CAES Newswire

 College of Agricultural & Environmental Sciences UGA Cooperative Extension
Menu
Published on 09/24/13

Georgia crop diseases linked to abundant rainfall, cooler temperatures

By Robert C Kemerait Jr

Weather played a significant role in the types of diseases that have been found on Georgia crops this season. Rainfall delayed harvest in some cotton and soybean fields and brought diseases to peanuts, cotton and corn fields. Cooler temperatures, however, kept at least one peanut mold at bay.

Pythium pod rot of peanut has been identified in a number of fields where it was not known before. Fusarium wilt of cotton has also appeared in an unusual number of fields, again likely due to the abundance of rainfall early in the season. Many corn diseases, including rusts, blights, leaf spots and especially ear rots, were tremendously important in 2013.

Other diseases, like white mold (southern stem rot) and Cylindrocladium black rot (CBR) of peanut were less common than expected, at least early in the season. Cooler-than-normal temperatures may have slowed the development of white mold.

University of Georgia plant pathologists are still scratching their heads to explain the very low severity of CBR this season. There is still much to learn about plant diseases.

Take away lessons

Five important points to be taken away from the 2013 field season are:

1. Climate, including warmer winter, cooler spring, or wetter and cooler summer, can have a tremendous impact on the types and severity of diseases important to our farmers during a season. Weather patterns associated with climate may be more or less favorable for the development and spread of diseases. These same weather patterns may keep growers out of the field and from making timely fungicide applications.

2. Climate (and hurricanes) can be difficult to predict. It seems that the prediction for “named storms” in 2013 continues to get less accurate as we move to the heart of hurricane season. This does not in any way diminish the importance of attention to climate predictive models for planning prior to a field season. It does however clearly show that Mother Nature is very complicated.

3. Use of fungicides continues to become more of the norm on corn and soybeans rather than the exception. Farmers have respect for preventative fungicide applications and an appreciation for the damage that diseases like southern corn rust, northern corn leaf blight and Asian soybean rust cause. Best management practices for diseases like northern corn leaf blight remain uncertain.

4. Target spot, caused by Corynespora cassiicola, remains very common where cotton is grown in Georgia and can cause significant premature defoliation. Effective management of this disease, including if and when to spray, still requires much additional study.

5. Management of nematodes will become an ever-increasingly important consideration for row-crop growers. Not only are farmers becoming more aware of the impact of nematodes, like the stubbyroot nematode on corn, but they will also have access to new tools. Whether the promise of new nematicides, new nematode-resistant varieties, or site-specific applications of Telone II, growers should learn all they can about the impact of nematodes and tactics that can be deployed to protect their crop.

Growers should prepare for next year

The five most important steps growers can take to prepare for the 2014 season are:

1. Assess the performance of varieties planted this year with regards to disease, and begin to consider ways to improve disease control for next year.

2. Consider steps to take to improve crop rotation in the new season.

3. Take nematode samples from fields to identify problem areas.

4. Assess diseases that were of particular importance in 2013, and consider options for improving management in 2014.

5. Learn about new, resistant varieties, fungicides and nematicides that are available, and determine how to use them effectively in the new season.

For more information about diseases on Georgia crops, visit the UGA Plant Disease Library website at plantpath.caes.uga.edu/extension/DiseaseLibrary.html.

Bob Kemerait is an Extension plant pathologist with University of Georgia Cooperative Extension.

