Confirmation by fluorescent tracer of coverage of onion leaves for control of onion thrips using selected nozzles, surfactants and spray volumes

Abstract

Track sprayer and field sprayer trials were completed to assess the effect of different nozzles, surfactants and carrier volumes on product delivery to the inner leaves of onion plants using a fluorescent tracer. Track sprayer trials revealed more tracer on the inner leaves of onions using either the TeeJet s XR8004 flat fan or D4/DC25 disc-core hollow cone nozzles. In three of four experiments, more tracer was detected on onions sprayed alone or combined with Sylgard s 309 at 200 L/ha than plants sprayed with tracer+Companion s . When the carrier volume was increased to 400 L/ha, more tracer was detected on onions sprayed alone or combined with Companion. In field trials, the XR8004 delivered more tracer than the D4/DC25 (F ¼ 32.8; Po0.00; d.f. ¼ 1,77). The best coverage was observed on plants sprayed with the flat fan combined with Agral s 90, sprayed at either 400 L/ha (29% coverage) or 600 L/ha (23% coverage).

Quantification of insecticide spatial distribution within individual citrus trees and efficacy through Asian citrus psyllid reductions under different application methods

“…These spatial distribution results of insecticides may be especially inadequate for citrus trees due to their larger canopies and total foliar surface area. [22][23][24][25][26] Few studies have investigated canopy penetration in citrus with metal or fluorescent tracers and have reported that outer canopy receives more spray deposition than inner canopy regions. 14,20,27,28 Therefore, inner canopy leaves could risk receiving an inadequate amount of insecticide necessary to target ACP populations.…”

Effects of nozzle type and spray angle on spray deposition in ivy pot plants

“…The importance of the application technique, and more specifically the effect of spray quality and volume, on the control of pests in open field crops has been highlighted in several studies in different crops including soybean,26–28 onion,29 canola,30 cereals,2, 31–33 peanut,34 potatoes35 and cotton 36. Other studies suggest that spray quality and pressure are not so important with regard to deposition and disease control,37–40 and that coarse‐droplet applications are able to produce equal results in terms of biological efficacy 41–45…”

Effects of spray height and spray angle on spray deposition in tobacco plants

“…Better application techniques could improve the sustainable use of the plant protection products still available. The importance of the application technique, and more specifically the effect of spray quality and volume, on the control of pests in open field crops has been highlighted in several studies in different crops including cotton [1], onion [2], and potatoes [3]. The effects of charging voltage, application speed, target height has been studied in the laboratory [4].…”