PT  - JOURNAL ARTICLE
AU  - Watson, Gary
AU  - Jacobs, Karel
TI  - Control of Apple Scab and Cytospora Canker with Paclobutrazol
AID  - 10.48044/jauf.2012.018
DP  - 2012 May 01
TA  - Arboriculture & Urban Forestry (AUF)
PG  - 112--116
VI  - 38
IP  - 3
4099  - http://auf.isa-arbor.com/content/38/3/112.short
4100  - http://auf.isa-arbor.com/content/38/3/112.full
AB  - Forty Malus ‘Radiant’ crabapples, a variety known to be highly susceptible to apple scab disease, were field-planted then treated three months later with paclobutrazol (PBZ) as a basal drench, at rates of 0, 0.8, 1.6, and 2.4 g a.i./cm caliper. Apple scab was significantly reduced for two years post treatment by all rates of PBZ applied. However, significant growth regulation occurred through the third and final year of the study. Thirty Picea pungens (Colorado spruce) trees in containers were treated with PBZ, applied as a basal drench, at rates of 0, 1.6, and 3.2 g a.i./cm caliper. Cytospora canker development from subsequent branch inoculations was significantly reduced by both PBZ treatment rates and persisted through the end of the two year monitoring period. Cytospora canker disease control with only moderate growth regulation indicates that a PBZ basal drench could be developed into a viable landscape treatment.