scholarly journals Economic threshold level (ETL) of okra shoot and fruit borer, Earias spp. on okra

2015 ◽  
Vol 10 (7) ◽  
pp. 697-701
Author(s):  
Kaur Sandeep ◽  
Kaur Ginday Kulwinder ◽  
Singh Subash
Keyword(s):  
Threshold Level ◽  
Economic Threshold ◽  
Fruit Borer

DETERMINATION OF ECONOMIC THRESHOLD LEVEL FOR CHILO AGAMEMNON BLES. INFESTATION IN RICE PLANTS, BASED ON SIMULATED DEAD HEARTS

2016 ◽  
Vol 94 (1) ◽  
pp. 59-69
Author(s):  
ALY M. SOLIMAN ◽  
AHMED S. HENDAWY ◽  
AMANY S. EL-HEFNY ◽  
MAHMOUD R. SHERIF
Keyword(s):  
Threshold Level ◽  
Economic Threshold ◽  
Rice Plants

scholarly journals Criteria for Decision Making and Economic Threshold Level for Wild Radish in Wheat Crop

2019 ◽  
Vol 37 ◽  
Author(s):  
L.C. TAVARES ◽  
E.S. LEMES ◽  
Q. RUCHEL ◽  
N.R. WESTENDORFF ◽  
D. AGOSTINETTO
Keyword(s):  
Dry Matter ◽  
Competitive Ability ◽  
Soil Cover ◽  
Wheat Cultivar ◽  
Wheat Yield ◽  
Threshold Level ◽  
Wheat Crop ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Economic Threshold

ABSTRACT: Weed competition limits wheat yield by reducing the availability of essential resources for its growth and development. In this sense, this study aimed to estimate the economic threshold level (ETL) of wild radish (Raphanus raphanistrum) in competition with wheat cultivars. Treatments were arranged in a factorial scheme. The factor wheat cultivar consisted of early (BRS 328), medium (BRS 177), and late (BRS Umbu) cycles and the factor wild radish population ranged from 0 to 564 plants m-2 (10 populations) for the cultivar BRS 328, 0 to 472 plants m-2 for the cultivar BRS 177 (11 populations), and 0 to 724 plants m-2 for the cultivar BRS Umbu (10 populations). The early-cycle BRS 328 presented a higher competitive ability when compared to the medium-cycle BRS 177 and late-cycle BRS Umbu. Yield losses of wheat grains due to wild radish interference can be satisfactorily estimated by the rectangular hyperbola model using the variables plant population, shoot dry matter, soil cover, and leaf area of the weed. ETL values varied as a function of the cultivar cycle, being higher for the cultivar BRS 328 (early) > BRS 177 (medium) > BRS Umbu (late). Wild radish is competitive in wheat crop, requiring at least 1.6 plants m-2 for control to be justified.

scholarly journals Effect of Acalypha australis Occurrence on Soybean Growth and Economic Threshold Level of Acalypha australis

2012 ◽  
Vol 1 (4) ◽  
pp. 13-17 ◽  
Author(s):  
Ji-Hyock Yoo ◽  
Byeong-Chul Moon ◽  
In-Yong Lee ◽  
Doo-Ho Kim
Keyword(s):  
Threshold Level ◽  
Economic Threshold

scholarly journals Weed interference period and economic threshold level of ryegrass in wheat

Bragantia ◽  
2019 ◽  
Vol 78 (3) ◽  
pp. 409-422
Author(s):  
Leandro Galon ◽  
Felipe José Menin Basso ◽  
Leonardo Chechi ◽  
Thalita Pedrozo Pilla ◽  
Carlos Orestes Santin ◽  
...  
Keyword(s):  
Threshold Level ◽  
Economic Threshold ◽  
Weed Interference

scholarly journals Effects of Sowing Date on Sunflower (Helianthus annuus) Damage by Pachnoda interrupta (Coleoptera: Scarabaeidae) and an Economic Threshold Levels for Its Management at Maiduguri, Sudan Savannah Ecological Zone of Nigeria

2013 ◽  
Vol 2 (3) ◽  
pp. 1
Author(s):  
Abdullahi G ◽  
B. M. Sastawa ◽  
Shehu A
Keyword(s):  
Yield Loss ◽  
Insect Pests ◽  
Cost Benefit ◽  
Threshold Level ◽  
Sowing Date ◽  
Planting Date ◽  
Control Measures ◽  
Economic Threshold ◽  
Pachnoda Interrupta ◽  
Cost Benefit Ratio

<em>Pachnoda interrupta</em> is one of the head-infesting insect pests of sunflower in Maiduguri. Two separate field experiment(one each for sowing date effect and threshold level) were conducted to investigate the influence of sowing date on damage and yield loss by <em>P. interrupta</em> on sunflower and the economic threshold level for its control in Maiduguri. The result for influence of sowing date experiment shows that percentage incidence of infestation was highly significant on sunflower sown on the 5<sup>th</sup> July than other planting date except that of 26<sup>th</sup> July. Significantly lower damage was recorded on sunflower sown on 19<sup>th</sup> July than those on the 5<sup>th</sup> and grain yield loss was also significantly higher on 26<sup>th</sup> July sowings than all other dates. The results for economic threshold level experiment indicated that 2.38 and 2.36 beetles/head were the economic threshold level for flowing and milky grain stage respectively and there was a 1:4.9 cost: benefit ratio/ ha. This means that there is a 20% return for every unit of inputs. The result implies that 19<sup>th</sup> of July is the best planting date to reduce infestations, damage and yield loss from <em>P. interrupta</em> in Maiduguri and artificial control measures should be initiated when there are 1.9 to 2.0 beetles/plant.

