Corn Silage Resources: For those making corn silage this year, hopefully the following resources can be of help. The multiplier for corn silage value from UNL is 7.65 times the market value of corn grain.
- Making corn silage considerations: https://go.unl.edu/qven
- Estimating a fair value for standing forage (including silage): https://go.unl.edu/sy6j
- Value of Standing Forage excel spreadsheet (scroll to mid-page): https://cap.unl.edu/forage
Spidermites: I’m hoping that the cooler weather and either rainfall/irrigation are helping a beneficial fungus help us in the battle against spidermites. Last week I was showing growers how to distinguish this via a hand lens. We mostly have two-spotted spidermites in fields, which are yellow with two black spots on them. Anytime they start looking different (darker, cloudy, white) where the spots are no longer visible, it can be an indication that they are infected and will die. Unfortunately I didn’t grab any pics from the field. The economic threshold from Colorado State says spraying is no longer beneficial past hard dough. I can appreciate that’s hard with the severity in some upper canopies, so here’s hoping the cooler weather helped with the battle.
Pollination: I sure appreciated seeing and smelling all the pollen shed in these replant fields last week! It was perfect weather for it, hopefully a bright spot in the midst of a difficult situation. Been hearing and seeing complaints about poor pollination in non to less severely hailed areas. I don’t remember smelling pollen this year like I normally do in July, but I also admit most of my time has been spent in this large replant area this year. The following is about poor pollination, not kernel abortion.
What I’ve learned from Dr. Tom Hoegemeyer and Dr. Roger Elmore about corn pollination through the years: Heat over 95F depresses pollen production with prolonged heat reducing pollen production and viability. When soil moisture is sufficient, one day of 95-98F heat has little or no yield impacts. After four consecutive days, a 1% yield loss can occur for each day above that temperature with greater yield loss by day 5 or 6. High humidity, without a drop in humidity during the day, can delay pollination or prevent pollen from leaving the anther sacs. Pollination mostly occurs between 8:30 a.m. and noon. When the temperature is 90°F to 95°F, the pollen is eventually killed by heat and is seldom viable past 2 p.m. Pollination typically occurs over a span of six to ten days depending on variability of growth stages in the field.
So, I did some digging into weather data. I don’t have all the tools that you may have, so do something similar for your operations based on the timing of when your specific fields were pollinating and where you’re located. First, I did a general map of Nebraska showing the number of days over 95F from July 9-19, 2022. The eastern 1/3 of the State only had 0-1 days that fit this criteria.
Perhaps bigger factors may have been humidity and timing of silk emergence compared to pollen shed? We’ve had high humidity. For pollen shed to occur, relative humidity needs to drop between 50-65% and the pollen is no longer viable at 30%. As I look at weather data for different locations in the area, many places had over 65% relative humidity as an average for the day for at least 5 days in the time period listed above. It really comes down to at what time the relative humidity dropped enough during the day to release viable pollen. It’s possible that for several days, the anther sacs dropped without releasing pollen if the humidity didn’t drop in the morning. I also remember mentioning in July about how extra long the silks seemed this year prior to pollen shed. That can be a problem, particularly for pollination on the lower end of the ear. The first silks that emerge from the husk are attached to kernels at the base of the ear and they begin to form 8-10 days prior to R1. Silks then continue to emerge sequentially up the ear with the ear tip silks emerging last. Silks are receptive to pollen anywhere along the silk, but after 10 days, the silk senesces (and they’re most receptive to pollen in the first 4-5 days of emergence). Some drought tolerant hybrids may have genetic X environmental responses which trigger silks to emerge 4-5 days prior to any pollen shed (which can result in poor pollination). Older silks can also get covered up by newer silks and miss exposure to pollen. Drought stress adds an entire other complexity to this discussion. Japanese beetles clipped silks in some areas, but it sounded like most were sprayed timely or the silk clipping occurred after the silks had pollinated (turned brown). I don’t know the specifics of every individual situation. These are some thoughts to consider if you’re dealing with pollination issues this year.
The buildings and barns are now emptied, exhibits taken home and people are weary. But what remains
are the friendships, the connections re-established, the smiles, the gratitude, the pulling together, the awards given to the youth, the lessons learned. When I was in 4-H, I had no idea the amount of time that Ag Society, Extension staff, volunteers, my 4-H leaders or even my parents put into the fair. I could’ve said ‘thank you’ so much more! This was my 19th county fair on ‘the other side’ and it never ceases to amaze me the list of items to accomplish in order to ensure a successful fair. It takes many dedicated people to achieve all of this. I’m so grateful to the ag society, 4-H Council, Extension staff and board, FFA advisers, 4-H leaders, numerous volunteers, and parents that pull together each year to pull off county fairs! As I reflect, things that make my heart happy and make me smile are thinking about the number of wonderful people who help me in Ag Hall each year, the youth proudly wearing their medals around the fairgrounds on Thursday evening after the award’s ceremony in York Co., the crop plot for ag literacy in Seward Co., seeing the fairgrounds so busy in spite of the heat, watching people from across the counties reconnect, people pulling together in the midst of adversity, and the hard work that especially ag society puts into the fair behind the scenes to ensure that attendees enjoy the fairs. Thank you also to all of the sponsors! Grateful to all for making the York and Seward Co. fairs a success!
Produce not Ripening: Many have green tomatoes. My colleague, Scott Evans shared it’s due to the heat as temps over 90F prevent the plant from producing lycopene and carotene. You can bring mature green tomatoes indoors to ripen (sunlight isn’t needed) or you can wait for cooler weather for them to turn. How do you know if they are mature enough to bring indoors for ripening? Look for an off-green to a tinge of white on the shoulders of the fruit on the stem side on fruit that is the right size of for that variety. He said the same can be done for peppers that aren’t turning orange, red, or yellow. For cucumbers, fruit production declines with the heat but doesn’t impact maturity.
