2018 Crop Protection Guide for Tree Fruits in Washington

Bioregulator Sprays

Friday, September 21, 2018

Critical Temperatures / Bud Death Table

(from WSU Extension)

  Bud Stage
1 2 3 4 5 6 7
degrees Fahrenheit
 Apple
  silver tip green tip 1/2 inch green tight cluster first pink full pink first bloom
10% kill 15 18 23 27 28 28 28
90% kill 2 10 15 21 24 25 25
Pear
  buds opening buds exposed tight cluster first white full white first bloom full bloom
10% kill 15 20 24 25 26 27 28
90% kill 0 6 15 19 22 23 24
 Peach
  first swelling calyx green calyx red first pink first bloom full bloom postbloom
10% kill 18 21 23 25 26 27 28
90% kill 1 5 9 15 21 24 25
Apricot
  first swelling tip separates calyx red first white first bloom full bloom in the shuck
10% kill 15 20 22 24 25 27

27

90% kill 0 9 14 19 22

24

Plum (Prune)
  first swelling side white tip green tight cluster first white first bloom full bloom
10% kill 17 20 24 25 26 27 28
90% kill 3 7 16 20 22 23 23
Cherry
  first swelling side green tip green tight cluster open cluster first white first bloom
10% kill 17 22 25 26 27 27 28
90% kill 5 9 14 17 21 24 25
Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us