Renewable Farming

One foliar spray with Mainstay Si and WakeUP Summer raised sweetcorn brix 5%

Rivers of rainstorms drowned out my second and final foliar spray application in a simple experiment on sweetcorn in late August. But with only one foliar application of Mainstay Si, the data showed a “signal” of silicon at work. That’s what John Kelly of Redox advised in an August 20 seminar

September 9, 2018 by Jerry Carlson — Bottom line first: Just one foliar spray of the silicon-carrying product Mainstay Si on sweetcorn at the six-leaf stage led to:

— a 17% increase in leaf thickness

— a 5% uptick in brix level.

After I finished the 24 brix measurements, I taste-tested the results by eating more of the sweet corn ears than I should have.

Researchers have published many scientific papers on the benefits of silicon in plants. The challenge has always been: How do you encourage a crop to metabolize this element? It never translocates into plants alone. The scientists at Redox found a way to react silicon dioxide with calcium. When foliar applied, this blend enhances the health and structural integrity of fruits and vegetables. Redox has marketed this product for years to produce growers in California and Florida. Now they’re eying the big-acreage markets here in the Midwest.

Our little experiment had intended to foliar-feed Mainstay Si on 12 rows of a 24-row sweetcorn patch, then come back a week later and overspray six rows again. We’d intended to measure the brix of sweetcorn, and thickness of leaves, on each of these three variations:  Control, single treatment and double treatment. Owner of the research field, Steve Schmidt, sprayed the first 12 rows on time at about the six-leaf stage. My intended job was to make the second pass by spraying just six rows by hand with a wand sprayer and our Honda 350, which carries a 25-gallon tank and a 12-volt sprayer. 

As is the way of farming, weather forced us to settle for half — just one spray of Mainstay Si. However, that single application created a 17% difference in leaf thickness. The data table, based on 12 random readings each of treated and untreated leaves, is at the bottom of this report.

A thicker leaf allows room for longer palisade cells and more chloroplasts. The chloroplasts are little metabolic engines which convert sunlight energy to sugars and other plant nutrients with photosynthesis.

Measurement of the electronic caliper is in millimeters. When the reading on the LCD screen is 0.44, that means 44 one-hundredths of a millimeter.

Evaluating the brix level of sweetcorn with a refractometer is a bit of a judgment call, because there are many compounds other than sugar in the milky sap of sweetcorn kernels (see nearby photo). Thus the horizon line you see when looking into the refractometer is shaded, not sharp.  To be consistent, I split the difference by scoring against the line at the halfway point of shading from white to blue. 

A five-percent gain in brix level doesn’t sound like much, especially when sweetcorn is already fairly decent at 20 to 24 brix. We’d like to see it in the 25 to 30 range, but this was an older variety and not our favorites — Honey N’ Pearl and Illini Xtra-Sweet. We used to buy those from Illinois Foundation Seeds. 

Notably, the raccoons also had a challenge differentiating between corn in the 20.75 brix rows and that in the 21.75 brix rows. It looked like they ravaged all rows about equally, although I didn’t take the time to quantify their destruction. 

This little field experiment is a bit more evidence that Mainstay Si does what the Redox folks say it does. I’d like to see Mainstay Si used widely with WakeUP to mobilize it into metabolism. It can also be tank-mixed with biostimulants such as Vitazyme.

Update Sept. 10: I checked this article with John Kelly, who has worked with Redox for 23 years. Kelly’s e-mailed response:  “Outstanding information. Thanks for sharing. Our focus in sweet corn has been on yield, and we have not evaluated for Brix. Pacific Northwest sweet corn goes to processing and of course is all irrigated. Eight or nine tons is the norm, but we’re pleased that growers on our Redox programs are achieving closer to 13 tons.”

Iowa crop consultant Bob Streit also sent a note: “Last year Jim Porterfield at Arise Research in Illinois measured a 32% increase in Brix within 46 hours [after spraying Mainstay Si]. That was in late planted field corn.”

Porterfield is a research agronomist who has also conducted studies for us. Bob’s observation raises an intriguing question: If Mainstay Si triggers an increase in sugar production (which would also increase total yield), what is the timing and “endurance” of that response? Our measurement of brix in sweetcorn came a month after spraying. Possibly, the “curve” of raised brix peaked early and gradually stabilized at a lower level. It would be a fairly easy study to perform on both leaves and fruit or kernels.  Porterfield’s research for us in 2012 found that young (V4) field corn roots showed a 71% increase in brix level over the control when measured 45 hours after a foliar spray with WakeUP and Sea-90, a mineral mix from seawater. After eight days, Jim took the same measurements and found that treated root brix levels had faded somewhat, to 60% higher than the control.

It would be useful to have the “response curve” — over time — of such foliar treatments, to make it possible to enhance effectiveness. In sweetcorn for example, a grower might be able to spray a product combination that would trigger a surge of extra sugars and other flavorful minerals in the corn kernels — at the perfect moment to maximize the taste of fresh sweetcorn.



Raw data on field observations is in this nearby table: