I recently evaluated four Honeycrisp blocks in the Champlain Valley for their percentage of flowering buds so the growers could adjust their pruning practices. The blocks are described in the following table:

Below are this year’s results:

I considered strong floral buds those containing a full cluster of kings and laterals. I expect these buds will set fruit provided we have good spring weather and good pollination conditions. Weak floral buds were smaller, and often only had a single king in the cluster. I think these are going to be the smaller, single king flowers we often see on Honeycrisp, and are much less likely to set fruit.  Vegetative buds only had leaf scales in the buds, no floral parts were present.

I shared these results with Dr. Robinson. He suggested that the two blocks with >50% floral buds should be pruned normally, but the two blocks with the low number of floral buds should be pruned very lightly or not at all. Given the early spring we’re seeing across portions of the state, this might give us even more reason to prune with a somewhat lighter touch this season.

These are of course just four blocks, and only serve as an example. Your Honeycrisp blocks are likely to vary in their percentages of floral buds this year, depending on:

·       your bloom density in 2023,

·       your thinning practices,

·       your return bloom practices,

·       along with other more difficult to define factors like tree stress during floral bud initiation.

With all that in mind, I generally expect we’re going to have lighter return bloom in Honeycrisp this year in the Champlain Valley where bloom was strong and trees were set heavily last year, and trees ended up set heavily.  To be certain though, knowing your percentage of floral buds can be helpful in determining how hard to prune.

If you are interested in evaluating buds in your own blocks, here are some of my thoughts from the experience:

·       I followed the protocol of two branches (one each from the upper and lower canopy) from 5 representative trees per block.

·        I looked at 10 spurs per branch, unless the branch had fewer than 10 spurs. If a spur had multiple buds, I chose a single bud from that spur at random. Since Honeycrisp spurs also have a tendency to produce bourse shoots, terminal buds on these were also fair game.

·        I used a single edged razor blade to cut through the middle of each bud length-wise (figure 1), and looked at the buds under a tabletop dissecting scope (figure 2). These can be purchased online for around $100. You’re also welcome to come in and use the one at the Clinton County CCE office.

·       In figure 3, you can see what a floral bud (top) vs. a vegetative bud (bottom) looks like under the scope. The vegetative buds are fairly narrow and will only have leaf primordia at the tip of the bud. Floral buds will appear more rounded, and will have small, light green floral tissues at the tip of the bud. These can be difficult to tell apart at first, so I recommend cutting open a few practice buds until you get your bearings on what is what. I find Honeycrisp particularly challenging to tell apart (it is Honeycrisp, after all). I also looked at buds with a hand lens but found I couldn’t distinguish the vegetative vs. the floral buds very readily with it.

·        After getting into the swing of things, each block was taking me about 70 minutes to fully assess. This does not include the time it took to cut the limbs from the orchard.

So, I recommend giving it a try if you have the time and interest. As stated above though, it can be very difficult to tell them apart, so you might want to prune lightly now, and then make more precise pruning adjustments after green tip when you can tell the buds apart on the tree. Feel free to give me or Dan a call with questions.