Techniques for collecting a sample of buds and dissecting them to assess flower numbers have been developed. The time in the season when the dissections are made will determine how difficult it is to see the flower primordia and how powerful a microscope will be needed.
In the month or so prior to flowering it is quite easy to determine the presence or absence of flowers and the flower numbers in a floral bud. If, however, the determinations are made during the previous summer and autumn, the assessments are more difficult and require more time.
- Each floral bud will produce on average 5-6 flowers. In a normal year 1 in 6 flowers will set a good fruit, which means that one fruit bud will be needed for each fruit set to provide a good crop.
- A safety margin of 15%-20% over and above this level should ensure adequate fruit numbers at harvest.
- Some varieties e.g. Gala can set more heavily than this, producing on average 2 fruits per bud and, in orchards with a history of heavy setting, bud numbers should be reduced at pruning time especially in shaded parts of the tree and on weak wood.
- Generally, the size (diameter) of the bud is a reasonable guide to its quality. Plump buds are indicative of good quality.