Carbohydrate Model Run - June 4 2018

The high temperatures experienced in most of Pennsylvania last week were relieved Saturday into Sunday as rain moved across the state.
Carbohydrate Model Run - June 4 2018 - News


Here in Central PA we had off and on showers for most of the day on Sunday. Today’s forecast for the rest of the week looks to have more seasonable temperatures and cloudy to partly cloudy weather. Shoot growth has been increasing daily with the high temperatures and abundant sunshine in some locations last week.

The result has been increased foliage and likely increased carbohydrate production. In all the sites of this report, application rates for thinners are suggested to be increased as a result of the foliage. Hopefully, you have been monitoring specific fruit clusters, and you have an idea of how your fruit set is proceeding.

Remember at this winter’s meeting we talked about the three legs of the triangle that influence fruit drop (Figure 1). The carbon balance is just one of those. Other considerations include the initial set, the variety, previous crop load, etc. The environment at the time of application, chemical material, and rate—all of these work in unison to achieve a balanced crop load. Temperatures this year have not been limiting. However, sunlight levels and frequent rainfall have been above normal.

Figure 1

Apple Carbohydrate Thinning Models for Pennsylvania Counties

How to Use the Carbohydrate Model

Where to Find Penn State's Recommendations on Chemical Thinning Materials