Pecan Cultivar Recommendations for the Southeast

by Bill Goff

Recently University of Georgia pecan breeder Patrick Conner updated the recommended cultivars for Georgia, and developed a table listing the cultivars by scab resistance category and recommendation status. His table can be seen at http://sacs.cpes.peachnet.edu/pecan/Scab%20Resistance.htm .

This table was a great idea, and the article and Conner’s table are full of information you should pay attention to if you are planting pecan trees. Because the Alabama pecan industry has smaller growers, often without the equipment or economic incentive to spray intensively with large airblast sprayers, we have focused more here on pest-resistance. We have evaluated many selections under heavy incidence of pests, especially scab. This has enabled us to identify susceptibility to scab that escapes other researchers with standard methods for years. On the other hand, our methods lead us to ruling out some good cultivars that perhaps could be grown with a very intensive spray program.

Similar to Conner, we developed a table by scab resistance (Table 1) listing cultivars we recommend by current observations of scab resistance category. Additional characteristics of recommended cultivars are listed in Table 2.

Regarding scab resistance level, I need to stress the word current, as strains of the scab fungus may develop on a selection which makes it worse than currently observed.  I further need to stress that the development of strains down the road that attack currently scab resistant cultivars does not mean that planting scab resistant cultivars has no usefulness.  With some cultivars, like Elliott, scab incidence has been minor for decades.  With Stuart, scab was very light for decades, then became moderate for more decades. Today, over 100 years since Stuart was introduced, it remains only middle of the pack or better in scab incidence. Similar cultivars to Elliott and Stuart certainly exist, we just need to subject the test selections to heavy enough scab pressure initially from multiple strains in many locations to identify which ones they are.

Scab resistance  categories.  I will group the cultivars into four categories of scab resistance, based on observations in our experiments as well as observations from other researchers. For established cultivars, the most useful and extensive observations are from growers orchards, mainly in Georgia, Alabama, and Louisiana, and these observations are included in the rankings as well.

The categories are excellent, good, mediocre, and poor. A cultivar with excellent resistance has exhibited no scab or minor occurrence even in the total absence of sprays in wet seasons. Good resistance means that we have observed damaging scab in the total absence of sprays in wet seasons, but the disease is usually minor in dry years, or in wet years with a modest spray program of 2-4 sprays.  Mediocre resistance means that we will see serious losses in wet seasons in the absence of sprays, but the disease causes little risk with a normal 8-10 spray fungicide program. Poor resistance implies total crop loss almost every season under Southeastern conditions if no sprays are applied, and considerable risk of loss in wet years even when a normal spray program is followed.

Bear in mind that these categories apply to conditions in humid areas with 50-60 inches of annual rainfall, and scab would be expected to be less in drier areas.

Recommendations. Cultivars are grouped into three categories according to how we recommend them.  Recommended cultivars are those we feel represent the best overall within their scab resistance category. Cultivars recommended conditionally or for trial are good choices also, but either have less supporting data or have problems identified with them that need to be considered before they are planted.

Excellent resistance. We recommend three cultivars, Gafford, Excel, and Amling, all of which have shown excellent scab resistance in our observations so far with no exceptions.

Gafford (AL seedling) Type I. 56 nuts/lb.  50% kernel.  Produces a moderate quality nut with bright kernels. Nuts are medium-sized, and harvest is midseason.  It has excellent resistance to scab and foliage pests. It is one of the most pest-free selections we have ever evaluated. Yields have been good, alternate bearing moderate, and quality has been good in on-years.

Excel (GA seedling, suspected to be Pierce x Success) Type II. 45 nuts/lb. 49% kernel. Excel  has a unique combination of large nut size, excellent scab resistance, and early harvest date. Kernels are bright, but kernel percentage is only moderate as shells are thick. Yields are high, but alternate bearing and overbearing may be a problem on older trees.

Amling (TX seedling) Type I. 60 nuts/lb. 53% kernel.   Amling has produced nuts of good quality with minimal care and no sprays. Nuts are moderate to small. Scab resistance is excellent, and harvest date is early, about October 11, similar to Elliott. Little is known about long-term yield potential.

