Radish Plot

Oct 05 2011

Cover Crop Radish Research reveals interesting data and information

In the summer of 2010 I entered a number of “cover crop” radishes into research plots in Michigan and Minnesota. Some of the products I entered were given to me from a supplier in Oregon. They had collected seed samples from Europe that had been touted as cover crop worthy. They weren’t. Fortunately those varieties never hit the US market – that I am aware of.

I also entered two other radishes that actually performed very well. What we found is that not all cover crop radishes are created equal. While many of the top selling radishes grew the way you would hope, there were some that did not perform well at all.

Here’s what I mean: The “lesser performers” either bolted and went to seed production early, or they had very small tubers, or both.

Now in the summer of 2011 we have planted new plots in MI and MN along with some plots in my garden “agronomy plot” in Winona Lake, IN (NE IN). I planted my plots WAY too thick as it was very dry and I was hoping to get emergence. I watered two times after planting the plot and that helped quite a bit. Over the last week we received nearly 5 inches of rain, so I have a very thick, robust radish stand.

What I am seeing after 6+ weeks of growth is interesting. I purposely planted the “wild looking radish” (“VNS Daikon Radish” on the tag) that was sold out of North Dakota in the summer of 2010 so I could compare it to Oregon grown VNS Radish. I included two named products, GroundHog and SoilBuster (a mixture of two varieties) in the plot as well. On the GroundHog I entered seed from two different years 2009 and 2010 to check for consistency (GroundHog is actually a true single variety of radish).

DSCN4150 — VNS stand for "Variety Not Stated" and in some cases "Buyer Beware." The Oregon grown VNS Daikon Radish is a far superior radish for cover crops than the VNS Daikon Radish from North Dakota.

I have a few early observations on these 6+ week old radishes (planted August 19, photos taken Oct 6):

The GroundHog from both seed crop years look the same (green top on tuber, similar tuber type and size).
The Oregon grown “VNS Daikon Radish” is far better than the North Dakota grown “VNS Daikon Radish” (seed purchased from the Pulse Group).
The North Dakota grown “VNS Daikon Radish” looks like it did in 2010 – already bolting (it started bolting at 4 weeks) and very little root.
The Oregon Grown “VNS Daikon Radish” has shorter top growth than both GroundHog and SoilBuster.
The Oregon Grown “VNS Daikon Radish” has smaller tubers than both GroundHog and SoilBuster.
GroundHog had more top growth than SoilBuster.

My conclusion so far:

The two named radishes (that are actually varieties) seem to actually show more “value” (more top growth and larger tubers) than either of the VNS products. What does that mean to producers? That maybe the few extra dollars you pay per acre is actually money well spent.

DSCN4122 — Both named products showed larger tubers and more top growth than the Oregon Grown VNS Daikon Radishes.

DSCN4184 — The tag from the North Dakota VNS Radish. Notice the "ND" under origin in the upper right. Click on the image to make it larger.

Aug 04 2010

May planted Radish Plot final results 8/4/2010

RADISH PLOT 8-4-10 009 — GroundHog Radish consistently had the larger and deeper tuber of all varieties tested. This photo is from the ~5#.acre seeding rate plot.

RADISH PLOT 8-4-10 012 — This photo shows the GroundHog Radishes dug from the ~12-15#/acre rate plot. Note how much smaller the tubers are than the 5#/acre rate.

It’s been 10 1/2 weeks since I planted my Radish test plot in my garden. I have recorded photos and reports in previous posts and now this is the “FINAL JUDGMENT” of the different varieties that were included this spring. I’ll report mainly via photos and captions. Just a reminder, about 5 weeks ago I thinned out plots of each variety so I’d reflect 2 different seeding rates; ~5#/acre, and ~12-15#/acre. The goal was to see if seeding rates matter and also if we can use fewer radishes and still accomplish great results.

I’ll be planting another radish plot in a week or so to see how a mid-summer planting plots might differ. I’ll also add some of the other popular varieties/brands and two more experimental varieties folks are sending for us to test.

RADISH PLOT 8-4-10 005 — This variety had the single largest radish...but only the one radish was of any size. This was from the ~5#/acre plot.

RADISH PLOT 8-4-10 024 — This is from the ~12-15#/acre plot area. One of the radishes was of good size but the others were quite small when compared to GroundHog.

RADISH PLOT 8-4-10 007 — I don't know how to say I'm disappointed in a variety...but this one sure surprised me. At first I called it "stubby". Later I found it "intriguing" because it had such a long skinny tap root. Now I call it "disappointing". I was anticipating lots of long skinny roots 15" deep or so...and all I got was what you see above. This is from the ~5#/acre rate plot.

RADISH PLOT 8-4-10 015 — You can see big differences in these two varieties both shown at the ~5#/acre rate.