scholarly journals Threats of fall armyworm (Spodoptera frugiperda) incidence in Nepal and it’s integrated management-A review

2020 ◽  
Vol 3 (1) ◽  
pp. 345-359
Author(s):  
Sudhan Bhusal ◽  
Enjila Chapagain
Keyword(s):  
Spodoptera Frugiperda ◽  
Integrated Management ◽  
Fall Armyworm ◽  
Threshold Level ◽  
Cereal Crop ◽  
Severe Damage ◽  
Economic Threshold ◽  
Trap Crop ◽  
Short Period ◽  
First Time

Fall Armyworm (Spodoptera frugiperda) is in the state of major threat for Nepal especially in maize although it has more than 80 host to continue its life cycle. After its first incidence in Africa in 2016, it has already spread in more than 100 countries within a short period of time. It was seen in India for the first time in 2018. Due to the open border between Nepal and India, there is high probability of incidence of pest in Nepal. The temperature regime of Nepal is highly suitable for the pest establishment. Now is the time to think about the pest which can cause severe damage to the second most produced cereal crop of Nepal i.e. maize. Management of the pest is possible through many biological, chemical and cultural means. Planting of legumes as a trap crop and ploughing field properly before planting the field can be a best possible cultural method of managing the pest. Natural enemies like Telenomus, Trichogramma chilotraeae for controlling the eggs, Bacillus thuringiensis for larvae and Brachymeria ovata for pupa of Fall Armyworm in Maize and Vegetables. Similarly, Neem extracts are found be larvicidal and the oil extracted from the seeds of long pepper are found to be checking Spermatogenesis of the pest. Chemicals like Methomyl, Cyfluthrin, Methyl parathion are used tocontrol the pest. Use of chemicals at the initiation of the pest spread is discouraged as it can hamper the natural enemy present in the surrounding ecology. However, the use of pesticides can be done below the economic threshold level so that the pest does not develop any resistance towards the chemicals.

scholarly journals INTERFERENCE AND ECONOMIC THRESHOLD LEVEL FOR CONTROL OF BEGGARTICK ON BEAN CULTIVARS

2016 ◽  
Vol 34 (3) ◽  
pp. 411-422 ◽  
Author(s):  
L. GALON ◽  
C.T. FORTE ◽  
R.L. GABIATTI ◽  
L.L. RADUNZ ◽  
I. ASPIAZÚ ◽  
...  
Keyword(s):  
Grain Yield ◽  
Ground Cover ◽  
Threshold Level ◽  
Dry Mass ◽  
Control Measures ◽  
Economic Damage ◽  
Hyperbolic Model ◽  
Yield Losses ◽  
Economic Threshold ◽  
Control Cost

ABSTRACT The aim of the study was to assess the interference and determine the economic threshold level of beggartick damage on bean crops. Treatments consisted of bean cultivars (IPR Uirapuru, BRS Supremo, BRS Campeiro, Fepagro 26, BRS Esplendor and IPR Tuiuiú) submitted to competition with ten beggartick populations. We evaluated plant population, leaf area, ground cover and shoot dry mass of beggartick. Dry mass of shoots of beggartick fitted better to the hyperbolic model, and grain yield losses due to beggartick interference were estimated satisfactorily by this model. BRS Esplendor and IPR Tuiuiú were more competitive than the others in the presence of beggartick. Sowing of BRS Esplendor, IPR Tuiuiú and Fepagro 26 increases the level of economic damage, justifying the adoption of control measures only for higher densities of beggartick. Increase in grain yield, commercial price of beans, herbicide efficiency and reduction in control cost decrease the threshold level for weed control, justifying application of control measures for lower densities of beggartick.

scholarly journals Determination of economic threshold level for the timely management of cotton jassid Amrasca bigutulla (Ishida) on okra vegetable crop

2017 ◽  
Vol 9 (3) ◽  
pp. 1429-1433
Author(s):  
Sandeep Kaur ◽  
Amandeep Kaur ◽  
Gurpreet Kaur ◽  
A.K. Dhawan
Keyword(s):  
Pest Management ◽  
Management Practices ◽  
Threshold Level ◽  
Leaf Margin ◽  
Economic Threshold ◽  
Vegetable Crop ◽  
Pooled Data ◽  
Injury Grade ◽  
And Control

A field study was carried out at Vegetable Research Farm PAU, Ludhiana to determine the economic threshold level for the timely management of cotton jassid Amrasca bigutulla (Ishida) on okra vegetable crop. It was observed that significantly lowest jassid nymphal count per leaf in the pooled data (0.96 nymphs/leaf) were registered in the treatment where spray against jassid were given at 2 nymphs/leaf stage and first injury grade that is curling and yellowing of leaf margin as compared to others spray stages (1.54-1.72 nymphs/leaf) and unsprayed control (1.75 nymphs/leaf) significantly lowest jassid injury grade was also observed when spray stared at 2 nymphs/ leaf (0.58) and second spray stage curling and yellowing of leaf margin (0.65 nymphs/leaf) as against other spray stages (1.13 – 1.60 nymphs/leaf) and unsprayed control (1.63 nymphs/leaf). Maximum plant (110.33-110.44 cm) was also recorded as against other treatment (90.80 – 108.46 cm) and control (90.13cm). Total highest fruit yield (120.40-120.75) quintal /ha was also registered in these two treatments. Economic threshold level estimated for the management of cotton jassid on okra crop will help to develop an ecologically safe pest management practices against this pest.

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