TECHNOLOGIES TO MAXIMISE PRE-FLOWER SPRAY APPLICATIONS TO CONTROL SCALE ON KIWIFRUIT

摘要

The control of scale insects (Diaspididae) on kiwifruit (Actinidia chinensis) is difficult because scale inhabit sites not easily accessed by sprays. Early spring insecticide applications, which target scale living on the bark of canes and leader wood, are vital to reduce populations prior to summer. This study identified, firstly, that targeted Masotti gun, dilute spray applications increased deposits on leader vines by approximately 30%, which should result in improved scale control. Secondly, using the Masotti technology, sprays applied at 2x concentrate with the addition of a superspreader adjuvant increased deposits on leader wood by >60% compared with standard volumes. The use of Masotti guns, concentrate spray applications and adjuvant addition did not increase off-target spray drift, and often reduced it, in moderate winds. Adjuvant cost can be offset against increases in work-rate efficiency for concentrate sprays, and increased deposits and target coverage are expected to improve scale control on kiwifruit leader vines from pre-flower spray applications.