September 30, 2014 · 2:02 PM
Brown Stink Bug Adult
Early planted soybeans are progressing and looking good. Some varieties are drying down and some have already been harvested. These soybeans are progressing at R6 (Full Seed)growth stage now. R6 is defined as the beans inside the pod are touching. We’ve had some questions about stink bugs this week. Stink bugs, corn earworms and fall armyworms are recognized as soybean pod feeders. I ran a sweep net through a few fields on a plantation yesterday and the highest number I found was 5 per 25 sweeps, which is below threshold. Above is a brown stink bug adult in the field. Below is a green stink bug nymph. This is probably one instar from being an adult. Southern Green Stink Bug nymphs usually have pink/reddish markings on them.
Green Stink Bug Nymph
Our decision to spray for stink bugs is determined by thresholds. You can use either a drop cloth and shake plants over the row to count insects by row foot or use a sweep net. When the soybeans are this far along, I like using a sweep net. Below are thresholds in the 2014 UGA Soybean Production Guide from UGA Extension Entomologist Dr. Phillip Roberts:
- Bloom to mid pod fill – 0.33 stink bugs per row foot or 3 per 25 sweeps.
- Mid pod fill to maturity – 1 stink bug per row foot or 6 per 25 sweeps.
*beans being grown for seed production, 1 stink bug per 6 row feet will justify control.
- Should be controlled at any time after bloom when an average of 2 per row foot (1/2 inch or longer) are found.
Since the beans are at R6, we still need to treat for pod feeders if thresholds justify. Once we hit R7 (Beginning Maturity), we no longer need to treat for insects. R7 is determined when at least one pod can be found on the plant which is mature or brown/tan in color. Pods and leaves start to “yellow” during this stage. This field is not there yet.
September 29, 2014 · 8:50 PM
We were looking at sorghum where damage form WSCA has been evident. But also seeing heads and stalks that are brown. The brown color on the outside and inside of the stalk turned out to be Charcoal Rot (Macrophomina phaseolina). Grain sorghum plants affected by this fungus won’t fill grain properly and may lodge in the latter part of the season. Infected stalks show an internal shredding at and above the ground line. When you split the stalk, you can see the small black dots from microsclerotia (below):
Below is information regarding control from UGA Extension Grain Pathologist Dr. Alfredo Martinez:
“Charcoal rot is particularly damaging under hot, dry weather specially post-flowering periods. Therefore maintaining soil moisture during these periods can help minimize the incidence of the disease. A balanced fertility program is beneficial, high N and low K should be avoided. Excessive plant populations should be also avoided. Growing drought tolerant sorghum can reduce losses.”
Microsclerotia under dissecting microscope
September 24, 2014 · 8:44 PM
The 2013 growing conditions continuing through early 2014 has increased the cost of production resulting from a rise in the number of fungicide sprays required on scab susceptible cultivars. The number of sprays has also risen as spray intervals shorten. And finally, growers are using higher fungicide rates because of insensitivity issues. All of this adds to the cost of production in which UGA Extension Pecan Specialist Dr. Lenny Wells and New Mexico State Pecan Specialist Dr. Richard Heerema have put together information on this topic. Below are notes from Dr. Wells:
“It looks as though this led to a 60% increase in the cost of scab control alone as you go up from 10 sprays to 16 sprays. In addition to the increased cost of managing pecan scab, black aphid and mite pressure were high in 2014. Both of these pests are expensive to control and many growers had to spray multiple times for both pests, which also increased the cost of pecan production. See the graph below for a breakdown of the annual variable cost of production, which totals over $1600/acre with 16 fungicide sprays.
At such a high cost growers are justifiably concerned about the price they need for their crop. See the chart below for break-even prices for pecans at various prices and yield levels given a cost of $1628.15/acre:
In a ‘normal’ year—neither too wet or too dry—10 fungicide sprays will usually be enough to manage scab. This brings the cost down to nearly $1500/acre as you can see below. Break even prices at a cost of $1485.88/acre follow:
Keep in mind that these are all variable costs only. Fixed costs like land payments, equipment, overhead, etc. will increase the total cost of production by another $450 or so. The cost of production will vary from one grower to the next but these numbers should give some idea of what the general cost may be for growing pecans.”
