Vertical distribution, spatial dispersion and sequential sampling plan for fruit damage byHelicoverpa armigera(Hübner) (Lepidoptera: Noctuidae) on tomato crop in Burkina Faso

1992 ◽  
Vol 38 (3) ◽  
pp. 250-253 ◽  
Author(s):  
Denis Bouchard ◽  
Amidou Ouedraogo ◽  
Guy Boivin
Keyword(s):  
Vertical Distribution ◽  
Burkina Faso ◽  
Spatial Dispersion ◽  
Sequential Sampling ◽  
Sampling Plan ◽  
Tomato Crop ◽  
Sequential Sampling Plan ◽  
Fruit Damage ◽  
Lepidoptera Noctuidae

Monitoring for Fruit Damage in Processing Tomatoes: Use of a Dynamic Sequential Sampling Plan

1983 ◽  
Vol 12 (3) ◽  
pp. 835-839 ◽  
Author(s):  
L. T. Wilson ◽  
F. G. Zalom ◽  
R. Smith ◽  
M. P. Hoffmann
Keyword(s):  
Sequential Sampling ◽  
Sampling Plan ◽  
Sequential Sampling Plan ◽  
Fruit Damage ◽  
Processing Tomatoes

scholarly journals Risk Assessment for Tomato Fruitworm in Processing Tomato Crop-Egg Location and Sequential Sampling

Insects ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Elisabete Figueiredo ◽  
Catarina Gonçalves ◽  
Sónia Duarte ◽  
Maria C. Godinho ◽  
António Mexia ◽  
...  
Keyword(s):  
Spatial Pattern ◽  
Sequential Sampling ◽  
Sampling Plan ◽  
Random Pattern ◽  
Growth Stages ◽  
Data Sets ◽  
Tomato Crop ◽  
Sample Number ◽  
Sequential Sampling Plan ◽  
Fixed Sample

Helicoverpa armigera is one of the key pests affecting processing tomatoes and many other crops. A three-year study was conducted to describe the oviposition preferences of this species on determinate tomato plants (mainly the stratum, leaf, leaflet, and leaf side) and the spatial pattern of the eggs in the field, to form a sequential sampling plan. Eggs were found mainly in the exposed canopy, on leaves a (upper stratum) and b (upper-middle stratum) and significantly fewer eggs on leaf c (middle-lower stratum) below flower clusters. This vertical pattern in the plant was found in all phenological growth stages. The spatial pattern was found to be aggregated, with a trend towards a random pattern at lower densities. A sequential sampling plan was developed, based on Iwao’s method with the parameters of Taylor’s power law, with minimum and maximum sample size of 20 and 80 sample units (plants), respectively (two leaves/plant). For its validation, operating characteristic (OC) and average sample number (ASN) curves were calculated by means of simulation with independent data sets. The β-error was higher than desirable in the vicinity of the economic threshold, but this sampling plan is regarded as an improvement both in effort and precision, compared with the fixed sample plan, and further improvements are discussed.

scholarly journals Within-plant distribution and binomial sequential sampling plan for Tetranychus evansi (Acari: Tetranychidae) in greenhouse tomato: implications for management.

2020 ◽  
Author(s):  
Willis Ndeda Ochilo ◽  
Gideon Nyamasyo ◽  
John Agano
Keyword(s):  
Sequential Sampling ◽  
Sampling Plan ◽  
Plant Distribution ◽  
Tetranychus Evansi ◽  
Sequential Sampling Plan ◽  
Red Spider Mite ◽  
Mite Density ◽  
Density Analysis ◽  
The Tropics ◽  
Best Fit

Abstract The red spider mite, Tetranychus evansi is a critical pest of tomato in the tropics. Control of T. evansi has traditionally depended on acaricide treatments. However, it is only in a handful of crops where monitoring techniques for mites, using statistical methods, have been developed to help farmers decide when to spray. The objective of this study, therefore, was to develop a sampling plan that would help farmers increase accuracy, and reduce the labor and time needed to monitor T. evansi on tomato. The distribution of T. evansi within-plant was aggregated, and intermediate leaves (YFL) was the most appropriate sampling unit to evaluate the mite density. Analysis based on Taylor's Power Law showed an aggregated pattern of distribution of T. evansi, while assessment of the fitness of the binomial model indicated that a tally threshold of 5 mites per YFL provided the best fit. Consequently, binomial sequential sampling plans premised on three action thresholds (0.1, 0.2 and 0.3) were developed. The binomial sequential sampling plan for T. evansi developed in this study has the potential to significantly increase the chance for targeted acaricide applications. This judicious use of pesticides is especially crucial within the context of integrated pest management (IPM).

Sign in / Sign up

Export Citation Format

Share Document