What did we learn in 2015: growth regulators and mid-season N applications on wheat yield, lodging and protein J Ransom, G Mehring, B Hansen, M Ostlie, E Eriksmoen

Background – growth regulators Lodging can be a significant constraint especially in years of high yield potential One class of growth regulators are chemicals that are used to reduce plant height Europe and other locations with very high yields have long used growth regulators to reduce lodging Little data available on currently registered products

Methods Experiments were conducted in five locations (will report on four locations only) Treatments consisted of a factorial combination of variety, and rate and timing of Palisade™ (Syngenta) –Varieties: Faller, Forefront, Carpio and Joppa –Timing: Feekes 5 (just starting to joint) and Feekes 7 (appearance of flag leaf) –Rates: 5 and 7 oz/a (these were half rates so only the 7 oz/a will be used to give an overview of the potential of this product)

Effect of Palisade rate and timing on plant height, averaged over locations and varieties.

Effect of Palisade rate and timing on lodging, averaged over locations and varieties.

Effect of Palisade rate and timing on plant height, averaged over locations.

Effect of Palisade rate and timing on yield, averaged over locations.

Recent experience in Chile Apply growth regulators twice: Cycocel at beginning of jointing Palisade at appearance of flag leaf

Impact of rate and timing of Palisade on lodging and plant height, MN (adapted from Wiersma et al., 2011) Rate (oz per acre)Jointing (Feekes 5) Two visible nodes (Feekes 7) Flag leaf visible (Feekes 8) 01.6a2.3c a2.1bc1.3abc 111.7a1.2ab 141.7a1.9bc1.5abc Rate (oz per acre)Plant height (cm)Growth stagePlant height (cm) 091aFeekes 587a 7.289abFeekes 786ab 1187abFeekes 884b 1485c

What did we learn? Don’t use a half rate! Later timing more effective in shortening Varieties will likely differ in their responsiveness May help but not a total solution – keep selecting varieties with good standability

Managing for protein and yield Finding the right balance between protein and yield can be difficult Cultivar selection can result in difference of >1%. –Negative relationship between protein and yield is fairly tight Environment can be critical –Dry years, low yield due to stress usually results in high protein –Wet years higher yield potential and more potential for nitrogen loss –Developing a strategy for fertilization that results in high yield and acceptable protein is needed in order to optimize returns to fertilizer N

Relationship between yield and protein – Northern MN 2014

Methods Field experiments were conducted at several locations Treatments included: –Additional N applied at different growth stages UAN at 4 lf and post anthesis Urea at boot Post anthesis application with a solution of urea ammonium nitrate at the rate of 30 lbs per acre (10 gallons per acre) plus an equal part water using flat fan nozzles Predictive models included weather data and the use of Greenseeker™

Can yield be predicted early enough in the season to inform late N applications Weather data –Days to reach 4 lf stage –Days to reach flowering Sensor data –Greenseeker –SPAD –Color Charts Tissue sampling

Did it pay? Comparison of returns –Protein from to 14.5 –Cost per acre $33.35 (application and material $24.71 plus lost of wheat to wheel tracks) –Premium/discount $.05 per fifth ($.25 per %) protein (71.1 bu/a x $4.55=$323.51) protein (71.1 bu/a x $4.80=$341.28) –Net benefit of $17.77 per acre

Drones N rich strips Precision applications of N

Conclusions Rescue N treatments were effective in increasing protein depending on the timing, yield. Foliar UAN was most effective in improving protein NDVI values just prior to heading hold promise in predicting yield in time for a late N rescue treatment Profitability of additional N will depend on the protein market