scholarly journals Economic injury level for sugarcane caused by the spittlebug Mahanarva fimbriolata (Stål) (Hemiptera:Cercopidae)

2008 ◽  
Vol 65 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Leila Luci Dinardo-Miranda ◽  
João Paulo Pivetta ◽  
Juliano Vilela Fracasso
Keyword(s):  
Field Experiment ◽  
Economic Importance ◽  
Sugar Yield ◽  
The Other ◽  
Regression Analyses ◽  
Economic Injury Level ◽  
Sugarcane Crop ◽  
Pest Infestation ◽  
Lack Of Information ◽  
Economic Injury

The sugarcane spittlebug, Mahanarva fimbriolata (Stål), is currently one of the most important pests of the sugarcane crop in Brazil. In spite of its economic importance, advances in the management of this pest have been limited by the lack of information on the economic injury level. In this study, the economic injury level for M. fimbriolata was estimated in a field experiment, over areas harvested in September, applying thiamethoxam at 200 g a.i. ha-1 or imidacloprid at 720 g a.i. ha-1. In one of the experiments, insecticide applications were made at pest infestation values of 4.2 (11/12/04), 7.1 (01/11/05), or 16.3 (01/18/05) insects m-1, and in experiment 2 when pest populations were 5.6 (11/12/04), 8.5 (01/11/05), or 15.3 (01/11/05) insects m-1. Control plots without insecticide were maintained. After the applications, spittlebug infestations were estimated monthly, and the experiments were harvested in September 2005. Spittlebug control with the application of insecticides resulted in stalk and sugar yield increases in relation to the control, for both experiments. Applications performed under smaller infestations resulted in higher yields than applications made under higher populations. There were no differences between insecticides in one of the experiments; in the other, however, thiamethoxan contributed to greater yield increases than imidacloprid. Insecticide applications made under lower infestations resulted in greater profits. Regression analyses allowed the estimation of the pest economic injury level to be between 2 to 3 insects m-1 for the conditions of this experiment.

scholarly journals A new concept of economic injury level that includes penalization of damage to quality and safety of agricultural products

2001 ◽  
Vol 37 (No. 4) ◽  
pp. 151-156 ◽  
Author(s):  
V. Stejskal
Keyword(s):  
Decision Making ◽  
Economic Importance ◽  
Agricultural Products ◽  
Decision Making Process ◽  
Traditional Model ◽  
Quality And Safety ◽  
Economic Injury Level ◽  
Qualitative And Quantitative ◽  
Pest Infestation ◽  
Economic Injury

The traditional model of Economic Injury Level (EIL) does not allow to directly incorporate aspects of damage to quality and safety of a product (Dq) into the decision-making process to control a pest (pathogen, weed, arthropod, vertebrate). This work now attempts to generalize a concept of EIL by (i) separating damages to quality and safety (i.e. Dq and EILq) from quantitative (i.e. Dw and EILw) types of damage (D) in the traditional EIL-equation, and (ii) by establishing a new way of estimation of EILq based on the penalization of quality and/or safety damage. The importance to distinguish between the terms EIL, EILw and EILq is discussed, and a calculation of the new index (Z), enabling the comparison of the relative economic importance of qualitative and quantitative damage caused by a particular level of pest infestation or disease severity, is proposed.

scholarly journals PENETUAN ALE DAN AE LARVA LEPIDIOTA STIGMA F PADA TANAMAN TEBU

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Alimin, Edhi Martono, dan Witjaksono
Keyword(s):  
Biological Control ◽  
Light Trap ◽  
The Other ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Other Hand ◽  
Economic Injury ◽  
Weight Proportion