Filed under Disease, Pecans
September 24, 2014 · 3:11 PM
An Area Wheat Meeting with Colquitt, Mitchell, and Thomas Counties will be held next Wednesday, Oct 1st. The meeting will be at the Colquitt Co. Ag Center (350 Building 1 Veteran’s Park North Moultrie, GA 31788.) UGA Extension Agronomist Dr. Dewey Lee will be keynote speaker. We’ll discuss cultural practices, varieties, weed, and pest management. Please call the Thomas County Extension Office at 229-225-4130 to RSVP by September 29th.
September 24, 2014 · 2:54 PM
A grower called me to look at a pond in the middle of a cotton field where fish had been dead a few days. There are a mixture of bass and bream that have died. I asked which fish died first, and he said the larger fish. Fish kills can often be associated with chemical runoff or oxygen depletion. When larger fish die first, it is generally the result of some kind of oxygen depletion, since lack of oxygen would affect larger fish first. UGA Extension Aquaculture Specialist Dr. Gary Burtle said there have been several fish kills related to low oxygen in south Georgia in the past week. With rain comes cloudy weather and low oxygen has been a problem recently. Below is what Dr. Burtle has to say:
“The usual reason for fish death after rains is a partial oxygen depletion caused by the influx of water which has no algae in it or a high concentration of bacteria in it. When algae are replaced by bacteria, the water turns brown in color and oxygen concentration drops. Bass are larger than bream, so may be affected first. The oxygen stress may cause the fish to become susceptible to disease, so fish deaths may occur for several days after the partial oxygen depletion.
When the pond begins to ‘green up’ again, oxygen concentrations will increase and fish deaths stop. Until oxygen concentration returns to normal levels, low oxygen each morning or during cloudy weather may cause more fish stress and death. The solution is to install an aerator and operate during cloudy weather, which seems to be more prevalent in Georgia in the late summer and fall.”
September 22, 2014 · 3:08 PM
We were able to look into some defoliation Friday. Varieties play more of a role with PGR management whereas environmental conditions play more of a role with defoliation. With the standard 3-way approach (Ethephon, thidiazuron, and tribufos), we do not want to cut our rates is with thidiazuron since regrowth potential is high during this time. There has also been reports of leaves sticking after spray. This is making us drop our desiccant rates in hot temperatures. Not only can too much of an increase in of any product cause leaves to stick, crop oil in the mix can play a roll also. Many are using lower as desiccant rates with hot temperatures. We are in an 8 – 12 oz/acre range of Folex at this time.
Another issue we we’re discussing is weeds. Some growers are still fighting some grass. In this case, it is okay to add a quart of RoundUp. If there is morningglory, we can at an ounce of Aim or 0.5 – 2 oz of ET. If we decide to add a herbicide UGA Extension Cotton Agronomist Dr. Guy Collins advises we follow by cutting back our desiccant rate. (If using 10z of Folex, cut back to 8oz, for instance.)
September 18, 2014 · 2:05 PM
Nut development has really progressed over the last few weeks. We’re not seeing shuck split in this orchard yet, but there are some ‘Pawnees’ starting shuck split. UGA Extension Pecan Specialist Dr. Lenny Wells says, “‘Pawnee shuck split starting in South Georgia means that nut maturity is still about 10 days or so behind normal. The calendar date of nut maturity for a given variety varies from one year to the next because the date of fruit maturity is dependent upon the accumulation of heat units in the early spring. Our spring in Georgia was cooler in 2014 than in 2013.”
