Pecan Harvest 2022: Making the best of a bad situation

    Following an extended summer drought and an early Fall freeze, the outlook for my 2022 pecan harvest season looked bleak. Staring up into the canopies of my trees all I could see were small black stick-tights. Should I just walk away from the whole mess or should I attempt to salvage what I could of the 2022 crop? I decided to shake the trees and see if I could recover at least a few edible nuts.   

    The photo above shows the nuts I collected from a row of Gardner trees using my pecan harvest equipment. Most were sticktights and would have no commercial value. Surprisingly, I discovered a sprinkling of good pecans among those collected.   Once I ran the harvested nuts through my pecan cleaner, I ended up with about 5% saleable pecans. I definitely won't be covering my production costs via pecan sales this year.

     Before the freeze, many Gardner nuts were showing signs of shuck-split. However, this past summer's drought prevented normal shuck dehiscence. The photo at right shows two Gardner nuts harvested this year. The sticktight appeared to have split along normal suture lines but the shuck is still firmly held in place.

   To discover a possible explanation for why one the Gardner nut released normally from the shuck while the other did not, I decided to cut the nuts open to check on kernel development (photo at left). Although both nuts had developed kernels inside the shell, the pecan with attached shucks did not produce the plump kernels associated with a normal Gardner nut. Full kernel development inside the shell is an important stimulant for shuck opening.

   Remember this year's fall freeze occurred on October 19th, three weeks after the normal shuck split date for Gardner. This year, all of my trees were suffering from intense water shortage. The drought delayed and even inhibited normal shuck opening. The deep freeze only stopped an already damaged crop-ripening process.     

Deep freeze blasts drought stressed pecan trees

Kanza leaves and shucks killed by freeze

    It has been over a week since a strong arctic air mass descended across the central plains and ended the 2022 growing season. I recorded 19 degrees F (-7 C) at dawn and knew immediately that pecan leaves and shucks would be killed.  Pecan leaves were freeze dried  on the tree and hung on for about a week before dropping to the ground. The freeze had little impact on the pecans that had already split their shucks. However, as I mentioned in earlier posts, the extended drought we have suffered this year inhibited normal nut ripening. 

   Fortunately, most of my Kanza nuts had split their shucks before the freeze and have opened up normally (photo at right). Young Kanza trees (< 6" DBH) suffered more from the drought and have produced much smaller nuts that did not open (100% stick-tights).

  

Thayer nuts after freeze

      Some cultivars appear to have opened partially after the freeze. The Thayer nuts pictured at left have full kernels and I hope the pecan harvester will beat the nuts hard enough to remove most of the shucks. During normal rainfall years, Thayer ripens 6 days before Kanza and should have opened well before the freeze. Unfortunately, it looks like my Thayer trees didn't get enough water to ripen normally.

Hark nuts after freeze

    Hark is a cultivar that usually ripens at the same time as Kanza. Not this year. The photo at right illustrates the current state of my Hark crop. Very few of these nuts will break out of their shucks, leaving me to harvest a bin load of stick-tights.
 

  Caney was one cultivar that split open before the freeze and will fall free from the shuck at harvest (photo at left). But since this was one of the very few trees that opened up early, Caney became a prime target for crows to devour. The nut cluster pictured at left had three nuts but only one remains. A hungry crow knocked two nuts out of their shucks and onto the ground. Flying down to the dropped nuts, the crow then used its beak to crack open the nuts and consume all the kernels.

    An early Fall freeze can damage the cambium of current season grafts. So while I was out inspecting my nut crop, I stopped at a vigorously growing scion to check for damage. The tree pictured at right was grafted this past Spring using a bark graft. The scion had grown over five feet in height (fantastic for a drought year). Unfortunately, this tree was not prepared for such a quick drop in temperatures. The freeze killed all the foliage but the most serious cold damage can only be revealed by inspecting the cambium on the scion shoot.

     Using my knife, I peeled back the bark to expose the inner bark and cambium. The inner bark of healthy twigs should be green in color. This tree had significant internal browning which indicates cold injury.

