Skip to Content

Dieback of Pecan Branches

Published on 07/19/19

UGA Extension pecan specialist cautions growers about dieback of pecan branches

By Clint Thompson for CAES News

Nearly a year after thousands of trees were destroyed by Hurricane Michael, Georgia pecan producers are reporting the dieback of pecan branches and leaf burning in trees that survived the October 2018 storm, according to Lenny Wells, University of Georgia Cooperative Extension pecan specialist.

The conditions, which are occurring in trees ranging from 2 to 15 years old, are not uncommon following storms that feature high winds, Wells said, attributing the problems to delayed hurricane damage.

“The trees got knocked around so much in that storm, even if it didn’t blow them down, it shook them around enough that it broke some of those roots underground and they haven’t been able to regrow enough roots yet to support the growth that the tree is trying to make,” Wells said.

Now that the temperatures have risen and the water demand has gone up, those trees are basically “in shock,” Wells said, and don’t have the roots they need to support them.

Wells says growers whose trees are showing these symptoms need to improve the root to shoot ratio and keep the roots watered.

“Growers need to cut some of the tree back and try to get the top of the tree back in line with what the roots can support,” he said. “The more severe the dieback, the more you need to cut the tree back. The worst trees may need to be cut back by half if the cambium is still green under the bark.”

Wells has seen similar symptoms in older trees that were pushed down by high winds but stood back up and righted after the storm by farmers. When the trees were erected, the roots were broken on the other side of the tree. These trees had enough root to survive initially, but the combination of intense summer heat and high water demand led to their demise, he said.

Scab disease

Wells has also fielded his share of calls regarding scab, a fungal disease that infects the leaves or nuts of pecan trees. If it hits early enough, scab can cause the pecan nuts to blacken and fall from the tree.

After a late dry spell in May, Georgia has received adequate rainfall in June and July, which has increased instances of scab disease in some orchards.

“It’s pretty rough so far this year. We’re seeing it on ‘Desirable’ and ‘Pawnee’. We’re starting to see it on some varieties we haven’t seen as much in years past, like ‘Stuart’,” Wells said. “The rain has certainly given us a lot of disease pressure and we’re at the point in the season where, if growers do have a crop, they can’t let up at all on those varieties that are susceptible.”

Wells recommends growers space their spray treatments 10 days apart.

For up-to-date information about Georgia’s pecan industry, see site.extension.uga.edu/pecan.

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

New Extension Publication on Herbicide Injury of Pecan

Georgia’s pecan industry at crossroads

Published on 04/01/19

Georgia’s pecan industry at crossroads

By Clint Thompson for CAES News

The pecan industry in the Southeast U.S. is at a crossroads, and the 2019 season could go a long way toward determining the financial future for many Georgia farmers, according to Lenny Wells, University of Georgia Cooperative Extension pecan specialist.

The cost to produce pecans continues to increase every year. With new tariffs imposed on goods exported from the U.S. to China, prices producers received dropped significantly last year.

Early-season ‘Desirable’ varieties sold for between $2.20 and $2.40 per pound in 2018, and ‘Stuart’ varieties were valued at approximately $1.75 per pound. At season’s end, Desirables dropped to $1.30 per pound and Stuarts were being sold for 85 cents per pound.

“In order to change the cost of production and the price our farmers are receiving for their crops, we have to change the way our industry operates,” Wells said.

So how do growers change the makeup of the industry? Wells believes that producers have three options to do things differently as they prepare for this year’s crop: reduce the cost of production, shell some of their own crop, or work with shellers to grow the nuts they want. Growers also can opt to keep with the status quo and be subject to the same market trends as in the past.

Wells believes that growers need to replace old cultivars with cultivars that have some level of scab disease resistance, which would decrease the cost of production. Scab is a fungal disease that infects the leaves or nuts of pecan trees. If it hits the nut early enough, scab can cause the pecan to blacken and fall from the tree. Some growers spray between 10 and 12 times during an average year to fight scab, Wells said.

