Monthly Archives: July 2016

July 29, 2016 · 5:25 PM

Second Hay Cutting

We are seeing our second hay cuttings now. We are variable in rain. This pasture has had 0.3 of rain in over a month, whereas more rain is hitting elsewhere. We dealt with some different nutrient issues at the very beginning of the season that seem to have gotten better. I don’t know if it “feels like” 102 degrees or 201 degrees. Since anything above 100 feels no different, we thought it would be a good idea to go ahead and take a forage analysis on hay cut in this field.

When it was cut, the producer felt hay looked better on one side than another. It is not a bad idea to separate samples where soil or some environemtal condition is different. Forage samples are good to do so we know what quality of hay we are feeding.We want to make sure to take samples by “lots” of hay or silage. This is hay from the same cutting, field or stage of maturity. Most cattleman purchase hay, and it is more difficult to differentiate “lots” in these samples. We separate it as best we can, and not represent more than 200 tons of dry matter.

Another important procedure is bale sampling. We need to get as much from the middle or core of the bale that we can. A hollow probe is best to use for this. I have a probe here in the office with a drill I can bring out to help sample. Here is a more detailed write up of Taking a Good Forage Sample.

Insects

We have certainly been spraying for bermudagrass stem maggot. In many cases, we are getting in the two sprays following cutting. This maybe why reports of armyworms are not high, and are not significant now.

Disease

We are also seeing some leafspot. Helminthosporium (Leaf Blight) and leaf rust is what we usually see. However, we can also have dollar spot (Sclerotinia). In either case, management is cultural. We must first have adequate nutrietion – especially potash. UGA Extension Pathologist Dr. Alfredo Martinez says, “Soil potassium is critical for leaf spot resistance. Most reported leaf spot cases are directly related to low soil potash. Nutrients are removed from bermudagrass hay fields in approximately a 4-1-3 ratio of N, P₂O₅, and K₂O with hay harvest. That means that 75 percent as much potash as nitrogen should be applied each season. Potash can be applied in single applications in the heavy soils of north Georgia or in split applications in any portion of the state. Split applications are particularly helpful in sandy soils.”

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July 29, 2016 · 12:48 PM

Herbicide, Fungicide, Foliar Fertilizer Combinations In Peanut

We have been fortunate in our county with adequate rainfall – in most areas anyway. Peanut crop is looking good, we have set pods and kernels are developing in our oldest peanuts. With many questions concerning mixing chemicals, and foliar fertilizers, here is an update on current peanut condition from UGA Extension Agronomist Dr. Scott Monfort:

We tend to think July is the half way mark for the season but the truth is we have a long season ahead of us due to the late plantings throughout the state. There are many acres that are lapped and are setting pods while others are barely 8 to 10 inches wide and are struggling to grow. The good news is a majority of the crop looks good with a large part of the area receiving some rains over the last couple of weeks. However, there are many dry areas that need rain. In some of these areas, a few peanuts have stopped growing and blooming as well as showing signs of elevated leaf burn (with some leaf scorch) as a result of applications of different combinations of adjuvants, herbicides, fungicides, and foliar fertilizers being made in extremely hot and dry conditions (mid to upper 90’s and bright sunny days). A few of these fields have lost more than a third of their leaves. Growers should use caution regarding potential burn as a result of these applications but it’s not something you can eliminate due to weeds and diseases need to be addressed.

Foliar Fertilizer?

I have noticed foliar fertilizers being recommended in these situations to turn the dry land field around. The problem is, the peanuts have shut down due to lack of moisture and are not going to recover until they receive rain. The use of the foliar fertilizer is only costing the growers money and adding to the excessive foliar burn. The best thing to do is to not add these products to their fungicide or herbicide applications under these conditions. Growers can also limit burn by not spraying during the middle of the day (again this might not be an option as growers have a lot of acres to cover).

Leaf Scorch – Dr. Scott Monfort

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July 21, 2016 · 7:37 PM

Soil Testing Pecan Herbicide Strips

This is pecan leaf sample time – July 7 through August 7. In addition to leaf samples, UGA Extension Horticulturalist Dr. Lenny Wells has information on soil testing, particularly in row middles.

Many have found that pH in the herbicide strip is lower than that found in the middles. When we were doing the work on fertilizer placement and comparing broadcast band applications of dry N fertilizers with broadcasting over the whole orchard area, herbicide sprayer application of N, and injecting N through the irrigation system, we observed that soil pH is always lower in the herbicide strip regardless of the fertilization method you use (Pecan Response to Nitrogen Fertilizer Placement). We do have the potential to drop the pH faster in some situations where you concentrate fertilizer N in the strip, but its always lower in the strip. This is because the vegetation growing in the middles keeps the organic matter levels up, which helps to buffer soil pH, allowing it to remain a little more stable than areas free of vegetation.

