Friday, April 15, 2022

Bud Break and Spring Fertilization

Kanza buds 14 April 2022

    As I have mentioned in previous posts, I like to time the application of fertilizer to my pecan grove to coincide with the very first signs of tree bud growth. We've had a cool spring in SE Kansas this year which has delayed the bursting of pecan buds. Here we are in mid-April and our pecan trees still appear largely barren of new growth. However, on close inspection I've found some trees have started to push their buds open (Kanza buds pictured at right).  

    Seeing bud growth, I rented a fertilizer spreader and applied 150 lbs./ac urea and 100 lbs./acre K-Mag. K-Mag is a naturally occurring mineral that contains potassium (K), Magnesium, and Sulfur. In my pecan grove, previous leaf analysis results indicated that my trees were low in Magnesium. This is what prompted my switch to K-Mag rather than use the more common potassium fertilizer, muriate of potash (potassium chloride).

    The cost of all fertilizer materials have increased dramatically over the past 18 months, which has made many pecan producers pause to question; "Can I really afford to apply fertilizer this year?".  At first, skipping a regular fertilizer application will seem to have little effect on pecan yield. The yield for 2022 is largely programed in the tree before you ever make a spring fertilizer application. The negative affect of skipping a fertilizer application this year will come in 2023. Without adequate nutrient applications in 2022, the tree will drain all of its reserves to grow and mature the current nut crop. This will leave the tree unable to create the pistillate flower buds that will form the basis of the 2023 crop.  Ultimately, skipping a fertilizer application will increase a pecan tree's tendency towards alternate bearing.   

USDA 61-1-X  14 Apr.2022

   While scouting my orchard for bud development, I observed that not all cultivars were at the same stage of bud development. For example, USDA 61-1-X had swollen buds that looked ready to burst open (photo at right).
Hark 14 Apr 2022





    In sharp contrast, Hark buds appeared fully dormant (photo at left). Late bud break is a positive trait for northern pecan cultivars. A delayed start to shoot growth often allows late budding pecan trees to avoid late spring frost damage.

    As a general rule, pecan trees are one of the latest tree species to break bud in the spring. On the same day that I was scouting pecans for bud break, my apple orchard was in full bloom, buzzing with the sound of hard-working honey bees (photo above).