Category Archives: Peanuts

December Row Crop Disease Update

A few things to think about with regards to disease and nematode management in preparation for the 2017 field season.

La Nina:  Our UGA Extension climatologist Pam Knox has good information available on our current conditions, but here are my thoughts:

We are currently in a “weak” La Nina situation, “weak” because the equatorial waters of the cost of Ecuador are more than a half degree COOLER than normal.  As best I can tell, the waters have been about 7/10 of a degree cooler which barely qualifies as a La Nina (as opposed to last year where we had a robust and sure-enough El Nino).  So what does this mean? During La Nina years, the Southeast tends to (“tends to” means more often than not, but not always..) experience warmer and drier winters. Because we have a weak La Nina, this forecast could change.

Pigweed seedhead in broccoli before Thanksgiving. We are yet to have frost to knock back pigweed growth.

Pigweed seedhead in broccoli before Thanksgiving. We are yet to have frost to knock back pigweed growth.

How does our current “La Nina” impact our recommendations?

  1.  Drier is not a good thing as it may mean we don’t fill up irrigation ponds for next year.  It my mean we have a lot of trouble establishing cover crops this fall.
  2.  Warmer temperatures may mean that kudzu, volunteer peanuts, corn, cotton-regrowth, etc. pathogens (like those that cause soybean rust and southern corn rust) may survive and increase longer than they would with an earlier “killing” frost.  Also, as long as the crops and volunteers are active in the field, nematode populations can continue to increase and build.  This will lead to larger populations for next season. Once the plants are killed, the nematodes can no longer feed. Once soil temps drop below 65F, the activity of the todes drops off as well.
  3.  We may get some very cold weather soon, so we may not need to worry that much; however the general prediction is that we will have a warmer winter.
  4.  The weather this winter will have some effect on TSWV and insects for next year.  It remains to be seen what and how… but it will impact them.

Leave a comment

Filed under Corn, Cotton, Disease, Peanuts, Soybeans, Weather

Peanut Harvest & Row Crop Disease Update

Boston Peanut

Boston Peanut

Golden Peanut in Meigs

Golden Peanut in Meigs

After afternoon showers and rain last week, we are really getting back to picking this week. Growers are also wide open on defoliating cotton. I saw some cotton being picked yesterday.

I visited our buying points this week and looked at grades and other issues. Thankfully, we are not having many Seg 2 burrower bug hits as last year and the year before. Between both buying points, I only know of one known burrowing bug Seg 2. In every other Seg 2 case, they’ve turned around and cleaned them and they were fine.

Grades are probably a little down this year compared to last, but are definitely not bad. Many good grades overall and low percentage of our sound splits and other kernels (pops). We could be pulling the trigger early on the some of the fields. Almost all growers are checking maturity twice in fields before digging, and many have checked more than two times. We’ve not seen maturity develop at a normal pace with our dryland peanuts which has made digging decisions tough. With more peanuts in the ground, growers are having to dig when they have help, or wagons are available, or weather permits. Vine condition is also a factor in our decision at this time. Overall, we’ve had good harvest conditions this week. Even with afternoon storms or showers, sunny days have been able to dry peanuts quickly.

Collecting grading samples at Boston Peanut

Collecting grading samples at Boston Peanut

UGA Extension Pathologist Dr. Bob Kemerait has this information on current disease issues:

Peanuts

Harvest is well under way by this time, but disease issues still affect peanuts that won’t be harvested for another three weeks or more. I have seen some fields where harvest is approaching and where white mold (stem rot) is still active, and I have recommended growers late in the season apply a mixture of tebuconazole and chlorothalonil to finish the season (both products have a 14-day preharvest interval). Other white mold products could also be applied (check preharvest interval first), but with time running out in the season, the value of tebuconazole is certainly a consideration.

Late Leafspot

Late Leaf Spot

I have also observed where leaf spot, especially late leaf spot, is aggressive late in the season, primarily on a susceptible variety like ‘Georgia-13M’. If less than two weeks to go before digging, it is doubtful anything should be applied (or legally can be applied). If peanuts are 30 days or more away from harvest, then the grower can mix a pint of chlorothalonil with 5.5 fl oz/A of Alto. If harvest is more than 14 days away from harvest, the grower can mix 5-10 fl oz/A Topsin with a pint of chlorothalonil. Fields where defoliation from leaf spot diseases has reached 50% or more and have not yet reached the optimal digging date should be considered for an early digging.