Authors:
Robert C Kemerait Jr
Experts/Sources:
Bob Kemerait
Georgia farmers fought diseases in their cotton, peanut and corn crops as a result of last spring's abundance of rainfall. Fusarium wilt of cotton appeared in an unusual number of fields, again likely due to the abundance of rainfall early in the season.
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Download Image
As a University of Georgia Cooperative Extension specialist in the UGA College of Agricultural and Environmental Sciences, Bob Kemerait is well known for his devotion to the agricultural community of Georgia. He is also known for his international work with colleagues and small-scale farmers around the world. Recently, Kemerait took a team from UGA Extension to the Philippines, where he serves as a Fulbright specialist and works with the faculty at Mariano Marcos State University and farmers in the northern Philippines to improve disease management and other production practices. CAES News
UGA plant pathologist works to improve crop management and empower farmers across the globe 11/05/24 Robert C Kemerait Jr
As a University of Georgia Cooperative Extension specialist in the UGA College of Agricultural and Environmental Sciences, Bob Kemerait is well known for his devotion to the agricultural community of Georgia. He is also known for his international work with colleagues and small-scale farmers around the world. Recently, Kemerait took a team from UGA Extension to the Philippines, where he serves as a Fulbright specialist.
Seth McAllister and farmer Mark Daniel discuss crop production and agritourism. CAES News
UGA Extension supports agritourism through expert advice and collaboration 10/24/24 Emily Cabrera
On a sunny day with bright-blue skies, I arrive at Mark’s Melon Patch in Sasser, Georgia, and immediately spot the familiar white University of Georgia Cooperative Extension pickup truck, the Terrell County Extension logo prominently displayed on the door. Seth McAllister, the Agriculture and Natural Resources agent for Terrell County, greets me with a broad grin and a firm handshake. Terrell County alone has 60,000 acres of row crops, half in cotton. But what McAllister loves most about his role as an Extension agent is the diversity of his work.
Combining data collection and analysis with plant pathology, precision agriculture and robotics, the UGA team will build a photographic library of the foliar symptoms caused by onion diseases and other physiological disorders, feed them into the AI software, and use machine learning to identify the diseases based on pattern and color recognition from the images. CAES News
UGA uses AI, robotics to improve Georgia’s Vidalia sweet onion crop 10/23/24 Jordan Powers
A multidisciplinary team of UGA researchers aims to enhance the competitiveness of Vidalia onion growers in Georgia by providing them with the ability to confidently detect onion diseases early, enabling them to make management decisions on their crop at a critical time. These abilities, researchers say, should result in increased yield and quality of marketable onions and an overall increase in efficiency and productivity.
Helenedamage web CAES News
Hurricane Helene: Preliminary damage assessment on Georgia agriculture and forestry industry 10/10/24 Claire Sanders Kinnard, Matthew Agvent
Today, Georgia Agriculture Commissioner Tyler Harper, in coordination with Governor Brian P. Kemp, the University of Georgia College of Agricultural and Environmental Sciences (CAES), and the Georgia Forestry Commission, announced the preliminary estimate of Hurricane Helene’s economic impact on Georgia agriculture is $6.46 billion.
Most of Georgia’s vegetable crops are grown in the southern part of the state, which, similar to California, faces drought risks. However, as the climate warms, the area is expected to receive slightly more rainfall than usual, according to CAES economist Jeff Mullen. If vegetable production in California decreases and prices rise elsewhere, Southeast producers may consider shifting from row crop to vegetable production. CAES News
Georgia vegetable production may expand as a result of climate change 09/17/24 Maria M. Lameiras
Changing weather patterns are influencing cropping systems and where certain crops can be successfully grown. Researchers in the University of Georgia’s College of Agricultural and Environmental Sciences recently published a study in the journal Sustainability examining the feasibility of expanding fresh vegetable production in Georgia as increased temperatures and more frequent and extreme droughts threaten producers in the Western United States.
Nino Brown stands in front of a peanut field holding up a red net bag of harvested peanuts above his head as he speaks to participants in the Georgia Peanut Tour in 2022. CAES News
CAES experts study oil production to boost Georgia’s peanut power 09/05/24 Maria M. Lameiras
A new study by experts in the University of Georgia’s College of Agricultural and Environmental Sciences is seeking to increase the value of Georgia’s peanut crops for new markets while reducing losses caused by aflatoxin, a consistent threat to the No. 1 peanut-producing state in the United States. The four-year, $490,000 grant will take a systems-based approach toward developing high-oil peanut varieties bred to withstand the unique climate and pest pressures of the Southeast.