|Background Information for this page|
|Return to Apple list for Belchertown MA|
|Chart version of thinner sensitivity ratings|
|Weather data for Belchertown MA. Forecast values begin April 26, 2015|
|Estimated Apple Sensitivity to Chemical Thinners|
| Other factors may outweigh the weather effects use for
these estimates. Other influences include: fruit diameter, fruit exposure to
temperatures >=75 F, pollination, this year's cropload, last year's
cropload, warm February-early April temperatures, frost and prolonged cool
and cloudy weather during bloom, previous fall weather, foliage condition
Ratings below are for the influence of weather on fruit sensitivity to chemical thinning agents. Ratings assume fruit are less than 13mm diameter. Dates in bottom rows are beyond 18mm diameter for most cultivars, and are intended only for late cultivars. Look at your fruit!
guess McIntosh King fruit diameter dates:
12mm - June 3, Wednesday 15mm - June 6, Saturday 18mm - June 9, Tuesday
|Marker for End of Observations|
|Apr 26, 1PM||Date after which fruit have exposure to 2 days of daily high temperature of at least 75 F: Sunday, June 7|
| Very warm night
temperatures (average > 69F = 19 heat units in table) can lead to
"EXCESSIVE THINNING RISK", especially if combined with cloudy
weather, or if combined with use of NAA.
Warm nights + Cloudy days -----> Increased sensitivity, maximum thinning.
Warm nights + Sunny days -----> Intermediate senstivity, moderate thinning.
Cool nights + Cloudy days -----> Reduced sensitivity
Cool nights + Sunny days -----> Reduced sensitivity, minimum thinning.
|THINNER APPLICATION DATE
Estimates assume morning application.
For afternoon application use rating for next day.
% CLOUD SHADING
on application day and the next two days.
< 20% = "sunny blue sky"
> 40% = "cloudy"
Cloudy weather on 3 days after application increases thinning.
NIGHT HEAT UNITS
= degrees above 50 F for 7pm--7am
for 3 nights after application.
Example: If average night time temperature is 55F, then value = 5.
Values above 10 for three nights after application increases sensitivity to thinning.
|Constant used by Postbloom thinner Appl|
95% Petal Fall
Sun, May 24
|100% Petal Fall Mon, May 25||25-May-15|
|Tue, May 26||26-May-15|
|Wed, May 27||27-May-15|
|Thu, May 28||28-May-15|
|Fruit Set Fri, May 29||29-May-15|
|Sat, May 30||30-May-15|
|Sun, May 31||31-May-15|
|Mon, June 1||01-Jun-15|
|Tue, June 2||02-Jun-15|
|Wed, June 3||03-Jun-15|
|Thu, June 4||04-Jun-15|
|Fri, June 5||05-Jun-15|
|Sat, June 6||06-Jun-15|
|Sun, June 7||07-Jun-15|
|Mon, June 8||08-Jun-15|
|Tue, June 9||09-Jun-15|
|Wed, June 10||10-Jun-15|
|Thu, June 11||11-Jun-15|
|Fri, June 12||12-Jun-15|
|Sat, June 13||13-Jun-15|
|Sun, June 14||14-Jun-15|
|Mon, June 15||15-Jun-15|
|Tue, June 16||16-Jun-15|
|Wed, June 17||17-Jun-15|
|Thu, June 18||18-Jun-15|
|Fri, June 19||19-Jun-15|
|Sat, June 20||20-Jun-15|
|Sun, June 21||21-Jun-15|
|Mon, June 22||22-Jun-15|
|Tue, June 23||23-Jun-15|
|Wed, June 24||24-Jun-15|
|Thu, June 25||25-Jun-15|
|Fri, June 26||26-Jun-15|
|Sat, June 27||27-Jun-15|
|Sun, June 28||28-Jun-15|