Thursday, May 24, 2018

Nut set after a late spring freeze.

     Between rain showers this week, I took a closer look at pistillate flower production on many of the cultivars in our collection. Back in early April, we experienced some some late Spring frosts that caused a lot of damage to terminal buds. The photo at right illustrates the typical response our trees have made following the April deep chill. The terminal buds on last-year's-wood were killed and never opened (red arrow points to dead buds). However, primary buds have grown from the mid-portions of the shoot and some of those have terminated in a cluster of female flowers (inside yellow circle).

     I looked at about 15 cultivars including short-season northern cultivars as well as full season southern cultivars. I found the same type of growth and flowering patterns among all cultivars. Trees are producing nut clusters on shoots that originate from mid-shoot primary buds. However, the number of nuts in a cluster seems fewer than normal; 2 or 3 nuts rather than the usual 4 to 5 (nut cluster in yellow circle at right). I also noticed that many new shoots did not produce pistillate flowers at all. Then end result of this year's late Spring freeze will be a below average nut crop come this Fall.