     I'll need to watch this tree carefully next Spring for signs of bud break. This tree will most likely suffer die-back or I could loose the entire scion. From past experience, I've noticed that a freeze damaged grafts usually re-sprout from below the graft union. If that happens, I'll need to train a trunk sprout to a central leader then re-graft the tree in the Spring of 2024. 

Erratic shuck-split during this drought year

 

Caney, 15 Oct 2022

    Our local weatherman is predicting a strong cold front to drop temperatures into the low 20's by tomorrow morning. Once that happens, the 2022 pecan growing season will come to an abrupt end. Pecan leaves will freeze and drop from the tree. Nuts that have not shuck-split at this point will be frozen in the shuck to cause what is commonly called "stick-tights".

   Because this massive cold wave has been predicted for some time now, I made sure to scout my pecan grove for shuck-split last weekend. All of the photos presented in this post where taken on  Saturday, Oct. 15th. All of the cultivars pictured normally ripen ripen much earlier, in late September or very early October. This year's extended and deep drought has changed everything.

  

Kanza, 15 Oct. 2022

   I was very pleased to see Kanza split (photo at left) on most of my trees. However, I noted that most of the younger Kanza trees (< 6 inches DBH) were still tight in the shuck. It is likely that the younger trees had more difficultly in competing with the ground cover for water. And without adequate water, the shucks can't open.

    Since Kanza represents about one half of my total production, it looks like I'll have some nuts to sell this Fall even if they are much smaller than normal (drought decreased nut size).

 

 

Gardner, 15 Oct. 2022

       Unfortunately, some cultivars are were not even close to opening their shucks. Gardner (photo at right) usually ripens at the same time as Pawnee in Late September. This year Gardner nuts are smaller than normal and have adequate kernel fill. The shuck has separated from the shell but it has not split open. It will be interesting to see if the freeze will pop Gardner shucks open. If not, I'll be amassing a huge pile of stick-tights  for the burn pile.

Thayer, 15 Oct. 2022

    This year, several cultivars are demonstrating a wide variation in shuck development within a single nut cluster. The cluster of Thayer pictured at left illustrates this observation. Note that the largest nut in the cluster is split while the three smaller nuts are still tight in the shuck. After tomorrow's deep freeze, will I have just a single saleable nut to harvest from this cluster. By next Saturday, when I scout the orchard again, I'll get a better idea of crop losses due to this early hard freeze. 

    The 2022 growing season in SE Kansas has proven to be one for the record books, and not in a good way. I keep thinking back to 2007 when we suffered a trio of weather disasters. First we had a late spring freeze that killed emerging shoots followed by the second highest river flood on record in July. The third shoe dropped when our trees were covered by a limb-breaking ice storm in December. Now in 2022, after drought and early fall freeze, I keep thinking, "What's next".  Fortunately, pecan trees are resilient and will bounce back to produce great crops in future years.  

Extreme drought impacts pecan shucksplit

     During the first week of October, I usually note several pecan cultivars that have split shuck. However, this year, the extended drought has delayed the normal timing of nut ripening. The photo at right shows a cluster of Earlton nuts with the first signs of shucksplit on October 3rd, 2022.  

    Earlton is a cultivar I released from my pecan breeding program primarily for its early ripening date. During a more normal rainfall year, Earlton ripens in mid-September. The photo at left was taken on 18 Sept. 2020 and shows a cluster of Earlton nuts as they normally appear at shucksplit. 

    Besides splitshuck two weeks later than normal, this year's Earlton nuts appear barely split open. This is a good reminder that adequate water supply is necessary for normal shuck opening.

    Liberty, another of my pecan cultivars, usually ripens around September 24th at my location. However, the drought has also delayed normal shucksplit for Liberty. The photo above shows a Liberty nut in cross section and a whole nut that I cut off a portion of the shuck to reveal the shell. This photo illustrates several impacts of the 2022 drought. First, these Liberty nuts are less that 1/2 the size of normal Liberty pecans. Although there is a good amount of kernel inside the nut, I noted that kernel fill was less than ideal. There are voids within the kernel halves and the central kernel partion is not fully compressed. These observations lead me to predict drier and less oily kernels at harvest. When this photo was taken on Oct. 3rd,  the shucks were not split open. When I cut off a portion of the shuck, I revealed a fully colored shell underneath. This tells me that the nut is fully mature but the tree lacks sufficient water to pop the shucks open on schedule.  

Tree spacing influences nut production during drought

 

    The other day I was scouting my orchard for pecan shuck split when I noticed a dramatic difference in nut size and ripening between a young grafted Caney tree and the mature mother Caney tree located in my pecan breeding block.

    Let's look at the trees in question. The photo at right is a young Caney tree. This tree has a good crop of nuts and the nuts are only slightly smaller than normal. The important thing to notice in this photo is how much open space there is around the tree. In a year of short water supply this Caney tree has very little competition from other trees for water.

    The photo at left shows the original Caney tree growing in my pecan breeding block. This tree is much larger (28 yrs. old) and is crowded by other large trees (note the shade on the ground). Note the yellowing of some of this tree's leaves. This is an indication of extreme water stress caused by the competition for water from neighboring large trees. Although there is a good crop of nuts on the tree, the nuts are tiny.

  

     The photo above illustrates the differences I observed in the nuts produced by the young, well-spaced Caney tree and the mature, crowded Caney tree.  First there is the obvious size difference. But secondly, note that the nuts produced by the young tree have split shuck while shucks are still firmly attached over the nuts collected from the mature tree. This simple observation leads me to a very important decision; After harvest, I need thin out more trees in the pecan breeding block.

      Caney is one of the scab-resistant cultivars I developed from my pecan breeding project. The photo above gives you a good idea of what Caney nuts look like. Over the years, Caney has produced nuts that are larger than Kanza with nearly 53% kernel. Caney matures a week before Kanza. This cultivar has a protandrous flowering habit making it a good pollen pairing for Kanza. Kernels are straw-colored and  have excellent quality.

Severe drought impacts pecan production

    For the past 4 months, I have watched clouds pass over SE Kansas without dropping significant rainfall. According to the National Weather Service, my farm in Cherokee County (extreme SE corner of Kansas) is experiencing an Exceptional Drought (figure above). I've lived through several Kansas droughts but this year is most memorable because of its extended duration. Extreme drought, although uncommon in SE Kansas has occurred several times in the past 100 years. The Dust Bowl of the 1930's is probably the most historically significant drought to impact Kansas agriculture. However, other exceptionally dry periods occurred  during the 1950's and as recent as 2012-2013.

   The dry weather has definitely illustrated why pecan trees prefer growing in the deep soils found in river flood plains. These soils have a large sub-surface reservoir of water that can move up through the soil profile to keep pecan trees green and growing. However, this year's limited water supply has impacted the 2022 nut crop. Nut size and kernel fill will both be reduced. Many trees aborted a portion of their nut crop in mid-summer due to drought. I have also noted that shuck-split is delayed compared to normal years. 

    Now that the days are getting shorter, I should have more time to post on this blog. As you might expect, the drought of 2022 will color my observations for the remainder of this crop year.    

 

Young tree's growth response to spring time directive pruning

    In previous posts, I've stressed the importance of practicing directive pruning during the spring flush of growth to encourage the development of a strong central leader. The photos at right show the pruning cuts I took back in late May of this year. At first glance, it looks like I'm trying to create a single-stemmed tree with no side shoots.

However, that is not the case at all. These early-season pruning cuts are designed with the single focus of promoting a single central leader. New lateral branches will develop, but later in the season and at much more desirable branch angles. 

 

  In mid June, I returned to the tree that I pruned in May. In the photo at left you can see that I have successfully maintained a single central leader. But you should also notice that there are now numerous lateral shoots sprouting out from the trunk all below the new central leader.

     On closer inspection (photo at right), you will note that the new lateral shoots are growing from secondary buds that are located just below each pruning wound (the pruning cuts I made in May). It is also important to note that these new shoots are growing out at a wide angle from the trunk. These shoots will develop into strong well-anchored branches that resist wind and ice breakage.

    By early July, all of the new lateral limbs are growing nicely (photo at left). It won't be long before I have well bushed out tree all while keeping a single central leader. I'll leave all these lateral branches on the young tree to help promote trunk diameter growth. The increased leaf area on the trunk catches more wind which, in turn, promotes a strengthening and thickening of the trunk. 

    Young, rapidly-growing trees need training throughout the summer months. Pruning cuts made to strengthen the dominance of the central leader usually means that stalked buds will start to form in mid-summer on the central leader near the top of the tree. Left to grow, stalked buds will produce narrow-angled branches that develop a bark inclusion at their base. If all the stalked buds that form on a central leader are allowed to grow, a pecan tree will become top heavy and take on a broom-like appearance (at the top of the tree). I pinch off all stalked buds as soon as I see them to preserve the central leader (photo above).

   
    

Pecan nut casebearer arrives late

  

    Every year I scout my pecan orchard for pecan nut casebearer damage to young nuts. Damage from this insect is easy to recognize by the pile of insect frass at the base of a nut and the silken threads that connect the damaged nut to the pedicel (photo at right). Left unchecked, a single pecan nut casebearer larvae will destroy 3 to 4 nuts in a cluster. 

    The first evidence of casebearer nut damage this year occurred a week later than normal. However, now that this first summer generation has started, the above average temperatures predicted for the next 10 days will cause the casebearer population to expand rapidly. I found the first damaged cluster on Wednesday June 16th and started spraying early Thursday morning.

    When spraying during a heat wave, I try to start at first light and quit around 11:00 am. Once temperatures start to approach 90 degrees F spray droplets can evaporate before they ever hit the foliage. 

Pollinated flowers vs. Fertilized Nuts

        Long before I found the first casebearer damaged nut, I knew things were running late by watching the developing nuts. When a female flower becomes pollinated the stigma becomes dry and black, however, it takes a little time for the pollen tube to grow down into the nut and become united with the ovule. Once the nut is fertilized, it starts to swell and the sepals (leaf like projections just below the stigma) will point straight up. This year, nuts didn't show the normal signs of fertilization until June 14th. A day after most sepals were pointing up, I found my first casebearer. Over the years, this relationship between nut development and the first sign of casebearer activity has been very consistent.  In fact, I now use observations of nut development as the primary method for timing a pesticide application to control casebearer.

Directive pruning last year's grafts

 

      Once I finish up grafting for this year, I turn my attention to pruning last year's successful grafts. The photo at right illustrates the typical appearance of a young grafted tree in its second leaf. Last year, I carefully pruned the graft to ensure a single, strong central leader. But this spring, the tree popped multiple new shoots from the terminal of last year's growth.  If allowed to remain for the rest of this summer, these multiple shoots will create what is commonly known as a crow's foot and I will have lost my central leader. That is why I'm such a strong proponent of directive pruning. By pruning during the period of active shoot grow, I can "direct" the tree's new growth into maintaining a single leader.

   The photos above shows the terminal of my young grafted tree. Three shoots have developed at the very top of the tree. I identify the strongest growing shoot among the three and then prune out the others.

     To help focus the tree's growth energy into my new central leader, I also remove all lateral branches that arise from the main stem within the top 2 feet of the tree (measuring from the top of this year's new shoot growth). (photo above)

     Since I still have the bamboo stake in place from last year, I tied the tree upright to encourage to formation of a straight tree trunk. Later this summer, I'll probably replace the bamboo with a longer (and stronger) tree stake that will help me keep this tree growing the way I want. I allow lateral branches to develop lower down on trunk (but above the graft union). Lateral branches will increase tree leaf area helping to capture more sunlight to produce the carbohydrates needed to sustain rapid tree growth. These lateral limbs also catch more wind which in turn promotes trunk diameter growth.

