Perhaps it was the hard winter, but I’m finding the flowering trees to be exceptionally pretty this year! Corn and even some soybean went into the ground this past week too. In last week’s column I shared regarding planting considerations yet would still encourage growers to keep considering your local field conditions before planting. You’re hearing some of these same things from both Extension and Industry partners and we realize field situations differ. We keep repeating these things to provide reassurance when you’re questioning decisions. We’ve already seen problems with anhydrous application in too wet of conditions in some fields. We’ve already seen some situations that were too wet when corn was planted leading to problems with compaction, depth issues, and not closing seed vee’s. With the cold snap, it’s important to consider soil temperatures (preferably around 50F or warmer for next 48 hours), soil moisture conditions, air temperatures for the next 48 hours, potential for cold rain, and cold tolerance of seed. Soil temperatures are listed at http://go.unl.edu/soiltemp and I would also encourage you to check your own particular field conditions. Last week, I was finding soil temperatures in local field conditions to be cooler than what was being reported from high plains regional climate center. If you don’t have a soil temperature thermometer, you can do this with a meat thermometer (and just dedicate it for field use).
I can appreciate the added concern and stress with this week’s forecast. There’s several planting-related articles in this week’s CropWatch at http://cropwatch.unl.edu. Two really helpful articles from Roger Elmore share on corn planting windows where he used USDA NASS data to show Nebraska data and also shared how other states throughout the Corn Belt have found similar results regarding planting windows. The key point is there’s a planting window between mid-April to mid-May within which optimum yields are usually obtained. After this period, yields decrease rapidly. So there’s still time and the planting conditions play a role in determining final yield by getting that seed off to a good start. You also keep hearing me talk about planting soybean early. Even as early as you can in May is better than mid to late May for higher yields if that works for your situation.
Browning Evergreen Trees and Shrubs: This past winter was hard on many things. When it comes to evergreen trees, the deep frost line and extreme cold led to the inability for transpiring trees to uptake moisture. This resulted in needles appearing brown and looking dead, particularly on the north and sometimes west sides of trees. I’m seeing this particularly on junipers, cedars, arborvitae, white pines, and some spruce. We’d recommend waiting till June before pruning any dead portions out or removing any trees/shrubs to see what happens with new growth.
Rhizosphaera Needle Cast in Spruce has been really bad the past few years. If you’re seeing spruce needles on lower parts of the tree turning yellow/reddish-purple/brown, then this disease may be the problem. The fungus continues moving upward on the tree. Affected needles are prematurely cast from the tree. Above average moisture during the growing season in parts of the State led to an increasing number of spruces affected by the Rhizosphaera fungus. What’s interesting is that the fungus infects the needles in spring but the symptoms often don’t appear till the following spring. One way to double check is to look for tiny black specks on the needles and on the twigs. The good news is that fungicide applications of chlorothalonil (Fungonil, Daconil, Bravo) or Bordeaux mixture in May can help when shoots are ½ to 2” in length! If we get frequent rains this growing season, applications can be repeated every 3-4 weeks.
Vegetable Planting Guide: Gary Zoubek had put together an excellent vegetable planting guide for the area which can be obtained at the Extension Office or at: https://go.unl.edu/d7qk.
Spring Lawn Seedings: With the difficulty of this past year, many didn’t get dormant seedings on because of all the snow and typically lawn renovation in the spring is difficult because of the inability for applying crabgrass preventer to newly seeded areas. However, a new product has changed this! Scott’s Turf Builder Starter Food for New Grass contains mesotrione which provides PRE and POST control of weeds without affecting the new bluegrass or fescue seeding. We’d still recommending seeding as soon as possible or else wait till August. Tenacity is also a product containing mesotrione that works as a POST for emerged crabgrass, foxtail, and for those dealing with nimblewill (best to apply on troublesome grassy weeds up to 1” tall).
Rhubarb and Frost: For those impacted by frost/freeze this past weekend, if rhubarb leaves are not damaged too much and the stalks remain firm, it is still safe to eat. If the leaves are severely damaged or the stalks become soft or mushy, do not eat these stalks. Remove and discard them. New stalks can be harvested and eaten. Rhubarb often develops seedheads following cold temperatures, but this also does not affect eating quality of the stalks. Remove rhubarb seedheads and discard.