A cultivar with excellent scab resistance that we recommend conditionally or for trial is Kanza. 

Kanza is a Major x Shoshoni cross released by USDA in 1996. It has excellent scab resistance and unlike Elliott excellent cold hardiness.  Similar to Elliott, it alternately bears but maintains good quality in on years.  In our tests at the EV Smith Research Center, kernel brightness has been much worse than Elliott, and percent kernel at only about 49% for Kanza is also less than Elliott. Kanza is suggested for trial plantings in North Alabama, where Elliott is too freeze susceptible.

Cultivars with excellent scab resistance that we don't recommend include Gloria Grande , Barton, and Jenkins.  

Gloria Grande is a cultivar producing a large nut of mediocre kernel percentage, about 47%. Yields are good and consistent.  A serious drawback of Gloria Grande is extreme susceptibility to black aphids. Barton overproduces and alternately bears badly as trees get older, and has a problem with leaf scorch. Jenkins can produce excellent quality nuts of medium size, with 53% bright kernels.  However, as trees get older and with irrigation resulting in larger nut size, kernels have frequently been off- grade and fuzzy. Yellow aphids and sooty mold accumulation, and susceptibility to zonate leafspot are additional problems with Jenkins.

Good resistance.  Next, we'll discuss cultivars with good scab resistance, which can be grown with a minimal fungicide spray program. The cultivar we recommend in this group is McMillan.

McMillan (AL seedling). Type II. 56 nuts/lb. 51% kernel. This cultivar has been highly productive and consistent. Scab resistance has been good on this cultivar, similar to Sumner.  In wet years with no sprays scab losses can occur, but scab is easily controlled with a modest fungicide program of 3-4 sprays.  Kernels are somewhat dark and occasionally, like Pawnee, have ugly dark kernel markings. Harvest date is about October 20.

Cultivars with good scab resistance that we recommend conditionally or for trial include Elliott, Sumner, Farley, USDA 82-17-680, and Carter.

Elliott is an older cultivar widely planted in the Southeast. It has been the standard for scab resistance and retains excellent resistance in most locations over 80 years since its release about 1925.  The reason for its conditional status is because Elliott has known flaws that need to be considered.  The widespread planting has allowed strains of the fungus to develop at certain locations such that the usual excellent scab resistance has weakened, resulting in our cureent scab resistance rating of good. In the face of these strains of the fungus, scab resistance is no longer strong enough to grow Elliott without sprays in many locations. Foliage condition on Elliott on unsprayed trees is often weak, as Elliott is susceptible now to foliage diseases and is quite susceptible to yellow aphids and sooty mold accumulation.  Alternate bearing is severe, though Elliott usually maintains high quality with excellent bright kernels even in heavy on-years. Elliott's early budbreak makes it quite susceptible to spring freezes.

Sumner is a productive cultivar with good kernel quality, high and consistent yields, and good scab resistance. A major disadvantage for Sumner, like Gloria Grande, is that it is highly susceptible to black aphids, and damage from these pests can be serious unless systemic insecticides or aggressive scouting and spraying are used. Sumner also has the disadvantage of late harvest, about 11 days after Stuart.

Farley is an older cultivar with good scab resistance, good kernel quality, and consistent yields. It is somewhat slow to begin producing nuts as a young tree, but has good and consistent yields as an older tree. Shells are thin, and nut size is fairly small, about 60 nuts per pound, making it vulnerable to bird predation. Harvest is late, about 10 days after Stuart. This cultivar may have a place for those who want a low-maintenance tree with steady yields of good quality nuts without having to mechanically thin.

USDA 82-17-680 is a selection we are encouraging for trial planting because of high yields and good pest resistance to-date in our trials. This selection resulted from an open-pollinated Wichita. It has high productivity, like Wichita, but has surprisingly good resistance to scab and foliage diseases. Kernel quality is good to moderate. It needs crop load control by mechanical thinning in on-years to improve quality and reduce alternate bearing.

Carter is a seedling selection from Mississippi with good scab resistance, good kernel quality, and large nut size. Harvest date is about October 18. Veins have been visible on kernels in some years. Yields have been light to moderate. It would be a good choice for someone who wanted large pecans of good quality and good scab resistance, but it doesn’t produce enough nuts for widespread commercial planting.