Managing soil chemistry in the herbicide strip is vitally important because that is where the tree’s feeder roots are located around irrigation emitters. After their transformation to nitrate-N, both ammonium and urea fertilizers have an acidifying effect on the soil to which they area applied. In order to manage this, growers should take their soil samples within the herbicide strip and lime based on this reading. Because the vegetation in the middles helps to buffer the pH, you probably won’t need as much lime in those locations. It would be wise to check pH in the middles every few years and make an additional lime application to the middles when pH drops below 6.0.

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July 21, 2016 · 7:26 PM

Peanut Pest Update

Our peanuts have been lapping for a few weeks now. They are looking good so far. We are more or less 60 days old now. Seeds are developing inside pods, and growers are starting another round of fungicides. Here is some information from specialists concerning insects and disease:

Insects

Here is an update from UGA Extension Entomologist Dr. Mark Abney:

There continues to be lesser cornstalk borers (LCB) in Georgia peanut fields, and I do not see any reason that should change over the next few weeks. Interestingly, most of the heavy pressure has not been in the Southwest but in the middle and eastern portions of South GA. I expect that some of the infestations we were seeing in irrigated fields prior to the vines covering the row middles will be diminishing as irrigation water is applied with greater frequency.

I have not received a call about two spotted spider mite on peanut in 2016, but I am betting it is coming soon. Mites have been hanging around on cotton now for several weeks, and with continued hot, dry conditions I think we will be seeing mites move into peanut fields. If this happens, it is going to create a lot of headaches for growers, Extension agents, and crop consultants.

We need to catch mite infestations early to have any chance of getting good control.
With the one miticide available for use in peanut (Comite), we need to use a minimum of 20 gallons of water per acre, and two applications may be needed because egg mortality is low.
The yield potential of some of our non-irrigated peanut acres is rapidly deteriorating; knowing when to pull the plug on inputs in these fields is going to be difficult, and most growers will be reluctant to “give up” on the crop. When making treatment decisions, we need to be realistic about the crop we already have set and our potential to add harvestable pods to it.
I say this a lot, but we need to be sure to avoid pyrethroid insecticides in fields where spider mites are present or in fields at high risk for mites (hot and dry) in areas where mites have been found in surrounding fields. There are a couple pyrethroids that will suppress mites, but “suppression followed by resurgence” is a better description of what usually happens.

Rain tends to be the best treatment for LCB and spider mites, but a single rainfall event will not eliminate either of these pests once they are established in a field.

I have not heard of damage from potato leaf hopper, but have seen threecorned alfalfa hopper. Here is a picture of their damage. Immatures girdle the stem, and sometimes adventitious roots will grow.

Three-cornered Alfalfa Leaf Hopper damage

Disease

Tomato Spotted Wilt Virus

This week we saw some spotted wilt, and there are other reports of spotted wilt – especially early planted peanuts.We are having the right conditions for white mold with the heat and afternoon rain showers. Only timely fungicides will protect us during this time. Here is a link to the 2016-PeanutRxwithVariousFungicidePrograms for the companies that provide them (BASF, Bayer, DuPont, Nichino, & Syngenta). We watch for white mold outbreaks now.

Brooks County Ag Agent Stephanie Hollifield makes a good point, that “If you have missed the afternoon thunderstorms and are experiencing the other extreme of dry weather, keep in mind that white mold control can be more difficult during drought. This is due to the fact that, dry weather prevents the ease of movement of the fungicide product from leaves of peanut plant to our target application spot in the crown of plant. To ensure white mold control products get down to crown/ground; irrigate if possible or apply white mold control fungicides with presence of dew on peanut plant and/or while leaves are still closed up.”

I’ve also had questions of mixing other products now. We should use caution with tank mix applications, especially during extreme hot and dry weather. The likelihood of plant burn can increase with any product, with the increase in environmental temperatures and tank mix partners.

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Filed under Disease, Entomology, Peanuts

July 21, 2016 · 2:07 PM

Stink Bugs & Spider Mites

We started checking for stink bugs this week. Many cotton fields are in the 3 – 5 week bloom period, which is an important time for stink bug management. So far, our numbers are below threshold. Scouting is important, because some scouts reports stink bugs present in one field and not an adjacent field.