    The photo at right is another example of a graft in its second leaf. In the past, I've called these trees "lolly-pop" trees because of the ball of new growth at the top of the tree. This tree also needs directive pruning.

     Whenever I go to prune a young tree, I always start at the top and work my way down. In this example, I have three shoots growing at the terminal but it appears I already have a strong central shoot. However, to reinforce the dominance of this new central leader, I'll prune off all competitors. Again, I stick to the 2 foot rule--No lateral branches within the top 2 feet of the central leader.

    Once I finished pruning I noticed that I already had a couple of lateral buds breaking further down on the stem (photo at right). I make sure I leave these in place for now. 

    Many grower make the mistake of pruning all lateral branches off as soon as possible. Their thought is that by removing low limbs the tree will grow taller, faster. However this is not the case.  Removing all laterals only serves to create a tall thin tree that bends over under it own weight, often snapping in a good wind storm. Nut production will also be delayed by over-pruning lateral limbs. 

    On my trees, I leave lateral branches on the tree until the tree has developed a nice full crown. At that point, I start to remove one or two low limbs each year. My goal is to develop a tree with 8 to 10 feet of clear trunk. However, it usually takes 12 to 15 years to get to that point.
 

Notes on pecan pollination

     Last weekend I took advantage of calm winds and sunny skies to photograph pecan flowering and pollination. I also like to scout my orchard at this time of year to get a feel for this year's nut crop. During the month of May, my trees are always covered with catkins--the long worm-like structures that hang down from last year's shoot growth. Male flowers (pollen sacs) cover each catkin and eventually split open to release millions of yellow pollen grains into the air to hopefully find their way to a receptive female bloom.

    Pecan female blooms are not very showy (photo at right) and can be found at the terminal new spring shoot growth. Look carefully at the flower cluster in the photo and you will note that the ends of each flower (the stigmatal surface) has started to turn dark brown-black indicating these flowers have been pollinated. The flower cluster pictured here is from a Kanza tree. Kanza is a protogynous cultivar meaning the female flowers on the tree become receptive early in the pollination season while Kanza pollen is released late.

     When scouting my orchard for yield potential, I concentrate on counting the number of terminals on a tree that have developed female flower clusters. The good news for my orchard is that the 2022 crop looks very promising at this point.

On my trip around the orchard, I decided to concentrate recording the flowering habits of the pecan cultivars originating from my breeding project. I took 2 photos of each cultivar. The first shows the entire fruiting shoot. The second is a close-up of a female flower cluster. All photos were taken on May 14th. I've noted the flowering habit of each cultivar.

CANEY - PROTANDROUS

Caney was actively shedding pollen at the time this photo was taken.

Caney pistillate flowers were still growing and not yet receptive. The stigmas will be bright red at receptivity.

 

 

 

 

 

 

 

 EARLTON - PROTOGYNOUS

Earlton has long slender catkins typical of protogynous cultivars.

A Earlton flower cluster shows signs of already being pollinated.

LABETTE - PROTOGYNOUS

Look carefully. See if you can spot the female flower cluster held at the end of the new Labette shoot.

Labette female flowers look ready to receive pollen.

LIBERTY - PROTANDROUS

Liberty was shedding pollen and should make a good pollinator for Kanza.

Liberty female flowers were still growing in size. Stigmas will be red in color.

PLEASANTON - PROTOGYNOUS

Pleasanton catkins are starting to turn yellow in color. It won't be long before pollen sacs start to open and release their pollen grains.

Pleasanton female flowers have started to turn brown indicating pollination has occurred.

ST. PAUL - PROTANDROUS

St. Paul catkins were shedding pollen. So much pollen that I had to clean off my camera lens.

St. Paul female flowers were still not fully formed. These females will have green stigmas.

THAYER - PROTANDROUS

Thayer catkins have shed most of their pollen and have turned brown in color.

Thayer female flowers are still growing. The stigmas will be bright red when receptive to pollen