scholarly journals Assessing Feeding Damage from Two Leaffooted Bugs, Leptoglossus clypealis Heidemann and Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae), on Four Almond Varieties

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 333
Author(s):  
Andrea L. Joyce ◽  
Apurba K. Barman ◽  
David Doll ◽  
Bradley S. Higbee
Keyword(s):  
Damage Assessment ◽  
Management Program ◽  
Western Hemisphere ◽  
Phytophagous Insects ◽  
Feeding Damage ◽  
Field Cage ◽  
Early Season ◽  
Late Season ◽  
Set Up ◽  
Kernel Necrosis

Leaffooted bugs (Leptoglossus spp; Hemiptera: Coreidae) are phytophagous insects native to the Western Hemisphere. In California, Leptoglossus clypealis and Leptoglossus zonatus are occasional pests on almonds. Early season feeding by L. clypealis and L. zonatus leads to almond drop, while late season feeding results in strikes on kernels, kernel necrosis, and shriveled kernels. A field cage study was conducted to assess feeding damage associated with L. clypealis and L. zonatus on four almond varieties, Nonpareil, Fritz, Monterey, and Carmel. The objectives were to determine whether leaffooted bugs caused significant almond drop, to pinpoint when the almond was vulnerable, and to determine the final damage at harvest. Branches with ~20 almonds were caged and used to compare almond drop and final damage in four treatments: (1) control branches, (2) mechanically punctured almonds, (3) adult Leptoglossus clypealis, and (4) adult Leptoglossus zonatus. Replicates were set up for eight weeks during two seasons. Early season feeding resulted in higher almond drop than late season, and L. zonatus resulted in greater drop than L. clypealis. The almond hull width of the four varieties in the study did not influence susceptibility to feeding damage. The final damage assessment at harvest found significant levels of kernel strikes, kernel necrosis, and shriveled almonds in bug feeding cages, with higher levels attributed to L. zonatus than L. clypealis. Further research is warranted to develop an Integrated Pest Management program with reduced risk controls for L. zonatus.

scholarly journals Impacts of compound hot–dry extremes on US soybean yields

2021 ◽  
Vol 12 (4) ◽  
pp. 1371-1391
Author(s):  
Raed Hamed ◽  
Anne F. Van Loon ◽  
Jeroen Aerts ◽  
Dim Coumou
Keyword(s):  
Soil Moisture ◽  
Synergistic Effects ◽  
Weather Data ◽  
Yield Variability ◽  
Critical Element ◽  
Early Season ◽  
Soybean Yield ◽  
Late Season ◽  
The Us ◽  
Dry Conditions

Abstract. The US agriculture system supplies more than one-third of globally traded soybean, and with 90 % of US soybean produced under rainfed agriculture, soybean trade is particularly sensitive to weather and climate variability. Average growing season climate conditions can explain about one-third of US soybean yield variability. Additionally, crops can be sensitive to specific short-term weather extremes, occurring in isolation or compounding at key moments throughout crop development. Here, we identify the dominant within-season climate drivers that can explain soybean yield variability in the US, and we explore the synergistic effects between drivers that can lead to severe impacts. The study combines weather data from reanalysis and satellite-informed root zone soil moisture fields with subnational crop yields using statistical methods that account for interaction effects. On average, our models can explain about two-thirds of the year-to-year yield variability (70 % for all years and 60 % for out-of-sample predictions). The largest negative influence on soybean yields is driven by high temperature and low soil moisture during the summer crop reproductive period. Moreover, due to synergistic effects, heat is considerably more damaging to soybean crops during dry conditions and is less problematic during wet conditions. Compounding and interacting hot and dry (hot–dry) summer conditions (defined by the 95th and 5th percentiles of temperature and soil moisture respectively) reduce yields by 2 standard deviations. This sensitivity is 4 and 3 times larger than the sensitivity to hot or dry conditions alone respectively. Other relevant drivers of negative yield responses are lower temperatures early and late in the season, excessive precipitation in the early season, and dry conditions in the late season. We note that the sensitivity to the identified drivers varies across the spatial domain. Higher latitudes, and thus colder regions, are positively affected by high temperatures during the summer period. On the other hand, warmer southeastern regions are positively affected by low temperatures during the late season. Historic trends in identified drivers indicate that US soybean production has generally benefited from recent shifts in weather except for increasing rainfall in the early season. Overall, warming conditions have reduced the risk of frost in the early and late seasons and have potentially allowed for earlier sowing dates. More importantly, summers have been getting cooler and wetter over the eastern US. Nevertheless, despite these positive changes, we show that the frequency of compound hot–dry summer events has remained unchanged over the 1946–2016 period. In the longer term, climate models project substantially warmer summers for the continental US, although uncertainty remains as to whether this will be accompanied by drier conditions. This highlights a critical element to explore in future studies focused on US agricultural production risk under climate change.