Grateful for beautiful weather and harvest progressing again! We got the York County Corn Grower Plot out on Friday and special thank you to Ron and Brad Makovicka for their work and dedication to that effort! I will share the official plot results next week. The York County Corn Grower Banquet will be held on Thursday, November 15 at Chances ‘R in York with social time at 6:30 p.m. and meal at 7:00 p.m. Tickets are only $10 per person for a wonderful meal! Tickets can be obtained from any of the local directors or from the York County Extension Office at (402) 362-5508.Nate Blum from Nebraska LEAD Class 36 will give a presentation on his international tour and there will also be updates from Local, State, and National Corn Directors. For those who estimated yields during the plot tour, you need to be present in order to win the Yeti cooler.
Corn Yields: There’s an interesting article in this week’s CropWatch at http://cropwatch.unl.edu regarding final yield forecasts. Interesting to me are the box plots showing the range of ’30 year average’ vegetative and reproductive stages vs. 2018. The high heat in June shortened the vegetative time-frame. However, the silking through grain fill period was relatively typical for most locations and the long grain fill period with lower temperatures allowed for the better yields we’re experiencing (where drought and late-season hail wasn’t a factor).
Soybean Harvest Losses: Four soybeans in one square foot equals 1 bu/ac harvest loss. Various publications show how to determine harvest losses in areas of 10 to 25 sq. feet. For those with the SoyCorn Pocket Field Guide, page 78 shows estimating loss based on combine header width: http://nebraskasoybeans.org/wp-content/uploads/2017/02/SoyCorn-Field-Guide.pdf.
Evergreen Trees: Some evergreen needles are also changing color right now. It is good to look at your trees to determine the cause of the needle color changes. Evergreen trees actually go through a natural needle drop process with some years resulting in more thinning than others. I think this year may be one of those years as stress events can make needle drop heavier. Needle drop appears as needles turning yellow and falling from the tree. Pine trees may keep their needles for 2-3 or more years while spruce keep theirs for 5-7 years before needle drop occurs. Natural needle drop tends to appear along the main trunk and inside needles of the tree.
I also check for the presence of fungal disease. If the pine tree needles have dark spots/bands on them, it may be a fungal disease like dothistroma needle blight (on Ponderosa and Austrian pines) or brown spot (on scotch pines). The fungi actually kill the needles both directions from the location of the infection. With our heavy rains and high periods of humidity, I’m seeing increased fungal disease in evergreen trees this year. Fungicides applied in mid-May and again in mid to late June can help prevent this.
Pine wilt disease occurs in Scotch and Austrian pines. It’s caused by a bark beetle that has nematodes in its gut. The nematodes are native to Nebraska but Scotch and Austrian pines are not. Ponderosa pines aren’t affected because they’re native to Nebraska. The beetle ‘vomits’ the nematodes into the xylem (water-carrying vessels of the tree). The tree senses the presence of the nematodes and shuts down water to various branches as a way to prevent the nematodes from attacking. Thus why one sees a major branch then side of a tree turning gray-green then yellow-brown. Unfortunately, the entire tree will die typically within 3-9 months. Some farmers have tried trunk injections and drenches around their trees in hopes of saving them, to no avail.
On spruce trees, I’m seeing yellow/purple/browning of needles. This often is due to a fungal disease called rhizosphaera needle cast. One way to determine if this is the culprit is to look for tiny black dots on the gray twigs next to affected needles. The black dots are actually fungal structures that allow for infection to occur. Fungicide applied in May and after heavy rains can help. I always intend to spray my spruce tree each May but have failed to get it done the past several years. With recent rains, I’m trying it this fall to see if it can help; will let you know!
There have been several calls about arborvitae rapidly turning brown and I’m seeing evidence of heavy spidermite pressure at one time. Spruce spidermites affect spruce, juniper, arborvitae, etc. The rains and snow washed them off, which is one way to manage them. Evidence can be stippling (tiny yellow-green dots on needles) and also using a magnifying glass, one may see some webbing on undersides of needles. One can also just bang the needles on a white piece of paper to see if any mites are still active. Mites are most active in the cooler times of the season…so August through October in this case. Great resources for additional information include: Diseases of Evergreen Trees and Insect Pests of Evergreen Trees which can be obtained here: https://nfs.unl.edu/publications.