For the first time in many years, we have many new products on the market. Here is an update from UGA Extension Entomologist Dr. Mike Toews and Auburn Entomologist Dr. Kathy Flanders:
Products for Empty Bins
- Centynal EC – This is a good product for treating empty bins and elevator boots. Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical so these are not good rotation partners.
- Defense SC (labeled for empty bin use only) – This is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain. Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical so these are not good rotation partners.
- Suspend SC – This is a good product for treating empty bins and elevator boots. Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical so these are not good rotation partners.
- Tempo SC (labeled for empty bin use only) – Tempo is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain.
Products for Application to Grain
- Actellic 5E (labeled for corn only) – This product has been the standard for many years, but it is expensive. A full rate will provide protection from weevils for 9-12 months. Reducing the rate will decrease the longevity of the protection. Our data suggest that Actellic is susceptible to heat degradation in the drier when grain temperatures exceed 120 F.
- Centynal EC (labeled for corn and wheat) – Centynal EC is a new formulation that will provide 3 to 6 months of protection from weevils at the 0.5 ppm rate or 6 to 12 months of protection at the 1.0 ppm rate. This material is heat stable in the drier (tested up to 150 F).
- Diacon (labeled for corn and wheat) – Diacon is an insect growth regulator that is effective for killing nearly all immature grain moths and beetles, except weevils. The 4 oz per 1000 bu rate is sufficient for tank mixing.
- Diacon IGR PLUS (labeled for corn and wheat) – This product is a premix of Centynal EC and Diacon. See comments above for rates and activity.
- Malathion (labeled for wheat and corn) – Although widely used in the past, this product is no longer recommended due to well documented resistance in many stored grain insect populations.
- Sensat (labeled for corn and wheat) – This product is new to the market, but has been in our evaluation program for several years. Test results show excellent weevil control for up to 12 months. No dryer stability data at this time.
- Storcide II (labeled for wheat only) – Storcide II is an industry standard for stored wheat, but is not labeled for use on corn. Protection will degrade with heat and time.
- Suspend SC (labeled for corn and wheat) – This product is an older formulation that must be completely suspended before measuring and requires frequent agitation. It provides 3 to 6 months of protection from weevils.
- Three-way tankmix (only tested on corn) – UGA tests from 2014-2016 showed that a threeway tank mix of Centynal (8.5 oz) plus Diacon IGR (4 oz) plus PBO-8 Synergist (13.5 oz) will provide 6-9 months of protection from weevils. This is a moderately priced option for growers in markets where other products are unavailable or cost is a limiting factor.
Regardless of the product used, be mindful that grain protectants are not a silver bullet. Shelled corn should be dried to a maximum of 15% moisture content before dropping it in the bin.
Chemical applications should only be made to clean grain that will be stored for more than 3 months. Apply protectants at the bottom of the auger in a course spray to maximize coverage as the kernels are moving up to the top of the bin. Long-term grain storage requires appropriate moisture content, proper housekeeping, use of a spreader when filling bins, and managed aeration.
Jeff Cook is County Agriculture Agent in Taylor & Peach Counties and the Area Peach Agent. He has this information on dusting wheat on his new blog: Three Rivers Ag News
Let me start by saying that I would not do try it. I Actually already did and it died!
Middle Georgia is under the worst drought conditions that many have ever seen. This would say that this is coming at a bad time, but it has been here for quite some time. This drought significantly impacted our warm season agronomic crops, fruits, vegetables and nuts as well as forages, landscapes, timber and wildlife. The conditions are also putting an almost complete halt on planting wheat or other small grains.
The optimum planting window for our area is either one week before or one week after November 17th (our average first frost date). Well, that came and went last week. As we move away from that planting window we begin to gradually lose yield potential. If you wait just two weeks you can easily lose 10 bushels, and easily 20 if you can’t plant until the end of December.
The first thing to consider is what the long-term forecast says. If we get seed planted and we do get rain it will have to be sustained moisture because there is no subsoil moisture for the emerging roots to find. The following is some helpful hints that I gathered from some midwestern states that must face this situation often:
If the dry weather is going to continue, and it appears it will, we should treat the fields like we are planting beyond the optimum plant date. It may be beneficial to up seeding rates and if add a seed treatment fungicide. Starter fertilizers would also be a good idea if prices were better, but I can’t tell anyone to fertilize a crop that may not emerge. The higher seeding rate is to account for reduced tiller production and the seed treatment should help that seed wait on a rain for a longer period of time.
Like I said earlier if we get some small showers it could cause seed to germinate but be unable to reach subsoil water resulting in plant death. Rain just after dusting in a crop can also cause crusting which will keep wheat from breaking the soil surface.
In a normally “dusting in” situation you would plant the seed a little shallower (1/2”) however with the lack of subsoil moisture you will want to go deeper (at least 1- 2”) . Getting the seed to the proper depth will be a challenge in extremely dry soils, so spend a little extra time setting your planter up.
Here is a field of triticale with a pathogen I have not seen before. I noticed these diamond-shaped lesions with a yellow border and dark brown spot in the center of lower leaves. It is called Tan Spot (Yellow leaf spot or Blotch) and is caused by Pyrenophora (Syn. Drechslera) spp. Disease development is favored by frequent rains and cool, cloudy, humid weather. I also noticed some of the leaf tips dying – this is also a symptom.