The photo on the right shows nut development of ‘Stuart’ on September 16th. The kernels are filling well and almost complete. Dr. Wells says, “‘Stuart’ nut maturity and shuck split is more prolonged and staggered, while that of ‘Schley’ is a little more uniform. Nut maturity in Schley normally precedes that of ‘Stuart’ by about 2 days on average. We had a pretty cold winter last year and this causes nut maturity of ‘Stuart’ and ‘Schley’ to be similar. Following mild winters ‘Stuart’ nut maturity may be delayed another 10-14 days due to its high chilling requirement, while ‘Schley’ maturity will remain roughly the same. ‘Desirable’ nuts (are) still mostly in the late water stage, although I did see some gel forming in some of them. From this point forward ‘Desirable’ nut maturity should develop rapidly. They always seem to linger in the water stage and then fill all of a sudden. I would expect that it will be late October or early November (depending on location) before harvest begins in earnest on these varieties.”
Economic Outlook- Dr. Lenny Wells
Chinese demand for pecans at this time seems strong. Size will play a large role in export prices offered to growers and our size is highly variable this year, largely as a result of scab pressure early and dry weather during nut sizing. Two weeks ago early contract offers I heard from various growers were at $2.20-$2.35 in-shell for ‘Stuart’ and $2.75 for ‘Desirable’. Over the past week, these prices seem to have gone up to around $2.40-$2.50 for ‘Stuart’ and $2.85-$2.95 for ‘Desirable’. I have heard blends priced in the $2.40-$2.45 range. Again, size will be the determining factor in price. Small nuts will not bring high prices.
September 17, 2014 · 4:45 PM
We checked quite a few more peanut hull scrape samples yesterday, and almost all of these were dryland fields. Many of the these fields a considerable time without rain and are now flowering and have recently set pods. The profiles show this later crop. We’ve had rain, but also cloudy days. Daylight time is getting shorter also. How long can we hold out in these situations? Here is some information from UGA Extension Agronomist Dr. Scott Tubbs:
A month ago, I was telling a few county agents there was a decent chance we would be looking at a late crop with recommendations to leave the peanuts in the ground longer than usual in order to progress maturity to optimum. There were several reasons behind this rationale:
- The crop was planted later than usual because of too much rain. When late planting occurs, it usually means a slightly longer growing season, because as the crop is nearing the 135-140 mark, it is also when day length is getting shorter and temperatures are dropping, thus requiring a little extra time to accumulate “Growing Degree Days” and advance to full maturity.
- The month of June would have constituted the period when much of the crop was setting its first pods, usually representing the densest and highest grading peanuts, but there was very little rainfall from June 20 through July 10 and thus there was a delay in flowering. And the lack of moisture was slowing movement of Calcium into the early forming pods, further pushing the crop behind in terms of maturity advancement. Then, with some mid-July moisture, the largest flush of flowers was set later in the season than normal, so advancing this steeper part of the curve further into the brown/black region on the maturity board would be worth the risk of losing a few early pods since they were slower to establish. However, the continuation of dry conditions through July and large chunks of August has changed things considerably. Having heard of reports and seen fields where kernels are turning loose in the hull, delaying harvest to progress the remainder of the pods that are behind may not be possible without risking sprouting on the vine once those seed break dormancy.
It will take a careful look at the number of small, underdeveloped pods to determine whether peanuts should be dug early or late. I am currently of the opinion that the maturity profile board for non-irrigated peanuts is going to be highly inaccurate this year, and we’re probably going to see very few peanuts actually dug “on-time”. Most peanuts are going to need to be dug early or late. If they do not have a lot of small pods on the plant, then the majority of the yield potential is already set. In those situations, there may be some opportunity for at least improving grade, but timing digging with enough moisture to put the digger in the ground (especially in heavier, higher silt and clay-fraction soils) is probably more important than taking the risk to further advance the TSMK, so early digging is justified in these type of situations.
In the case of plants that have a large number of smaller pods currently in development (swelling pods approaching the size of a dime, and the plants are around 100 days old), there is still an opportunity to bring those pods along if the plants are allowed to stay in the ground longer than usual. Remember that it takes in the neighborhood of 40 to 60 days for a pod to develop to a size large enough to be harvested and be maintained in the basket. Consider that about half of the peanut crop was planted after May 17 this year, and a peanut planted on May 17 would be 111 days old at the time of this writing (Sept. 5). Adding 40 days to those peanuts would put them at 150 days old on Oct. 11. I believe there is still time to advance a limb crop of small, currently forming pods to the point that they could be harvestable. If there are very few larger pods on the plant currently, this may be worth hanging on a bit longer. But it will require more frequent and consistent rains, and holding onto this hope will also require a decision to make the necessary inputs to carry the crop for a longer period of time, so there is certainly risk associated with the decision to continue maintenance or to cut losses and take what is there. Thus, the decision to go early or late will be on a case-by-case basis.
