Stone Fruit: Now’s Your Chance!

Stone Fruit: Now's Your Chance!

Brown rot (caused by Monilinia species) is a well-known disease of peaches around the world. It tends to be more problematic in areas with high spring/summer precipitation and high humidity. Wind, rain, and insects help to distribute spores to cause flower blossom or fruit infections during the growing season. Spores may also form latent fruit infections that can cause postharvest rots. If infected fruits are left on the tree and not harvested, they may remain there and become mummified (see top photo). In some cases, twig cankers may occur and wound gumming is produced (see bottom photo).

Perhaps you had a dry spring/summer in 2009 and experienced minimal losses due to this disease. Or, maybe you were faced with more rain than usual, the difficulty of making timely fungicide applications, reduced efficacy of materials you have historically used, and the disease simply “got away on you.” I know of cases in South Carolina where either a spring freeze or early season hail storm resulted in crop damage that caused some growers to “walk away” so-to-speak from problem blocks. In the latter case, we recommended a minimal spray program to help ensure that brown rot epidemics would not result but not everyone elected to do this because of cost.

If you had a brown rot problem last year, you have an opportunity this winter to take proactive steps to reduce the potential for a problem in 2010. According to my friend and colleague, Dr. Guido Schnabel (Extension fruit pathologist, Clemson University), orchard sanitation efforts this winter will go a long way to reduce inoculum and disease pressure this coming season. The first step is to deal with mummies. Because they are a source of inoculum for spring infections, these should be carried out of the orchard and disposed of.

At locations where there is a sod row middle and the orchard floor is vegetated, mummies that fall to the orchard floor may have sufficient spring moisture to become active spore producers. In locations where the orchard floor is kept bare by herbicides, mummies may dry out sufficiently so as not to be a problem. The second step is to deal with limbs that have cankers. The best practice is to remove them from the orchard and burn them. However, putting the prunings in the row middle and driving over them with a flail mower (to remove bark) can facilitate a more rapid decomposition and reduce inoculum level considerably. This is a useful practice for limbs that may also be infected by constriction canker (Phomopsis) or fungal gummosis (Botryosphaeria).

Research by Schnabel and colleagues has demonstrated resistance of brown rot fungi to various fungicide classes. Selection for resistance can occur when fungicides with a single site of action are used repeatedly for years. Whatever the reason, the number of tools available and the efficacy of those tools ultimately depend on their wise use by the grower. That is why thorough sanitation (now) is a wise step to take. Careful choice of fungicides during the growing season and rotation of products with different modes of action can help limit resistance development. However, if you did have product failure last year, you may want to visit Dr. Schnabel’s website (www.peachdoc.com) to learn more, especially about his brown rot resistance management program (ProfileTM).

