title: Evaluation of spray application methods for navel orangeworm control in almonds.
abstract: BACKGROUND
  Gear Up/Throttle Down (GUTD) and Inward Only strategies represent potential alternatives to conventional airblast applications to reduce spray drift. This study evaluates Inward Only and a modified version of GUTD in almonds, the largest US tree crop, at the recommended hull split treatment timing for control of navel orangeworm (NOW), the key almond insect pest.
  
  
  RESULTS
  Conventional treatment produced the most drift (15.6% of total bifenthrin load), while the GUTD and Inward Only treatments produced only 7.6 and 9.7% respectively. For all methods, 92-94% of the drift was found in the first 15.2 m downwind of the orchard. NOW control was lower for the Inward Only treatment compared with the GUTD and conventional treatments. NOW control was consistently lower at 4.88 m height relative to 2.44 m in all treatments, reflecting the reduced deposition higher in the tree canopy recorded in deposition samples.
  
  
  CONCLUSIONS
  While Inward Only treatments reduced spray drift relative to the conventional application method, poorer control of NOW, the key insect pest of almonds, in the Inward Only treatment would likely limit its voluntary use by growers. However, GUTD holds promise for use at the hull split treatment timing to address spray drift. © 2016 Society of Chemical Industry.
authors.affiliation: Coalition for Urban/Rural Environmental Stewardship, Davis, CA, USA. jcmarkle@sbcglobal.net.
authors.forename: James C
authors.initials: JC
authors.lastname: Markle
authors.affiliation: UC Cooperative Extension, Pomology, Yuba City, CA, USA.
authors.forename: Franz Ja
authors.initials: FJ
authors.lastname: Niederholzer
authors.affiliation: Department of Entomology, University of California, Davis, CA, USA.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Zalom
mesh_terms: D000818:Animals; D002140:California; D007300:Insect Control / Q000295:instrumentation / Q000379:methods*; D007306:Insecticides / Q000008:administration & dosage*; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects; D010063:Ovum / Q000187:drug effects; D000068181:Prunus dulcis
chemical_list: D007306:Insecticides
keywords: agriculture; airblast sprayer; almonds; drift; efficacy; navel orangeworm