Outside damage to boll and warts on inside

Lint stain

When walking through a field, pick 25 – 30 quarter size bolls. (A stink bug can damage any size boll, they just prefer smaller bolls.) Inspect the inside and outside. Many times, we see damage on the outside that is NOT from SB. Scouts tell me it is better to count damage when 1) warts are seen or 2) lint is stained. However, large spots like the ones seen above is likely from SB.

When we scout for stink bugs, the boll injury threshold is adjusted up or down based on the number of susceptible bolls which are present. Below is the threshold from UGA Extension Phillip Roberts:

Higher stink bug populations are typically observed on later planted cotton. For brown stink bug, organophosphates should be used. Also, if other pests are observed, such as spider mites or white flies, we need to be careful in insecticide selection not to flare these insects. Spider mites are being seen in cotton now for a while. This we need to be aware.

Spider mite damage

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July 15, 2016 · 8:15 PM

Beneficial Insect Populations

I was looking at peanuts yesterday for insects. I did see some alfalfa leaf hoppers, but no damage from immatures. I also saw a velbetbean caterpillar moth. They are usually later. So, we do need to scout and make sure our populations are at treatable thresholds before we spray. We have many beneficial insects that help us out in the field also. UGA Extension Entomologist Dr. Phillip Roberts says we should try to avoid scheduled applications of insecticides since unnecessary applications can not only be costly, they can also destroy beneficial insects. This is why we follow thresholds when treating insects. Here are some beneficial insects I’m seeing in the field now. Some photos I took elsewhere.

Assasin Bugs – I did not get this picture from the field yesterday, but I did see some assissin bugs in my sweep net. They have a long beak which is used to inject an enzyme into their prey. They then suck the body fluids out. They are in the same group of “kissing bugs” (Assissin bugs, wheel bugs, damsel bugs, leaf-footed bugs). They feed on soft-bodied prey like mosquitoes, flies, cucumber beetles and caterpillars. The nymphs (immatures) have their abdomen point upward like in the photo below.

Immature Assissin Bugs

Spined Soldier Bug – Here is a nymph from a spined soldier bug. They are a medium-sized predatory stink bug which preys on caterpillars and larvae of beetles. They can be hard to identify, especially at immature stage. If you see an instar that is red and black, those are younger instars. This is closer to a 5th instar where the wing pads are prominent, and the head and thorax become mottled with brown. The abdominal markings are white or tan, and black. Also, their mouthparts are larger than stink bugs’s mouthparts and are close to the width of the antennae.

Minute Pirate Bug

Minute Pirate Bug – I saw this pirate bug near a cotton square and looked like plant bug. Plant bug is actually in a different family, but share many similar characteristics. Pirate bugs are generalist predators. Adults and nymphs feed on insect eggs and small insects such as psyllids, thrips, mites, aphids, whiteflies, and small caterpillars.

Braconid Was Pupae

Braconid Wasp – In the peanuts I looked at Thursday, I saw what looked like ‘fuzzy rice’ on a few leaves. These are the cacoons of a pupating parasitoid wasps in the Braconidae family. Former Seminole Ag Agent Rome Ethredge showed this to me while training in a field. I feel like I see them all the time now. These wasps are parasites of aphids and caterpillars. A female wasp can attack hundreds of aphids in a two week span.

Lady Beetle Larvae

Lady Beetle – I’m seeing quite a few lady beetles in all fields. Unlike the pirate bugs, beetles have a complete lifecycle (egg, larvae, pupae, adult). Here is the larvae of a lady beetle. Larvae are usually carrot-shaped, warty and have well developed legs. The most commonly seen are the pink and convergent lady beetles. They are predatory and feed on a variety insects including mites, scales and aphids. Below is a photo of lady bug pupae on a cotton leaf from last year.

Lady Bug Pupae

Lacewing Egg

Green Lacewing – This is the egg of a green lacewing in the bottom of a cotton leaf. There are many species of lacewings, but green is most common. The eggs are often found on plants and are easily recognized since they are attached to a long, slender silken stalk which holds them above the surface. The larvae are sometimes called “ant lions” and are predators. They eat many small insects as they grow ranging from leafhoppers, scale insects, mites and also aphids. I took the picture of an “ant lion” last year eating a sugarcane aphid on grain sorghum.

Immature Green Lacewing – Antlion

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July 15, 2016 · 7:58 PM

Corn Denting

R5 Growth Stage – Denting

Here is some corn that is now denting (R5). We are getting closer to physiological maturity. At this time, the crop is still needing water but less than before. Once the milk line progresses to the bottom of the kernel, we will see the ‘black layer’ form. We can then cut off irrigation. In the photo below, you will also notice the “milk line.” This is the separation between the softer doughy white portion close to the cob and the starchy, solid portion at the top.

