New Citrus Greening Quarantine in Mission
A single grapefruit tree recently tested positive for citrus greening and this has triggered an emergency quarantine by the Texas Department of Agriculture (TDA). The tree is in downtown Mission in a residential area. The boundaries and provisions of the quarantine can be found at http://texasagriculture.gov/ RegulatoryPrograms/PlantQuality/ PestandDiseaseAlerts/Citrus
Greening. There are 1,760 acres of commercial citrus in this new quarantine.
The conditions for movement of fruit from the grove to the packing house are similar to the provisions used in the San Juan quarantine last year and shippers are familiar with the requirements associated with the harvesting and movement of fruit.
Citrus greening quarantines have a big impact on the movement of citrus nursery trees and TDA will be in contact with affected nurseries in the next few days. As we understand the regulations, nursery stock is not allowed to move outside of either quarantine unless it meets TDA and USDA requirements which include rearing the plants within an enclosed structure. Permits must be obtained from TDA by nurseries within the quarantine to sell host plants to customers who are not going to move them out of the quarantined area. If you have a nursery we would encourage you to contact the TDA office in San Juan at 956-787-8866 to learn more about the regulations for citrus nurseries.
The positive tree was detected by the ongoing USDA-APHIS sentinel tree survey. This tree has been tested before and citrus greening did not show up in those previous samples. It was a very large grapefruit tree and because of the latency of disease symptoms, it may have had the disease for quite some time. This latency situation is a reminder of the challenge of early detection, which includes knowing what the early symptoms look like and where in the tree to look for them. We have learned a good bit about early detection but there is still much to learn. Early indications are that symptoms are slightly different in Texas compared to other areas and that information will be shared in the upcoming grower meetings.
APHIS will be surveying (delimiting) the groves in the new quarantine area, beginning with those that are scheduled to be harvested first. If the APHIS crew has not finished surveying your grove and you are ready to harvest, you will be allowed to proceed with harvest.
Extensive plans have already been developed for outreach efforts with homeowners in the quarantine. The homeowner with the positive tree voluntarily agreed to remove the tree that tested positive and an additional tree that was touching it, even though that tree and all the other trees on the property were sampled and tested negative for the disease. The two trees were removed by Citrus Center personnel last Friday and this was carried out according to approved protocol procedures. The citrus industry and the team working on this situation are very grateful for the cooperation and understanding of the homeowner.
Part of the forthcoming outreach efforts with homeowners will include treating the immediate properties around the find with a pesticide and the strategic release of bio-control agents, including a type of wasp called Tamarixia. These parasitoids are being reared by the Center for Plant Health Science and Technology (CPHST) which is a division of APHIS at Moorefield AFB. Dr. Dan Flores has developed the rearing techniques and is overseeing the release operations as well. He has an excellent support team including Texas AgriLife Extension and the volunteer Master Gardeners. The TexaSweet Citrus Marketing Board has assigned the TexaSweet staff, including Eleisha Ensign, a major share of the responsibility for outreach with homeowners and smaller growers.
Detecting additional greening was inevitable. Letís hope we are finding the disease relatively early. Early detection and slowing the spread of the disease are our primary objectives. The leaders of our industry met last week and approved the plans described above.
Plans have also been made for the annual area wide management meetings with growers. Under the leadership of TCM, a new addition to the program will include more emphasis and suggestions on how to control psyllids at the interface between backyard citrus and commercial groves. There will also be more emphasis on having growers with properties in close proximity to one another treat their respective groves as close to the same time as possible. The purpose of this strategy is to make treatments more effective by reducing the chance of being re-infested by your neighbor.