Monthly Archives: July 2022
Fair Time! It’s fair time for both York and Seward counties. While unfortunate that the fairs are the same time (August 4-7th), there’s great opportunities at each one! Come on out to view the 4-H and FFA exhibits, eat great food including BBQ/steak fry served by various local commodity groups, enjoy the entertainment, and catch up with friends and neighbors from across the counties. Please view the schedule of events for Seward Co. at: https://sewardcountyfairgrounds.com/countyfairinfo/ and York Co. at: http://www.yorkcountyfair.com/.
Also, we know the weather greatly impacted gardens. I’m asking for York Co. fair that 4-H/FFA/Open Class participants still bring your produce even if it isn’t ‘market ready’. So, bring your green tomatoes, small peppers, etc. as we’d still appreciate your entries!
Crop Update: Tar spot was found on a leaf in a Saunders county field this past week. Very low incidence in the field and we’re not recommending fungicide for it at this time. Southern rust was found in northeast Kansas this past week, but hasn’t been detected in Nebraska yet.
Have had a number of comments this year about herbicides not seeming to kill palmer as in the past. Some common threads so far have been specific nozzle types used, weeds that had received hail at some point and potentially ‘hardened off’, and also some questions about water quality (pH, hardness) and any impacts there. If you’re noticing/hearing anything specific that worked or really didn’t work this year, I’d be interested in knowing it so I can keep compiling a list of considerations for weed scientists and ag industry to talk through this winter.
Also have received some questions/comments regarding irrigating shallower or deeper. We’ve been saying to get around as fast as one can if you are applying fungicide and/or insecticide through the pivot (0.15” and no more than 0.25”). For fertigation, we’d say 30 lb/ac can be applied in 0.25” and 50-60 lb/ac in 0.5”. Otherwise, we would recommend putting on closer to an inch at a time (depending on what the ground can take in without running off). This is also true for managing disease, particularly white mold in soybean and if tar spot in corn gets established years down the road (it’s better to reduce the frequency for leaf wetness when we irrigate).
Spider mites: Hot, dry weather has increased spider mite activity in crops (also FYI in gardens). Our Extension entomologists updated a CropWatch article that has more info. and a table with products listed for crops: https://go.unl.edu/9v6u. They write, “For effective control, spider mites must come into contact with the miticide. Since mites are found primarily on the underside of the leaves, they are difficult to reach with low volume applications. Using three or more gallons of water per acre by air to carry miticides may increase effectiveness. Aerial applications are generally more effective if applied very early in the morning or in the late evening. Applications made at these times avoid the upward movement of sprays, away from the plants, on hot rising air.
Eggs are difficult to kill with pyrethroid or organophosphate miticides, so reinfestation is likely to occur 7- 10 days after treatment as a result of egg hatching. The reinfestation is frequently heavy because natural enemies have been reduced or eliminated. A second application may be necessary to kill newly hatched mites before they mature and deposit more eggs.
Miticides with activity against eggs and immature stages include Zeal, Oberon and Onager. In many cases, especially with the twospotted spider mite, slowing the rate of population increase is all that can be accomplished with a miticide application.”
Also, I’ll speak more on this next week, but Soybean Management Field Days are quickly approaching Aug. 9-12. More info: https://go.unl.edu/xukf.
Even though few, the raindrops Saturday night were so refreshing after a hot week! I don’t know that it’s even really that hot compared to past years, but the sun seems extra intense to me this year. Cooler temps are welcome this week!
Crop Update: There is very little disease pressure thus far in both corn and soybeans. For corn, the most common thing I’ve seen this year is physoderma brown spot/purple leaf sheath, which is something we don’t worry about in Nebraska. Bacterial leaf streak is common on certain hybrids as always and is one we don’t worry about. A fungicide will not help against it and won’t protect against it. Gray leaf spot is very minimal to date in lower canopy, if it can be found. Same for common rust. The closest southern rust has been found is in southern Arkansas. So short story, fungicide isn’t necessary yet unless one is saving a trip for corn insects. For corn insects, there are still hot areas of Japanese beetles feeding on silks in addition to corn rootworm beetles. Spidermites are also flaring in some fields. Also be aware that spraying a fungicide can flare corn leaf aphids as it kills the fungus that attacks them.
