Cooperative Extension Service
College of Agricultural and Environmental Sciences
The University of Georgia
George Boyhan, Extension Horticulturist-Vegetables
East Georgia Extension Center
Nessmith-Lane Building, 2nd Floor
PO Box 8112
Georgia Southern University
Statesboro, GA 30460
912-681-5639 | 912-681-0376, Fax | 912-682-3481, mobile
Onion plant beds are in the ground and growers should be insuring these plants are growing well. This means making sure they have adequate fertilizer and water, with special attention to disease and weed control. It won't be long before they will be ready for transplanting.
Growers should be aware of several factors that can affect onion transplanting and the performance of the crop after transplanting. Transplanting should begin when the seedlings are about 8 weeks old. This will probably be some time in the latter half of November. The plants should be inspected for size. They should be about ½ inch in diameter at the base. Plants that are significantly smaller (less than half this diameter) will have trouble establishing and withstanding the colder winter temperatures. Plants that are larger (¾ inch diameter or larger) are more prone to seedstems in the spring.
Growers should expect adequate yield of quality onions from transplants set as late as the first one to two weeks of January. After that date, onion yields will drop off dramatically with an increased probability of seedstems.
Some fertilizer should be applied preplant or within a week of transplanting. Between 25-40 pounds of nitrogen and potassium along with all of the recommended phosphorus should be applied at this time. In addition, sulfur should be applied at this time. A good choice would be a premium grade 10-10-10, which has 12 percent sulfur. This could be applied at a rate of 400 pounds per acre, which would supply 40 pounds of nitrogen, phosphorus and potassium. In addition, this would supply 48 pounds of sulfur. This fertilizer application is critically important to insure plants begin to grow so they will have sufficient reserves to overcome disease and cold weather.
Transplant timing can be very important. If cold weather is expected shortly after transplanting, growers should postpone setting plants until temperatures warm. This can reduce losses to plants already shocked from the transplanting process.
Within one month of transplanting is the best time to apply herbicides. Plant tops have been removed so there is reduced danger of crop damage.
Within the past two years, the occurrence of Iris Yellow Spot Virus and Tomato Spotted Wilt Virus has been detected in onions. TSWV, of course, has been a serious disease of many crops in Georgia. Both tobacco thrips and western flower thrips are known to transmit TSWV, but they're not known to transmit IYSV, which is transmitted by onion thrips. Ironically, onion thrips are rarely found in Georgia. Testing to detect these viruses either with enzyme linked immunoabsorbant assay (ELISA) or polymerase chain reaction (PCR) has not always been successful. Symptomless plants can test positive and putative symptom expressions have tested negative. There may be compounds in onion tissue that interfere with the testing process. It is still unclear how serious this problem is or may become.
The USDA Agricultural Marketing Service (AMS) maintains grades for fresh vegetables. These voluntary grading standards are used to insure uniformity and quality for produce shipments, especially those entering interstate transport. The USDA AMS has proposed changes to the watermelon standards based on a petition from the National Watermelon Association.
The NWA has petitioned the AMS to include standards for seedless watermelons, which would define a seedless watermelon as follows: "Seedless Watermelons" are watermelons which have 10 or less mature seeds, not to include pips/caplets, on the face of the melon which has been cut into four equal sections (one lengthwise cut and one crosswise cut).
The AMS will take public comment for 60 days on this proposed change before acting. The change appeared in the Federal Register of September 7. Interested parties can submit comments to AMS until November 7.
In addition to changes to include seedless watermelons, changes to melon size are also proposed. The proposed change will allow melons to be 3 pounds above the stated average weight, which currently allows for size changes of 3 pounds under the stated average weight.
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The dry weather finally broke and we've had two weeks of rainy overcast weather. It has rained heavily at times, which has helped alleviate drought conditions. We will have 41 entries in the onion variety trial this year, which is fewer than the 49 from last year. We removed onions from CA storage a couple of weeks ago, and they looked pretty good. I should have those results with next month's newsletter.