Alfalfa

Alfalfa Weevil is in the County

For those of you who have Alfalfa in the county, be on the lookout for Alfalfa weevil. These are pictures shared with me last week.  A few weeks ago in the CORN Newsletter information was shared about scouting for this pest.

Alfalfa fields should be scouted weekly for weevils until at least the first harvest.  Follow-up scouting may be needed after the first harvest in heavily infested fields.

Spot problem fields early by checking alfalfa tips for feeding damage – small holes and a tattered appearance.  Fields that have a south-facing slope tend to warm up sooner and need to be checked for weevil earlier.

Green alfalfa weevil larvae (the main feeding stage) at various growth stages, and brown adults. Photo by Julie Peterson, University of Nebraska.

Here is a video about scouting weevils in alfalfa:  https://forages.osu.edu/video Continue reading Alfalfa Weevil is in the County →

Timely Frost Seeding Improves Pasture, Hay Stands!

Chris Penrose, Extension Educator, OSU Extension, Morgan County

If and when the seed can reach the soil in late winter while there is still freezing and thawing activity, clover can fill in bare spots and add to the density of the pasture stand.

In the past, as we’ve talked about the virtues of frost seeding, we’ve suggested it’s something that is best to occur in February or March during the period when the ground is freezing and thawing almost daily. In recent years freezing and thawing temperatures haven’t always happened after mid-February. Since it’s the freezing and thawing over time that gives frost seeding a great chance to work, the time for frost seeding may be upon us soon.

Frost seeding is a very low-cost, higher-risk way to establish new forages in existing fields by spreading seed over the field and letting the freezing and thawing action of the soil allow the seed to make “seed to soil” contact allowing it to successfully germinate. When you see soils “honeycombed” in the morning from a hard frost, or heaved up from a frost, seed that was spread on that soil has a great chance to make seed to soil contact when the soil thaws. I think the two biggest reasons why frost seeding fails is people wait too late to frost seed and the seed never makes good contact with the soil. I have heard some say that they like to “overseed” or just spread seed over an established stand. Let’s face it, if the seed does not land on the soil but on existing living or dead vegetation, it does not have a chance to successfully germinate: you need exposed soil. In light of the recent snow that’s arrived and/or expected throughout Ohio, it’s important to also note that frost seeding can be done over a thin layer of snow, however, it’s important to realize that rapid snowmelt can cause the seed to be washed away from where it’s needed. Continue reading Timely Frost Seeding Improves Pasture, Hay Stands! →

Don’t get Burned by Hopperburn—Check Alfalfa for Potato Leafhoppers

By:  Andy Michel, Mark Sulc, Curtis Young, CCA, Kelley Tillmon

alfalfa leaf hoppers on dimePotato leafhopper (PLH) adults arrived in Ohio during the last week of June and the first week of July. Since then, the eggs have hatched and we are now seeing late-stage nymphs and adults infesting alfalfa fields.  A few fields are showing the typical “hopper burn”, which is a triangular yellowing from the center of the leaf to the leaf margin. The more mature the crop of alfalfa is since the last cutting, the more the hopper burn symptoms will be showing. Hopper burn will also become more pronounced in areas of the state that are short on rain or are predicted to become drier because the alfalfa will not be able to outgrow the feeding activity of PLH.  Scouting now and making appropriate management decisions based on the scouting can help avoid serious damage to the crop. Continue reading Don’t get Burned by Hopperburn—Check Alfalfa for Potato Leafhoppers →

Alfalfa Weevil Infestations Becoming Severe in Some Fields

GDD

Figure 1: Accumulated growing degree days (base 48°F sine calculation method) for January 1- May 2, 2021, at several CFAES Ag Weather System (https://www.oardc.ohio-state.edu/weather1/) locations and additional NOAA stations around Ohio (data courtesy of the Midwestern Regional Climate Center (https://mrcc.illinois.edu).

By Mark Sulc, Aaron Wilson, Kelley Tilmon, Greg LaBarge, CPAg/CCA, Curtis Young, CCA, Andy Michel, Beth Scheckelhoff

Alfalfa fields across Ohio have been observed with alfalfa weevil infestations, some with high numbers and severe feeding damage to the alfalfa.

Accumulation of heat units (growing degree days or GDDs) for alfalfa weevil growth have progressed across Ohio and are now in the 325 to 575 heat unit range indicative of peak larval feeding activity (Figure 1). We are about 2 weeks ahead of GDD weevil accumulation last year.

From the road, severe weevil feeding can look very much like frost injury (Figure 2). Do not be fooled, get out and scout! We have observed very minor frost injury to alfalfa from last week’s cold nights, so if you see “frost injury” in alfalfa, it is more likely to be severe alfalfa weevil feeding damage.  For more information on scouting and signs of damage, see the April 20 article in this newsletter: (https://agcrops.osu.edu/newsletter/corn-newsletter/10-2021/alfalfa-weevil-%E2%80%93-it%E2%80%99s-closer-you-think). Continue reading Alfalfa Weevil Infestations Becoming Severe in Some Fields →

Late Season Forage Harvest Management

Alfalfa Harvest

The best time to take the last harvest of alfalfa and other legumes is sometime in early September in Ohio, for the least risk to the long-term health of the stand. These forages need a fall period of rest to replenish carbohydrate and protein reserves in the taproots that are used for winter survival and regrowth next spring.

 

Many forage producers around the state have been cutting this past week and are continuing into this week. It will be ideal if this is indeed the last harvest of the season. But some growers might try to squeeze out another late cutting, and others have fields that are not quite ready for harvest right now. Like most farming decisions, there are trade-offs and risk factors to consider when making a fall harvest of forage legumes after the first week of September. This article reviews the best management practices and risk factors affecting fall cutting management. Continue reading Late Season Forage Harvest Management →

Late Summer Establishment of Perennial Forages

Preparing a firm seedbed for foragesBy Mark Sulc

The month of August provides the second window of opportunity for establishing perennial forage stands this year. The primary risk with late summer forage seedings is having sufficient moisture for seed germination and plant establishment, which is a significant risk this summer given the low soil moisture status across many areas.

The decision to plant or not will have to be made for each individual field, considering soil moisture and the rain forecast. Rainfall/soil moisture in the few weeks immediately after seeding is the primary factor affecting successful establishment.

No-till seeding in August is an excellent choice to conserve soil moisture for good germination. Make sure that the field surface is relatively level and smooth if you plan to no-till seed because you will have to live with any field roughness for several years of harvesting operations.

Sclerotinia crown and stem rot is a concern with no-till seedings of alfalfa in late summer and especially where clover has been present in the past. This pathogen causes white mold on alfalfa seedlings and infects plants during cooler rainy spells in late October and November. Early August plantings dramatically improve the alfalfa’s ability to resist the infection. Late August seedlings are very susceptible to this disease, with mid-August plantings being intermediate. Continue reading Late Summer Establishment of Perennial Forages →

Scout Alfalfa NOW For Potato Leafhopper

Management of potato leafhopper was needed weeks before this hopper burn.

Management of potato leafhopper was needed weeks before this hopper burn.

By Christian Krupke and John Obermeyer, Purdue University

Potato leafhopper populations were noticeably higher after last week’s tropical storm remnants blew through, and now the warmer temperature will drive further increases. Potato leafhoppers won’t mind this heat, and alfalfa pest managers should begin sampling their alfalfa shortly after cutting. Continue reading Scout Alfalfa NOW For Potato Leafhopper →