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Commercial Horticulture > Comm Hort Blog > Posts > ​PEACH TREE SHORT LIFE: A COMPLEX PROBLEM FOR FRUIT GROWERS
Peach, nectarine and plum growers in Central AL have experienced a higher than normal amount of tree death, as well as limb dieback in their orchards this spring. Some of these trees may have exhibited symptoms of stress or limb dieback in the past year, however nothing gets a grower’s attention like multiple tree deaths occurring seemingly “all at once” in what was previously a young and vigorous orchard.
 
Last week, Dr. Tom Beckman, of the USDA-ARS Southeastern Fruit & Tree Nut Research Lab in Byron, GA and Dr. Kassie Conner, Extension Plant Pathologist at the Plant Diagnostic Lab in Auburn, Jim Pitts, Director of the Chilton Research and Extension Center and I visited several farms with growers in Chilton County to identify the various causes of the tree death and decline. The increased tree deaths following excessive rains last year, and extremely cold temperatures this winter and spring reminded me of those we saw after similar conditions in the spring of 2010.
 
The primary problem that we observed was bacterial canker which is one of the causes of limb dieback and often associated with “peach tree short life” (PTSL) resulting in the death of young peach, plum and nectarine trees. We also observed some trees collapsing from oak root rot (Armillaria spp.).
 
According to Dr. Beckman and Dr. Andy Nyczepir, also of the USDA-ARS Southeastern Fruit & Tree Nut Research Lab, “In the southeastern United States, peach tree short life (PTSL) refers to the sudden spring collapse and death of young peach trees. Generally, trees 3 to 7 years old are affected. PTSL is not caused by a single specific factor, but rather by a complex of cold damage and bacterial canker, caused by Pseudomonas syringae pv. syringae,which act together in some years and independently in other years. In any case, the final result is the same (i.e., tree death). Many other factors contribute to the PTSL complex, including time of pruning, rootstocks, orchard floor management, fertilization practices, and rapid fluctuation in late winter/early spring temperatures. The primary biotic factor responsible for predisposing peach trees to bacterial canker or cold injury or both is the ring nematode, Mesocriconema xenoplax.”
 
Nematode samples taken previously in one of the affected orchards confirmed the presence of ring nematodes there.  
 
This sudden collapse of young peach trees after bloom in the spring is the classic symptom of PTSL. Cutting into the bark will reveal brown, decaying tissue above the soil line, while the tissue below ground remains bright and apparently healthy. Trees affected by PTSL will commonly produce suckers, sprouting from below the soil line, whereas trees succumbing to other diseases such as oak root rot do not.
 
PTSL control includes good orchard site selection and preparation, rootstock selection and sound cultural practices.
 
Test soil for nematodes and avoid sites positive for ring nematode. If necessary, fumigation can greatly reduce nematode populations. One five year old orchard that we visited had 99% tree survival on fumigated rows compared to 50% tree survival on non-fumigated rows with dying trees showing PTSL symptoms. Rotating land with wheat for 3 years prior to establishing a peach orchard has been shown to be as
effective as pre-plant fumigation in suppressing the ring nematode.
 
Guardian rootstock has survived better than other commercial peach rootstocks, including Lovell, on sandy, replant sites infested with ring nematodes in the Southeast. Guardian
is more tolerant of the bacterial canker and resulting cold injury common to the peach tree short life syndrome.
 
Lime soils to raise the pH to 6.5 at a depth of 16 – 18 inches. Subsoil to break up hardpans.
 
Avoid pruning peach trees between 1 October and 1 February, especially those less than 6 years old, or those where ring nematodes are present.
 
For more information on PTSL, nematodes, oak root rot as well as many other aspects of peach production and pest management, see two excellent publications, the “Southeastern Peach Growers' Handbook”,http://www.ent.uga.edu/peach/peachhbk/hbk.htm and the “2014 Southeastern Peach, Nectarine and Plum Pest Management and Culture Guide”, http://www.ent.uga.edu/peach/PeachGuide.pdf .
 
Gary Gray
Regional Extension Agent, Commercial Horticulture
Central West AL and the Black Belt Region

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