Lesions may coalesce, causing tip of leaf to die
UGA Extension Pathologist Dr. Alfredo Martinez has this information:
The disease is more problematic susceptible varieties, poor fertility and in fields with wheat residue left on soil surface. Initial infections come from diseased crop debris in the soil, or from diseased grass hosts. Usually the lower leaves are infected first, and the disease progresses to the upper leaves and leaf sheaths if conditions are favorable. This disease develops over a wide range of temperatures and is favored by long periods of dew or rain. Crop rotation with non-host crops reduces the severity of tan spot. Seed treatment seems to be effective in reducing the disease.
Fungicides applied timely are effective in reducing the disease severity and improving yield. Most fungicides are label to be applied up to Feekes 10.5 (fully headed) but before flowering. Only a couple of triazol fungicides are labeled to be applied for Fusarium Head Blight at 10.5.1, which is flowering.
Tan Spot can be serious by itself or it can contribute to other leaf spot complexes, like Stagnospora Glume Blotch, which we saw last year. This field has already been treated with a fungicide, and the pathogen is not highly infected our flag leaf. This is the leaf below the head which is pulling most of the photosynthate to the grain. This is what we are aiming to protect.
Filed under Disease, Grain
We spent lots of time this past week looking at grazing and small grain crops. This photo of triticale above is real common in many fields. Stripes indicate nitrogen deficiency between former layby rows. This time last year, we were also seeing affects of barley yellow dwarf virus (BYDV) which is vectored by aphids. Last season, aphids were very bad early (November and December). The earlier planting of small grain/forage crops is more likely to contract BYDV based on early aphid presence. The issue is that we must plant our grazing earlier so they are established.
The presence of aphids were low early this season – opposite of last year. Following Christmas, however, I noticed evidence of aphid feeding was showing up in all small grains. We are now seeing symptoms of BYDV in some fields. The difference in cold injury, BYDV, phosphorus, and nitrogen and potash deficiency can be difficult to tell. Additionally, all elements depend on all other elements – if one is deficient, the whole thing collapses. UGA Extension Forage Agronomist Dr. Dennis Hancock sums up some of the issues we are seeing in the field:
Discoloration can mean different things in different situations. Yellow tips and leaf margins usually mean K deficiency, if N is sufficient. Yellow to tan tips but not leaf margins usually mean cold injury. Purpling tips usually means cold injury, but if temps have been mostly mild and we are dealing with susceptible species (oats, wheat, etc.), then it could also mean BYDV – especially if yellowing extends all the way to the base. Purpling at the base of the plant can also be cold temperature related or it could mean P deficiency. Usually in those situations, it is actually P deficient because of the cold (which slows down mycorrhizal fungi that assist the plant in absorbing P and Zn).
Lower leaves of triticale showing tip burn
Classic symptoms of BYDV on oats
Fields have been wet the past 2 weeks, and anaerobic conditions could also be causing problems. Growers have been sidedressing when fields have been dry enough. Looking over the past month, some fields are looking better.
Though little to no wheat is planted this season, we are still looking at other small grains and forages for winter weeds. Yesterday, we were looking at wild radish in oats that need to be treated. Sometimes we have injury reported after using broadleaf herbicides in small grain, particularly oats. There are many things that influence herbicide injury, but the timing of our broadleaf products, such as 2,4-D and MCPA is critical in small grains.
UGA Extension Weed Scientist Dr. Stanley Culpepper says we do not need to use 2,4-D and MCPA until we have full tiller and before jointing.
What is full tiller? Following emergence and the spike stage, small grain crops begin to tiller. These are essentially stems that will produce a grain head in the future. When we have 4, 5, or 6 tillers on a plant, it is considered full tiller. Depending on growing degree days, it will generally take between 20 and 35 days to reach full tiller.
We looked at two oat fields yesterday – one planted in October and one in November. The later planted field had just 3 tillers per plant (above) where the older field had 5 tillers. The difference here and in other small grain is that these oats are planted for grazing only. Therefore, we have less concern over injury. It will be fine to go ahead and treat both fields.
With the same herbicides, we don’t want to treat once crop enters the jointing stage. Just before jointing, the stems will elongate. At the base of the stem, you will feel a swelling of the stem (almost like a bee bee inside the stem) which is the first node or joint. The joint is the growing point. The plants have now moved into the reproductive growth stages. Here is a shot of growth development from the 2015-2016 UGA Wheat Production Guide.
With most of our peanuts out of the ground, we’re looking at putting in cover crops with talk of an El Niño year. UGA Extension Soil & Fertilizer specialist Dr. Glenn Harris answers the question: Should we give that cover crop which follows peanuts a nitrogen (N) credit (lower than normal N fertilization) since our peanut harvest was good?
Short answer: No!
UGA Extension recommends 20 to 40 pounds per acre credit to a cover crop after peanuts.
UGA Nitrogen recommendations for Rye, Wheat & Oat fall planting are 20 to 40 pounds per acre at planting following peanuts and another side dress application in February are the standard nitrogen recommendation in Georgia.
Filed under Fertility, Grain