Producers need to plant scab-resistant varieties with goal of spraying no more than six to eight times. Some recommended varieties include ‘Avalon’, ‘Caddo’, ‘Creek’, ‘Eclipse’, ‘Ellis’, ‘Excel’, ‘Lakota’, ‘McMillan’, ‘Oconee’, ‘Sumner’ and ‘Zinner’.

Wells stresses that growers need to stop planting ‘Desirable’ pecans. Although it produces a good quality nut, its susceptibility to scab disease makes it an undesirable choice. If producers choose to plant a susceptible cultivar, he suggests growing either ‘Caddo’ or ‘Pawnee’, both of which have an early harvest date and short season.

Growers also need to focus on quality over quantity and produce pecans with a percent kernel in the mid-50s.

“We have to grow better-quality nuts with more uniformity and a lower cost of production to compete on the traditional domestic market, and we have to develop new domestic markets,” Wells said.

Though much of Georgia’s pecan crop will always be sold to domestic shellers, Wells recommends that farmers diversify their market opportunities.

One option is for farmers to work together or individually to develop grower-owned shelling plants. They can also selling online with the shell-bag-and-ship formula. These options are not without risk and will be slow to develop.

Producers can develop new markets by highlighting the health aspect of pecans, market pecans as snack foods, and emphasize value-added products like pecan milk and pecan oil.

Growers also can implement management practices that will help reduce costs. Adequate tree spacings are recommended. Tighter spaces can increase early yield but require more inputs, and more trees per acre lead to increased disease and insect pressure.

Georgia producers find themselves in a difficult position largely because of the rise of pecan production in Mexico, Wells said. Mexico produced 278,176 acres in 2015 and is adding 10,000 new acres every year. Mexican pecan production has grown from 270 million pounds in 2015 to nearly 300 million pounds now, and the U.S. is the country’s largest customer. Production isn’t slowing down and pecan production costs in Mexico are approximately $860 per acre, compared to approximately $1,500 in the Southeast U.S.

“We cannot grow the pecans we have been growing and compete economically with Mexico,” Wells said.

The U.S. is importing more pecans from other countries at a time when exports have slowed, specifically with China.

“The market to China is our lifeline. If we don’t have that, we’re in trouble,” Wells said.

Storing pecans is another gamble for producers. Wells estimates farmers have a six-month window to wait for prices to improve and move their pecans accordingly before South Africa’s crop comes into season in May and June. South Africa is the No. 3 producer of pecans and ships to the U.S. and China.

For more up-to-date information about pecan production in Georgia, see https://site.extension.uga.edu/pecan/.

UGA Pecan Extension | Pecan Beginners Course

UGA Pecan Extension | Pecan Beginners Course

The Pecan Beginners Course will be held on April 16, 2019 from 8:30am-4:30pm at the UGA Tifton Campus Conference Center. See agenda below.

Pre-Registration = $10. Day-of Registration at door = $15

Register here

Beginner’s Pecan Production Course

9:00       Welcome                                                                                      

9:10       Cost of Pecan Production                                                                       

Lenny Wells, UGA Horticulture

9:30       Pecan Varieties                                                                                                                        

Patrick Conner, UGA Horticulture

10:15     Break

10:45     Pecan Irrigation                                                                          

Lenny Wells, UGA Horticulture

11:15     Pecan Tree Planting & Establishment                                   

Lenny Wells, UGA Horticulture

12:00     Break for Lunch

Meal Sponsored by Savage Equipment    

1:00       Pecan Insect Management                                                                                                   

Angel Acebes and Will Hudson, UGA Entomology

1:45       Pecan Fertilization

Lenny Wells, UGA Horticulture

2:30       Break

2:50       Pecan Disease Management

Jason Brock, UGA Plant Pathology

3:20       Pecan Weed Control

Timothy Grey, UGA Crop & Soil Science

4:00       Pecan Equipment

Lenny Wells, UGA Horticulture

Refreshments & Lunch Provided

Georgia Forestry Commission Announces Debris Management Program to Include Pecan Orchards

