Extension Update from Jenny Rees

June 6:  Winter Wheat Field Day-Washington Co., 6pm, RSVP Nathan Mueller (402) 727-2775
June 7:  Winter Wheat Field Day-Fairbury, 6:30 pm, RSVP Randy Pryor (402) 821-2151
June 12:  Generational Transition for Ranchers, Noon-5pm, Belvidere Community Bldg, RSVP erin.laborie@unl.edu or (308) 268-3105
June 13:  Summer Grazing Tour (Reynolds, Belvidere, Bruning), RSVP:  erin.laborie@unl.edu or (308) 268-3105
June 17:  Cow-Calf Management Field Day, 1pm, Cuming County,  Larry Howard, 402-372-6006
June 19:  Winter Wheat Field Day-UNL Research Farm North Platte, 3 p.m., RSVP Rodrigo Werle (308) 696-6712
June 20:  Field Pea, Forage, and Cover Crop Tour, Hastings-Webster Co, RSVP:sstepanovic2@unl.edu or (308) 352-4340
June 20:  Winter Wheat Field Day-Henry J. Stumpf Wheat Center Perkins Co, 9am, RSVP Rodrigo Werle (308) 696-6712
June 28:  South Central Ag Lab Weed Science and Cover Crop Field Day, SCAL near Clay Center, registration 8am, Weed Program 8:30-Noon, Free lunch, Cover Crop Program 1-3pm, Register:  http://agronomy.unl.edu/fieldday
July 10-11:  Youth Tractor Safety Class, 8am, Grand Island College Park (308) 385-5088.
July 18:  Crop Management Diagnostic Clinic:  Soil Health, ARDC (now ENREC) near Mead
Aug. 2:  Crop Management Diagnostic Clinic:  Precision Ag Training, ARDC (now ENREC) near Mead
Aug. 8:  Soybean Management Field Days, North Platte
Aug. 8-9:  Nebraska Grazing Conference, Kearney
Aug. 9:  Soybean Management Field Days, Ord
Aug. 9:  Nebraska Cover Crop Conference, during Lancaster Co. Fair at Fairgrounds
Aug. 10:  Soybean Management Field Days, Auburn
Aug. 11:  Soybean Management Field Days, Tekamah
Aug. 23:  Crop Management Diagnostic Clinic:  Soybean Production Training, ARDC (now ENREC) near Mead
Aug. 24:  Crop Management Diagnostic Clinic:  Corn Production Training, ARDC (now ENREC) near Mead

Farm Finance Clinic Sites and Dates To sign up for a clinic or to get more information, call Michelle at the Nebraska Farm Hotline at 1-800-464-0258.

Crop Update:  This week’s rains have been more beneficial to some and detrimental to others with flooding/ponding in some fields. For corn seeds that have germinated in flooded fields, seeds will survive for four days in general although genetic differences do exist regarding response to flooding.  Longer periods of flooding can result in lower yields due to reduced plant stands, reduced nitrogen, and potentially crusted soils following flooding.  Emerged corn seedlings right now that are underwater (6” of water on the surface) will survive for four days when the air temperature is less than 77F.  When temperatures are above this, survival greatly decreases to as little as 24 hours.  Plants that are partially underwater have a greater chance of survival longer than those completely underwater.  Plants buried by sediment and/or residue that washed as a result of flooding may not survive.      

Regarding soybeans, this is more difficult to know as minimal research is available.  Information from K-State suggests that during germination, flooding occurring for 48 hours can reduce germination 30-70% which results in twice the yield reduction compared to seeds in saturated soils for 24 hours.  For emerged plants (they specifically cite V2-V4 which is further along than we currently are), yield reductions of 0-50% were observed depending on soil texture, variety, and the weather after flooding occurred.  Yield reductions were attributed mostly to reduced branching with fewer pods per plant and disease issues. 