Effect of In-Furrow Application of Fluopyram on Leaf Spot Diseases of Peanut

Plant Disease ◽  
2021 ◽  
Author(s):  
Albert Culbreath ◽  
Robert Kemerait ◽  
Timothy Brenneman ◽  
Emily Cantonwine ◽  
Keith Rucker
Keyword(s):  
Arachis Hypogaea ◽  
Leaf Spot ◽  
Fungal Pathogens ◽  
Field Experiments ◽  
Resistance Management ◽  
Feeding Damage ◽  
Early Season ◽  
Late Leaf Spot ◽  
Frankliniella Fusca ◽  
Tobacco Thrips

In peanut (Arachis hypogaea) production, in-furrow applications of the pre-mix combination of the SDHI fungicide/nematicide, fluopyram, and the insecticide, imidacloprid are used primarily for management of nematode pests and for preventing feeding damage on foliage caused by tobacco thrips (Frankliniella fusca). Fluopyram is also active against many fungal pathogens. However, the effect of in-furrow applications of fluopyram on early leaf spot (Passalora arachidicola) or late leaf spot (Nothopassalora personata) has not been characterized. The purpose of this study was to determine the effects of in-furrow applications of fluopyram + imidacloprid or fluopyram alone on leaf spot epidemics. Field experiments were conducted in Tifton, GA in 2015, 2016, and 2018-2020. In all experiments in-furrow applications of fluopyram + imidacloprid provided extended suppression of early leaf spot and late leaf spot epidemics compared to the nontreated control. In 2020, there was no difference between the effects of fluopyram + imidacloprid and fluopyram alone on leaf spot epidemics. Results indicated that fluopyram could complement early season leaf spot management programs. Use of in-furrow applications of fluopyram should be considered as an SDHI fungicide application for resistance management purposes.

Availability of existing early-season rice cultivars as resources for selecting high-yielding short-duration cultivars of machine-transplanted late-season rice

2019 ◽  
Vol 56 (2) ◽  
pp. 218-226
Author(s):  
Jiana Chen ◽  
Min Huang ◽  
Fangbo Cao ◽  
Xiaohong Yin ◽  
Yingbin Zou
Keyword(s):  
Grain Yield ◽  
Short Duration ◽  
Good Yield ◽  
Rice Production ◽  
Hunan Province ◽  
Rice Cultivars ◽  
Growth Duration ◽  
Yield Performance ◽  
Early Season ◽  
Late Season

AbstractHigh-yielding short-duration cultivars are required due to the development of mechanized large-scale double-season rice (i.e. early- and late-season rice) production in China. The objective of this study was to identify whether existing early-season rice cultivars can be used as resources to select high-yielding, short-duration (less than 115 days) cultivars of machine-transplanted late-season rice. Field experiments were conducted in Yongan, Hunan Province, China in the early and late rice-growing seasons in 2015 and 2016. Eight early-season rice cultivars (Liangyou 6, Lingliangyou 211, Lingliangyou 268, Xiangzaoxian 32, Xiangzaoxian 42, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with growth durations of less than 115 days were used in 2015, and four cultivars (Lingliangyou 268, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with good yield performance in the late season in 2015 were grown in 2016. All cultivars had a growth duration of less than 110 days when grown in the late season in both years. Zhongjiazao 17 produced the maximum grain yield of 9.61 Mg ha−1 with a daily grain yield of 108 kg ha−1 d−1 in the late season in 2015. Averaged across both years, Lingliangyou 268 had the highest grain yield of 8.57 Mg ha−1 with a daily grain yield of 95 kg ha−1 d−1 in the late season. The good yield performance of the early-season rice cultivars grown in the late season was mainly attributable to higher apparent radiation use efficiency. Growth duration and grain yield of early-season rice cultivars grown in the late season were not significantly related to those grown in the early season. Our study suggests that it is feasible to select high-yielding short-duration cultivars from existing early-season rice cultivars for machine-transplanted late-season rice production. Special tests by growing alternative early-season rice cultivars in the late season should be done to determine their growth duration and grain yield for such selection.

scholarly journals Evaluation of Insecticide Combinations Against Late Season Populations of Bollworms, Tobacco Budworms and Boll Weevils, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 198-198
Author(s):  
J. B. Graves ◽  
J. H. Pankey ◽  
B. R. Leonard ◽  
C. A. White
Keyword(s):  
Test Area ◽  
Tobacco Budworm ◽  
Research Station ◽  
Feeding Damage ◽  
Seed Cotton ◽  
Hollow Cone ◽  
Late Season ◽  
High Clearance

Abstract Six insecticide treatments were evaluated at the Macon Ridge Branch of the Northeast Research Station, Winnsboro, LA, to determine their efficacy in controlling the bollworm/tobacco budworm complex and boll weevils. Cotton was planted 18 Jun in plots consisting of 4 rows (40 inch centers) × 50 ft. Treatments were arranged in a RCBD with 4 replications. Treatments were applied with a high clearance sprayer calibrated to deliver 6 gal total spray/acre through Teejet X-8 hollow cone nozzles (2/row) at 46 psi. Insecticides were applied on 22, 26 Aug and 1 Sep against established populations of bollworms, tobacco budworms (primarily tobacco budworms) and boll weevils. Efficacy of the various treatments against these species was determined on 25, 31 Aug and 7 Sep by examining 50 squares/plot for evidence of feeding damage. Also numbers of larvae per 50 squares were recorded for the bollworm/tobacco budworm complex. The plots were mechanically harvested on 25 Oct to determine seed cotton yields. The test area received 0.57 and 0.20 inches rainfall on 1 and 6 Sep, respectively.

scholarly journals Field Evaluation of Yield and Yield Component Traits of Breeding Lines of Maize over Two Seasons in Derived Savannah Agro-Ecology

2018 ◽  
Vol 10 (4) ◽  
pp. 567-574
Author(s):  
Charles U. UBA ◽  
Christian U. AGBO ◽  
Uchechukwu P. CHUKWUDI ◽  
Andrew A. EFUSIE ◽  
Stella O. MUOJIAMA
Keyword(s):  
Grain Yield ◽  
Block Design ◽  
Field Evaluation ◽  
Yield Component ◽  
Seasonal Effects ◽  
International Institute ◽  
Early Season ◽  
Breeding Lines ◽  
Late Season ◽  
Positive Effects

The understanding of yield and the interaction with its components is very important for selection in early generations of crop breeding. Twelve maize genotypes were collected from International Institute for Tropical Agriculture (IITA) along with seven landraces in order to identify the contribution of different traits to yield improvement. The experiments were carried out in two different seasons (March/April-early and July/August- late) in a randomized complete block design with three replications. Early season planting had a higher grain yield than late season planting. The difference in grain yield between early and late season was 3.92 tons/ha. This represents a 27.8% increase in grain yield during the early season over the late season planting. Number of ears per plant and shelling percentage were not influenced by seasonal effects. Ear weight and days to tasselling showed the highest direct positive effects of 0.972 and 0.665, respectively on grain yield, during early season. Furthermore, ear weight, followed by shelling percentage, exerted the highest direct positive effect on grain yield in late season. Higher indirect positive effects were obtained for ear diameter, ear length, ear height and plant height via ear weight in both seasons. Ear weight, days to tasselling and ear length were identified as the major traits affecting yield of maize in both seasons in the derived Savannah agro-ecology.

scholarly journals Response of Sesame to Selected Herbicides Applied Early in the Growing Season

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
W. James Grichar ◽  
Jack J. Rose ◽  
Peter A. Dotray ◽  
Todd A. Baughman ◽  
D. Ray Langham ◽  
...  
Keyword(s):  
No Reduction ◽  
Field Studies ◽  
Yield Reduction ◽  
Early Season ◽  
Application Timing ◽  
Late Season ◽  
Growing Seasons ◽  
Leaf Chlorosis ◽  
Untreated Check ◽  
Dinitroaniline Herbicides

Growth chamber experiments were conducted to evaluate the response of sesame to PRE and POST applications of soil residual herbicides. PRE applications of acetochlor andS-metolachlor at 1.26 and 1.43 kg ai·ha−1showed little or no sesame injury (0 to 1%) 4 wks after herbicide treatments (WAT). POST treatments of acetochlor and trifluralin made 3 wks after planting (WAP) resulted in greater sesame injury (40%) compared to applications at bloom (18%). Field studies were conducted in Texas and Oklahoma during the 2014 and 2015 growing seasons to determine sesame response to clethodim, diuron, fluometuron, ethalfluralin, quizalofop-P, pendimethalin, pyroxasulfone, trifluralin, and trifloxysulfuron-sodium applied 2, 3, or 4 weeks after planting (WAP). Late-season sesame injury with the dinitroaniline herbicides consisted of a proliferation of primary branching at the upper nodes of the sesame plant (in the shape/form of a broom). Ethalfluralin and trifluralin caused more “brooming” effect than pendimethalin. Some yield reductions were noted with the dinitroaniline herbicides. Trifloxysulfuron-sodium caused the greatest injury (up to 97%) and resulted in yield reductions from the untreated check. Early-season diuron injury (leaf chlorosis and necrosis) decreased as application timing was delayed, and late-season injury was virtually nonexistent with only slight chlorosis (<4%) still apparent on the lower leaves. Sesame yield was not consistently affected by the diuron treatments. Fluometuron caused early-season injury (stunting/chlorosis), and a reduction of yield was observed at one location. Pyroxasulfone applied 2 WAP caused up to 25% sesame injury (stunting) but did not result in a yield reduction. Quizalofop-P caused slight injury (<5%) and no reduction in yield.

Heterogeneity in fire severity within early season and late season prescribed burns in a mixed-conifer forest

2006 ◽  
Vol 15 (1) ◽  
pp. 37 ◽  
Author(s):  
Eric E. Knapp ◽  
Jon E. Keeley
Keyword(s):  
Sierra Nevada ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Basal Area ◽  
Conifer Forest ◽  
Fuel Loading ◽  
Early Season ◽  
Late Season ◽  
Fuel Loads ◽  
In Fire

Structural heterogeneity in forests of the Sierra Nevada was historically produced through variation in fire regimes and local environmental factors. The amount of heterogeneity that prescription burning can achieve might now be more limited owing to high fuel loads and increased fuel continuity. Topography, woody fuel loading, and vegetative composition were quantified in plots within replicated early and late season burn units. Two indices of fire severity were evaluated in the same plots after the burns. Scorch height ranged from 2.8 to 25.4 m in early season plots and 3.1 to 38.5 m in late season plots, whereas percentage of ground surface burned ranged from 24 to 96% in early season plots and from 47 to 100% in late season plots. Scorch height was greatest in areas with steeper slopes, higher basal area of live trees, high percentage of basal area composed of pine, and more small woody fuel. Percentage of area burned was greatest in areas with less bare ground and rock cover (more fuel continuity), steeper slopes, and units burned in the fall (lower fuel moisture). Thus topographic and biotic factors still contribute to the abundant heterogeneity in fire severity with prescribed burning, even under the current high fuel loading conditions. Burning areas with high fuel loads in early season when fuels are moister may lead to patterns of heterogeneity in fire effects that more closely approximate the expected patchiness of historical fires.

System Target Damage Assessment Based on FAHP

2013 ◽  
Vol 321-324 ◽  
pp. 2367-2370
Author(s):  
Xiao Nan Zhang ◽  
Si Lang Du ◽  
Jun Feng Yang ◽  
Wei Cao
Keyword(s):  
Analytic Hierarchy Process ◽  
Damage Assessment ◽  
Target Function ◽  
Assessment Method ◽  
Analysis Method ◽  
Analytic Hierarchy ◽  
Base Damage ◽  
Hierarchy Analysis ◽  
Set Up ◽  
Hierarchy Process

It is found that the traditional BDA methods are not appropriate the system target BDA. A new method of the system target BDA is proposed in this paper. Firstly, based on Hierarchy Analysis Method (AHP), the system target function index system is set up. Secondly, the step of system target function damage assessment method is analyzed and proposed based on Fuzzy Analytic Hierarchy Process (FAHP). Finally, an example of air base damage assessment is given to verify the validity and availability of the proposed method.