By Lenny Wells: This is the best news I have heard for Georgia pecan growers since the Hurricane in October. On November 18, Governor Nathan Deal signed into law HB 1EX, which provides emergency disaster relief assistance for cleanup efforts for timberland  and pecan orchard land in the 28 counties included in the Hurricane Michael Disaster Area. The cost of debris management will be shared at a rate of 80 percent FDMP and 20 percent landowner with maximum payment limitations possible. Applications will be accepted by GFC from January 14, 2019 through February 11, 2019. Landowners may apply for funds retroactively. Approved applications will be notified in writing beginning February 25, 2019.

Contact your local Georgia Forestry Commission office or click on link below for details

Forest Debris Management Program

Where Do We Go From Here?

By Lenny Wells UGA Pecan Specialist.  I’ve had a lot of questions recently about the long-term effects of the Hurricane on our pecan trees and the pecan crops we can expect in the next few years. Until recently our state has not had to endure the after-effects of a direct hit by a major hurricane.

The impact of the extensive tree loss we have suffered will certainly be felt in a general drop in production over the next 3-5 years. For growers that lost 30-40% of the trees in some orchards this will be a large hit if their orchards were not overcrowded. The long-term impact will be felt less in orchards that were overcrowded prior to the storm but it may take a few years for production to get back to where it needs to be. Many overcrowded orchards had young trees inter-planted among older trees. Where large older trees were destroyed, these younger trees and the remaining older trees will now have access to more sunlight, soil water, and air flow. As a result, once these trees recover, they will be more productive and the production in that orchard should return to normal or may even improve somewhat from what it was before. Orchards that lost more trees will feel the effects for a much longer period of time. In addition, surviving trees that have been broken up may be more likely to develop heart rot and reduced vigor.

Trees remaining in orchards along the storm’s path will likely take some time to recover. Many of these trees lost much of their fruiting wood in the storm. This will have to re-grow for a year because pecan flowers are generally borne on the new growth that develops from one-year old wood. Since many of the young shoots from the 2018 crop, which could have fruited in 2019, were lost or damaged in many orchards, the trees will likely have to sit out a year to have very much production at all. Another thing to consider is that trees that were salvaged but were severely broken up will likely produce an over-abundance of water sprouts in the coming year. Such growth usually has a weak attachment point and is easily broken by wind once some weight develops on the ends of these sprouts. In certain situations, selective pruning can help alleviate this problem but often as we do this, the remaining shoots are left more exposed to the wind and will break as well, so it may be better in many cases to let mother nature prune these out until the limbs gain some strength.

Remaining trees also likely had a few roots broken as they were rocked back and forth by the wind. It will also take time for these roots to re-grow to support optimal growth and nut production. We will likely even see some trees that made it through the storm initially, begin to decline somewhat over time and possibly even die as a result of damaged root systems.

History can teach us a lot. If we look at what happened to pecan production in Mississippi following Hurricane Camille in 1969, we see that annual in-shell nut production of improved cultivars in Mississippi the decade prior to Camille averaged ≈3400 t per year, but only 1900 t per year the decade after Camille. The 1969 crop was estimated to be ≈4000 t, but dropped to 2800 t because of direct storm damage. In-shell yield the following year was 900 t, probably ≈25% of what it would have been without Camille. The intensity of alternate bearing increased by 258% during the 6 years after the storm. Production in 1970, the year following the storm, was only ≈27% of the average for the previous 5 years. Thus, slow recovery from hurricane-enhanced alternate bearing can be a long-term problem. For comparison, Camille’s winds were 100-65 mph as the storm moved inland. Michael’s winds were 115-100 mph as it moved from Bainbridge to Albany, falling off further from there.