For soybean insects, there’s still some Japanese beetles feeding and some spidermites flaring. For disease, have seen very minimal phyllosticta leaf spot and frogeye leaf spot and not anything close to levels for spraying. Seeing lots of phytophthora root rot this year in fields that is continuing to kill plants and there’s nothing we can do about that this year. Fields with a history of white mold may have been sprayed to help reduce disease pressure.
Tar spot has not been found in Nebraska yet this year. A great resource to track diseases such as southern rust and tar spot is: https://corn.ipmpipe.org/diseases/. Click on the disease of interest to see a U.S. map of where the disease has been found. Suspect samples can be submitted to the Plant and Pest Diagnostic lab in Lincoln for free. You can also get your samples to me locally if you’d like. There’s been a lot of confusion so far with insect “poop” and tar spot. A quick field test is to either get your finger wet or spit on the leaf and rub the spot to see if it comes off. Physoderma and tar spot won’t rub off but insect excrement will.
Fungicides and insecticides are helpful when we need them. Everyone’s trying to make the best decisions possible. Concerned we let fear of ‘protecting the crop’ drive decisions. Crop prices continue to be volatile and economics should be considered. Sometimes fields are sprayed a second time when disease comes in later once the residual wears off (regardless of product and because the product only makes it so far into the canopy unless chemigated). In terms of resistance management, we have fewer modes of action with fungicides than herbicides available to us, and we use those same modes of action in all our crops. We already have resistance to the quinone outside inhibitor (group 11 formerly strobilurin) class of fungicides to frogeye leaf spot in soybean. Concerned it’s only a matter of time before this impacts us on the corn side too.
I realize I’m continually an outlier in saying to wait and not automatically apply at tassel. Based on the Nebraska research (shared last year here) and observation I feel we can wait till disease pressure warrants applications and allow them to help with stalk strength. I also realize this column would’ve been more timely last week with the spraying that’s occurred.
South Central Ag Lab Field Day Aug. 4 will begin with registration at 8:30 a.m. with program from 8:45 a.m.-3p.m. at the South Central Ag Lab near Harvard/Clay Center. There are several tracks to choose from throughout the day including the latest in weed, disease, insect, nutrient, irrigation management, and soil health. Free lunch and CCA credits available. More info. and RSVP at: https://go.unl.edu/scalfieldday.
The first picture on the left has been common of both physoderma brown spot and insect poop. With physoderma brown spot, most often these purplish spots are more prevalent on the midribs, leaf axils, and leaf sheaths (as seen in the middle photo). Often the spots outside of the midrib are more yellow/tan in color and are often confused with southern rust. Photo 3 on the right-hand side was tar spot that was found in Oct. 2021 in York Co. Would recommend getting your finger wet or spitting on the leaf and rubbing the spot to make sure it’s not insect poop as several samples looking like the first photo have been that instead. Physoderma won’t rub off and neither will tar spot. Feel free to submit any suspect samples to the diagnostic lab for free.
Japanese beetles: Hopefully this is the last week I talk about these! Hoping they’re coming to an end for this year as I’m not hitting as many while driving! Seems like each week brings new questions that I hope will be helpful to share. For tree and garden products, please check the handout which can be downloaded from the front page of york.unl.edu.
In replant corn and soybean fields, the beetles are attracted to the older plants (check strips/original bean plants); they shouldn’t be going after the replant ones. I’ve heard areas (not hail damaged) have sprayed beans at least twice. People wondered if this is to be expected with products that should have 14 days residual. In talking with Bob Wright, he says there’s little research on Japanese beetles on chemical efficacy. The soybeans continue to produce new leaves and the herbicides, although there’s residual in the pyrethroid products, doesn’t translocate to new leaves. Sunlight also breaks down the herbicide in leaves. Increasing water helps with coverage (helpful if increase to at least three gallons in aerial applications-same for fungicide applications). Chemigation is an option too.
I’ve also been asked about adding other nutrient and biological products, etc. to tanks to increase the plant health. While I’m not opposed to the concept of healthy plants fending off insects/pathogens, I don’t know of research to comment on that for Japanese beetles. Sidenote (not necessarily Japanese beetle related), when I’ve been called out to problem situations in fields this year, numerous times there’s been a large number of products placed in the tank. I just wonder how all these things are truly interacting together and if we’re potentially creating problems (increasing selection pressure and resistance) on weeds, insects, pathogens by potentially reducing efficacy of the original pesticide product that was meant to be sprayed before everything else (plant growth regulators, micros, etc.) was added. Again, no research, just a consistent observation in field calls with problems this year.
White Grub Prevention/Control in Lawns: Been getting questions about grub prevention as well since the Japanese beetles lay eggs in lawns. Control depends on proper timing of the application and moving the insecticide into the root zone where grubs feed. Preventive control applications are made from mid to late June. They can work in early July (it’s potentially too late now). Curative or rescue treatments are made in August or September and I will talk about those products next month.
Preventive – Most of the preventively-applied insecticides are systemic in nature and will be taken up by the plant and translocated to roots. The following products are effective against young grubs and are labeled for homeowner use: Chlorantraniliprole –Scotts GrubEx; Imidacloprid –Bonide Grub Beater, BioAdvanced Season Long Grub Control + fertilizer.
Check Grain Bins: With all the work of starting crops over the month of June, checking grain bins wasn’t as high on the list for many in this area. Two farmers suggested I mention checking grain bins this week as they had found some hot spots and were thankfully able to get things under control.
Take Care of Yourself! I know how worn down I’m feeling each week, and I’m not in the shoes of you as the farmers and landowners who have went through so much loss. These storms keep giving as people find additional damages to buildings, equipment, trees, crops, etc. I realize with the heat it’s not realistic for many to get away for long. There will always be a list and few of us ever ‘catch up’. But there’s only one of each of us. My challenge for us this week is to take some intentional time to reset…whether a half hour or a few hours. Spend the time doing a hobby, resting, strengthening your faith, catching up with someone. We need these breaks and I’m doing that as well. Be sure to stay hydrated with the heat too!
Cover Crop and Soil Health Field Day: This snuck up on me and I failed to talk about it sooner; it will be held this Tuesday July 19th from 10 a.m.-2 p.m. (Registration at 9:30 a.m.) at the 4-H Building at York Co. Fairgrounds. Topics include: understanding soil health, the Nebraska soil carbon product cover crop study; On-Farm research cover crop study update; and Cover crops for upland game birds. Following lunch there will be a cover crop field site visit with a demonstration of how to conduct a soil health inventory. There is no charge but please RSVP for meal count to Nate Pflueger at 402-646-5426.
Grateful for some rain last week! Hail damaged trees (particularly evergreen trees) need water now to help them heal all the open wounds on the branches, stems, trunks.
Western Bean Cutworm Moths should be around 25% flight for corn nearing or tasseling in much of the area. It was predicted for Guide Rock on July 5, York on July 10, and Clay Center on July 11. This CropWatch article shares dates to watch for around the State: https://go.unl.edu/nmye.
Japanese Beetle Control: I posted a second blog post last week on organic and conventional control products that are sold in this area at local farm stores, lawn/garden centers, Wal-Mart, and Ace. You can print it out from the font page of the York Co. Extension website: https://go.unl.edu/bvqf.
Even after applying pesticides, beetles will continue to emerge and fly in from grassy areas (ditches, lawns, pastures) for a good 4-8 weeks. Plants that are being chewed on elicit responses signifying they’re in trouble. It’s those responses that signal other beetles to come. Even though linden, fruit, and other trees and plants are rapidly defoliated, they should not die. On younger trees that were hail damaged, I’m unsure if the hail + the beetle defoliation is too much stress for survival; we will have to see. I’m also unsure if we will see new leaves in general after beetle defoliation this year or not; trees are super stressed already from all the hail damage. I’m observing new leaves are very slow coming back on broadleaf trees post-hail and that was before we also had the beetle defoliation.
I probably should’ve realized this, but another thing I learned this week is there’s two formulations of ‘Sevin’ being sold. I don’t mention that on the print-out mentioned above. One is the traditional carbaryl that lasts 5-7 days. The other is zeta-cypermethrin which has a residual of 14 days (farmers would recognize this ingredient in Hero and Mustang Maxx). I’m not sure why the company branded both products the same name. The Sevin carbaryl product says it will ‘cause damage to boston ivy and virginia creeper’…both of which are favorites of Japanese beetles. So, that was something new I learned by reading the labels and being called out to an unfortunate incident with boston ivy. I didn’t see that same warning on the Sevin zeta-cypermethrin product, but please check it for yourself if you use it.
Japanese beetles are in corn and bean fields as well. Watch silk clipping in corn and pod clipping in beans (seeing both occurring). Tasseled corn threshold: three or more Japanese beetles per ear, silks have been clipped to less than ½ inch, and pollination is less than 50% complete. Soybean has 20% defoliation once flowering occurs. It’s been interesting seeing beetles defoliating palmer, waterhemp, smartweed, etc. Too bad we couldn’t train them to just eat the weeds!
Hail Damage and Corn Pollination: This one is just hard and I’m genuinely hoping this isn’t as big of an issue as what it looks like. For corn that was V9-V11 during the June 14th storm, check the tassels and the ears. What I’m seeing in fields that were severely stem bruised but not totaled, are ears that are hip high on me with silks that are up to 5” long right now. Tassels are mostly 1-2 leaves from tasseling. Opening up the leaves shows severely damaged tassels with minimal to no anthers. Some anthers are trying to pollinate within the leaves (pics on my blog). It’s normal for silks to emerge before tassels as that’s what breeders have bred corn to do. It’s not normal for the tassels to emerge this much later than the silks and to be so severely damaged. It will be something to watch in all the hail damaged fields that were kept from June 14 storm to see if the pollination timing is impacted in them as well. What I’m recommending is for now, check your fields and take pictures of the tassels and ears for documentation of any problems if crop insurance can’t come out. I’m hoping I’m wrong and that we can still get some decent pollination in these fields.
This is one of a few fields looked at that was between V9-V11 during the June 14th hailstorms. It had severe stalk bruising at the time and around 22-24K for population. Long silks with very few tassels out. Top left tassel was a decent tassel found that was out. Most tassels are within 1-2 leaves of emerging, are severely damaged from the hail, and some were shedding what pollen they were producing while inside the leaves (bottom left photo).
With the Japanese beetle invasion in the area and their territory spreading further each year, I checked with local retailers (nurseries, lawn/garden centers, farm stores, Wal-Mart, Ace) to see what they have on hand to hopefully be of help.
First, Please Read the Label on any product before you purchase it to make sure:
1: the product says it controls Japanese beetle adults
2: the product is labeled for where you wish to apply it (vegetables, trees, ornamentals, fruit trees, berries, etc.)
3: follow all pre-harvest intervals (PHI) for when you can safely harvest vegetables, fruits, and berries after a product is applied.
Last year I had to unfortunately tell three people they couldn’t eat the produce from their gardens due to the product they sprayed.
Second, there are a number of insecticide options available. Know that most anything applied to flowering plants will also impact pollinators. For flowering plants like roses, cannas, etc., knocking the beetles off around 7 p.m. in the evening into soapy water will protect pollinators visiting them.
There are also ready to use and concentrate versions of chemicals available. The easiest are ones where you simply attach the garden hose and spray. Others need to be mixed with water into a sprayer.
Organic Insecticide Options include Neem, Pyola, Spinosad Soap, Pyrethrin products (ex. Beetle and Boxelder bug killer), and Bt. Neem may repel more than kill Japanese beetle adults. These products will all last around 3-7 days and will need to be reapplied. Products containing these active ingredients should be safe on fruits, vegetables, in addition to using on flowers, shrubs, and trees. Be sure to read and follow directions as there may be a temperature restriction on applying some of them that contain oils to avoid burning leaf tissue.
Conventional insecticide Options can provide up to two weeks of control. I’m going to separate these into products I found locally based on the location they can be applied. Ultimately, this is NOT a complete list and many other products can also be found online. There are also products containing insecticide + fungicide that I don’t list here. Please be sure to read the label for yourself as to the insects controlled and where it can be applied before purchasing.
1. Ornamental shrubs, plants, trees (like linden, elm, birch): DO NOT use these products on vegetables, fruits, or berries. Hi Yield 38+ and Tempo. There’s home defense products labeled for Japanese beetle adults but they don’t mention they can be applied to trees or shrubs.
