Lowndes County Agent Jake Price has put together another Satsuma Production and Marketing in South GA and North FL. It’ll be held at the Lowndes County Extension Office at 2102 East Hill Avenue, Valdosta, GA 31601. (229) 333-5185. Below is a flyer:
Monthly Archives: August 2015
The 29th annual Georgia Peanut Tour will be held September 15-17, 2015, and located at the Best Western Rose City Conference Inn, Thomasville. Tour stops will be made in Thomas, Grady, Decatur, Seminole and Early Counties.
Pecans look fairly well in the county now. I’ve gotten reports of some aphids and spider mites but not many. I looked through an orchard yesterday evening and some aphids were present. Nuts are developing and didn’t see nut scab, only very little leaf scab. I’ve seen some nuts on the ground and here is an update from UGA Extension Pecan Horticulturalist Dr. Lenny Wells on nut drop:
The first drop occurs immediately after pollination and often goes un-noticed. The second drop, occurring in June, is the most commonly recognized drop. Certain varieties such as Desirable undergo a very obvious June drop each year.
The third drop occurs in July and results from problems with endosperm development. A fourth drop, resulting from problems with embryo development may occur in August. The endosperm provides nourishment for the developing embryo. If the endosperm fails to develop properly, the embryo may be weak and the tree may abort the nut. Also, self-pollination or poor pollination can contribute to the failure of embryo development.
For many varieties, this is the nut drop we are seeing now. This is something that occurs annually and is a natural aspect of the pecan tree. They will lose a certain percentage of nuts each year. It may be worse on some varieties than others and worse in some years than in others, depending on pollination, etc.
For ‘Sumner’, ‘Schley’, ‘Oconee’, ‘Caddo’, ‘Cape Fear’ and other relatively thin-shelled varieties, we are also at the point where water stage fruit-split or “water-split” occurs. The problem occurs when the shell, seed coat, and sometimes the shuck splits about the time of the initiation of kernel filling and shell hardening, resulting in abortion and drop of damaged fruit about 7 days after splitting.
Water split is highly erratic, with incidence and severity varying depending on cultivar, crop load, location, environmental conditions, and year. Crop loss can be severe in certain years and nearly absent in others. It occurs during the “late water stage”; a time when turgor pressure inside the nut is high and the shell is beginning to harden. This typically occurs during mid-August for susceptible cultivars growing in the southeastern U.S. This year we are seeing it a little earlier because the crop is at least 10 days ahead in maturity. See my previous post on water split for more details.
Like the fourth drop resulting from embryo development, water-split is a natural process which pecans undergo. They will lose a certain percentage of nuts to these maladies each year, and there’s not much we can do about it. If no obvious signs of insect damage are apparent on the shuck of the fallen nut, my suggestion is for growers to stop looking at the nuts on the ground and instead keep looking at the crop remaining on the tree.
Other factors we can control may lead to nut drop this time of year as well. These include nut curculio, pecan weevil, and stink bugs. See last year’s post for a description of curculio damage. Weevil and stink bugs are pests that should be dealt with but you want to hold off spraying for them as late as possible unless there is a known problem because the broad-spectrum insecticides required for control will quickly flare aphids and mites this time of year and once you start you will be battling them the rest of the growing season.
I’ve looked at a few pastures this week that show signs of fertility and cultural issues. These are horse pastures which were planted in bermudagrass but have been overtaken by centipedegrass. This is very common in pastures that have not been limed over the years. Centipedegrass can withstand a lower pH than bermudagrass. Bermuda likes a pH no lower than 6.0.
I observed another pasture today where bermuda was established but now taken over by bahia and broadleaf weeds. Bahiagrass can also tolerate low pH and fertility. Horses also graze this pasture which results in soil compaction. In this pasture many broadleaf weeds have taken over like serrated ground cherry and chamberbitter. When much of the pasture is struggling to produce, it is recocomended to do a pasture renovation.
The first step in renovation is killing out the current grass species. This is better accomplished in the late summer/early fall with glyphosate. It can then be followed up by another spray, followed by planting a winter grass, like ryegrass. The next spring, that site needs to be cut or grazed real close and then sprig/seed your desired grass. UGA Extension Forage Agronomist Dr. Dennis Hancock has information on the UGA Forages website on specific grass species. (Click on Establishment Guidelines on the left and scroll down.) Here is what Dr. Hancock recommends:
“Renovating an old common bermudagrass stand is very difficult. Even with repeated glyphosate sprays, there will be some survival of old rhizomes. Some tillage in combination with glyphosate sprays with help expose rhizomes and increase percent control. Common bermudagrass can be more completely controlled if the land can be rotated for one to three years to crops where intensive grass control measures can be employed, in addition to using the glyphosate sprays.”