Development of Risk-Based Inspection Methodology in River Crossings

2017 ◽  
Author(s):  
Eduardo Lopes de Paula ◽  
Markus Moratti ◽  
Eduardo Henrique da Silva Rodrigues ◽  
Elivelton Pinheiro Scherrer
Keyword(s):  
Oil And Gas ◽  
Management Program ◽  
Third Party ◽  
Evaluation Methodology ◽  
Control Actions ◽  
Hydrological Hazards ◽  
Static And Dynamic Loads ◽  
Set Up ◽  
Definition Of ◽  
Survey Evaluation

The transportation system for hydrocarbons consists of an important and complex network of pipelines used by oil and gas logistics companies, designed to quickly and efficiently transport oil and gas from its origin, to areas of some demand along territory where operates. Currently Brazil has 15,000 km of transportation pipelines within about 7,500 km of right-of-way pipelines. Along its territorial extension it faces several influences along its route, being the main ones influenced by the external hazards from nature and by third party actions. TRANSPETRO has about 450 water crossings in cataloged water bodies currently. These crossings are currently characterized only according to their geometric characteristics, not considering several aspects inherent to them. The inspections at these crossings are laborious and have a high cost due to necessity of divers and bathymetry in some cases. To monitor the condition of all pipeline water crossings it is important to ensure the pipeline integrity. Depending on hydraulic phenomena, it is possible result in an exposure of the pipelines, free spans, changes in the original pipeline or excessive vibration. These changes can generate high mechanical stresses with both static and dynamic loads. The present study was characterized by the development of a methodology for assessing the susceptibility to the exposure of pipelines as a result of the hydrological hazards present at the crossings in which they are found. Moreover, this evaluation methodology offers a tool to define inspection extent and frequency, as well as the corresponding risk control actions. For this purpose, a pipeline management program has been set up, which consists in the definition of water crossings that constitute a potential hydrological hazard and where they can interact with the pipeline considering the probability of a specific hydrotechnical hazard leading the pipeline the exposure. As a result of this research it was defined a methodology to characterize pipeline crossing areas as well as field survey, evaluation of the susceptibility of pipeline exposure at crossings and the programming of control actions were defined according to the susceptibility found. Finally, the study has also presented a cost analysis of crossings inspections comparing the traditional method to the new premises adopted in this project.

Weed Control in Soybean (Glycine max) with Flumetsulam, Cloransulam, and Diclosulam

1999 ◽  
Vol 13 (4) ◽  
pp. 791-798 ◽  
Author(s):  
David R. Shaw ◽  
Andrew C. Bennett ◽  
Donald L. Grant
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Standard Treatment ◽  
The Other ◽  
Early Season ◽  
Late Season ◽  
Pitted Morningglory

Cloransulam postemergence (POST), diclosulam preemergence (PRE), and flumetsulam preplant incorporated (PPI) and POST were evaluated in six trials at two locations for control of sicklepod and pitted morningglory in soybean. Sicklepod control with cloransulam plus flumetsulam POST was equivalent to chlorimuron POST in seven of eight comparisons both 3 and 6 wk after treatment. Sicklepod control with cloransulam POST was equivalent to chlorimuron in only three of eight comparisons 3 wk after treatment, but late-season control was equivalent in five of six comparisons. Pitted morningglory control with cloransulam alone or in tank-mixture with flumetsulam POST was equivalent to chlorimuron in all comparisons. Control of sicklepod and pitted morningglory was greater in most comparisons when a POST application followed flumetsulam plus trifluralin PPI compared to only trifluralin PPI. In a total PRE stale seedbed system, where all treatments were tank-mixed with pendimethalin plus glyphosate, sicklepod control with all rates of flumetsulam and 26 or 35 g ai/ha diclosulam was equivalent to the standard treatment of imazaquin or metribuzin plus chlorimuron. None of the total PRE programs controlled sicklepod as well as when glyphosate was applied sequentially POST. Pitted morningglory was controlled 83 to 93% with 26 or 35 g/ha diclosulam, equivalent to imazaquin, metribuzin plus chlorimuron, or sequential glyphosate applications 8 wk after the PRE application. Increasing flumetsulam rate increased pitted morningglory control early season, but flumetsulam was not as effective as the other herbicides.

Sign in / Sign up

Export Citation Format

Share Document