scholarly journals Establishing Defoliation Thresholds for Insect Pest of Peanut in Mississippi

2019 ◽  
Vol 46 (1) ◽  
pp. 1-7 ◽  
Author(s):  
C. C. Abbott ◽  
J. M. Sarver ◽  
J. Gore ◽  
D. Cook ◽  
A. Catchot ◽  
...  
Keyword(s):  
Photosynthetic Capacity ◽  
Plant Biomass ◽  
Insect Pest ◽  
Canopy Height ◽  
Growth Stages ◽  
Economic Injury Level ◽  
Pod Yield ◽  
Economic Injury ◽  
Plant Emergence ◽  
The Impact

ABSTRACT Defoliation of peanut by foliage-feeding insects reduces photosynthetic capacity, and in turn, may reduce pod yield, particularly when canopy loss occurs at critical growth stages, i.e., 40 or 80 d after full plant emergence (DAE). The objective of this research was to determine the impact of peanut defoliation levels of 0, 20, 40, 60, 80, and 100%, at 40 or 80 DAE on canopy height and width, plant biomass, pod grade and yield, and economic injury level. Research was conducted in Stoneville and Starkville MS in 2015 and 2016. The experimental design was a six (defoliation level) by two (defoliation timing) factorial arranged in a randomized complete block. Up to four wk after defoliation, canopy height, canopy width, and plant biomass were negatively correlated with defoliation level regardless of defoliation timing (40 and 80 DAE). Neither defoliation level nor timing had an effect on peanut grade or maturity. Similarly, defoliation at 40 DAE did not affect pod yield but when damage occurred 80 DAE, pod yield was reduced 18.6 kg/ha for every 1% increase in defoliation. Considering average crop value and insect control costs, the economic injury for peanut defoliation at 80 DAE is 5% defoliation. These data indicate that control of canopy-feeding insects is only economically viable when defoliation exceeds 5% defoliation at 80 DAE.

Managing cabbage seedpod weevils (Coleoptera: Curculionidae) in canola (Brassicaceae) – are Lygus (Hemiptera: Miridae) affected?

2018 ◽  
Vol 151 (1) ◽  
pp. 85-93
Author(s):  
H.A. Cárcamo ◽  
S.B. Meers ◽  
C.E. Herle
Keyword(s):  
Insect Pest ◽  
Economic Injury Level ◽  
Action Threshold ◽  
Southern Alberta ◽  
Economic Injury ◽  
Flower Stage ◽  
Significant Yield ◽  
Cabbage Seedpod Weevil ◽  
The Impact ◽  
Early Flower

AbstractCabbage seedpod weevil (Ceutorhynchus obstrictus Marsham; Coleoptera: Curculionidae) and Lygus Hahn (Hemiptera: Miridae) species are part of the late season insect pest complex of canola (Brassica Linnaeus; Brassicacea) in the southern prairies of Canada. From 2010 to 2013, large strips in 73 commercial fields were studied in southern Alberta to validate action thresholds for cabbage seedpod weevil and assess the impact of insecticide spraying at the early flower stage for cabbage seedpod weevils on abundance of Lygus at the pod stage. Only fields planted in April accumulated the damaging populations of cabbage seedpod weevils, such that the application of an insecticide resulted in significant yield protection. The economic injury level for the cabbage seedpod weevil was calculated at 20 cabbage seedpod weevils per 10 sweeps, but an action threshold of 25–40 is recommended because sampling mainly occurs along the edge where cabbage seedpod weevils are initially concentrated. At the pod stage, Lygus were lower in strips sprayed with insecticides at the early flower stage than in those not sprayed, but the differences were not statistically significant. Furthermore, Lygus were generally below economically damaging levels in early seeded fields. Therefore, there is no benefit of spraying early seeded fields to attempt to prevent Lygus outbreaks when cabbage seedpod weevils are below thresholds because Lygus may pose a risk only in fields planted later in the season.

scholarly journals Pest status of the leafhopper Empoasca dolichi Paoli on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria

