Developing cluster of ‘Yellow Delicious’ apples.
Recent warm temperatures have provided excellent pollination for the apple trees. Although temperatures did dip to freezing and below two consecutive nights last week, we feel the damage is minimal. Any damage that did occur just caused a little thinning. When the petals drop from the trees (petal fall), apple growers need to make a perplexing and often risky decision regarding chemical thinning of the apple fruitlets.
From the time of bloom and for the next month or so, there are thousands of flowers developing fruitlets on the trees. All of these fruitlets are struggling to grow and make tremendous demands on the tree. Thinning of these abundant fruitlets is necessary to prevent a heavy crop of small apples. Thinning is a tricky call to make. A certain amount of fruitlets will drop naturally from the tree while others will have to be removed chemically. The effectiveness of a chemical thinner application depends on many factors and to hit it just right takes as much art as science. Different orchards respond differently to a given thinner application. There is much published research on thinning practices but generally speaking there is no “one size fits all” when developing a thinning strategy. Different strategies work differently in different orchards and it is impossible to develop a recipe approach. Experience is the basis for a good thinning plan.
Our first thinning applications were made last week with follow-up this week. We’re not pros at the whole process by no means, but each year we are learning a little more and experiencing more success. Each season seems to bring new challenges with some varieties thinning better than others while others don’t seem to respond to the thinning applications at all. Techniques sound good on paper but we find thinning to be a somewhat head-scratching but necessary process.