When we stage kernels in R5, we look at the milk line: 1/4, 1/2, or 3/4. This is good for observing kernel development. Progression of the milk line varies due to temperature, moisture, and hybrid maturity. Here is a table from “Corn Growth & Development” that shows the expected trend:

Milk line progression

Southern rust can still hurt us until about 1/2 milk line. We have sprayed most everything for rust right now, but there are reports of rust in many fields still. This is a good time to evaluate the control we got from gungicides. We may also look for stinkbug damage on field borders. If the ears are curved, the damage from SB was early. If individual kernels are damaged, damage from SB occurred late.

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July 15, 2016 · 12:49 PM

Feeding Cattle During Drought

All of GA has seen some level of drought this summer. Down here, we have been fortunate to get recent rains from afternoon thunderstorms recently. In any case, drought affects hay producers by not having pastures to graze and also not being able to harvest hay. With the ebbs and flows of cattle industry, UGA Extension Animal Scientist Dr. Lawton Stewart has some information on managing to minimize effects of drought on farm’s finances. It is important to maintain the nutrient requirements of the herd through a drought so animal performance is not compromised in upcoming seasons.

What if hay is not available? The key is to develop a ration that meets the nutrient requirements of the cows.

The stage of production of your herd is critical to knowing exactly what to feed. Table 1 lists some example rations to use for different stages of production.
Consider early weaning to reduce the nutrient requirements of the brood cows.
Utilize a roughage source such as wheat straw, conttonseed hulls, crop residue, grazing drought stressed crops, gin trash.
Examples of energy and/or byproduct feed include: grains such as corn, oats, etc., soybean hulls, citrus pulp, wheat midds, hominy.
Examples of protein feed include: soybean meal, cottonseed meal, corn gluten feed, dried distillers grains, whole cottonseed.

Is buying hay the economic choice?

ALWAYS, ALWAYS, ALWAYS ask for a forage analysis and/or test the hay before purchasing it. If not, you may be paying a premium for something that will not meet the requirements of your cows.
Take into consideration the cost of the supplement AND hay.
Also, take into consideration the method of feeding hay. If hay is not fed in a ring or other way to minimize lost, hay losses can be as high as 30%, or more.
Table 2 compares the cost of buying hay versus feeding a hay replacement diet
Note that if hay is being wasted, it is more economical to buy a replacement ration. This is point is not necessarily to steer you towards the feed, more so, to show the value of proper handling of purchased hay.

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Filed under Livestock, Pasture

July 12, 2016 · 6:27 PM

Pecan Leaf Sampling

It is time for us to take leaf tissue samples in pecans. UGA Extension Pecan Specialist Dr. Lenny Wells has this information:

The general recommended period for leaf sampling is July 7-August 7.

Why does it matter when you sample?

Concentrations of N, P, and Zn on a leaf dry weight basis start off relatively high early in the season, decline rapidly, reach a fairly steady state after mid-June, and then decline near leaf fall. K tends to start high, then decreases and plateaus at about the same time as N, P, and Zn. Most of the P and Zn that accumulates in the leaves have done so by the time the leaves reach full size. Calcium (Ca) accumulates in the leaves as the season progresses, peaking in August-September. Magnesium (Mg) Manganese (Mn), and Boron (B) also tend to increase as the season progresses, but to a lesser extent than Ca.

Collect middle-pair leafleats

How do we sample?

Collect 50- 100 middle-pair of leaflets from the middle leaf of this year’s growth (right). Use terminal shoots exposed to the sun. Avoid twigs from the interior of the tree. Collect leaflets from all sides of the tree. Avoid leaflets damaged by insects and diseases.
Abnormal trees or trees not representative of the area should be sampled separately. A complete and accurate description of abnormalities should accompany these samples.
Sample trees of the predominant variety in a given block. If Schley is the main variety, sample Schley; etc.
Immediately upon collection, wipe leaves (entire surface, both top and bottom) with a damp cellulose sponge or cheese cloth to remove dust and spray residue. Do not allow the leaves to come into contact with rubber or galvanized containers. Partially air dry and place in the large envelope of the mailing kit.
If recent soil test data is not available, it would be advisable to collect a soil sample and have it sent to a soil testing laboratory. By sampling the same trees each year, growers can more readily see the results of any changes to their nutritional programs.

**Some growers have taken leaf samples throughout the growing season to determine the fertility needs of the tree. This is really unnecessary. Leaf analysis does not necessarily reflect the actual use pattern of mineral nutrients, but instead indicates concentrations of those elements in the leaf at the time of sampling. The tree knows what it needs and when it needs it.

