By Clint Thompson Farmers of Georgia’s Vidalia onions are crossing their fingers and hoping for minimal impact from the rains the Southeast Georgia region has experienced in recent weeks. Onions are vulnerable to secondary pathogens during weather events, especially as the crop is being harvested. Bhabesh Dutta, University of Georgia Cooperative Extension plant pathologist, believes the impact could be felt …
Phytoplasma Disease Confirmed in Florida
Scientists at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) have recorded the first North American case of a harmful phytoplasma disease known for its threat to fruit, vegetable and ornamental crops in South America and the Middle East. The phytoplasma species called Candidatus Phytoplasma brasiliense is documented in regions of Brazil and Peru to harm hibiscus, …
New Viruses to Watch for in Watermelon and Other Cucurbits
By Pamela D. Roberts Whitefly-transmitted viruses are the major disease problem for watermelons grown in South Florida. For the past few decades, whitefly-transmitted viruses have included squash vein yellowing virus (SqVYV), cucurbit leaf crumple virus (CuLCrV) and cucurbit yellow stunting disorder virus (CYSDV). A HISTORY OF VIRUSESAlthough SqVYV was first identified from squash in Florida in 2005, it had most likely been …
South Florida Pest and Disease Hotline: Gummy Stem Blight Concerns
Gummy stem blight disease has increased in recent weeks in cucurbit fields across southwest Florida, according to the South Florida Pest and Disease Hotline. It has become the predominate disease in some watermelon fields in the area. The disease remains moderate in cucumber crops on the east coast. Gummy stem blight’s symptoms appear as light to dark brown circular spots …
Pecan Growers Should Delay Fungicide Applications, Unless Crop is Highly Vulnerable to Scab Disease
By Clint Thompson Increased rainfall last week had pecan producers feeling antsy about applying fungicide sprays for scab disease. But that should only apply to a small percentage. Most growers still can wait to start their fungicide applications, says University of Georgia Cooperative Extension Pecan Specialist Lenny Wells. “I’ve had calls from some (growers), and some of them I agree, …
Cucurbit Farmers: Two Diseases Already Observed in North Florida
By Clint Thompson Cucurbit farmers in North Florida, South Georgia and South Alabama need to be wary of certain diseases that are already present in some fields. Mathews Paret, associate professor of plant pathology at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), describes what growers should be concerned about with regards to angular leaf spot and …
Watermelon Anthracnose: Current Trends and Future Directions
By Navjot Kaur and Bhabesh Dutta Watermelon anthracnose is caused by the fungal pathogen Colletotrichum orbiculare, which impacts all above-ground parts of the plant. C. orbiculare also causes anthracnose in other cucurbit crops such as cucumber, muskmelon, squash, gourd, pumpkin, cantaloupe and honeydew. The disease is favored by conditions including high humidity, rainfall, overhead irrigation and warm temperatures in the …
Powdery Mildew: What Cucurbit Growers Need to Know
By Clint Thompson Powdery mildew is a disease all cucurbit farmers need to be familiar with this spring season. Unlike other pathogens that need wet, rainy conditions to flourish, powdery mildew prefers a drier environment. If weather conditions turn dry this spring, powdery mildew could be most concerning, says Ed Sikora, professor and Extension plant pathologist in the Department of …
Improving Pre-emergent Herbicide Use in Vegetable Row Middles
By Ramdas Kanissery, Ruby Tiwari and Nirmal Timilsina Weeds are problematic in vegetable production as they compete with crops for nutrients, water and other resources. Weeds that emerge in the spaces between the raised beds (row middles) not only serve as hosts for pests and diseases but can potentially interfere with farm operations (Figure 1). Weeds can negatively affect field …
Fungicides to Manage Cercospora Leaf Spot on Beets
Cercospora leaf spot disease, the most damaging disease on beet greens and bunch beets, can be managed just as equally with either conventional or organic fungicides, according to The South Carolina Grower, Clemson plant pathologist Tony Keinath. Based on previous research in New York with processing beets, Keinath evaluated the best conventional program – Tilt alternated with Quadris – and …