Wheat:  Wheat progressed rapidly last week from boot-flag leaf stage to headed and pollinating in many Clay/Nuckolls county fields.  Along with this wheat growth progress has been disease progress.  Stripe rust has rapidly developed in fields and I’m also seeing leaf rust.  Wheat that is at beginning flower to 50% flower only has a few options for fungicides right now.  Those are:  Caramba, Prosaro, Folicur, and Proline.  These are the only fungicides labeled for wheat in flowering; all other products are off-label.  These specific products can help prevent scab in addition to killing the fungal diseases (like rust) on the leaves right now.  Once your wheat is 50% flowering these products are also off-label and the weather isn’t looking helpful right now in applying these fungicides.  I’m also seeing some barley yellow dwarf and some loose smut in fields.  There’s nothing you can do for either disease right now.  You can see a wheat update with photos on my blog at http://jenreesources.com.

Horticulture Updates:  There are some social media posts going around regarding neonicotinoid insecticides in bedding plants.  Neonicotinoid insecticides can be applied to seeds as a seed treatment, to the soil as a drench, trunk injections, or foliar sprays.  They are then taken up by the plant and translocated throughout the plant including the flowers which can then affect pollinators.  The University of Minnesota has released an article about this at:  http://www.extension.umn.edu/garden/plant-nursery-health/toxicity-to-pollinators/.  The following is some information from that resource:  “There are few systemic insecticides, while there are many systemic herbicides and fungicides. Systemic, neonicotinoid insecticides are the most widely used insecticides in the world, due to their low mammalian toxicity and the ability of the insecticide to move systemically from soil into the entire plant, including pollen and nectar. Flowers that open after being sprayed with contact insecticides do not contain insecticide residue, while toxicity to pests lasts for 1-3 weeks. However, flowers that open after systemic insecticides are sprayed can contain the insecticide residue for many months in both the leaves and pollen and nectar.

There are six neonicotinoid active ingredients, imidacloprid, dinotefuran, thiamethoxam, and clothianidin, of which acetamiprid and thiacloprid are the least toxic to bees. There is another systemic insecticide, fipronil, that is used around structures that is also toxic to bees. You will find these active ingredients listed on the insecticide label in small print. The neonicotinyl class of insecticides is highly toxic to bees and kills bees at around 180 ppb in flower nectar or pollen. However, sublethal doses of neonicotinyl insecticide starting around 10 ppb, causes bees to lose navigation and foraging skills. The longevity and amount of the neonicotinoid in the pollen and nectar will depend on application method, concentration applied, and binding capacity of the soil.

The use of neonicotinyl insecticides as trunk injections and soil drenches for ash trees is important to slow the spread of the exotic, invasive Emerald Ash Borer and other invasive pests. As bees do not collect ash pollen in quantities, the risk to bee pollinators is low. In contrast, the use of neonicotinyl insecticides on flowering garden plants, shrubs and trees, including linden and basswood trees can kill bees and beneficial insects that utilize the flowers for pollen and nectar. It is wise to avoid using systemic neonicotinyl insecticides on flowering plants that bees visit regularly. Instead use spot treatments of contact insecticides.”  This is also the reason why we’re advising people to remove landscape plants away from the base of ash trees they wish to save in the future as soil drenches will allow the product to also systemically enter those landscape plants.  While a low risk to pollinators of ash trees, the risk to pollinators feeding on landscape plants below those trees is fairly high.  I’ve also mentioned this before, but we aren’t advising treatment for ash trees in this part of the State yet.  A list of different contact insecticide products can also be found on the above-mentioned article.

Garden centers can choose what insecticide products they use to control insects.  Some gardeners have been asking if there’s an easy way to know whether plants they wish to purchase have been treated with neonicotinoids. The best way is still to ask nursery professionals or look for special labels in plants that have been treated with neonicotinoids. Gardeners should also understand the toxicity level of insecticides they use in their landscapes and minimize pesticide use as much as possible through adoption of integrated pest management strategies to protect pollinators in their landscapes.  Integrated pest management is essentially using a variety of methods to control pests; these include plant resistance, cultural and mechanical practices, letting beneficial insects/pathogens increase, and use of chemicals.