A number of self–sterile cherry varieties appear to have a reduced crop this season.
How much they are affected depends on the weather conditions experienced at flowering.
Some self–fertile cherry varieties may also have a lesser crop than expected. Conditions at flowering will have influenced this, as would other climatic issues such as winter chill.
Beware of over cropping
Self–fertile cherry trees that have been allowed to over crop for two or three seasons sometimes begin to develop fewer fruit buds or set a lower percentage of cherries than normal.
I also have serious doubts about the shelf life and qualities of a crop of sweet cherries that exceeds 25 tonne per hectare. Apart from reduced fruit size due to the crop, the calcium available from the tree to each cherry is reduced, which can affect the quality and shelf life of the product.
Should you over crop the trees for two or three years in a row, then the trees decide that a rest is required, which results in fewer fruit buds being developed, or a lower percentage of fruit being set or staying on the tree.
By ‘staying on the tree’, the thing being identified in self–fertile cultivars is fruit shedding or fruit drop.
Cherries might shed because of incomplete pollination, severe carbohydrate stress during cloudy weather, and heavy crop loads.
Consider the weather at flowering
Think about the weather during blossom time—did your area experience lower than average temperatures, or reduced sunlight hours, or water stressed and cooler soils, or strong winds (wind is an inhibitor to growth)?
Many cherry growing regions experienced some of these conditions and it is likely to have had an impact on the forthcoming crop.
Fewer, larger cherries likely
The good news is that the remaining cherries should be larger than average and of better quality—depending on the right weather conditions from now until harvest.
Scientists and researchers have said that the best way to control over cropping in sweet cherries is by pruning annually.
See this article in Tree Fruit Nov 2016
