In Apple, the largest fruit 16 and 18 mm. Most orchards have king fruit in the 13 to 15 mm range. Fruit set varies widely. Drop in some orchards has left singles that require little thinning. Other orchards have heavy set with 4 fruit per spur.
Many growers are unsure of the effectiveness of their previous thinning sprays.
The weather conditions forecast for this upcoming week are terrible for thinning. These cool temperatures will reduce and mask the effectiveness of thinning sprays. Growers need to wait until warm weather returns. The cool weather will also slow fruit growth. There should be an opportunity for a final thinning spray early next week when temperatures warm.