Extension Update from Jenny Rees

Jenny’s REESources-August 28, 2016

UPCOMING EVENTS: 

Aug. 26-Sept. 5: Nebraska State Fair, Nebraska State Fairgrounds, Fonner Park, Grand Island, NE
Sept. 13-15: Husker Harvest Days, Husker Road, Alda, NE
Sept. 28: Sustainable Ag Research Education Field Day on Corn Stalk Grazing, US MARC near Clay Center
Nov. 14: Ag Land Lease Workshop and Flexible Cash Lease Workshop, 4-H Building, York
Dec. 1: Solar Power in Ag Workshop, 4-H Building, York

Bacterial Disease of Corn:  USDA released a statement a few days ago which stated, “Some states have observed disease symptoms in corn that are caused by the bacterium Xanthomonas vasicola pv. vasculorum (Xvv). This plant disease presents no health risks to people or animals, and there is no evidence of adverse impact on corn yield or quality from this plant disease.
USDA does not consider this plant disease to be of quarantine significance for domestic or international trade, and intends to address it like any other bacterial disease of corn. Corn for consumption poses a negligible risk of establishment of the disease in plants, and unprocessed corn to be fed whole to animals poses a low risk of establishment of the disease in plants. Processed corn products will not transmit the disease to plants.  Growers, working with their state departments of agriculture and Extension, have safeguards, best management practices, and other tools to reduce risk of establishment of the disease in plants.”  Please also see the article in this week’s CropWatch at http://cropwatch.unl.edu for additional details and photos. 

Pivot Pressure Regulator Testing at Husker Harvest Days:  Nebraska Extension is offering free testing of center pivot irrigation pressure regulators at the IANR building all three days of Husker Harvest Days September 13-15 in Grand Island.  Irrigators are encouraged to bring two regulators per pivot span for testing. They can be dropped off at the IANR building in the morning and picked up, along with a report, later in the day.  Regulators typically work correctly for many years, but should be inspected regularly for damage or malfunction.  Regulators have a flexible membrane that may rupture over time and lead to water spraying out the sides of the regulator.  Spring tension also wears down over time. If the spring becomes weak, it decreases the pressure of the water going through the regulator and increases the flow rate. Irrigators may see the irrigation system pressure decrease and the gallons per minute increase on a flow meter. These issues may indicate failed regulators. For more information on pressure regulators see this NebGuide:  http://go.unl.edu/nmcm.

Fertilizing Lawns:  Fall is still the most important time to fertilize cool-season turfgrass. Fall fertilization helps promote recovery, builds roots, and increases sugar reserves going into winter. Here are the current recommendations for fertilizer applications.

Newly seeded areas: Starter fertilizer with higher levels of P2O5 should be applied at or slightly after seeding. A second application of starter fertilizer should then be applied 4 weeks after emergence or mid-October (whichever occurs first). Newly seeded golf or sports turf can also benefit from frequent applications of soluble nitrogen (urea or ammonium sulfate) every 10 to 14 days to accelerate establishment.

Newer turf areas (<10 years old>: New stands of turf require more fertilizer than older turf areas. Additionally, turf areas that are thin or were damaged by a pest will also benefit from additional fall N to accelerate recovery prior to winter. For these sites apply a balanced (50% soluble and 50% slow-release) nitrogen fertilizer in late-August to early-September. Then make a follow-up application of a quick release fertilizer in mid-October. Again, aim to apply 0.5 to 1.0 lbs N per 1000 ft2 or buy a fertilizer with your spreader setting on the bag.

Established turf (10+ years old): One application of a balanced released nitrogen source in mid-September. Look for a fertilizer product with 30 to 50% of the total nitrogen as quick release/soluble nitrogen. This will provide even release during the fall. Aim to apply 0.5 to 1.0 lbs N per 1000 ft2. If unable to calibrate your spreader, then buy a fertilizer with spreader settings for your particular fertilizer spreader on the bag.

Tomato Ripening:  I’ve received several calls about tomatoes this year.  Optimum temperatures for ripening of mature green tomatoes is 68-77 degrees F. The further temperatures vary from optimum, whether hot or cold, the slower the ripening process will be. Tomatoes do not produce lycopene and carotene, the pigments responsible for ripe tomato color, when temperatures are above 85 degrees F. So extended periods of extreme heat cause tomatoes to stop ripening. Tomatoes during this time may appear yellowish-green to yellowish-orange.

Yellow shoulders is a related problem and seen as areas at the top of tomatoes that never ripen properly. These areas stay green or yellow as the fruit ripens, having a firm texture and poor flavor when the tomato is eaten. Heat, environmental stress and variety susceptibility are all factors in the development of yellow shoulders. As mentioned above, high temperatures within the tomato prevent the development of lycopene and carotene needed for proper ripening. Areas of the tomato exposed to direct sunlight, like the top shoulders, get hottest and are most prone to the disorder.  Keep plants well-watered during hot periods and maintain adequate fertility when plants are fully loaded with fruits. Once temperatures cool, the ripening process should get back on track. Alternately, gardeners can harvest tomatoes at the pink stage and allow ripening to finish indoors. Development of yellow shoulders can sometimes be avoided if fruits are brought indoors to complete ripening away from high heat and other stresses.