Saturday, September 26, 2009

Beware The Leaf Clot

The top picture is a bur oak leaf clot looking down a tube. You cannot see the shoot and that is bad.

The second is a side view of an Autumn Blaze Maple leaf clot.

Leaf clots are bad. They prevent gas exchange and can trap the shoot. Always prune to a single stem.

Temped to jam the foliage in the tube?

Don't own a pruner?

Don't have time to prune?

Here's more detail.

Have to admit I love the next picture - and not just because the growth and form benefits of Plantra Vented Tree Tubes are so obvious. The other reason is that there are so many lessons from these two trees.

At the bottom you can see the "leaf clot" I want to talk about. The a shoot escaped the clot and screamed to the top of the emerged and formed a new area of dense foliage.

Standard Plantra recommendations are to cut back to a single stem before installing the tube. There are three reasons for this recommendation.

Structure: First is that we want to produce a straight single stem. If you want the tree to live a long productive life, you have to get a sound structure and that means a single straight trunk.

Root System Energy: The most important thing you purchase in a seedling is the carbohydrate stored in the root system. It matters how this energy is used. If there are three shoots the energy is divided between the three and you get three short stems producing leaves that compete for light and CO2. We want one shoot to command that energy. The key to the Plantra Growth Engine is to rapidly fill the tube to the top with an array of spaced out leaves that do not overlap. We want leaves fully expanded and intercepting light through the wall with the stoma on the underside wide open and absorbing CO2 from the humid-CO2 rich air the vents move past the stoma on backside of the leaf.

Leaf Clots: A tangle of leaves can trap the shoots. In the confined space of a tube bunched leaves can form an impenetrable blockage.

Please PRUNE Preventively

Tuesday, September 22, 2009

This Bud Is For You - If You Want A Straight Tree

On 23 June 2009 this Autumn Blaze Maple was tubed with a 4 foot tall Plantra Vented O-Style Tree Tube.

As you can see in 11 weeks there was a tremendous difference in growth.

The untubed maples are shrubby and about 17-20 inches tall and the tubed maple is 5-1/2 FEET tall with a gun barrel straight stem.

Given the fact that all 1,000 maples in this picture are under two feet and the Plantra maple is well over 5 feet, I think it is safe to say the Plantra Tree Tube made a difference. I would go so far as to claim statistical significance. If the difference is great enough - all you need is one!

Quite a difference - an important difference, but not what I want to call to your attention.

My purpose is to explain some of the hidden mysteries of plant growth in a well designed tube.

The next image is a close-up of the leaves and buds that formed just at the point the maple was emerging from the Plantra Tree Tube into full sun. There is something odd about that picture - it looks upside down. Can you see it?

Notice the dark bark has developed above the younger looking green bark.

Normally you would expect the newer parts to look newer and the older parts to look older. Not in this case.

The lower - older - stem parts were protected from intense sun, strong winds and scouring sand, so the plant kept the protected area photosynthetically active. There is chlorophyll in the stem inside the tube. This effectively increases the leaf surface area and the growth potential of the plant. Not sure if I have every read that observation before.

But that is not what is truly interesting here. Let us look at the next set of leaves below the dark stemmed area.

The first thing you will notice is the angle of the leaf stalk or petiole. It is angled upward because it developed in the restricted space of a tree tube. Next again notice the photosynthetically active green stem.

But wait... there is more.

The most significant difference between the two images is that in the upper picture small branches have emerged between the stem and the leaf stalk. Scroll back up and take a look.

In the lower picture all we have are two leaves. This two leaves only pattern continues exactly the same down the stem for all of the new growth in the tube.

Why is this significant?
  • It means the grower has a labor-free method to control the height of the first branches
  • It means the plant has not wasted energy producing useless branches
  • It means the grower has far fewer branches to prune
  • It means the stem it straighter
  • It means the stem is stronger - no narrow crotches or included bark
  • It means the stem has a more appealing form for a veneer or landscape buyer
  • It means more growth due to excellent air flow within the tube to replenish CO2 consumed in growth
  • It means no excess of fungus harboring moisture trapped by over crowded leaves and branches
There will of course be a dormant bud at the leaf site, but it will not form a branch under normal conditions.

Branches do not form readily in the tube because of the absence of blue light and a surplus of red light. Not all tubes take this important plant response to account when designing products. At Plantra we try to think of everything.

Sunday, September 13, 2009

Borlaug and Plantra

In November of 2008 Steve Tillmann, Chris Siems and I had an offsite meeting to set the future direction of Plantra. One of the tasks Steve set for us was writing a vision and a mission statement. I was as enthusiastic as a five-year-old wait for a shot. I think it is fair to say Chris thought it was a waste of time. Steve pulled vision and mission statements from deep within us. Much to my amazement and relief, I strongly believe in both. This morning I realized where our vision really came from and I am deeply honored to realize we are just continuing a path blazed by Norman Borlaug.

A blog entry at Instapundit noted that Norman Borlaug had passed away and had two links. One article referred to him as The Man Who Saved More Human Lives Than Any Other. The other link went to a 1997 article by Gregg Easterbrook titled Forgotten Benefactor of Humanity. That article contained the seeds of the Plantra vision.

By producing more food from less land, Borlaug argues, high-yield farming will preserve Africa's wild habitats, which are now being depleted by slash-and-burn subsistence agriculture.

Our vision
Revolutionize woody plant establishment to make agriculture lands more productive and wild lands more wild.

Borlaug's vision is not limited to subsistence agriculture in the third world. The Borlaug Effect (it deserves a name) can be seen for those who look in every practice of modern sustainable horticulture and agriculture. The beauty of the vision is the way it links Plantra's horticultural and habitat work. When Plantra Grow Tubes get a vineyard into full production a full year sooner we create a surplus of land. That saves 300 year old Coast Live Oaks in California. When Plantra Tree Tubes take a year or two off the time to produce an ornamental shade tree for sale at a lawn and garden center in Illinois, it frees up land for corn and soybeans. That in turn reduces the demand to convert CRP acres back to cropland. That means more wildlife with more wild land.

If you think I'm exaggerating, look at this example. Let's say you currently need a 100 acre field to produce shade trees for sale at Green Acres Lawn & Garden Center. It takes five years to grow the trees to marketable size. The Plantra Tree Tube produces the same tree in four years. That means you only need 80 acres to meet the demand for shade trees. What do you do with the extra land? With 20% fewer acres, less diesel fuel, less fertilizer, less herbicide, less labor and generally less of everything that goes into producing the tree for sale we have saved money and contributed to the environment. We have freed up 20 acres of land and substantially reduced the other economic and ecological impacts to produce a tree.

That was Norman Borlaug's vision and Plantra unknowingly followed in his footsteps. Maybe this is not as surprising as you think. Norman Borlaug's undergraduate degree is in forestry and from the University of Minnesota. Chris Siems and Steve Tillmann both have forestry degrees from the University of Minnesota. Coincidence? I think not.