RADISH PLOT 8-4-10 003 — This variety was one that I pegged early as one I thought would be the "best" radish. Needless to say, I was wrong. This is from the ~5#/acre plot.

RADISH PLOT 8-4-10 023 — Columbia from the ~12-15#/acre plot.

Jul 15 2010

Cover Crop Radish – Rate Per Acre

Radish plot 7-10 028 — Two different cover crop radish varieties both had larger tubers in the area where I thinned the plants to 4" apart (shown).

In my cover crop radish plot I have thinned some rows to 4″ between plants and in two rows I have left them thick (I figure I’m at the 12-15#/acre range). After 6 weeks there are some pretty telling signs that 12-15#/acre is too thick and possibly a waste of money. Most of the varieties that have been thinned to 4″ have larger tubers than in the thicker plots. That is not always the case, but I think it’s safe to say that the heavier planted radishes do not have the larger of the tubers.

Radish plot 7-10 011 — Cover crop radish tubers planted at the 12-15#/acre rate after 6 weeks.

Radish plot 7-10 013 — Here is the same variety at 6 weeks when thinned to the approximately 5#/acre rate.

Jul 15 2010

Cover Crop Radish Plot from July 10, 2010

Radish plot 7-10 022 — Groundhog cover crop radish was consistently the largest tuber in the plot

My cover crop radish plot was planted on May 29, 2010 and now 6 weeks later we can see some characteristics even different from 2 weeks ago.

A variety that was 8-9″ deep 2 weeks ago still appears to have that same depth.

Another that I called “Stubby” is now looking quite interesting!

Yet another variety, Groundhog, is showing the best depth and girth so far…at least the biggest girth at 8-9″ deep.

One variety has a very long tap root but very little girth at all…in fact it looks like a small turnip with a 15″ tap root! I’ll leave the plot in for another few weeks but then rip it out and plant some late squash for the family.

Jun 30 2010

How deep can radish roots go?

GroundHog Radish at 6 weeks 001 — I imagine that the finer roots went deeper than 15"...and maybe much deeper from what I am learning!

After 6 weeks my GroundHog Radish is around 12″ deep and 1″ in circumference at the top. How deep can radish roots go? Because we need to know things like that I have been doing quite a bit of research. The attached chart shows how deep some radishes can go…over 4 feet deep! WOW!

Radish Root depth — Research done in the 1950's shows Early Scarlet Turnip White-tipped radish roots can go over 4' deep!

Jun 30 2010

Radish Plot Report from June 26

Radish plot 013 — This is is the variety I called "Stubby" in the previos post...it's very shallow rooted versus the other varieties in the test. Let's hope that this is not the variety that someone sells as "Big Bubba" Radishes for your cover crops!

Radish plot 006 — This variety was among the deepest rooted in the trial.

I planted a cover crop Radish plot over Memorial Day Weekend (5/29) in my garden plot. I have 5 varieties in the plot from around the world. My goal is to see what differences there are in the different Radishes being sold in the USA for cover crops. I replicated the plots so that each variety would be in 2 times with one variety as a check in each of the 4 rows. My children and I did some plot work on June 26, 4 weeks after I planted the plot. We thinned out on rep so that there is approximately 4″ between the radishes. The other two reps are thick…too thick actually, but I want to show what happens at an approximately 12#/acre rate (as some seed company folks recommend). When thinning the rep I measured the roots of each variety. BOY, what a difference I found! Two varieties have around 8- 9″ deep roots. two varieties have around 4-6″ deep roots, while one variety has 3″ deep roots. Now, when purchasing a VNS Radish you might get any of these…or all of them mixed together. I am also testing these varieties because companies want to sell these on the market as deep rooted cover crop radishes. They will be called “Big Bubba” Radishes or something like that, but buyer beware.

Jun 14 2010

Cover Crop Radishes – differences in varieties

On May 29th I planted 6 different cover crop radish varieties in a plot. In those 16 days we’ve had good moisture, and I did apply some 30-0-5 fertilizer around 60 days ago (with slow release N). I had to thin the plots to have 1 radish per 4″ (recommended distance between radishes by those who seem to know those things). I am doing this experiment for three different Oregon companies that sell cover crop radishes. I have this same experiment going on in Michigan, central Indiana, and NW Ohio.

The goal…to identify the “best” cover crop radish. I hope that by planting in spring and late summer, we will be able to choose the radish variety/selection that works best for cover cropping in the Midwest.

I brought 4 varieties up from the plots to show the differences after 16 days. 2 varieties have nice long tubers already. The other two have some catching up to do! I have a feeling that they never will. I’ll keep you posted!

Radish plot 016 — cover crop radish plot...16 days old (and needing weeded!).

Radish plot 017 — 4 different varieties of "cover crop radish." 1 on far left I'll call "Stubby;" 2 just to the left of the stick look promising so far; 1 just to right of the stick I'll call "Shorty;" and the far right selection also looks very promising. all 16 days after planting.