Soybeans

Soybean producers in southern Georgia have experienced losses to Asian soybean rust this year; however it appears that most have successfully protected their crop with judicious fungicide applications. MORE IMPORTANTLY, I have observed a SIGNIFICANT amount of frogeye leaf spot (Cercpospora sojina) disease in a number of fields this year; something I have not seen in many years. I am not sure why this is so; however it is something we will need to watch again next season as well. Additionally, I am seeing pre-mature defoliation to Cercospora blight (Cercospora kikuchii) in a number of fields; this disease often results in purple stain of the soybean seed. Cercospora blight is diagnosed, in part, by the prominent loss of leaves in the top of the plant leaving only the petioles, reaching like bony fingers to the sky.

Cotton

Bacterial blight (Xanthomonas citrii pv malvacearum) continues to cause concern to many growers in the state. From your reports, reports from our consultants, and from my own observations, it is clear that bacterial blight can be found in a number of fields across the Coastal Plain. Classic symptoms or bacterial blight on leaves, bracts, bolls, stems and petioles are fairly easy to diagnose; still symptoms of other diseases may inadvertently be diagnosed as “bacterial blight”. 

It is my belief, based upon my observations and discussions with a number of experienced individuals, that losses to this disease are likely to be small and even negligible in many fields. Finding a little bit of disease in a field is an important contribution to understanding the occurrence of bacterial blight in 2016; but incidence alone does not mean significant yield loss.

Certainly there are some fields, especially in extreme SW Georgia, were boll rots appear to be closely associated with bacterial blight and losses are likely to occur. Effective management of bacterial blight by a grower revolves around variety selection (we are composing such a list for Georgia cotton producers now) and management of crop debris/residue as the pathogen can overwinter in such. Crop rotation and burying of crop debris can help to minimize the development and spread of the disease in upcoming seasons.

Bacterial Blight

Bacterial Blight

Leave a comment

Filed under Cotton, Disease, Peanuts, Soybeans

Digging & Picking Peanuts

picking-diggingpeanuts-017

If there was anything done in the field this week, it has been digging and picking. We really got heavy digging last week, and many of those peanuts have already been picked. Our conditions have overall been good. If anything, we are worried about it getting a little dry for digging. Some irrigated peanuts have been watered to soften up dirt.

We had lots of rain in forecast this week, but we really didn’t get any. Early in the week, we were cloudy and this stalled picking a day or so as it took longer for peanuts to dry. We have been sunny for the past 3 days however, and growers are super busy now.

picking-diggingpeanuts-020

picking-diggingpeanuts-014

peanuts-dug-2016-001

Peanut Maturity

So many of our o6G’s – especially irrigated – are coming out of the ground between 130 and 140 days. I’ve talked with other agents around us who are seeing the same thing. UGA Peanut Agronomist Dr. Scott Monfort has also reported peanuts ready at this time also. He says GA 09B may be a little earlier than 06G with many of the other High Oleic varieties running near 140-150 days. GA 14N may be 145 to 150 days.

For our dryland crop, we are seeing results from extreme drought and heat on the peanut boards. We will see peanuts with varying color, peanuts turning loose in the hull, and insect damage. In dryland situations, the Tropical Storm made plants look better, but no necessarily pods. Dr. Monfort says some fields will be on the early due to lack of blooming in latter part of growing season. With moisture running low for advance, we are starting to look at vine condition in the field.

Split Crop

When we see a “split crop” it is not easy to determine when to dig. Dr. Monfort says that typically, a profile that is split evenly, we make the decision to dig on the leading edge. But, if the leading edge is minimal compared to the fruit load behind the “split”, then the decision is more difficult.

peanutmaturity-splitcrop-002

**And last, do not take risk in contaminating good quality peanuts with non-irrigated peanuts that might have aflatoxin (dryland corners.) A few bad pods can cause a trailer load to move to SEG 2 or SEG 3.