This research was conducted to determine the value of Economic Injury Level (EIL) and Economic Threshold (ET) for the larvae of Lepidiota stigma instar 1, 2 and 3 in three different locations. The amount of larvae population and plant per m2 in the field, and the weight proportion of the vanished root or to-be-eaten by a larva were needed to determine the loss of result per m2 data on the maximum harvest outcome and the harvest outcome in the field per m2. The highest proportion value of the outcome loss per m2 based on the Walker Model, which has been modified on biological control with Nematode Entomo Patogen (NEP) Steinernema spp. combined with light trap, was in Tempel Sari, i.e. larvae instar 1 (0.0108), instar 2 (0.0174), and instar 3 (0.0221). The lowest value was in Grenjeng, i.e. larvae instar 1 (0.0048), instar 2 (0.0078), and instar 3 (0.0099). There were significant differences among the three instars, where the consumption greediness of instar 3 is higher than instar 1 and 2, so the proportion value of the outcome loss per m2 of larvae instar 3 in the respective locations was higher than that of the two other instars. Determination of EIL value based on the Bode & Calvin Models gave the highest EIL value in Grenjengwith larvae instar 1 in the amount of 15.50 with ET value 12.40, instar 2 in the amount of 9.59 with ET value 7.67, and instar 3 in the amount of 7.54 with ET value 6.03. On the other hand, the lowest EIL value was found in Tempel Sari, with larvae instar 1 in the amount of 6.97 with ET value 5.58, instar 2 in the amount of 4.31 with ET value 3.45, and instar 3 in the amount of 3.39 with ET value 2.71. 

scholarly journals Perception and Use of Economic Thresholds Among Farmers and Agricultural Professionals: A Case Study on Soybean Aphid in Minnesota

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natalie Hoidal ◽  
Robert L Koch
Keyword(s):  
Soybean Aphid ◽  
Educational Outreach ◽  
Economic Injury Level ◽  
Economic Thresholds ◽  
Foundational Principle ◽  
Economic Injury ◽  
Fundamental Misunderstanding ◽  
The Difference ◽  
Commercial Pesticide ◽  
Agricultural Professionals

Abstract Economic thresholds (ETs) are a foundational principle of integrated pest management but are not always widely accepted by farmers and agricultural professionals. This article reports on a survey of Minnesota farmer and agricultural professional perceptions of the ET for soybean aphid, Aphis glycines Matsumura (Hempitera: Aphididae). We discuss insights for Extension programs on how to frame the importance of thresholds and teach stakeholders to use them effectively. Key takeaways include farmers and agricultural professionals often worry about combined effects of insect, disease, and physiological pressures, whereas effects of interactions with these other stressors are seldom discussed in educational outreach. Across groups, there is a fundamental misunderstanding about the difference between ETs and economic injury level. Many survey participants reported believing in the ET but lacked the time and capacity to fully implement it. Sales agronomists and farmers were the least likely groups to trust the university-determined soybean aphid ET, whereas commercial pesticide applicators and independent consultants were the most likely groups to trust it. Based on these results, we recommend adapting communication about ETs based on the target audience to address common misconceptions and barriers to ET use that are unique to each group.

scholarly journals Compatibility of Bt biopesticides and adjuvants for Spodoptera frugiperda control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cicero Antônio Mariano dos Santos ◽  
Joacir do Nascimento ◽  
Kelly Cristina Gonçalves ◽  
Giovani Smaniotto ◽  
Leonardo de Freitas Zechin ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
Economic Importance ◽  
The Other ◽  
Distilled Water ◽  
Bt Crops

AbstractSpodoptera frugiperda is a pest of economic importance for several crops with resistance reports to Bt crops and pesticides. Eco-friendly Bt biopesticides may be an alternative to chemical insecticides due to their selectivity and specificity. However, the efficacy of Bt biopesticides may be influenced by the association with other chemicals, such as adjuvants. This study evaluated the compatibility and toxicity of Bt biopesticides mixed with adjuvants for the control of S. frugiperda. The treatments included the association of Dipel SC and Dipel PM with adjuvants. Compatibility tests were used to evaluate the Bt mixture. Bt suspensions obtained from mixtures of Bt and adjuvants at 106 and 3 × 108 spores/mL−1 were used to evaluate S. frugiperda mortality and distilled water was used as the control. The addition of the adjuvant LI increased growth and sporulation, indicating compatibility with Bt biopesticides. The other adjuvants were toxic to reducing Bt growth and sporulation. Only the mixture of Bt with LI and Bt alone was effective to S. frugiperda. The addition of adjuvants to Bt biopesticide affect the Bt sporulation, growth and mortality.