2. Vegetables, fruits, ornamentals, shrubs, trees: BioAdvanced Rose and Flower Insect Killer, BioAdvanced Tomato and Vegetable Insect Killer, BioAdvanced Vegetable and Garden Insect Spray, Eight, Spectracide Acre Plus Triazicide Insect Killer, Hi-Yield Lawn/Garden/Pet/Livestock Insect Control, Sevin, Ortho BugClear, and Ortho Bug B Gone.
Many of the conventional insecticide products contain pyrethroids such as bifenthrin or permethrin. Thus, there are also products that just say ‘bifenthrin’ or ‘permethrin’ that can also be purchased. Be sure to read the label as some have restrictions such as “can’t be applied to apples” while others can.
Hope everyone has a safe and wonderful 4th! Some food safety tips from our Food and Nutrition educators: hot days above 90F means we need to keep warm foods 140F or warmer. Perishable food should stay in the fridge or on ice before and after eating. Leave perishable food out an hour or less in hot weather. For more picnic and bbq tips, check out https://bit.ly/3xjYWwz.
ET and GDD: Also praying for rain; pics of drought monitor map at my blog. Our CropWatch GDD and ET resources if you don’t have your own ET gage are at: https://cropwatch.unl.edu/gdd-etdata.
From CropWatch: The forages team shared more detail on summer annual forage options at: https://go.unl.edu/7z5p. A team of Extension and Industry professionals led by Dr. Amit Jhala shared info. regarding herbicide options for soybean after the June 30 RUP dicamba restriction: https://go.unl.edu/2i5a.
Hail Damaged Trees: Evergreen trees have rapidly turned brown on the hail-damaged sides of trees the past 7-10 days. We don’t recommend applying anything to them; just water them to help them with healing. Next spring, they may be more sensitive to fungal disease and insects. Sarah Browning, Extension horticulture educator shares, “Hailstone damage to a tree’s vascular system limits its ability to move water up from the roots and into the secondary branches and leaves. Movement of nutrients throughout the tree is also reduced. Over the next few years, previously healthy vigorous trees will produce callus tissue to seal off bark wounds and re-establish vascular function. Until then, they have a reduced ability to move water and cope with dry conditions….In most cases, homeowners should take a “wait and see” attitude. Trees and shrubs should be kept well-watered throughout summer and fall to avoid drought stress. Keep plants well mulched to prevent secondary injury from mowers and string trimmers.”
Japanese Beetles: The adult beetles are ½” in length with metallic green heads and white ‘tufts’ of hair that look like spots on the abdomen. Don’t use Japanese beetle traps! Research shows they attract beetles to the landscape.
Organic control options: Wait till 7-9 p.m. then knock beetles off plants into a bucket of soapy water to drown them. This method takes diligence but is effective. You can also spray trees with water to knock them down to the ground and then drown in soapy water. Neem and Pyola are organic options that will protect for 3-7 days. Applying these products once per week can be effective as a repellent. Bt provides 7 days protection and is safe for bees.
Conventional control options: Japanese beetles impact flowering plants that other pollinators visit. Avoid spraying insecticides on windy days or when pollinators are present (best to spray late in day near dusk) and follow label instructions and harvest intervals (for cherries, plums, vegetables, etc.). Chlorantraniliprole (Acelepryn®) provides two to four weeks protection and is low risk to bees. Pyrethroids, including bifenthrin, cyfluthrin, lambda cyhalothrin, and permethrin, last about two to three weeks. Carbaryl (Sevin) or acephate will provide one to two weeks’ protection. Pyrethroids, carbaryl, and acephate are toxic to bees and other pollinators.
Corn and Soybean Thresholds: Soybean thresholds are 20% defoliation in the reproductive stages. In talking with Dr. Bob Wright, Extension Entomologist, we’re going with a 30% defoliation threshold for corn prior to tassel (same as soybean prior to flowering). Tasseled corn threshold: three or more Japanese beetles per ear, silks have been clipped to less than ½ inch, AND pollination is less than 50% complete. Pyrethroids are very effective against beetles. If one is concerned about flaring spidermites, a product like bifenthrin can be used.
Japanese beetle feeds on 300 different plant species preferring ones like roses, lindens, birch, and fruit trees. Early on, they can be managed by knocking them off plants in the evening and drowning in soapy water.
Concerning. Drought monitor maps: June 30, 2022 on the left compared to June 26, 2012 on the right.