Corn and Soybean Late Season Nutrition with Fungicides

Posted on: Jul 17, 2019

With many spring crops varying in development stages throughout the Midwest, there is still time to consider a fungicide application.  Depending on a number of local scenarios, producers typically take one of two primary approaches to this decision: (1) A proactive approach to provide the crop disease protection and general plant health; or (2) Reactive due to the presence of certain diseases with the understanding yield might have already been negatively impacted.  For many regions, crops are trying to play “catch up” in this rapid growth phase, as the inherent time clock keeps telling them to progress forward each day.  If corn or soybeans were planted into tough conditions or with marginal fertility, applications of additional nutrients can provide solid returns.


Dr. Fred Below’s, University of Illinois, extensive research programs provide some worthy insights for several key nutrient demands, especially as corn and soybeans enter into the reproductive and grain fill stages.  Listed below are a few key takeaways from Dr. Below’s multi-year field research trends, plus some other general agronomic tidbits on Helena Products to keep in mind during this important part of the crop life cycle:

Corn

Nitrogen (N):

  • Approximately 40% of the total N needs will occur from tasseling through R5 (late dent)
  • Coron® 25-0-0-0.5B is a great product to provide additional N to meet this late season demand

Phosphorus (P):

  • V10 – 14 is “ramp up time” for nutrients with daily needs of 2 lb of phosphate for a 200 bushel crop
  • >50% of P uptake occurs after VT/R1 (season-long supply is dang critical!)
  • Ele-Max® Hi Phos LC (8-30-2) is an extremely effective way to provide ortho-phosphate that will immediately be used by the plant

Potassium (K):

  • About 12 pounds of K are needed daily in a 200 bushel corn crop
  • Soil K struggles to become available during wet or dry soil conditions
  • Ele-Max K-Leaf 0-0-30 is an excellent foliar product to supply K to the actively growing plant

Sulfur (S):

  • >50% of S uptake occurs after VT/R1 (season-long supply is critical)
  • Consider Ele-Max Sulfur LC

Boron (B) and Zinc (Zn):

  • 71% of soil Zn and 65% of soil B uptake occurs in late vegetative and reproductive growth
  • By R6, 60% of stalk Zn gets directed to help fill kernels; and leaf B is moved to help with the reproductive processes
  • Axilo® BMZ makes a great selection for providing foliar B, Zn and Mn (manganese)

Soybeans

(Products listed in the corn discussion above are equally effective in soybeans)

Nitrogen (N):

  • Soybeans generally need some supplemental N added to R2-3 soybeans, especially if they have the potential to yield more than 60 bushels per acre

Potassium (K):

  • The soybean plant takes up 3.5 lbs. of K20 per day over a 50-day period beginning at pod set (R3), and banks K in stems and petioles so it’s readily available to fill pods

Phosphorus (P):

  • Phosphorus uptake continues over a 70-day period beginning at pod set
  • The plant doesn’t store available P in the stem, and the majority of its supply must come directly from the soil and foliar
  • 80% is removed with the grain with very little remaining in the stover
  • Maintain proper P/Zn ratios during pod fill – Foliar P with Zn has provided a strong relationship to yield and ROI

- Sam Bartee & Ben Wilson, Helena AGRIntelligence Agronomists