I am frequently asked how all trees in an orchard or region can all get on the same cycle. Well, hurricanes are one of the environmental events that can do this. Since most trees within an orchard or region are similarly damaged from a hurricane, they all begin to bear on roughly the same cycles, resulting in little or no crop one year, followed by a heavy but low quality crop the next.  Such trees and orchards may require 5–10 years to recover sufficiently to once again display relatively stable fruit production.

Most orchards in our affected area carried a heavy crop into the storm, so the trees were already set up to go into an “off-year” in 2019. Our production practices have changed a lot since 1969 and we like to think that with fruit-thinning, hedging, irrigation, spray programs, and fertility, our trees are in much better shape now, so hopefully our drop-off won’t be this severe. But as we can see, the potential is there for our production to be drastically affected. More recent experience with hurricanes in Alabama has shown that trees tend to be off in the year following the storm but come back surprisingly well the year after that.

Given all the young trees we have in this state, all the trees that will be re-planted, and the improved sunlight in orchards that survived the storm, my suspicion is that, on a state-level, we will certainly have an off year in 2019 but I am hopeful that we will see production begin to improve in 2020. While the total volume of pecans Georgia produces going forward will be reduced from what it would have been, I feel that we will return to levels of production in the state similar to what we were seeing prior to our planting boom within 5 years and we will be the top producing state again within that time period. This is a testament to our growers and the stewardship with which they grow the crop.

Hedging has proven to be one of the best management practices you can employ for minimizing hurricane damage. We saw with Tropical Storm Irma that we had a 60% reduction in wind damage in 2017 on hedged vs non-hedged trees. A similar trend was observed for hedged trees under Michael’s wind. Hedged trees can still suffer damage, but because they do not present as large a sail to the wind and do not have such long, hanging branches, the damage is reduced.

Growers who are re-planting should be looking to plant varieties that have better scab resistance and quality. Good options would include Avalon, Zinner, Ellis, Sumner, Kiowa, Caddo, Oconee, Creek, Cape Fear, and Excel. The merits of some of these varieties lie in scab resistance more-so than quality, while in others, quality is the biggest advantage. Some of these have both quality and scab resistance.  Take a good look at your operation and consider which suits your situation best.

I think we have to start considering that we can’t continue growing pecans the way we have been. This marketing season has shown us that we can’t always rely on a good price to pull us out of the hole created by spraying 16 times or more in a season, no matter how large and high quality the nut may be. Ideally, we should be growing varieties that require 8 or preferably, fewer sprays.

A diversity of good quality cultivars with some level of scab resistance and being able to grow good yield with high quality on fewer inputs for a greater profit margin is going to be the key to the future of pecan production in our state. Its not really about how many pounds you can produce in a given year, its being able to produce consistently with the maximum amount of net profit and healthy, non-stressed trees that will remain consistently productive that makes you a good grower. The key to this is cultivar selection, sunlight, and water. Anybody can spend money (if they have it). If you spend more than you make, it doesn’t really matter how many pounds you grow.

Scab and the Cost of Pecan Production in 2018

By Lenny Wells UGA Pecan Specialist. If nothing else, 2018 has been a wet year. As far as nut scab is concerned, the frequency of rainfall really starts to matter in June and its importance continues on through the rest of the season until shell hardening occurs (or shortly after shell hardening if you grow a scab susceptible variety). During years in which we get frequent rains, we have to spray—a lot in some cases—to control scab. This quickly cuts into profit potential.

A quick check of the UGA Weather station in Albany shows 9 days of significant rainfall (0.1″ or more) in June, 11 days in July, and 13 days in August. Often the rain fell in successive days or with no more than 2 or 3 days between. But even on those days when we didn’t get a significant rainfall event, most areas got some light rain, often late in the evening which would keep the nuts wet all night. Conditions like this make the battle with scab a nightmare for certain varieties, causing most growers to end up spraying at least 14-16 times to have any hope of keeping scab susceptible nuts clean.