Leave a Reply

Featured Stories
CitrusWith Big Data Comes Big Concerns For Agriculture [Opinion]
January 30, 2015
Many believe technologies like UAVs and precision ag represent the second Green Revolution, but it only will happen if farmers feel safe using them. Read More
Apples & PearsNew Bactericide Now Registered in Top Apple Growing States
January 30, 2015
KASUMIN is active on a wide array of plant pathogenic bacteria, including resistant strains. Read More
FruitsCalifornia Drought Meeting Called
January 30, 2015
State and federal officials will discuss potential actions for the coming year. Read More
GrapesRecord Crowds Flock To California Winegrape Show
January 30, 2015
Unified Wine & Grape Symposium attracts 14,000 industry professionals. Read More
Insect & Disease UpdateResearchers Develop Electronic Citrus Greening Detector
January 30, 2015
New, easy-to-use technology could help growers get a leg up on the disease. Read More
VegetablesSakata Seed Highlights Specialty Golden Beet
January 29, 2015
The company highlights specialty golden beet, Touchstone Gold. Read More
FruitsUse The Off-Season To Focus On Farm Safety
January 29, 2015
Prevention, planning, and preparedness are essential for all agritainment operations. Read More
Protected AgricultureHow To Successfully Produce Vegetables In Controlled Environments
January 28, 2015
Greenhouse expert Merle Jensen offers pointers on growing systems, pest control, plant nutrition, harvesting, and more. Read More
IPMWhat You Need To Know To Maintain An Effective IPM Program In The Greenhouse
January 28, 2015
Greenhouse expert Karin Tifft discusses the importance of scouting, pest identification, control options, and the importance of sanitation. Read More
Apples & PearsPears Get A Hefty Shout-Out From Rapper
January 28, 2015
The pome fruit is on mainstream media's radar thanks to a rapper's quote and ensuing social media blitz. Read More
The Latest
CitrusWith Big Data Comes Big Concerns For Agriculture [Opini…
January 30, 2015
Many believe technologies like UAVs and precision ag represent the second Green Revolution, but it only will happen if farmers feel safe using them. Read More
Apples & PearsNew Bactericide Now Registered in Top Apple Growing Sta…
January 30, 2015
KASUMIN is active on a wide array of plant pathogenic bacteria, including resistant strains. Read More
FruitsCalifornia Drought Meeting Called
January 30, 2015
State and federal officials will discuss potential actions for the coming year. Read More
GrapesRecord Crowds Flock To California Winegrape Show
January 30, 2015
Unified Wine & Grape Symposium attracts 14,000 industry professionals. Read More
Insect & Disease UpdateResearchers Develop Electronic Citrus Greening Detector
January 30, 2015
New, easy-to-use technology could help growers get a leg up on the disease. Read More
VegetablesSakata Seed Highlights Specialty Golden Beet
January 29, 2015
The company highlights specialty golden beet, Touchstone Gold. Read More
FruitsUse The Off-Season To Focus On Farm Safety
January 29, 2015
Prevention, planning, and preparedness are essential for all agritainment operations. Read More
Protected AgricultureHow To Successfully Produce Vegetables In Controlled En…
January 28, 2015
Greenhouse expert Merle Jensen offers pointers on growing systems, pest control, plant nutrition, harvesting, and more. Read More
IPMWhat You Need To Know To Maintain An Effective IPM Prog…
January 28, 2015
Greenhouse expert Karin Tifft discusses the importance of scouting, pest identification, control options, and the importance of sanitation. Read More
Apples & PearsPears Get A Hefty Shout-Out From Rapper
January 28, 2015
The pome fruit is on mainstream media's radar thanks to a rapper's quote and ensuing social media blitz. Read More
FruitsHighlights From The Mid-Atlantic Fruit And Vegetable Co…
January 28, 2015
Bio-control use, media literacy, and disease control were just a few of the topics discussed at the convention held in Hershey, PA. Read More
GrapesCalifornia Table Grape Growers Offer Agricultural Schol…
January 28, 2015
The application deadline for the agricultural scholarships is 5 p.m., Feb. 13. Read More
GrapesNew Wine Hybrid Establishment Cost Resource Available
January 28, 2015
Research from Cornell University breaks down the cost of producing hybrid winegrapes. Read More
FertilizerEasy Access To Fertilization Guidelines
January 28, 2015
New, easy-to-follow brochures take the guesswork out of almond and walnut fertilization. Read More
BerriesDormant Pruning Tips For Your Berries
January 28, 2015
Proper dormant pruning increases berry size and improves overall health of blackberry and raspberry plants. Read More
NutsHow Freezing Temperature Affect Bearing and New Trees
January 28, 2015
Key points before and after the critical bloom period make exposure to freezing temperatures relevant. Read More
CitrusFlorida Citrus Is Still A Big Deal [Opinion]
January 28, 2015
Even while in the grips of greening, citrus continues to be a big contributor to the Sunshine State's economy. Read More
FruitsUSDA Forecast Predicts Normal Water Supply For Parts Of…
January 27, 2015
The Southwest, Sierra Nevada region, and Pacific Northwest are starting the year drier than normal. Read More