di-allate and tri-allate, were compared for the pre-emergence control of Wimmera ryegrass (Lolium rigidum) in wheat at three different locations in the Victorian wheatgrowing areas. Both herbicides significantly reduced ryegrass populations in the crop, but di-allate was consistently more effective than tri-allate. Grain yields were generally enhanced by spraying, but 1.12 kg a.i. per hectare of either material sometimes caused crop damage when applied before sowing. On an economic basis, di-allate at 0.56 kg a.i. per hectare was superior to all other treatments whether applied just before or just after sowing.

scholarly journals Damage Assessment of Rice Crop after Toluene Exposure Based on the Vegetation Index (VI) and UAV Multispectral Imagery

2020 ◽  
Vol 13 (1) ◽  
pp. 25
Author(s):  
Hyewon Kim ◽  
Woojung Kim ◽  
Sang Don Kim
Keyword(s):  
Grain Yield ◽  
Chlorophyll Content ◽  
Damage Assessment ◽  
Vegetation Index ◽  
Chemical Exposure ◽  
Crop Damage ◽  
Growth Stages ◽  
Multispectral Imagery ◽  
Chemical Accident ◽  
Toluene Exposure

Chemical spill accidents lead to environmental problems, especially for plants. Plant vegetation assessment is necessary after a chemical accident; however, conventional methods can be inaccurate and time-consuming. This study used the vegetation index (VI) extracted from unmanned aerial vehicle (UAV) multispectral imagery for crop damage assessment after chemical exposure. The chemical accident simulations were conducted by exposure of rice at five growth stages to four levels of toluene. The VI was measured at five days after damage and 67 days after planting. Physiological characteristics (chlorophyll content and grain yield) were also measured. As a result, the mean normalized difference VI (NDVI) of toluene-exposed rice was significantly decreased with respect to toluene exposure concentration increases at most growth stages. Recovery after toluene exposure was lower in rice exposed to higher concentrations at the earlier growth stages. The chlorophyll content and grain yield were also decreased after toluene exposure with respect to increasing toluene concentrations and showed positive correlations with the NDVI. It indicates that the NDVI is capable of reflecting the plant response to chemical exposure. Thus, the results demonstrated that the VI based on UAV multispectral imagery is feasible as an alternative for crop monitoring, damage assessment after chemical exposure, and yield prediction.

Selective chemical control of annual ryegrass (Lolium rigidum) in oilseed rape, field peas and lupins

1974 ◽  
Vol 14 (71) ◽  
pp. 771 ◽  
Author(s):  
TG Reeves ◽  
JM Lumb
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Chemical Control ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Grain Yields ◽  
Pisum Arvense ◽  
Field Peas ◽  
North Eastern ◽  
Selective Chemical

The effectiveness of herbicides for selective control of annual ryegrass (Lolium rigidum) in oilseed rape (Brassica napus), field peas (Pisum arvense) and narrow-leafed lupins (Lupinus angustifolius) was investigated in nine experiments in north-eastern and southern Victoria. Of the herbicides tested, di-allate, trifluralin and simazine significantly reduced ryegrass populations in all experiments where they were used. Pre-planting incorporated treatments were generally more effective than post-sowing or post-emergence treatments in oilseed rape and field peas. Control of ryegrass generally resulted in higher grain yields in all three crops, although lupins showed the greatest response. Dalapon, applied to oilseed rape after emergence, caused flower distortion and reduced yields in some experiments.

scholarly journals Yield and grain quality of spring barley as affected by biomass formation at early growth stages

2014 ◽  
Vol 60 (No. 5) ◽  
pp. 221-227 ◽  
Author(s):  
J. Křen ◽  
K. Klem ◽  
I. Svobodová ◽  
P. Míša ◽  
L. Neudert
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
Growth Parameters ◽  
Nitrogen Nutrition ◽  
Spring Barley ◽  
Early Growth ◽  
Growth Stages ◽  
Above Ground Biomass ◽  
Ground Biomass