We have had a good crop load this year on many varieties, most notably Stuart. Desirable had a heavy drop in most areas. Scab control overall was pretty good considering the pressure we were under but even if growers are doing all they can to keep it at bay, scab often wins the war in this situation. And that is the case this year. I have seen more scab out there as I travel around the state than I have seen since perhaps 2003, one of the wettest years we have encountered. Without question, scab is going to take a fair amount of the Desirable crop.

Surprisingly, we are also seeing more scab on Stuart than we have seen before. In fact, I have talked to a number of growers all over the state who have both Desirable and Stuart in the same orchard and are seeing more scab on Stuart than Desirable under the same spray program. This is very concerning and Dr. Tim Brenneman is currently working to try to get a handle on what is going on there.

All of this brings to mind the elephant in the room. The trade issues with China understandably make a lot of growers nervous because it really makes you think about how much money you have invested in this crop and most growers have had to put much more into it than they had hoped. So, just how much does it cost to grow this crop?

At 2015 variable production costs, we were looking at $1628 per acre to grow pecans with 16 sprays. That puts the break even price for a yield of 1000 lbs per acre at around $1.63/lb and you would still have to subtract your assessments from that. Since chemical costs have gone up slightly, I think its safe to say the variable cost this year for 16 sprays is up to $1800/acre, which makes $1.80 the break even price at 1000 lbs/acre. None of this considers fixed prices in the equation. If a grower still has land and equipment to pay for, even $1.80/lb won’t cut it.

Based on USDA statistics, the average price obtained by Georgia pecan growers across all varieties from 2015-2017 was $2.35/lb. Yes, pecan prices for growers have been profitable in recent years but not lavishly so. For years before the China market took off, I heard shellers saying they needed growers to plant more acreage to increase the supply and with the new marketing order in place to help develop the domestic market, the increased acreage will be a necessity for a consistent supply. But, it has only been recently with the improved prices that growers have been able to afford the considerable cost ($2200/acre) of planting more orchards to increase pecan acreage. At the same time, the entire industry has grown, thrived, united, and garnered more attention than it ever has. If we go back to $1.50 per lb nuts, it won’t be long until we are right back in the same boat we were in 12-15 years ago, if not worse off.

We all know that in the face of the current trade situation with China, we will likely see lower prices this year than we have been seeing. Everyone I have talked to says China wants the nuts, we just have to figure out how to get the pecans to them. In addition we have heard presentations in various meetings over the last couple of years that domestic consumption is on the rise. So, demand for pecans is out there.

When prices fluctuate from one extreme to another, its impossible for an industry to thrive. I don’t know what things are like on the sheller/buyer side of the pecan industry but I do know that with the current cost of production, we can’t grow quality pecans for much less than $2.00/lb and survive.

To be certain, this will be a year in which the quality of your crop will bring the best price possible.

Managing Scab Pressure/Leaf Roll Mites

UGA Pecan specialists Lenny Wells shares information on scab pressure and leaf roll mites. With 10 successive days of rain behind us and no relief in site and a potential tropical storm bearing down on us, pecan growers are under the gun for scab pressure right now. Most days have provided some breaks in the rain showers that have allowed growers to get out and spray at least a portion of their acreage. But, the question is what to spray with when growers can get into the orchard.

We are currently transitioning from worrying about leaf scab as the leaves should be hardening off soon to worrying about nut scab as the nuts begin the sizing period. One of the best materials to be using at this stage with the pressure we are having would be one of the DMI/Strobi mixes (Group 3 + Group 11) like Absolute or Quadris Top if  you have not used them 2 or 3 times already. The problem we are running into is that most growers are coming off of spraying this chemistry in their last couple of sprays. If this is the case, what should growers go to at this point?

The answer would largely depend on what has been used already but in the scenario above—if you have already used a couple of group 3 & 11 mixes—you have a few options. The right choice will probably depend on variety.