September 12, 2014 · 12:51 PM
White Sugarcane Aphids are a pest of grain sorghum that showed up in the county a few weeks ago. Thomas County has just over 1,000 acres of sorghum with high populations of WSCA. Brooks County Agents Ben Shirley and Stephanie Hollifield confirmed WSCA in Brooks County this week. The EPA has approved a Section 18 request for use of Transform insecticide on sorghum. See White Sugarcane Aphids blog post below for more information on WSCA.
Here is information from David Buntin, UGA Grain Crop Entomologist:
A Section 18 Emergency Use Exception for Transform WG insecticide on sorghum has been approved for the state of Georgia as of September, 11, 2014. Transform WG may be applied to grain and forage sorghum for control of sugarcane aphid from now until November 30, 2014. Additional details of the product use are as follows:
Foliar applications may be made by ground or air at a rate of EITHER 0.75-1.5 oz of product (0.023-0.047 lb a.i.) per acre with a maximum of 2 applications per acre per year OR 1.0 oz of product (0.03 lb a.i.) per acre with a maximum of 3 applications per acrew per year; resulting in a seasonal mazimum application rate of 3.0 oz of product (0.09 lb a.i.) per acre per year.
The minimum application retreatment interval of 14 days and a restricted entry interval (REI) of 24 hours must be observed.
A 7-day pre-harvest interval (PHI) for forage and a 14-day PHI for grain or stover must be observed.
A maximum of 50,000 acres of sorghum fields (grain and forage) may be treated in Georgia.
This product is highly toxic to bees exposed through contact curing spraying and while spray droplets are still wet. This product may be toxic to bees exposed to treated foliage for up to 3 hours following application. Toxicity is reduced when spray droplets are dry. Risk to managed bees and native pollinators from contact with pesticide spray or residues can be minimized when applications are made before 7:00 am or after 7:00 pm local time or when the temperature is below 55 degrees F at the site of application.
The registered product, Transform TM WG (EPA Reg. No. 62719-625; 50% sulfoxaflor), manufactured by Dow AgroSciences, may be applied. All applicable direction, restrictions, and precautions on the EPA-registered Section 3 label, as well as those outlined in the Section 18 use directions, except as modified by this authorization must be followed.
September 10, 2014 · 9:12 PM
We checked many peanut samples yesterday from all around the county. Peanuts are looking a lot better with rain. It rained more while we were sampling. Some parts of the county have had 7 inches in the last week and a half. We are having more reports of white mold, and seeing some pod rot as result. We need to observe vine strength. Most profiles are showing a 130-140 day maturity. Last year, 150 days was average. Looking at maturity last week, we noticed wider rangers. We normally start sampling at 120 days, however with more variability in maturity, UGA Extension Peanut Agronomist Dr. Scott Monford recommends evaluate fields that are 90 DAP or older. We are seeing a large variation of peanuts on the vine. Several fields have shut down around 105 DAP and are now coming loose in the hull. If the growers are not checking them until 135 DAP or more, they may indeed lose what they have.
Segregate Dryland Corners
With dryland maturity differences, one thing to consider is dryland areas of the field. Here is a note from Terrell County Ag Agent Nick McGhee:
Once harvest begins, growers need to consider segregating the peanuts they harvest in the dryland corners (or areas that received poor irrigation) from the peanuts that are harvested from irrigated areas. It does not take many poor quality pods to cause a load of peanuts to be graded as Seg 2 or worse. Growers need to consider separating these areas using a disk harrow and keeping them separate as they are loaded onto trailers. Do not let a few bad pods from a dryland corner affect the grade on an entire load of otherwise good quality peanuts.