scholarly journals Economic Injury Level of Canjiqueira in Native Pastures in Pantanal of Nhecolândia

2019 ◽  
Vol 37 ◽  
Author(s):  
C. BERSELI ◽  
J.A.M. BONO ◽  
S.A. SANTOS ◽  
F.A.R. PEREIRA ◽  
J.F. REIS NETO
Keyword(s):  
Threshold Level ◽  
Human Intervention ◽  
Effective Management ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Shrub Species ◽  
Invasive Shrub ◽  
Economic Injury ◽  
Native Pastures ◽  
Livestock System

ABSTRACT: Pantanal plain has large extensions of land formed by many types of landscapes suitable to extensive livestock system. Open grasslands and lowlands are formed by forage such as grasses and forbs widely consumed by cattle. However, climatic and human factors can promote the dissemination of invasive shrub species such as canjiqueira (Byrsonima cydoniifolia A. Juss) making it necessary, in many cases, the human intervention to control the invasion. The present work had as objective to determine the economic threshold level to control canjiqueira through two methods: tractor driven blade and link chains pulled by tractor in different invasion levels plants per hectare. Economic Threshold proved to be a tool for efficient and effective management for making decisions of when and how to do the control of canjiqueira in natural pastures of Pantanal of Nhecolândia.

Economic threshold levels for Chilo partellus (Lepidoptera: Pyralidae) control on resistant and susceptible sorghum plants

1997 ◽  
Vol 87 (1) ◽  
pp. 89-93 ◽  
Author(s):  
J. van den Berg ◽  
G. D. J. van Rensburg ◽  
M. C. van der Westhuizen
Keyword(s):  
Chilo Partellus ◽  
Yield Loss ◽  
Threshold Level ◽  
Field Trials ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Insecticide Application ◽  
Yield Increase ◽  
Linear Relationships ◽  
Economic Injury

AbstractThe effect of various infestation levels of Chilo partellus Swinhoe on resistant and susceptible sorghum genotypes was assessed under artificial infestation in two field trials, conducted over two seasons. In the first season, infestation levels were 0, 10, 20, 40, 60 and 80 larvae per 2 m plot row. In the second season, additional treatments of one and two larvae per plot were included. A series of all infestation levels on susceptible plants was also included with an insecticide application 5 days after inoculation. Non-linear relationships between infestation level and yield loss were observed. In susceptible plants, small increases in initial larval infestation levels resulted in sharp increases in yield loss. An opposite tendency was observed in resistant plants where a tolerant reaction at lower infestation levels was observed. Gain threshold (GT) value, indicating the yield increase necessary to compensate for control costs, economic injury level (EIL) and economic threshold level (ETL) at which control actions should be initiated were determined for each genotype. Insecticide application on susceptible plants resulted in a 10% reduction in yield loss. However, the yield was still less than that of unsprayed resistant plants. The GT values indicated that insecticide application was economically warranted at an ETL of 20% and 2% of plants with visible symptoms of whorl damage, for the resistant and susceptible genotypes respectively.

THE DYNAMICAL BEHAVIOR OF NON-SMOOTH SYSTEM WITH IMPULSIVE CONTROL STRATEGIES

2012 ◽  
Vol 05 (03) ◽  
pp. 1260018 ◽  
Author(s):  
YUAN-SHUN TAN ◽  
JU-HUA LIANG ◽  
SAN-YI TANG
Keyword(s):  
Impulsive Control ◽  
Control Strategies ◽  
Dynamical Behavior ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Pest Population ◽  
Different Types ◽  
Economic Injury ◽  
The Given ◽  
Smooth System

Non-smooth system including impulsive strategies at both fixed and unfixed times are analyzed. For the model with fixed impulsive effects, the global stability of pest eradication periodic solution and the dominance of dynamic behavior are investigated. This indicates that the model with fixed moments has the potential to protect the natural enemies from extinction, but under some conditions may also serve to extinction of the pest. The second model is constructed according to the practices of IPM, that is, when the pest population reaches the economic injury level, a combination of biological, cultural, and chemical tactics that reduce pests to tolerable levels is used. Numerical investigations imply that there are several different types of periodic solutions and their maximum amplitudes are always less than the given economic threshold. The results also show that the time series at which the IPM strategies are applied are quite complex, which means that the application and realization of IPM in practice are very difficult.

Life table and economic threshold concept for ecologically sustainable management of Diacrisia casignetum Kollar (Lepidoptera: Arctiidae) on Jute

ENTOMON ◽  
2019 ◽  
Vol 44 (2) ◽  
pp. 103-110
Author(s):  
Nayan Roy
Keyword(s):  
Life Table ◽  
Demographic Data ◽  
Intrinsic Rate ◽  
Natural Increase ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Potential Fecundity ◽  
Rate Of Increase ◽  
Economic Injury ◽  
Ecologically Sustainable

Life table and economic threshold (ET) level of Diacrisia casignetum Kollar on jute was calculated in West Bengal condition during 2016-2018 for environmentally benign management and better production of jute. The demographic data of D. casignetum always construct type-III survivorship curve like most of the insects. Potential fecundity (Pf) and total fertility rate (Fx) were 384.667±5.487 and 30893.60±1063.586, respectively. The average intrinsic rate of natural increase (rm) and the daily finite rate of increase (ë) were 0.106±0.001 and 1.111±0.003 respectively with the generation time (Tc) of 41.520±0.069 and doubling time (DT) of 6.563±0.021 days. Their mean population momentum factor of increase (PMF) was 19.676±0.605 including vital index (VI) and trend index (TI) of 0.522±0.003 and 92.359±2.648, respectively with different levels of significance. The economic injury level (EIL) and ET based on percent yield loss of jute were 7.119±2.166 and 6.385±1.969 pests per plant, respectively. At single pest observation per plant, the possible time taken to reach EIL (Ti) and ET (Tt) were 6.377±3.292 and 5.377±3.292 days, respectively which will be useful for better cultivation of jute and other subsequent crops.

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. 

Economic Injury Level (EIL) and Economic Threshold (ET) Concepts in Pest Management

2008 ◽  
pp. 1282-1286
Author(s):  
James C. Dunford ◽  
Louis A. Somma ◽  
David Serrano ◽  
C. Roxanne Rutledge ◽  
John L. Capinera ◽  
...  
Keyword(s):  
Pest Management ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Economic Injury

PEST STATUS AND ECONOMIC THRESHOLDS OF THE TARNISHED PLANT BUG, LYGUS LINEOLARIS (HEMIPTERA (HETEROPTERA): MIRIDAE), ON GREEN BEANS IN QUEBEC

1980 ◽  
Vol 112 (3) ◽  
pp. 301-305 ◽  
Author(s):  
R. K. Stewart ◽  
A. R. Khattat
Keyword(s):  
Regression Analysis ◽  
Phaseolus Vulgaris ◽  
Lygus Lineolaris ◽  
Economic Injury Level ◽  
Economic Threshold ◽  
Green Beans ◽  
Tarnished Plant Bug ◽  
Economic Thresholds ◽  
Economic Injury ◽  
Sweep Net

AbstractAdult and nymphal populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on “Contender” green beans, Phaseolus vulgaris L., were sampled during the summers of 1971–1972. Sweep net and D-Vac® suction apparatus samples were taken concurrently, and both estimates were compared by regression analysis.The tarnished plant bug reached levels above the economic injury levels for both early and late crops in 1971–1972. The economic threshold was determined as 0.5 insect/10 plants below the economic injury level.

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