2010 ◽  
Vol 41 (No. 4) ◽  
pp. 158-164 ◽  
Author(s):  
E.A. Egwurube ◽  
O. Ogunlana M ◽  
C. Dike M ◽  
I. Onu
Keyword(s):  
Arachis Hypogaea ◽  
Growth Stages ◽  
Northern Nigeria ◽  
Economic Injury Level ◽  
Pest Status ◽  
Growing Seasons ◽  
Economic Injury ◽  
One Year ◽  
Empoasca Dolichi ◽  
Different Growth Stages

Population studies and tests on the relationship between density and damage were conducted in 1999 to 2001 to determine the pest status of <I>Empoasca dolichi</I> on groundnut (<I>Arachis hypogaea </I>L.) in the Zaria area of northern Nigeria. Analyses showed that <I>Empoasca</I> numbers varied significantly from one year to another, and within each year the numbers of leafhoppers observed at the different growth stages of the plant were significantly different (<I>P</I> = 0.01). There was an inverse and highly significant relationship between the mean kernel yield and the <I>Empoasca </I>damage at the different growth stages of the plant. When natural population densities were plotted against economic injury level (EIL), the densities did not reach the EIL throughout the groundnut growing seasons. The insect was thus not an economic pest on groundnut in Zaria during the period of the study.

Dynamic analysis of the impact of free-air CO2 enrichment (FACE) on biomass and N uptake in two contrasting genotypes of rice

2018 ◽  
Vol 45 (7) ◽  
pp. 696 ◽  
Author(s):  
Jingjing Wu ◽  
Herbert J. Kronzucker ◽  
Weiming Shi
Keyword(s):  
Elevated Co2 ◽  
Seed Yield ◽  
Crop Yields ◽  
Plant Biomass ◽  
N Uptake ◽  
Yield Response ◽  
Growth Stages ◽  
Rice Cultivars ◽  
Total N ◽  
The Impact

Elevated CO2 concentrations ([CO2]) in the atmosphere often increase photosynthetic rates and crop yields. However, the degree of the CO2 enhancement varies substantially among cultivars and with growth stage. Here, we examined the responses of two rice cultivars, Wuyunjing23 (WYJ) and IIyou084 (IIY), to two [CO2] (~400 vs ~600) and two nitrogen (N) provision conditions at five growth stages. In general, both seed yield and aboveground biomass were more responsive to elevated [CO2] in IIY than WYJ. However, the responses significantly changed at different N levels and growth stages. At the low N input, yield response to elevated [CO2] was negligible in both cultivars while, at the normal input, yield in IIY was 18.8% higher under elevated [CO2] than ambient [CO2]. Also, responses to elevated [CO2] significantly differed among various growth stages. Elevated [CO2] tended to increase aboveground plant biomass in both cultivars at the panicle initiation (PI) and the heading stages, but this effect was significant only in IIY by the mid-ripening and the grain maturity stages. In contrast, CO2 enhancement of root biomass only occurred in IIY. Elevated [CO2] increased both total N uptake and seed N in IIY but only increased seed N in WYJ, indicating that it enhanced N translocation to seeds in both cultivars but promoted plant N acquisition only in IIY. Root C accumulation and N uptake also exhibited stronger responses in IIY than in WYJ, particularly at the heading stage, which may play a pivotal role in seed filling and seed yield. Our results showed that the more effective use of CO2 in IIY compared with WYJ results in a strong response in root growth, nitrogen uptake, and in yield. These findings suggest that selection of [CO2]-responsive rice cultivars may help optimise the rice yield under future [CO2] scenarios.

scholarly journals Comparing Biochar-Swine Manure Mixture to Conventional Manure Impact on Soil Nutrient Availability and Plant Uptake—A Greenhouse Study

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 372
Author(s):  
Chumki Banik ◽  
Jacek A. Koziel ◽  
Darcy Bonds ◽  
Asheesh K. Singh ◽  
Mark A. Licht
Keyword(s):  
Nutrient Uptake ◽  
Corn Stover ◽  
Biomass Yield ◽  
Plant Biomass ◽  
Swine Manure ◽  
Growth Stages ◽  
Manure Application ◽  
Total N ◽  
The Impact ◽  
Extractable Soil

