By Megan Dewdney Greasy spot and melanose are two fungal diseases that have long needed the attention of Florida citrus growers. While they are more of a concern for fresh fruit growers, trees for processing can be damaged, too. In terms of management priorities, greasy spot is the greater concern since it reduces tree photosynthetic capacity and causes defoliation. Melanose …
Soil Moisture Sensor Q&A
By Sandra Guzman Understanding how to obtain and interpret data from soil moisture sensor (SMS) systems is crucial for efficient irrigation management. These systems help create an efficient and informed irrigation schedule based on soil moisture readings collected from the field. Below are answers to some common questions about managing SMS systems, including how to view SMS data on a …
Trials to Seek Hamlin Alternative
Twenty-four citrus scions were approved by the Citrus Research and Development Foundation (CRDF) on March 23 for eventual use in multiple field trials around Florida. The purpose of the trials will be to find an early-season orange that is more tolerant of HLB disease than Hamlin, said CRDF Chief Operating Officer Rick Dantzler. Hamlin has long been the primary early-season …
Plan Now for Phytophthora Season
By Evan Johnson The Florida citrus spring leaf flush is hardening off, which means the first root flush of the year is beginning. With the spring root flush comes thoughts of phytophthora foot rot. Spring roots are at particular risk in groves that had high phytophthora pressure last fall because many of the resting spores will start activating with the …
Instant Information on Herbicides
By Ramdas Kanissery Citrus growers face weed management problems throughout the year due to favorable conditions that allow the rapid growth of weeds in groves. A weed-free tree row is desired in citrus to minimize competition with the trees. This can be achieved by utilizing post-emergent herbicides that control the weeds that have already emerged. Growers have several product options …
What to Do About Citrus Black Spot
By Megan Dewdney Citrus black spot is one of the newer diseases to worry Florida citrus growers. The fungal disease was first detected in Southwest Florida in 2010. The vast majority of finds have been in the southwestern citrus-producing counties of Collier, Hardee, Lee, Charlotte and Glades, but the disease has slowly moved northward. Black spot is still considered a …
Protect Young Citrus from Weeds
Protect Young Citrus from Grasses, Broadleaf Weeds & Nutsedge Weeds in citrus groves can cause yield loss of up to 33%, according to research published by the University of Florida (UF) Citrus Research & Education Center. This significant – yet largely preventable – level of yield loss can be due to weeds that interfere with harvesting, serve as alternate hosts …
Time to Check Under the Hood for Nematodes
By Larry Duncan Monitoring population levels of plant parasitic nematodes and phytophthora is best done in springtime prior to the rainy season. Peak population density of the citrus nematode (Tylenchulus semipentrans) occurs at that time, and the accuracy of sample results increases with population density. The sampled population levels of this nematode and those of Phytophthora spp. can be compared …
Scout for Scale and Mealybug Crawlers
By Lauren Diepenbrock While scale and mealybug pests commonly found in citrus have historically been controlled by predators and parasites, management advice for this group of insects is often requested. There are likely several underlying factors to these insects becoming more frequently encountered. This includes changes in insecticide management practices, changes in nutritional management, and increased scouting due to the …
Prepare for Citrus Canker Season
By Evan Johnson Now that bloom has arrived, it is time to start thinking about canker management. As the fruitlets develop, they will become susceptible around the end of March to the beginning of April. The spring fruit lesions are particularly concerning because they cause fruit drop. Without proper management, early season canker can cause 90 to 100% crop loss …
Minimize Blemishes on Tangerines and Grapefruit
Megan Dewdney Since tangerines and grapefruit they are eaten fresh, a blemish-free peel is highly desired. Two diseases that frequently mar the peels of tangerines, and occasionally grapefruit, are Alternaria brown spot (ABS) and citrus scab. Both diseases cause symptoms on leaves and fruit. ALTERNARIA BROWN SPOTThe early foliar symptoms of ABS are small yellow flecks that quickly become larger …
Georgia Owari Rootstock Trial Update
Ongoing citrus rootstock trials being conducted by the University of Georgia (UGA) hold promise for Georgia’s growing citrus industry. Jake Price, UGA Extension agent and Lowndes County Extension coordinator, has produced six local citrus rootstock/variety trials with varying objectives. The oldest trial, planted in 2014, is growing Owari satsuma trees on standard and new trifoliate hybrid rootstocks. Each year, as …
Scout Early Bloom for PFD
By Andre B. Gama and Megan M. Dewdney Postbloom fruit drop (PFD) of citrus is a disease caused mostly by the fungus Colletotrichum acutatum. This fungus survives by producing resting structures on leaves and stems. When flowers start to appear in groves, these resting structures produce spores that can cause PFD. However, the fungus requires specific weather conditions to be …
Time to Cut the Dead Wood
By Megan Dewdney, Tripti Vashisth and Lauren Diepenbrock Dead wood has long been challenging for fresh citrus fruit production. Spores in twigs can form which cause blemishing diseases that downgrade fruit for lower profits. More recently, it has come to light that there are horticultural and entomological reasons to remove this wood as well. Many growers are familiar with melanose, …
Plan Your Insect Management for 2021
By L.M. Diepenbrock Insect and mite management is a year-round challenge in Florida citrus. With the warm climate, pests are at the ready as soon as plant resources are available to them. With knowledge of insect and mite biology in relation to tree phenology, plans can be developed to protect fruit and maintain productive citrus trees. Populations of many of …
Avoid Salt-Out of Liquid Fertilizers
By Ajia Paolillo The use of liquid fertilizers in citrus production has increased over the years. Liquid fertilizers offer the grower a way of applying frequent doses of fertilizer to trees to optimize nutrient efficiency. Now that the winter months are here with cooler weather and some cold nights, growers may face the issue of liquid fertilizer salting-out in the …
Compost Use and Weed Management
By Ramdas Kanissery Application of compost as a soil amendment could be an integral part of citrus production’s best management practices. Compost application can potentially improve soil quality and provide additional nourishment to trees. Citrus-producing soils in Florida are generally sandy and low in soil organic matter. Compost addition tends to enhance the soil’s ability to retain both nutrients and …
Time for ACP Dormant Season Sprays
By Lauren Diepenbrock Pest management is an ongoing effort in Florida citrus. Taking advantage of pest life cycles, whether they are tied to the season or plant phenology, can make management efforts have greater impacts on pest populations. For many citrus growers, managing the impacts of Asian citrus psyllid (ACP), the vector of huanglongbing (HLB), is part of the annual …
New Year’s Resolutions for 2021
By Ruth Borger It is time for a new year, and many of us cannot see 2020 end fast enough. It is almost time for 2021, and there is a lot to be hopeful for. New vaccines to fight the coronavirus hold great potential for beating the pandemic. U.S. citrus sales so far this season continue to show strong performance. …
High-Tech Scouting in Citrus Production
By Yiannis Ampatzidis and Tara Wade Traditional sensing technologies in citrus production for pest and disease detection and field phenotyping rely on manual sampling, which is time consuming and labor intensive. Since availability of personnel trained for field scouting is a major problem, small unmanned aerial vehicles (UAVs) equipped with various sensors and artificial intelligence (AI) can simplify the surveying …