A field investigation to examine the effects of sprayer type, ground speed, and volume rate on spray deposition in Florida citrus

Whitney, J. D.; Salyani, M.; Churchill, D. B.; Knapp, J.L.; Whiteside, J. O.; Littell, Ramon C.

doi:10.1016/0021-8634(89)90030-9

Cited by 34 publications

(42 citation statements)

References 2 publications

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“…Secondly, spray equipment, spray volume and rate have also been shown to have considerable influence on pesticide retention 12, 40, 41. Thirdly, potential differences in canopy structure may be another important contributing factor, as many studies have shown that initial spray deposit and retention are critically influenced by canopy structure in tree crops 8, 13, 15, 42. Finally, inherent differences in the characteristics between the tracer and pesticides might also affect the initial deposition process.…”

Section: Discussionmentioning

confidence: 99%

Variability in initial spray deposit in apple trees in space and time

Thorbek

et al. 2006

Pest Management Science

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Variation in pesticide residues in space and time has not been investigated systematically in spite of the large variability found at single scales (e.g. between trees or orchards). Information on variability at different scales will support the development of sampling methods and more reliable prediction of residues. Experiments were conducted to quantify the spatiotemporal variability in initial spray deposit on apple leaves and fruit using a substitute tracer (zinc EDTA chelate). Five hierarchical spatial scales were defined as (1) between orchards, (2) between plots within an orchard, (3) between trees within a plot, (4) between zones within a tree and (5) between leaves/fruit within a zone. Similarly, two temporal scales were defined as (1) between applications within a single year and (2) between years. The initial zinc concentration was approximately log-normally distributed; the variability in initial deposit concentration was greater on leaves than on fruit. The average initial zinc deposition was significantly greater in the top and outside zones than in the middle zones within individual trees. The most important scale for driving residue variability is the within-zone unit-to-unit variation, contributing to 71 and 49% of the observed variability for leaf and fruit samples respectively. Variability at other scales was related to the variation in the tree architecture. The results indicated that stratified sampling on the basis of within-tree zone structures, with the effort focused on within-zone sampling, should be used for the determination of pesticide residues.

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Section: Discussionmentioning

confidence: 99%

Variability in initial spray deposit in apple trees in space and time

Thorbek

et al. 2006

Pest Management Science

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“…The width of plant canopy is the parameter that decides the width of spray to be applied on it such that the width of spray should go inside the average width of plant canopy to get maximum coverage (Speelman and Jansen, 1974;Giles and Comino, 1989). Whitney et al (1989) examined the effect of ground speed (1.6, 2.8 and 4.0 km h -1 ) on upper and lower leaf surface deposition using different air blast sprayers and spray volume and stated that the speed of operation significantly increased deposition on the upper leaf surface, but not on the lower leaf surface. Optical sensors can be used for recognition of plants and discrimination between plant species by utilizing image analysis methods and/or multi-spectra information.…”

Section: Introductionmentioning

confidence: 99%

Performance evaluation of tractor operated target actuated sprayer

Jayashree¹,

Dhanabalan²

2012

Afr. J. Agric. Res.

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“…Fruit collection zones were chosen at three heights bottom (ground to 1.1m), middle (1.1 to 2.2m), and top (2.2 to 4.0m) into the canopy (the inter-plant canopy region of the planting row) on one side between two consecutive plants. The establishment of the selection sites was due to the high difficulty of spray droplets to reach this part (WHITNEY et al, 1989;ARAÚJO et al, 2013). Two fruits were collected and individually packaged -in plastic bags -from each canopy collection site.…”

Section: Fruits Spray Depositsmentioning

confidence: 99%