The use of swine manure as a source of plant nutrients is one alternative to synthetic fertilizers. However, conventional manure application with >90% water and a low C:N ratio results in soil C loss to the atmosphere. Our hypothesis was to use biochar as a manure nutrient stabilizer that would slowly release nutrients to plants upon biochar-swine manure mixture application to soil. The objectives were to evaluate the impact of biochar-treated swine manure on soil total C, N, and plant-available macro- and micronutrients in greenhouse-cultivated corn (Zea mays L.) and soybean (Glycine max (L.) Merr.). Neutral pH red oak (RO), highly alkaline autothermal corn stover (HAP), and mild acidic Fe-treated autothermal corn stover (HAPE) biomass were pyrolyzed to prepare biochars. Each biochar was surface-applied to swine manure at a 1:4 (biochar wt/manure wt) ratio to generate mixtures of manure and respective biochars (MRO, MHAP, and MHAPE). Conventional manure (M) control and manure-biochar mixtures were then applied to the soil at a recommended rate. Corn and soybean were grown under these controls and treatments (S, M, MRO, MHAP, and MHAPE) to evaluate the manure-biochar impact on soil quality, plant biomass yield, and nutrient uptake. Soil organic matter significantly (<0.05) increased in all manure-biochar treatments; however, no change in soil pH or total N was observed under any treatment. No difference in soil ammonium between treatments was identified. There was a significant decrease in soil Mehlich3 (M3) P and KCl extractable soil NO3− for all manure-biochar treatments compared to the conventional M. However, the plant biomass nutrient concentrations were not significantly different from control manure. Moreover, an increasing trend of plant total N and decreasing trend of P in the plant under all biochar-manure treatments than the controls were noted. This observation suggests that the presence of biochar is capable of influencing the soil N and P in such a way as not to lose those nutrients at the early growth stages of the plant. In general, no statistical difference in corn or soybean biomass yield and plant nutrient uptake for N, P, and K was observed. Interestingly, manure-biochar application to soil significantly diluted the M3 extractable soil Cu and Zn concentrations. The results attribute that manure-biochar has the potential to be a better soil amendment than conventional manure application to the soil.

scholarly journals Comparing Biochar-Swine Manure Mixture to Conventional Manure Impact on Soil Nutrient Availability and Plant Uptake – A Greenhouse Study

2021 ◽  
Author(s):  
Chumki Banik ◽  
Jacek Koziel ◽  
Darcy Bonds ◽  
Asheesh Singh ◽  
Mark Licht
Keyword(s):  
Nutrient Uptake ◽  
Corn Stover ◽  
Biomass Yield ◽  
Plant Biomass ◽  
C:N Ratio ◽  
Swine Manure ◽  
Nutrient Concentrations ◽  
Growth Stages ◽  
Manure Application ◽  
The Impact

The use of swine manure as a source of plant nutrients is one alternative to synthetic fertilizers. However, conventional manure application with &gt;90% water and a low C:N ratio results in soil C loss to the atmosphere. Our hypothesis was to use biochar as a manure nutrient stabilizer that would slowly release nutrients to plants upon biochar-swine manure mixture application to soil. The objectives were to evaluate the impact of biochar-treated swine manure on soil total C, N, and plant-available macro and micronutrients in greenhouse-cultivated corn (Zea mays L.) and soybean (Glycine max (L.) Merr.). Neutral pH red oak (RO), highly alkaline autothermal corn stover (HAP), and mild acidic Fe-treated autothermal corn stover (HAPE) biomass were pyrolyzed to prepare biochars. Each biochar was surface-applied to swine manure at a 1:4 (biochar wt/manure wt) ratio to generate mixtures of manure and respective biochars (MRO, MHAP, and MHAPE). Conventional manure (M) control and manure-biochar mixtures were then applied to the soil at a recommended rate. Corn and soybean were grown under these controls and treatments (S, M, MRO, MHAP, and MHAPE) to evaluate the manure-biochar impact on soil quality, plant biomass yield, and nutrient uptake. Soil OM significantly (&lt;0.05) increased in all manure-biochar treatments; however, no change in soil pH or N was observed under any treatment. No difference in soil ammonium between treatments was identified. There was a significant decrease in soil M3-P and soil NO3- for all manure-biochar treatments compared to the conventional M. However, the plant biomass nutrient concentrations were not significantly different from control manure. Moreover, an increasing trend of N and decreasing trend of P in the plant under all biochar-manure treatments than the controls were noted. This observation suggests that the presence of biochar is capable of influencing the soil N and P in such a way as not to lose those nutrients at the early growth stages of the plant. In general, no statistical difference in corn or soybean biomass yield and plant nutrient uptake for N, P, and K was observed. Interestingly, manure-biochar application to soil significantly diluted the M3-extractable soil Cu and Zn concentrations. The results attribute that manure-biochar has the potential to be a better soil amendment than conventional manure application to the soil.