For moderately susceptible varieties like Sumner, Stuart, Schley, Oconee, etc. you could go with something like a 2 qt rate of Phosphite alone or a group 3 fungicide (Tebuconazol, Propiconazol, Tetraconazol, etc.) + either Phosphite or Tin

For highly susceptible varieties like Desirable, Pawnee, Caddo, Cunard, a better option would be something like 25 oz Elast and 1 qt of Phosphite.

Regardless of what you use, it is probably a good idea to tighten that spray window to 10 days minimum on scab susceptible varieties.

 

We have also had a number of calls about leaves curling at the edges a seen in the photo below:

This is a result of feeding by pecan leaf roll mite. Their feeding causes galls at the outer margin of the leaflet, which causes the edges to curl up and sometimes turn brown. This distorts the leaflet but does not usually cause defoliation. Most of the time this damage is only cosmetic and does not require treatment.

 

 

Lowndes Pecan Meeting

Lowndes Pecan Update Meeting

 

Tuesday, May 29, 2018

Lowndes County Extension Office

12:00-2:00pm

 

Call 229-333-5185 by Friday, May 25, if you are attending so we can prepare for lunch and room set up.

 

12:00               Welcome

Mr. Jake Price

Lowndes County Extension

 

                        Lunch Served    

 

Word from sponsors

 

12:45               Pecan Updates         

 

Dr. Lenny Wells

Extension Pecan Specialist

Dr. Will Hudson

Extension Pecan Entomologist

Mr. Jason Brock

Extension Pecan Pathologist

 

Closing Comments

                       

                        Pesticide Credits

 

 

Plant Food Systems

Gary Veal (229) 425-1407

 

Miller Chemical

Darin Singleton   (229) 400-1194

 

Bayer Crop Science

                    Jake Ford – (229)-686-4203

 

 

 

Pecan herbicide injury

Dr. Lenny Wells shares shares information on herbicide damage in pecan trees.  Row crop planting has started in south Georgia and this means herbicide drift season has arrived. I have been on the road all week looking at drift-damaged trees. Since I cannot make it to every orchard in which this occurs, here are the steps that should be taken when a drift incident happens:

Glyphosate injury on both leaves to the left. ZInc deficiency on leaf to the right.

Glyphosate injury to pecan

If growers have had herbicide drift injury occur on their trees, they should first contact their county agent and take photos for documentation. The Georgia Department of Agriculture should also be contacted to take their own samples as soon as possible if a complaint will be filed. Many of these herbicides have a very short half-life and samples must be taken quickly in order to detect them in leaf tissue.  The next step is to contact the neighbor from whom the drift originated and contact the neighbor’s insurance agency to notify them the incident occurred. Once everything has been documented it is usually a wait and see situation because of the high degree of variability from one case to the next. Often with glyphosate, glufosinate, paraquat, and flumioxazen, the injury is more cosmetic than economic unless there is extensive coverage, leading to significant leaf and flower/nut loss. Quality may also be affected if extensive foliage damage occurs because the trees must expend energy to re-grow new foliage. The only way to know the extent of damage for sure is to evaluate the crop at the end of the season. Repeated injury, of course, will lead to more serious losses and can cause long term damage to the trees.

Paraquat injury to pecan. Damage initially appears as yellowing of tissue and then turns brown and necrotic.

Older paraquat injury to pecan. All damaged tissue has turned brown and necrotic.

Dicamba and 2,4-d may throw a more complicated scenario into the equation. Based on data from the trials Dr. Eric Prostko and I have been conducting, injury from these materials, especially 2,4-D can be more serious if a high rate of the chemical makes direct contact with the tree’s tissue. In this case we have seen death of those branches that had direct contact. Once again, the degree of damage severity will depend on the rate and coverage. The same steps described above should be taken in the event of drift from these materials.

Initial appearance of auxin (2,4-D and dicamba) herbicide injury

Arrested nut development of terminals affected by auxin herbicide

Branch die-back from auxin herbicide injury