Monday, August 14, 2017

Crop load management

   This year, several of our pecan cultivars have set an over-abundance of nuts. So many nuts in fact that the tree couldn't possibly fill all those kernels and nut quality would suffer. So, I've been cutting nuts to determine when pecans enter the water stage (photo above) and when it's the right time to shake trees to reduce the crop load.  Today, with the nuts at the right stage and the sun shinning we used our tree shaker to remove a portion of our crop.

Lakota before nut thinning
   The cultivars in our orchard that required nut thinning this year were Pawnee, Gardner, Faith, Lakota, and Osage. Even some of the trees in our Kanza block needed crop load reduction. We used a Savage PTO shaker equipped with doughnut pads to give each tree a light shake. When the nuts are at full water stage, it only takes a short burst of vibration to rain down green nuts.  

Lakota after nut thinning
    Summer shaking is not an exact science but once you become accustomed to the practice you get a feel for the technique. During shaking you can actually see heavily laden limbs spring back upwards as the weight of nuts is reduced. Look closely at the before and after photos of shaking a Lakota tree, you can see the limbs have moved upwards.

   The one thing you can't do is look at the ground. Seeing hundreds of green nuts on the ground can make you feel like you've just thrown away a good portion of your crop (photo at left). But just remember, the remaining nuts on the tree can now fully pack kernel inside the shell resulting in a yield equal to or greater than if the tree was never shook. In addition, better quality nuts will command a better price and the tree will return with a good crop next year.
    One advantage to shaking for crop load regulation is that you can always skip over trees that are not overloaded. This year we shook about 80% of our Pawnee trees and 15% of our Kanza trees.

   The greatest danger it using a trunk shaker in mid summer is the risk of bark damage (photo at right). Clamp on the shaker improperly or not tight enough and you can tear off bark. This causes lasting tree damage that is hard to reverse. My advice is to not get in a hurry, and clamp on and off the tree with great care.