Here is some information from UGA Extension Climatologist Pam Knox:
This has been an interesting growing season from a climate perspective. April started out with minor dryness, especially in western Georgia. That disappeared under the extremely wet conditions that lasted through most of April. But once May started, the skies dried up and many parts of the Southeast experienced almost no rain for the first three weeks. This allowed fields to dry out and farmers to catch up on their planting but caused some stress on corn and other crops by the end of the month. Since that time, rain has returned in much of the area, but it has been spotty. Above normal temperatures have also contributed to stress on plants, and many farmers had to irrigate to provide water for the growing crops. At the end of July, abnormally dry conditions covered almost 60 percent of Georgia and a small area of severe drought was present in an area centered on Clinch County.
We are now entering what is usually the most active part of the tropical season. Due to the presence of El Nino, the number of storms is expected to be lower than average this year. Dust blowing off of Africa over the Atlantic Ocean is also contributing to the lack of storms so far. However, the main part of the season is still likely to produce some activity in the coming weeks. And it only takes one storm, like Hurricane Andrew in 1992 (also a strong El Nino year) to cause tremendous damage, so producers should keep abreast of current forecasts and watch for more activity in the coming weeks.
The prediction for the next few months is for the continuation of above normal temperatures, particularly in southern Georgia and into the Florida peninsula. As is typical for summer, there is no prediction one way or the other for precipitation. Scattered thunderstorms and the occasional tropical system will provide rain in some areas, but the exact locations are impossible to determine at this point. The strong El Nino will continue through the winter, and will likely bring rainy, cool and cloudy conditions to a lot of the Southeast. In a strong El Nino, the onset of the winter rainy season is likely to be abrupt and could start as soon as the beginning of November, so producers should be prepared to deal with rainy conditions if they are harvesting late in the year
We are having really conducive conditions now for white mold (Sclerotium rolfsii). It is very hot and having more showers across the county. This field has had a good fungicide program and has been nearly 7 years without peanuts, still white mold is showing up in spots. There may also be some underground white mold which is the same pathogen as above white mold. Often with underground white mold, the top of the plant look okay. We see damaged pods and pod rot. In hot weather, we often see the underground type. We are going to have to tighten up on our spray intervals and use good chemistries. Below is an up close of white mold. You can see the white mycelium growth and round BB’s, which are sclerotium.
Here are some tips from UGA Extension Pathologist Dr. Bob Kemerait as we continue to fight this disease with conducive conditions:
- REMEMBER: In a season like this, the perfect storm of a season, even our BEST fungicide programs for white mold may only provide ~70% control. No program will stop all initial “hits” of white mold where a plant here, there and across the field wilts. BUT a fungicide program MUST prevent the disease from spreading from that plant to other plants within the row and down the row.
- Though most most growers will not adopt this practice, spraying the peanut field at night or in the darkness of early morning when the leaves are folded is a GREAT way to get the fungicide where it needs to be (the crown of the plant).
- Where a grower is not satisfied, he may consider using a more aggressive fungicide. For example, Tebuconazole/Bravo is good but not the best. If problems are developing, he may shift to a more effective (an more expensive) program.
- Consider extending the white mold schedule. Even if the grower has completed a “traditional” white mold program, he may extend the program, perhaps using the Tebuconazole/Bravo program mentioned above.
- Use anticipated rain events and irrigation to move the fungicide to the limbs and to the crown of the plant.
Soybeans are reaching reproductive growth stage. It is now time to be scouting for caterpillars. We are looking for velvetbean caterpillars, green cloverworms, and soybean loopers.
- The velvetbean caterpillar has 4 pair of abdominal prolegs. This one will wiggle when touched and usually fall to the ground.
- The green cloverworm has 3 pair of abdominal prolegs.
- The soybean looper has 2 pair of abdominal prolegs. We need to check fields since not all insecticides target the same worm.
This field has been sprayed with Dimlin, which has been a UGA recommendation to spray as preventative at R2. However, I was still seeing 1 inch soybean loopers. This is because Loopers are not controlled by Dimlin as the other two caterpillars. This field is still under threshold nonetheless. We can also look at leaf damamge. Following flowering, leaf damage exceeding 15% needs to be treated. Below is a guide for scouting soybean caterpillars from UGA Extension Entomologst Dr. Phillip Roberts: