White flies!: Dr. Philip Roberts, UGA Cotton Entomologist, and Scott Carlson, Tift County Extension Agent, have reported a couple of Tift County cotton fields at treatable levels for white fly. Some fields may be at less risk if the cotton is closer to maturity; but later planted, younger cotton may require treatment. The treatment decision should be based on immature whiteflies being observed. Following is the method to check for whiteflies: 1) Count down from the terminal of the plant to the fifth vegetative leaf (starting with any leaf that is the size of a quarter or bigger). 2) Turn the 5th leaf over to view the underside of the leaf, 3) See if there are any immature whiteflies present. If 50% or more of the 5th leaves checked have multiple immatures on them (see photo below), then treatments should be started. Insect growth regulators like Knack or Courier can be used if the population is not too high. These options are slow acting, and results are not seen until 5 to 7 days after treatment. If whiteflies are present, growers should avoid using dicrotophos (Bidrin or others) or limit its use, as it could allow whiteflies to flare.
Irrigation Termination in Cotton?: It is generally recommended that irrigation be terminated when a noticeable number of bolls have opened, especially when the majority of harvestable bolls are located on lower plant nodes. However, if the majority of the targeted harvestable bolls remain relatively immature when only a few lower bolls begin to open, irrigation may still be required for a short time. Irrigation termination can be a difficult decision. A final irrigation event is often applied when the crop begins to open. Commonly, NO additional irrigation is applied once the crop reaches 10% open boll to minimize problems with boll rot, hard lock, light spot,and other fiber quality issues..
Peanut Maturity Clinics: I have done a couple of maturity checks on some April planted peanuts over the last week and have had a couple of questions from growers about up coming clinics. The Colquitt County Extension will be offering peanut maturity clinics beginning August 28, 2015 thru October 2, 2015. The clinics will be offered Tuesday, Wednesday and Friday from 8:30AM to 12:00PM and will be held at the Colquitt County Extension office. If you need peanut samples done earlier this week please call. Remember, that maturity checks are only as good as the sample taken!! If you have questions about sampling for maturity checks please call or email. Below is information from Dr. Scott Monfort on maturity ranges of peanut varieties grown in Georgia. Actual maturity is dependent on the season long environmental conditions.
RUNNER-TYPE VARIETIES
Florida-07: This is a medium-to-late maturing peanut (150 days +)
FloRunTM ‘107’: This is a medium- maturing peanut (135 to 140 days).
Georgia-06G: Georgia-06G is a medium maturing peanut (135 to 140 days).
Georgia-09B: Georgia 09-B is a medium maturing peanut (135 to 140 days).
Georgia-12Y: This is a medium-to-late maturing peanut (140 days +)
Georgia-13M: This is a medium-to-late maturing peanut (140 days +)
Tifguard: Tifguard is a medium maturing peanut (135 to 140 days).
TUFRunnerTM ‘297’: This is a medium to medium-late maturing peanut (135-145 days)
TUFRunnerTM ‘511’: This is a medium to medium-late maturing peanut (135-145 days)
TUFRunnerTM ‘727’: This is a medium to medium-late maturing peanut (135-150 days)
Taking a good sample is CRUCIAL in determining the proper time to dig, so here is a reminder of how to pull a sample for profiling peanut maturity. A peanut hull scrape maturity check will be as accurate as the sample that you take. Pull or dig up at least 5 to 6 adjacent plants from at least three representative parts of a field which can be dug in on day. Keep these samples from each area of the field separate. Pick ALL the peanuts off the plants until you get around 200 peanuts (a sample should contain between 180 and 220 peanut pods). Pick the vine clean. If it will be a while before you can bring the sample then pick off the sample and keep the peanuts in a bucket of water to keep them fresh.
White Mold Concerns: This is no doubt that white mold management in Colquitt County has been a challenge this year. Below are a few comments from Bob Kemerait on the current situation.
WHITE MOLD ON PEANUTS has been EXTREME this year for many growers because of prolonged, very warm temperatures and, at times, adequate rainfall. NO PROGRAM will stop all white mold, BUT your program should be able to CONTAIN “hits” of white mold to a few plants and not to long streaks in the field.
Further notes on white mold: a) growers should consider prolonging their white mold programs, perhaps adding mixes of tebuconazole and chlorothalonil at the end. b) the labeled rate of tebuconazole is 7.2 fl oz/A (not a pint………) c) GOOD NEWS! Cooler morning temperatures forecast this week (mid 60s in Tifton) coupled with a drier air mass should help to SLOW the development of white mold. d) dryland fields may have less-than-desired white mold control IF rains have not been timely to more fungicides to the crown of the plant. Growers need to watch and see what Tropical Storm Ericka will do in the Caribbean over the weekend. Words of advice- if storm heads our way, it would likely hit on Tuesday. If I was a grower and needed to protect my crop(s) with fungicides, I would make sure I was prepared to do so before the storm arrives.
Peanut Insects: I have noticed spider mites in couple of peanut fields in Colquitt County. You should be monitoring fields for pests including spider mites. Spider mite infestations usually start at field borders, especially those adjacent to dirt roads, and dry corners. Comite and Omite (same AI) are the only legitimate option(s) available. Early detection and good miticide coverage are essential to control.
What about TCAH in peanuts? I get questions about three cornered alfalfa hopper management in peanuts. There is no validated economic threshold and they are very hard to scout for. If you are 75 to 25 days before digging then the threshold is 1 adult or nymph per 3 foot of row. If you are less than 25 days before digging then do not worry about them.
Soybeans: Still no Asian soybean rust found in Georgia. The soybean crop in Colquitt County ranges from R6 to R2 depending on maturity group. Any of our soybean crop that has not reached R6/full seed growth stage is still vulnerable if the diseases arrives.
Soybean irrigation: Below are some rules of thumb for soybean irrigation based on growth stage. The following water balance method is suggested for 45 to 50 bushel soybean yields:
1. Prior to first bloom, irrigate with 1.0 to 1.5 inches of water if wilting is observed by late afternoon.
2. From first bloom (R1) to beginning pod elongation (R4) irrigate with 1.0 to 1.5 inches of water if wilting is observed by midday.
3. From beginning pod fill (R5) to full-bean stage (R6) irrigate, using some means of irrigation scheduling, to keep soybeans from wilting.
4. From full-bean stage (R6) to physiological maturity (R7) irrigate with 1.0 inch of water if wilting is observed by late afternoon.
Thank you for your time,
Jeremy Kichler
County Extension Coordinator
Colquitt County