Concentrations of mineral nutrients in the leaves change as leaves emerge, expand, and finally senesce in the fall. For many elements, the least change in concentration occurs from early July-early August.

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July 8, 2016 · 4:42 PM

Grain Sorghum Dough Stage: Terminating Insect Sprays?

Our grain sorghum is past flowering and moving through the soft dough stage. Grain fill is rapid with about half the total dry weight of the grain accumulating during this time. We may see nutrient stress and leaf loss since mobile nutrients are transolocated from the lower to the upper leaves. Between soft dough and hard dough stage, irrigation increases yield by improving grain fill test weight. We don’t see much if any response from water once grain reaches hard dough stage.

Sugarcane Aphids

Once we get to hard dough stage, color, we no longer have to worry about sugarcane aphids. Also, keep in mind should try to avoid using pyrethroids for other insects and aphids. We need to check fields 2 – 3 weeks before harvest. We had issues with honeydew from SCA messing up the combines. A treatment may be needed if large numbers are in the head to prevent damage to combines. Hybrids with taller stalks and more space between the grain and upper leaves may make harvest easier by reducing the amount of leaf material going through the combine. Large infestation producing large amounts of honeydew and sooty mold may interfere with harvest desiccants.

The best way to tell hard dough is by pinching the kernel. The hard dough color is still similar to soft dough. MSU Grain Scientist Dr. Erick Larson says, “Grain Sorghum kernels change color and accumulate hard starch much the same as corn kernels mature. Kernels will mature first at the top of the head, so focus scouting on the kernels at the base of the heads. If you can quickly see a considerable amount of green kernels, rather than the burnt orange / brown color of mature kernels, you need to give the crop some more time to fully mature.”

Like corn, grain sorghum also forms ‘black layer’ from crown of the kernel to the base. Here is a photo by Dr. Erick Larson showing the progression from hard dough to ‘black layer.’

Sorghum Kernel Maturity - Dr. Erick Larson

Sorghum Kernel Maturity from hard dough (left) to physiological maturity or ‘black layer’ (right) – Dr. Erick Larson

Here is information from UGA Extension Grain Entomologist Dr. David Buntin on pre-harvest intervals, rates, and efficacies:

Sivanto Prime (Bayer Crop Protection). Sivanto prime has a full section 3 label and a supplemental 2ee label for lower rates on sorghum and other grain crops. The rates are 4 – 7 fl. oz per acre. Sivanto was very effective in my trials at rates of 4 to 7 fl. oz. per acre with Control usually lasting 21 days or more. At the 4 oz rate it can be applied up to 7 times during the season but has a 21 day PHI.
Transform WG (Dow AgroSciences). Transform WG federal label was vacated last winter and a new federal label has not been approved yet. But Transform WG has an approved Section 18 emergency exception for use on sorghum in Georgia in 2016 through April 8, 2017. The big label change for 2016 is Transform cannot be used during bloom to protect pollinators. The label allows for 2 applications per season and not more than 3 oz per acre per crop and has a 14 day PHI. In my insecticide trails last season, rates of 1.0 and 1.5 oz per acre were effective. Use the 1.5 oz rate if aphid populations are increasing rapidly.
Chlopyrifos (Lorsban Advanced, Nufos, other). Lorsban is labeled at 1 to 2 pints per acre. The 2 pint rate has a 60 day harvest interval. The 1 pint has a 30 day harvest interval, but is usually not effective. The 2 pint rate was 60-90% control for up to 2 weeks. At the 2 pint rate it cannot be used after the boot stage due the 60 day PHI. DO NOT USE CHLORPYRIFOS ON SWEET SORGHUM.
Dimethoate ( Dimethoate, Cygon). Not recommended. In my trials dimethoate is variable in control and control if it occurs is only for a week or so.

Sorghum Midge

The susceptible damage period for midge is bloom. Treatment after bloom is too late. The adults are hard to find. We either put a plastic Ziploc bag over the head. The midge will fly to the top of the bag. You can also use a white paper plate, but the midge can fly off. If it’s wings are wet in the morning, it may not fly as well. In either case, we only treat when an average of 1 adult per head is observed after 25 – 30% of heads are blooming. We can treat again 5 – 10 days later if midge is present. The eggs and larvae cannot be killed inside the glumes with insecticide.

NOTE: For midge, try not to use a prethroid because it may flare sugarcane aphids. If SCA are present and pyrethroid is used, we would have to tank mix with Transform or Sivanto.