Timely and reliable prediction of grain yield and quality of spring barley represents a key prerequisite for effective crop management. Within this study we evaluated the relationships between yield components, grain quality, biomass production and the number of tillers in different growth stages. For this purpose, in three years (2011&ndash;2013) multifactorial field trials focused on the combined effects of cultivar, sowing density and nitrogen nutrition were conducted. Based on ANOVA it was found that the formation of grain yield was affected by individual factors in the following order of importance: year, nitrogen, cultivar and sowing rate. The final grain yield significantly correlated both with the number of tillers and dry weight of above-ground biomass per unit area. The best estimation of yield provided both parameters at early growth stage (R = 0.83** and 0.81** for number of tillers and the above-ground biomass at BBCH 25). The grain protein content was inversely related to early growth parameters (R = &ndash;0.64** and &ndash;0.41** for number of tillers and above-ground biomass at BBCH 25). Based on the comparison of relationships between the years, it can be concluded that the early growth of barley and tiller differentiation is a key parameter for the formation of yield and grain quality.

scholarly journals Osmotic Stress or Ionic Composition: Which Affects the Early Growth of Crop Species More?

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 435
Author(s):  
Agnieszka Ludwiczak ◽  
Monika Osiak ◽  
Stefany Cárdenas-Pérez ◽  
Sandra Lubińska-Mielińska ◽  
Agnieszka Piernik
Keyword(s):  
Osmotic Stress ◽  
Stress Responses ◽  
Ionic Composition ◽  
Degradation Process ◽  
Early Growth ◽  
Cultivated Plants ◽  
C3 Plants ◽  
Growth Stages ◽  
Crop Species ◽  
Ionic Salt

Salinization is a key soil degradation process. An estimated 20% of total cultivated lands and 33% of irrigated agricultural lands worldwide are affected by high salinity. Much research has investigated the influence of salt (mainly NaCl) on plants, but very little is known about how this is related to natural salinity and osmotic stress. Therefore, our study was conducted to determine the osmotic and ionic salt stress responses of selected C3 and C4 cultivated plants. We focused on the early growth stages as those critical for plant development. We applied natural brine to simulate natural salinity and to compare its effect to NaCl solution. We assessed traits related to germination ability, seedlings and plantlet morphology, growth indexes, and biomass and water accumulation. Our results demonstrate that the effects of salinity on growth are strongest among plantlets. Salinity most affected water absorption in C3 plants (28% of total traits variation), but plant length in C4 plants (17–27%). Compensatory effect of ions from brine were suggested by the higher model plants’ growth success of ca 5–7% under brine compared to the NaCl condition. However, trait differences indicated that osmotic stress was the main stress factor affecting the studied plants.

scholarly journals Coastal Mangrove Response to Marine Erosion: Evaluating the Impacts of Spatial Distribution and Vegetation Growth in Bangkok Bay from 1987 to 2017

2020 ◽  
Vol 12 (2) ◽  
pp. 220 ◽  
Author(s):  
Han Xiao ◽  
Fenzhen Su ◽  
Dongjie Fu ◽  
Qi Wang ◽  
Chong Huang
Keyword(s):  
Spatial Distribution ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Mangrove Ecosystem ◽  
Early Growth ◽  
Growth Stages ◽  
Human Disturbances ◽  
Vegetation Growth ◽  
Two Parameters ◽  
The Impact

Long time-series monitoring of mangroves to marine erosion in the Bay of Bangkok, using Landsat data from 1987 to 2017, shows responses including landward retreat and seaward extension. Quantitative assessment of these responses with respect to spatial distribution and vegetation growth shows differing relationships depending on mangrove growth stage. Using transects perpendicular to the shoreline, we calculated the cross-shore mangrove extent (width) to represent spatial distribution, and the normalized difference vegetation index (NDVI) was used to represent vegetation growth. Correlations were then compared between mangrove seaside changes and the two parameters—mangrove width and NDVI—at yearly and 10-year scales. Both spatial distribution and vegetation growth display positive impacts on mangrove ecosystem stability: At early growth stages, mangrove stability is positively related to spatial distribution, whereas at mature growth the impact of vegetation growth is greater. Thus, we conclude that at early growth stages, planting width and area are more critical for stability, whereas for mature mangroves, management activities should focus on sustaining vegetation health and density. This study provides new rapid insights into monitoring and managing mangroves, based on analyses of parameters from historical satellite-derived information, which succinctly capture the net effect of complex environmental and human disturbances.

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