A good pruning job achieves several goals, including shaping the tree to intercept the maximum sunlight, and renewal of the bearing surface. More recently, we've been learning more about the importance of dormant pruning in achieving fruit size - by reducing the number of fruitful buds.

Most apple trees produce many more flowers than are needed to set a crop. Several of our orchard practices encourage this - dwarfing rootstocks, tree support, good fertility and moisture, fruit thinning and sunlight interception. Although this holds true in conventional orchards, the effect is magnified in high density systems like Tall Spindle.

We know that all of the flowers will not set, and that many of the pollinated fruitlets will be removed by chemical and/or hand thinning. But think of the energy used by the tree to produce flowers, pollen and unnecessary fruitlets — this energy is wasted, resulting in reduced fruit size potential on the remaining fruitlets — which are your marketable crop.

Dormant pruning offers an easy and efficient opportunity to control how many flowers will share the tree's energy to set your crop. Maximizing this opportunity takes some management time — assessing buds, calculating the target cropload, and adjusting your pruning strategy, perhaps even sending crews through extra times. But it is time well spent to achieve better fruit size.

Dormant pruning as a precision cropload strategy works — because there is a horticultural advantage for trees to produce fewer flowers and fruitlets. Saving and re-directing the tree's energy before bloom will produce larger fruit - and may make a difference in your markets next winter.

Your challenge: Try this technique this spring on 2 blocks to learn for yourself.

  • Calculate your yield goal, and determine how many fruit per tree are needed (see "Research results from a trial on precision pruning", February Orchard Network. This step can be done in the office.
  • Choose 2 blocks of smaller trees, one under 5 years old, and a more mature block around 10 years old. Uniform trees are the easiest to count, and small fruited cultivars like Gala may show the greatest effect.
  • Count fruit buds on 5 to 10 trees. On larger trees, you can count several of the larger branches and multiply for the total.
  • If the bud count is more than 2x what is needed (as an insurance factor), more pruning should be done. The fastest way is remove entire branches to reduce the bud count.
  • Flag the trees, and return after thinning, and at harvest to observe the fruit size. Return next year to observe return bloom.

Your Equilifruit disk or Cornell Young Tree Gauge can also help to remind the pruning crew how many buds per branch. Whatever method you try, keep notes, and plan to observe results on these trees this year and next. Let's recapture the horticultural advantage of early cropload management through pruning.