 

Leave a comment

Filed under Peanuts

Peanuts: Terminating Fungicide Sprays

We are starting to dig some peanuts this week in the county. Profiles are showing high percentage of mature, gradable peanuts. This week, it seems as profiles have slowed and not much change. One of the most difficult decisions is terminating our fungicide sprays. Some fields still show hits of white mold. Remember that if we get 60-70% control of soilborne disease, this is considered good – especially fields prone to WM.

peanuthullscrape-001

Here is an update from UGA Extension Pathologist Dr. Bob Kemerait on cutting off fungicide sprays based on our profile charts:

  1. Grower is 4 or more weeks from harvest and DOES NOT currently have disease problems in the field:
    • Suggestion – I recommend the grower apply at least one more fungicide for atleast leaf spot control.
    • Suggestion – Gen the low cost of tebuconazole, the grower may  consider applying a tank-mix of tebuconazole + chlorothalonil for added insurance of white mold and leaf spot.
    • NOTE: If white mold is not an issue, then the grower should stick with a leaf spot spray only.
  2. Grower is 4 or more weeks away from harvest and HAS disease problems in the field:
    • If leaf spot – Grower should insure that any fungicide applied has systemic/curative activity. If a grower wants to use chlorothalonil, then they would mix a product like thiophanate methyl (Toppsin M) or cyproconazole (Alto) with chlorothalonil. Others may consider applying Priaxor, if they have not already applied it twice this season.
    • If white mold – Grower should continue with fungicide applications for management of WM. If they have completed their regular WM program, they should extens the program, perhaps with a tebuconazole/chlorothalonil mix.
    • If underground white mold – Underground white mold is difficult to control. Applying a white mold fungicide ahead of irrigation or rain, or applying at night can help increase disease management.
  3. Grower is 3 weeks or less from harvest and DOES NOT current have a disease issue. Good news! This grower should be good-to-go for the remainder of the season, and no more fungicides are required.
  4. Grower is 3 weeks or less from harvest and DOES have a problem with disease.
    • If leaf spot – A last leaf spot fungicide application may be beneficial. If leaf spot if very severe, a last application will not help.
    • If white mold – It is likely beneficial to apply a final white mold fungicide. If harvest is 2 weeks away or less, then it is unlikely that a fungicide will be any benefit.
    • NOTE: If harvest is likely delayed by threat from a hurricane or tropical storm, then the grower may reconsider recommendation for end-of-season fungicide applications.

Leave a comment

Filed under Disease, Peanuts

Peanut Maturity

We’re getting closer to looking at peanuts to check maturity. I checked my first sample yesterday. We were really just wanting to see how far away we were to make decisions on last fungicides. Peanuts looked further along than expected.

PeanutMaturitySample-PlantedApril27 002

These 06G’s were planted April 27th and 28th, and show a maturity between 14 and  days away. We didn’t have a perfect representative sample, so this may affect it. Peanuts mature based on temperature and available moisture. With high temperatures since June, questions have been about crops maturing early. UGA Agronomist Dr. Scott Monfort says this won’t necessarily affect everything the same. For instance, our early April planted peanuts (in cooler temperature) will stall, then later April planted peanuts will mature faster. Every field situation is going to be different, so sampling is the best way to really know.

In this sample, I was finding a lot ‘turning loose’ in the hull. We need to remember to crack open the pods to observe the funiculous. This is the umbilical cord that connects the kernel to the pod. Once it turns loose, the next rain can make them sprout.

Sometimes it’s hard to see the ‘umbilical cord’ before you break it yourself. Another way to make this observation is just look at the kernel. If the kernel is white with few oil spots, it’s still feeding. If the kernel is dark and shriveled, it has turned loose. I took a picture of these two. They are not always this easy to tell, but looking at them this way has helped me. I start on the right side (mature pods) and work my way back. I cracked 35 pods in this same and 6 were turned loose. 17% is pretty significant.

Top peanut still feeding; bottom peanut turned loose in the hull

Top peanut still feeding; bottom peanut turned loose in the hull

Sampling Procedure

Growers, make sure you have a good representative sample. Get plants from at least 3 spots in the field. Also, don’t just pick off the larger pods. We really need to pick off small pods as well. If we pick off large pods, it can bias the sample toward digging early. There is enough data to show that we lose as much as yield if we dig a week early than a week late. If we dig a week late, there is no difference. We don’t see difference again until we dig 2 weeks too late. We still have to consider the condition of the vines. Definitely look at the vines well as you pull off pods. Also, 180 – 200 pods is good for a sample.

Prevent Digging Losses

Miller County Ag Agent, Brock Ward was talking with me about losses just from the digger. He went back and found good information from former UGA Agronomist Dr. John Beasley on digging losses that I think is good to share:

You can do everything just right during the season to maximize yield and grade potential but blow it all at harvest.  It is very easy to lose several hundred pounds per acre in yield by not being careful when digging. Growers need to take their time and set the digger-shaker up properly and then run at the proper ground speed to maximize digging and inverting efficiency.

In 1990, Dr. Mike Bader and I conducted a digging efficiency trial at the Sunbelt Expo Farm. We had a replicated trial in which we dug as close to perfect as possible, too fast, too slow, too shallow, and too far left or right. We took an area the width of the planted bed (6 feet) by 3 feet in length from each plot within the trial and collected pods on the soil surface and from the top three inches of the soil. We threw out the obviously diseased or non-harvestable pods, and weighed the harvestable pods that would have yielded and graded.

Even where we dug as close to perfect as possible we calculated losing approximately 120 pounds per acre. We know that producers do not harvest too shallow on purpose, but if they are not paying attention the digger blades can ride up more shallow if the soil is too hard. We measured pod yield losses in the range of 1,000-1,200 pounds per acre in the too shallow, too far left or right, and the too fast treatments.

Bottom line is that digging losses can take a significant chunk of yield potential. Another critical factor is to make sure they are using sharp digger blades. A set of digger blades is usually good for a limited number of acres, depending on soil type. On the heavier soils 15-20 acres may be the limit on a set of digger blades so check them often to make sure they are wearing evenly.  Growers need to be very careful at digging to reduce harvest losses.

Leave a comment

Filed under Peanuts

August Peanut Insect Update

Peanuts-06G

This is kind of been a cotton week for me; I haven’t looked at many peanuts this week. Here’s a field I was going to pop in and scout for disease until I saw this water. I’m tired of losing my boots in these kinds of fields.

UGA Entomologist Dr. Mark Abney wrote an insect update I’ll pass along for everyone:

Drs. Monfort, Srinivasan, and I spent several days last week walking peanut fields to get a measure of how severe tomato spotted wilt is in this year’s crop. Incidence of virus symptoms varied from 0 to over 30% in the fields that were surveyed. This effort also gave me an opportunity to see first hand what else was happening in terms of insect and mite activity over a large area of South Georgia. As a general rule, insect pressure was low, but there were a few fields with real or developing problems.

Redneck Peanut Worm & Lesser Cornstalk Borer

Several non-irrigated fields had lesser cornstalk borer infestations, and a couple fields had two spotted spider mites. Redneck peanutworm was the most common foliage feeder I saw. This insect has been very abundant in my test plots this year. I thought the redneck peanutworms had run their course a week or so ago, but we seem to have another generation showing up on the research farms around Tifton. There are no thresholds for this insect, and I doubt that it will cause measurable yield loss in most situations. It does however, make the foliage look ragged.

Southern Corn Rootworm

Southern Corn Rootworm - Adult - Dr. Mark Abney

Southern Corn Rootworm – Adult – Dr. Mark Abney

Some fields had relatively high numbers of southern corn rootworm (cucumber beetle) adults, and I received a couple more reports of pod damage this week. As I mentioned in a post last week, there is little that can be done to manage rootworm infestations in peanut once the larvae are feeding on pods.

Caterpillars

I have not seen much in the way of caterpillar pressure, but I have gotten calls that indicate some fields are experiencing moderate to heavy infestations. There are velvetbean caterpillars, soybean loopers, and armyworms in spots. Most of the moths I saw in fields last week were tobacco budworm. I will be watching my plots closely for caterpillars in the coming weeks.

Whiteflies

Whiteflies are not typically a pest of peanut, but we are seeing some whitefly activity in peanut fields in Tift and surrounding counties. So far, there have been no reports of reproduction occurring in peanut, and we should all hope that does not change. There are few options available for whitefly management in peanut, and most fields still have a long way to go before harvest. If anyone observes whitefly nymphs on peanut, please let me know.

Garden Fleahopper

Garden Fleahopper

Garden Fleahopper

Folks are seeing garden fleahopper in peanut again this year. The impact of this insect on peanut is unknown, but some fields were treated in 2015 due to very high populations and subsequent defoliation. We do not have a good option for controlling garden fleahopper; pyrethroids have generally provided only partial control.

Growers should be aware that there is a “little bit of everything” in terms of insect and mite pressure in Georgia peanut fields right now, but that does not mean every field is infested or will need to be treated.

Leave a comment

Filed under Entomology, Peanuts

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

Leaf Scorch – Dr. Scott Monfort

Leave a comment

Filed under Fertility, Peanuts