For almost 10 years, we've seen the benefit of season-long crop nutrition

One of our farmer clients just phoned to order a new WakeUP supply along with some Vitazyme, adding the comment: "What convinced me to keep up a summer foliar nutrition program is based on what I'm seeing in our garden."

July 8, 2017 — He told us, "We've sprayed WakeUP alone — no traces, no NPK — every week. The garden looks great. We've not seen the insect pests that usually show up by July. And we haven't seen the fungal wilts that usually hit the squash leaves."

We asked if he had ever sprayed crops with foliar nutrients and WakeUP three or four times a season before. "No, I used it only once a season."

Once a season on corn and soybeans is a typical routine; often piggybacked with herbicide and WakeUP as the surfactant/carrier.  On our test farm, we've usually hit the garden at least once a week with WakeUP Summer and a payload of nutrients. Sometimes we just swing out the sprayer boom and spray the garden with whatever nutrient blend is left over when we're done spraying test plots. Not scientific, but the garden veggies really respond (especially the butternut squash, for some unknown reason).

But more growers are seeing profitable responses by testing for hidden hunger in crops, and foliar-spraying the elements needed through the growing season. That often includes zinc, manganese, boron, and some other traces along with potassium and nitrogen (an ammonium form).  The "Coke break" foliar recipe reported on our site a few days ago includes some phosphorus.

Shotgunning an array of trace elements without tissue or sap testing may generate a profitable response. But in several years of field tests without testing crop needs, we've seen micronutrient mixes earn a return over costs in only one trial out of three. That's not a fault of the micronutrient blend: It's a treatment without a prescription. One of our most astute growers grumbled,  "I've spent a lot of money on foliar traces and it usually comes out all the same, with or without." But he has never tissue tested. Never tested the corn or soybean sap for nutrient needs.

Keeping the crop healthy and growing with the aid of ongoing fertility during peak nutrient demands of the season. The chart nearby, from the smart-fertilizer.com website, shows how NPK nutrients rise through the growing season for corn. It's likely that demand for trace elements has a similar curve for each element. Since the crop will translocate nutrients out of older leaves to supply new growth, measuring the older leaves offers the earliest indication of an impending deficiency. In sap testing, paired samples of young and old leaves are compared for the most accurate signals of what to apply. Testing sap instead of tissue gives you extra two weeks of "alert" time before deficiencies bite into yields.

About a year ago, Purdue agronomist Tony Vyn recommended applying up to 25% of required N on corn after the V10 stage. Newer hybrids use more nitrogen later. A shortage of N late in the season could be contributing to early die-down.  

Preventing early die-down of corn, for example, almost certainly depends on full-season nutrition. Relying on fungicide or even excellent enzymatic products like Bio-Empruv may not help much without full season-long nutrition to provide the needed metabolic energy. Virtually all the national corn yield contest winners apply foliar nutrients through the growing season. Their mantra is almost, "If it's green, spray it."