Tuesday, March 22, 2016
For pecan growers with just a few trees you can calculate your springtime fertilizer needs by measuring the diameter of your trees. Apply 1/2 lb. of urea fertilizer for each inch of trunk diameter. In other words a 10 inch diameter tree should have 5 lbs. of urea spread over the tree's entire rooting zone. When it come to potash, apply 1/3 lb. of fertilizer per inch of trunk diameter.
Many backyard pecan growers buy their fertilizer in bags containing a 10-10-10 mix of N, P and K. To apply the recommended levels nitrogen, 2.5 lbs. of 10-10-10 should be applied per inch of trunk diameter. Again, the fertilizer should be applied over the entire root zone.
Thursday, March 17, 2016
|Surecrop, 17 March 2106|
This morning I collected some terminal branches from several cultivars which will help me illustrate the first event in pecan bud development -- outer scale split. The twig I collected from a Surecrop tree (photo at right) had buds that were fully dormant. Each primary bud appears to be encased in a smooth, hard shell offically known as the outer scale.
|Kanza, 17 March 2016|
The Kanza twig pictured at right shows the very first sign of bud swell. The outer bud scale on the upper-most bud has cracked open. (The shriveled stem above this bud is last years pedicle that held a cluster of nuts).
|Peruque, 17 March 2016|
Once the outer scale cracks open, the scale drops off to reveal an expanding pecan bud covered by an inner scale. The photo of the Peruque terminal (at right) demonstrates that the outer scale split process begins with the terminal bud and continues sequentially down the stem.
|Greenriver, 17 March 2016|
The photo at right of a Greenriver terminal shows what is revealed when the outer scale separates from the bud. Each bud contains a primary vegetative bud in the center surrounded on each side by smaller axillary buds containing catkins. The vegetative bud will eventually grow out into a new shoot that terminates in a cluster of pistillate flowers.
Monday, March 14, 2016
Earlier this year I removed a fire damaged pecan tree from my farm. This gave me the opportunity to cut a cross section of the trunk to reveal the fire damage and how the tree responded to that damage (photo at right).
The tree was located in a field of tall native grasses. When a grass fire moved through this field, it was pushed along by a strong southern wind. The south side of the trunk was exposed to such intensely high temperatures that the bark was singed and the cambium underneath was killed. The red arrow in the photo points to the burned portion of the trunk.
In response to fire damage, the tree attempted to grow over the wounded area. Note how wide the wood growth rings are in the areas that are attempting to grow over the wound (marked A and B). This tree was moving quickly to seal over the wound. If this tree was left standing, it would have taken just a couple more years before these two fingers of wood growth to meet and grow together to completely seal over the burned portion if the trunk.
Young pecan trees, with their relatively thin bark, are especially prone to fire damage. Older, mature trees with decades of bark thickness are more resistant to fire, however, these tree can also be severely damaged by fire. Keeping the pecan orchard mowed, thus minimizing the potential for a run-away grass fire, is the best method for preventing fire damage to you pecan orchard.
Friday, March 4, 2016
Yesterday, I photographed the nuts from trees that will be entering advanced trials this year. When you look at each photo, be aware that the two inshell nuts were placed on different sides to give you a feel for overall nut shape. A table of the 2015 average nut weights and percent kernel for these selections is given at the bottom of this post.
The next group of selection are the results of crosses made between Pawnee and Major.
The last seedling to enter into advanced trials this year will be an open pollinated Kanza seedling.
Nut weight and percent kernel data for the 2015 crop season is given below.