Spidermites: Just a reminder of this helpful article as the heat has really brought on spidermites in crops: https://go.unl.edu/9v6u. For those with gardens, spidermites are also impacting vegetable and flower plants. Symptoms include webbing and yellowish ‘stippling’ or tiny spotting on the leaves which eventually turn brown. You can take a white piece of paper and knock the leaves on it. If you see tiny insects the size of pinpoints moving, it’s most likely spidermites. Spraying plants with heavy streams of water ensuring each side of the leaf is hit helps knock them down. Proper watering (reducing drought stress) can help reduce spidermites. Those two things can drastically and naturally help with spidermites in garden settings. Insecticidal oils and some plant extract products can help. Just be sure to read the labels to ensure the product is safe for the plant you’re applying it to and never apply these products when temperatures are above 90F to avoid damage to the plant.
Irrigation: The heat is progressing plant and seed development in crops not replanted. Corn at dough needs 7.5” till maturity, 5” at beginning dent, 3.75” at ¼ milk, 2.25” at ½ milk, and 1” at ¾ milk. Soybean at beginning seed (R5) needs 6.5”, end of seed (R6) needs 3.5”, and 1.9” at leaves beginning to yellow.
Soybean Management Field Days are this week (Aug. 9-12)! Last year a team of us tried an approach of more discussion with attendees and this year we’re seeking to format more parts of the field days this way. Each location will be unique to the situations that area of the state is experiencing. Join us for discussions on insects, diseases, weed management, cover crop implementation, precision ag, economics, irrigation, and biodiesel. Closest locations are Blue Hill on Aug. 9 and Central City on Aug. 10. Hope to see many at one of the locations this week! More info. here: https://go.unl.edu/xukf.
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.
Fair: As fairs wrapped up in the area, in my opinion, it was a great way to cap off the summer for the youth. So much has been taken away from them and I really appreciate Ag Societies working hard with Extension staff to give the youth an opportunity to showcase their projects! There were several moments throughout fair where I thought “this is why we do this”…to watch youth and adults so excited to see the ribbons on projects, watching siblings and club members supporting each other, families helping other families, and friends catching up. Fair did look different this year. But it forced us to think about things differently with the blessing of some changes may be kept as a result! Thank you to all the Ag Society, 4-H Council members, Extension staff, newspaper staff, and volunteers who gave youth and adults alike the opportunity to showcase projects and safely gather at fairs! Thank you also to health departments for advising on directed health measures and providing PPE and nurses who helped with screenings!
Crop Updates: I didn’t get into the field much this past week but the primary questions I received were regarding tip back on corn, spidermites flaring, and if it was too late to spray fungicides in corn. The answer to the latter is no. If southern rust is showing up pretty good low-mid canopy of your field, it’s something to consider to help with stalk strength as that’s my concern. I’m hearing of some guys having to apply a second round of fungicide due to rust. Hard for me to see guys spending the money to do that thus prefer avoiding automatic tassel applications. While I’m not aware of research to prove it, I think coverage is another issue. Consider asking the aerial applicator to use 3 gallons/acre to increase coverage. I hear some are refusing to do more than 2 gallons/acre and I think that’s part of the problem. Some farmers are also chemigating fungicide and insecticide through the pivot in hopes of improving coverage.
Typically we’d say southern rust occurs on the top side of leaves unless severe, whereas common rust typically occurs on both sides of leaves. On leaves that were flipped over from the wind, I’m seeing southern rust spores (confirmed via microscope) on the undersides of leaves that are now technically facing upward, but not on the ‘normal’ top side of leaf (an interesting observation that a crop consultant asked me about and then I also saw this week to confirm it truly was southern).
Spidermites continue to flare 7-10 days later because most of the products used don’t kill eggs. Sometimes second applications are needed. Insecticides with activity against eggs and immature stages (not adults) include Zeal, Oberon, and Onager whereas the pyrethroid (Bifenthrin products like Brigade in corn and soybeans) and organophosphate products (like Lorsban used in soybean) can help with adults but not eggs. Product has to come in contact with the mites. Thus at least 3 gallons/acre are recommended with aerial applications. Entomologists share aerial applications early in the morning or late in the evening can be more effective to avoid hot rising air away from plants (be careful of inversions). With twospotted spider mite, perhaps all that can be accomplished is to slow the rate of population increase.
Tip back on corn occurs most often from some sort of stress. For this year having good pollination weather, some are surprised regarding how much tip back we’re seeing. It’s important to count kernels long as there may be more kernels than one realizes in spite of tip back occurring. You can tell approximate timing of stress events by the appearance of the kernels. If kernel formation isn’t evident, the stress occurred before or during pollination. If kernels are very small or appeared to have died, the stress was after pollination as the kernels were filling. Water stress is a major stress outside of temperature as to kernels not pollinating and/or aborting. Each ovule (and later, each kernel), competes for water and nutrients. Water and nutrients are necessary for pollen tube formation down silks to fertilize ovules. Water and nutrients are necessary to fill individual kernels with the tips being sacrificed for filling kernels at the base of the ear first.
CARES Act Tax Planning for Farmers: The CARES Act included the Payroll Protection Program (PPP) and Economic Injury Disaster Loans (EIDL), which many farmers utilized. However, several other provisions didn’t get as much attention. For tax planning this fall, check out this helpful info. from Tina Barrett: https://go.unl.edu/re6e.