Notes on two Locusts of minor economic Importance in the Sudan

1932 ◽  
Vol 23 (1) ◽  
pp. 49-64 ◽  
Author(s):  
H. B. Johnston
Keyword(s):  
Economic Importance ◽  
The Other ◽  
Other Hand ◽  
Mutual Independence ◽  
Gregarious Locusts ◽  
Distinguishing Character

The so-called short-horned locusts are frequently, for convenience sake, regarded as comprising two classes: the true locusts (Arabic: Girad) and the short-horned grasshoppers (Arabic : Gabura). It is difficult, however, to find definitions of these classes by means of which every species may be correctly assigned to its true place. The swarming habits of the true locust are often cited as connoting this class only, involving, as these habits do, the periodical appearance of excessive numbers of both hoppers and adults. Moreover the true locust is gregarious, in that the hoppers move in bands from one place to another, and the adults fly in vast swarms often over long distances. The fact that the grasshoppers are solitary in habit and manifest mutual independence of action is often taken as their chief distinguishing character. There is no doubt that these features do partly separate these two classes of insects from each other, but there are certain species which appear to occupy a position intermediate between the two. One normally solitary may, in certain circumstances, multiply rapidly and give rise to hoppers, which in certain respects act like those true locusts. Moreover the winged adults may undertake short massed flights resembling the migrations of swarms. On the other hand the fact, now fully established, that most true gregarious locusts have their solitary forms, which never associate, places even them in this respect with the grasshoppers.

Improving U-Net architecture and graph cuts optimization to classify arterioles and venules in retina fundus images

2021 ◽  
pp. 1-12
Author(s):  
Nguyen Thanh Binh ◽  
Nguyen Mong Hien ◽  
Dang Thanh Tin
Keyword(s):  
Graph Cuts ◽  
The Other ◽  
Retinal Vessels ◽  
Fundus Images ◽  
Vascular Structure ◽  
Vascular Changes ◽  
Lack Of Information ◽  
Retinal Artery ◽  
Diagnostic Indicator ◽  
Better Than

The central retinal artery and its branches supply blood to the inner retina. Vascular manifestations in the retina indirectly reflect the vascular changes and damage in organs such as the heart, kidneys, and brain because of the similar vascular structure of these organs. The diabetic retinopathy and risk of stroke are caused by increased venular caliber. The degrees of these diseases depend on the changes of arterioles and venules. The ratio between the calibers of arterioles and venules (AVR) is various. AVR is considered as the useful diagnostic indicator of different associated health problems. However, the task is not easy because of the lack of information of the features being used to classify the retinal vessels as arterioles and venules. This paper proposed a method to classify the retinal vessels into the arterioles and venules based on improving U-Net architecture and graph cuts. The accuracy of the proposed method is about 97.6%. The results of the proposed method are better than the other methods in RITE dataset and AVRDB dataset.

scholarly journals USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL CHEMICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL

2015 ◽  
Vol 39 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Ivanildo Amorim de Oliveira ◽  
Milton César Costa Campos ◽  
José Marques Junior ◽  
Renato Eleotério de Aquino ◽  
Daniel de Bortoli Teixeira ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Spherical Model ◽  
Exponential Model ◽  
Soil Samples ◽  
Soil Chemical Properties ◽  
Sampling Density ◽  
Sugarcane Crop ◽  
Lack Of Information ◽  
Set Up ◽  
Almost All

The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were determined at these points. Data were analyzed by descriptive and geostatistical analyses. A large part of the data analyzed showed spatial dependence. Chemical properties were best fitted to the spherical model in almost all the environments evaluated, except for the sugarcane field with a better fit to the exponential model. ADE and sugarcane areas had greater heterogeneity of soil chemical properties, showing a greater range and higher sampling density; however, forest and agroforestry areas had less variability of chemical properties.

Paranormal Belief, Experience, and the Keirsey Temperament Sorter

2000 ◽  
Vol 86 (3_part_2) ◽  
pp. 1104-1106
Author(s):  
Jezz Fox ◽  
Carl Williams
Keyword(s):  
College Students ◽  
Multiple Regression ◽  
The Other ◽  
Minor Role ◽  
Regression Analyses ◽  
Keirsey Temperament Sorter ◽  
Paranormal Belief ◽  
Anomalous Experience ◽  
A Minor ◽  
Paranormal Experience

121 college students completed the Anomalous Experience Inventory and the Keirsey Temperament Sorter. Multiple regression analyses provided significant models predicting both Paranormal Experience and Belief; the main predictors were the other subscales of the Anomalous Experience Inventory with the Keirsey variables playing only a minor role.

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