Mediocre resistance. Among the many cultivars in this category, we recommend three – Caddo, Forkert, and Surprize.

Caddo (Brooks x Alley). Type I. 70 nuts/lb. 54% kernel.          The small, football shaped nut of this cultivar is consistently well filled with bright kernels.  The nut has good cracking qualities, and is suited to shelling markets.  It is a very prolific and consistent bearer.  Scab is easily controlled with sprays, but it can be susceptible to fungal leaf scorch and black pecan aphids. Harvest is early, about October 11.

Forkert (Success x Schley). Type II. 53 nuts/lb. 58% kernel. Consistently produces very high quality kernels with bright color and good taste.  A disadvantage is that kernel groves are tight and retain packing material. The nut is large and thin-shelled, and may be cracked during mechanical harvest.  The tree is strong and easy to train.  Requires a good scab control program, but is an excellent cultivar for retail/inshell marketing. Harvest is midseason to a few days earlier. Be aware that Forkert sheds pollen so late that it is not a good pollenizer for most cultivars. To pollenize Forkert, you need a very late pollen shedding cultivar, like Moreland, and since Forkert is no help in pollination of Moreland, a third cultivar must be in the planting to pollenize Moreland, like Cape Fear.

Surprize (Alabama seedling). Type I. 49 nuts/lb. 49% kernel. This cultivar originated in Baldwin Co., AL, and is a vigorous tree with strong branches.  Nut size is large, making it a good choice for inshell/retail marketing.  Kernels may not fill out well in some years if not irrigated properly.  Production from year to year is very consistent.  Susceptible to yellow aphids and sooty mold accumulation. Harvest is late. Surprize is recommended in south Alabama because the strong tree structure resists hurricane damage, and because it produces consistent yields there.

Cultivars with mediocre scab resistance which we recommend conditionally or for trial include Creek and USDA 48-13-311.

Creek is a Mohawk x Starking Hardy Giant cross from USDA, the same parentage as Pawnee. It has much better scab resistance than Pawnee, and grower experience indicates that alternate bearing is easier to control with Creek  than with Pawnee. Variety trial results understate the yield potential of Creek, as the small compact trees tolerate crowding and should be spaced closely, resulting in high per acre yields. It is only conditionally recommended, as trees must be crop thinned, have good irrigation, aphid control and late fertilizer applications or quality and alternate bearing are intolerable.

USDA 48-13-311 is a Moore x Schley cross which has demonstrated remarkable yields of excellent quality small nuts. Harvest is early, about October 8, so that early marketing, high quality, and high yields often offset the price penalty for the small nut size. Kernel percentage is about 58%, with 84 nuts/lb. In addition to small nut size, problems include alternate bearing and black aphid susceptibility. Kernels can be dark, especially if left to lay on wet ground.

Poor resistance. Since scab is such a major limiting factor in pecan production in the Southeast, we do not fully recommend any cultivars with poor scab resistance. However, some cultivars are so exceptional regarding other characteristics, that they are worthwhile to plant despite enormous scab risk.

One such cultivar is Desirable, which we conditionally recommend. The conditions involve scab control. Desirable should not be planted in low wet areas with poor air flow. Desirable orchards need to be open, with no more than 50% canopy coverage. Growers need to be prepared to spray fungicides at 7-day intervals, 1.5 mph speed, during wet periods. Advantages of Desirable are well-known, a large nut that shells well with bright kernels, and the most consistent yields of any widely-planted cultivar. A major and often overlooked advantage for Desirable is that it is not as susceptible to aphids or sooty mold as most cultivars. In addition to scab susceptibility, disadvantages include weak limb structure and susceptibility to pecan leaf scorch mites.

There are many other cultivars with good or outstanding characteristics but with poor scab resistance. Because of the devastation of this disease and the high risk, we do not recommend planting them. These include Pawnee, USDA 70-6-15, Sioux, Nacono, Western, and Wichita.

Table 2. Characteristics of recommended cultivars for the Southeast.

Goff is a Professor and Extension Pecan Specialist at Auburn University