Response of canola to simulated diamondback moth (Lepidoptera: Plutellidae) defoliation at different growth stages

2000 ◽  
Vol 80 (3) ◽  
pp. 639-646 ◽  
Author(s):  
Suresh Ramachandran ◽  
G. David Buntin ◽  
John N. All
Keyword(s):  
Diamondback Moth ◽  
Maximum Yield ◽  
Field Trials ◽  
Crop Growth ◽  
Growth Stages ◽  
Economic Injury Level ◽  
Leaf Stage ◽  
Filling Stage ◽  
Crop Development ◽  
Economic Injury

In field trials conducted during 1995–1998, canola cultivar "Falcon" was subjected to different levels of simulated insect defoliation at four stages of crop growth. Plants were 0, 33, 67 and 100% defoliated at rosette and flowering stages during the 1995–1996 season as well as 2–4 leaf stage during the 1996–1997 and 1997–1998 seasons. Plants were 0, 50 and 100% defoliated at pod filling stage during all seasons. Over all seasons, defoliation did not consistently affect the number of plants per unit area, plant height, 1000 seed weight, and oil content of seeds for most of the defoliation treatments. However, defoliation at the 2–4 leaf and rosette stages made plants more susceptible to cold injury. Generally, canola could withstand a higher level of defoliation as crop development progressed. Maximum yield reductions occurred for defoliations at the 2–4 leaf stage followed by the rosette and flowering stages of the crop. No significant yield losses were recorded for defoliations at the pod filling stage. Results suggest that canola is most sensitive to defoliation in its early stages of growth. Greater amounts of defoliation can be tolerated as crop development progresses. The relationships between defoliation and yield loss were used to establish diamondback moth economic injury levels for canola at different crop growth stages. Key words: Canola, Brassica napus, oilseed rape, simulated defoliation, economic injury level

Reevaluating the Economic Injury Level for Brown Stink Bug (Hemiptera: Pentatomidae) at Various Growth Stages of Maize

2020 ◽  
Vol 113 (5) ◽  
pp. 2250-2258
Author(s):  
Tim B Bryant ◽  
Seth J Dorman ◽  
Dominic D Reisig ◽  
DeShae Dillard ◽  
Roger Schürch ◽  
...  
Keyword(s):  
Grain Yield ◽  
Growth Stage ◽  
Early Stage ◽  
Growth Stages ◽  
Stink Bug ◽  
Infestation Level ◽  
Economic Injury Level ◽  
Euschistus Servus ◽  
Economic Injury ◽  
Late Stages

Abstract Economic yield loss and reduction in grain quality from brown stink bug, Euschistus servus (Say), feeding injury in early and late stages of maize, Zea mays (Poales: Poaceae, Linnaeus), development was assessed in Virginia and North Carolina in 2018 and 2019. Varying levels of stink bug infestations were introduced to seedling maize (V2—early stage), and a range of late-stages of maize, including 1) the last stage of vegetative development (V12/V14), 2) prior to tasseling, 3) at tasseling (VT), and 4) across all tested late growth stages. Euschistus servus infestation levels included 33, 67, and 100% of maize seedlings, and 25, 50, 100, and 200% of plants during later stages. Infestations were maintained on seedling maize for 7 d, and 8 or 16 d in reproductive stages. Infestation level in seedling maize had an impact on grain yield. Infestation level and growth stage both had an impact on grain yield in reproductive maize. The percentage of discolored kernels was also affected by infestation level, but not growth stage. Regression analysis between grain yield and infestation level indicated that the average economic injury level is 7% in seedling maize (7 bugs/100 plants) and 12% (12 bugs/100 plants) from the last vegetative stages (V12/V14) through pollination (VT). The economic injury level in the late vegetative stages is only applicable when infestations are present for an extended period of time (16 d), emphasizing the need for continued scouting of maize throughout the season to make informed management decisions.

