In the right temperatures, stroma is infested with fungal spores that, in turn, spread over the tree, causing infection. These groups include: Group 1 – MBC fungicides, MOA – cytoskeleton and motor protein, high risk for resistance. Give the trees what they need but don’t engage in luxury spending for practices, products, or applications you may not necessarily need. *Check mixing compatibility of your phosphite and foliar zinc (or other foliar nutrient) choices prior to application. Young Trees All of our pecan fungicides have begun at this point. The same goes for all aspects of management. What to Spray Pecan Trees With Pecan Trees Are Huge. 1 Pint Liquid Concentrate (treats at least 5-6 large trees) Liquid Copper Fungicide Spray is a key tool in disease prevention and treatment on a large variety of trees. The UGA Pecan Team provides timely information relevant to pecan production in Georgia for use by county extension agents and pecan producers. I have a small pecan orchard (23 trees). Even if they are not, the tariff for pecans going to China was 24% as recently as 2014/2015 and the market remained strong. In Louisiana, control of diseases is required for consistent production of high quality pecans. Because scab disease can occur any time during the growing season it is necessary to make several preventative fungicide applications from spring through summer. A standard calendar-based spray program for pecan disease control calls for sprays during the prepollination period (bud break to nut set) every 10-14 days for pecan scab and downy spot (Brock and Brenneman, 2012 Georgia Pecan Spray Guide).Downy spot is an important disease to prevent in a pecan orchard (Picture 2). However, the best bets for home growers are to select resistance cultivars and to use good cultural practices. Everyone has likely heard by now of the increased tariff applied to U.S. pecans going to China (up an additional 15% now to 22%). Prevention & Treatment: Some pecan cultivars are more susceptible to powdery mildew than others. Pecan Scab, a disease cased by the fungal pathogen Fusicladium effusum, can drastically reduce nut yield. It has a moderate resistance risk. Leaves will turn yellow or brown and will remain attached to the tree. 7 Homemade Fungicides. The product you have been using has a moderate risk of developing resistance. Powdery mildew affects many plants from lilacs to pumpkins to pecan trees. The Best Fungicide for Fruit Trees. Crown Gall. Plant Food Systems, Inc., manufacturer of Kphite 7lP Fungicide/Bactericide says the product is moving into the southeast as pecan growers initiate their 2020 fungicide program. There are many products on the market for the control of pecan scab. A thin film of the fungicide prevents the scab fungus from developing by killing spores before they can invade susceptible tissues. Stuart and Schley are extremely susceptible. Unfortunately, once the fungus has invaded the tissues, it becomes protected from most fungicides and can continue to produce spores. The responsible fungus is most active in warm, humid conditions with temperatures between 60° and 80°F (15.5 to 26.6°C). The severity of pecan scab is directly related to moisture and humidity levels. Spring rains likely provide the needed moisture for infection to occur. Fungicide Application Recommendations for Pecan Disease Control. It is most common in young seedlings. + Tin. A list of recommended fungicides, all of which are effective, can be found in the LSU AgCenter Fungicide Application Recommendations for Pecan Disease Control. Big commercial growers spray fungicides repeatedly on their pecan trees in an attempt to reduce pecan scab symptoms. Not much has changed from previous years with the exception of the use of phosphite alone in one of the early sprays. Teviotdale, Beth L., Themistocles John. Bear in mind that scab grows within a range of 50-95 degrees but 59-77 is the optimum range. There are several other fungal diseases that can infect pecan, but they are usually controlled when using a fungicide spray program to control pecan scab. Cultural Control. Pecan trees generally thrive in U.S. Department of Agriculture plant hardiness zones 6... Spraying for Scab. Last year I had a ZERO crop due to SCAB. I have heard of a number of folks spraying already. Not much has changed from previous years with the exception of the use of phosphite alone in one of the early sprays. Symptoms of infection are similar on all parts of an infected plant. Growers who have pruned in the winter months will benefit from … Sanitation measures, such as plowing or disk harrowing under fallen leaves and shucks, help reduce primary infections. Vein spot infections (lesions) are very similar to those caused by the scab fungus. Other products you might price include Enable, Orbit, Bumper, Folicur, or Monsoon. The important thing to remember is to rotate chemistries and use the fungicides to their strengths. Another recommended product is Enable (active ingredient fenbuconazole).