Competitive Effects of Hybrid Corn (Zea mays) on Replanted Corn

2014 ◽  
Vol 28 (4) ◽  
pp. 685-693 ◽  
Author(s):  
Tye C. Shauck ◽  
Reid J. Smeda
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Plant Biomass ◽  
Negative Impact ◽  
Biomass Accumulation ◽  
Field Trials ◽  
Growth Stages ◽  
Hybrid Corn ◽  
Volunteer Corn ◽  
The Impact

Initial corn (IC) in a replant situation, which is surviving corn from the initial planting, as well as volunteer corn from the previous season, is a competitive weed, but little is known regarding the effect of IC density on grain yield of desirable replant corn (RC). Field trials were established in central and northeast Missouri during 2008 to 2010 to determine the impact of IC on the leaf chlorophyll, stalk diameter, and grain yield of RC. Glyphosate-resistant RC was planted in 76-cm rows, with hybrid glyphosate-resistant IC established for season-long competition between rows at densities of 0 to 8 plants m−2. At vegetative growth stages with six and eight leaf collars and at tasseling (V6, V8, VT), RC leaf nitrogen levels were reduced by 5 to 30% in the presence of IC at densities of one to eight plants m−2compared with control plants lacking competition. Stalk diameters of RC at the VT growth stage were reduced from 8 to 30% by IC as densities increased from 0.5 to 8 plants m−2. Grain yield of row corn was reduced by IC, with yield losses ranging from 7 to 81%. Growth rate and biomass accumulation of hybrid and volunteer corn from V2 to VT were compared in the greenhouse to determine if competitive potential was similar. The second filial generation (F2) of corn from hybrid (DKC ‘63-42′) corn was collected from a field in central Missouri and southeastern Nebraska. There were no statistical differences found in growth rate or biomass accumulation between hybrid and F2corn up to VT, although F2plant biomass was numerically (up to 41%) lower at numerous growth stages. Hybrid corn is likely to be equally or more competitive with RC than volunteer corn. This research documents that in areas where IC remains among replanted corn, the IC has a negative impact at all densities evaluated.

scholarly journals Effect of Imidacloprid and Acephate for Tobacco Thrips (Thysonaptera: Thripidae) Management on Flumioxazin Injured Peanut

2021 ◽  
Author(s):  
J. C. Moor ◽  
Jeffrey Gore ◽  
J. Gore ◽  
A. Catchot ◽  
D. Cook ◽  
...  
Keyword(s):  
Untreated Control ◽  
Heavy Rainfall ◽  
Plant Biomass ◽  
Saturated Soils ◽  
Management Options ◽  
Insecticide Treatment ◽  
Pod Yield ◽  
Plant Canopies ◽  
Tobacco Thrips ◽  
The Impact

Experiments were conducted in 2016 and 2017 in Stoneville, MS and Starkville, MS to determine the impact of different insecticide management options for thrips on herbicide injured peanut. Insecticide treatments included imidacloprid in-furrow at-planting, one or two foliar applications of acephate, and an untreated control with and without an application of flumioxazin. In Stoneville, herbicide applications were made immediately following planting, and in Starkville, applications were made as plants were emerging to maximize herbicide injury. The Stoneville experiment also had an additional factor in which plots were flooded or not flooded to simulate a heavy rainfall in order to maximize herbicide injury and also to give added stress from saturated soils. Thrips counts, thrips injury ratings, plant vigor ratings, plant biomass, width between plant canopies, and yield were recorded.  Few interactions were observed, but temporary flooding, herbicide injury, and thrips injury affected peanut growth as measured by biomass and canopy.  Imidacloprid was the most consistent insecticide treatment for reducing thrips numbers and injury, but acephate provided some protection.  Temporary flooding during the seedling stage, flumioxazin injury, and thrips injury all reduced peanut pod yield.  Based on these results, every attempt should be made to minimize early season stress in peanuts including the use of an effective in-furrow insecticide.

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