Koa Planting, Kaiholena, Kaʻu, Hawaii
The Nature Conservancy Hi, I’m JB Friday, Extension Forester with the University of Hawaii. We’re here on another virtual field day for forestry in Hawaii. And I’m Steve Coffee, senior environmental educator with Educational Solutions here on the Big Island We’re here today to talk about planting forestry trees and the key thing about planting forestry trees whether it’s for production forestry or for Conservation forestry is to get a lot of trees in the ground and do it quickly and efficiently but making sure the trees survive. So today we’ll walk through the steps in doing that. So Steve what do we have set up here? We have the basic tools needed for a day of Planting in the field with some simple seedlings. The first step is to get a hole into the ground and we use this Dibble Provided that we’re using seedlings in Dibble tubes, you can see the shape is the exact same, So it’s a quick and easy way to make a perfect size and shape hole. If the substrate is a little more rocky or lava, Weʻll get you started with the oʻo bar and then we can come behind and fine-tune the shape with our Dibble. We also use, what do we call this J.B.?
hori knife We use the hori knife to Supplement and fine-tune the planting hole sometimes after we get the seedling in the ground, we can okay snug it in using this tool I like to carry two buckets into the field, one is the wet bucket half full of water where my siblings are soaking and get the root ball nice and wet, and I’ve got a cup in here to pour a big Big amount of water on the plant after it goes into the ground, and one dry bucket to put our empty dibble tubes And to carry some fertilizer around in as we move through the field. And that’s the basic tools we need in a typical planting situation Okay, sounds good. Alright. When you plant trees, any kind of forestries into a pasture like this, It’s important to control the grasses before you start planting, otherwise the grasses will swamp the trees and out-compete them. In this site we control grasses by spraying with herbicides. There’s a fairly thick mat of kikuyu grass. What did you spray here Steve? We sprayed here about two and a half weeks ago with the combination of glyphosate and imazapyr. So the glyphosate gives you a quick takedown, the imazapyr is a much longer lasting herbicide. Indeed, and we use a combo for a quick preparation. This also was grazed down, the grass was grazed fairly low before you sprayed. How tall was the grass before you came in here? When I first came in here the grass was easily up to my waist, and there’s no way to work in that grass, so I arranged with the Rancher to get the cattle in here before our project started, and within a week they had the grass down to maybe a foot tall. And then I could apply the herbicide a little more effectively and lay out the rows for planting. The seedlings that were planted today are koa seedlings. They were grown by Jill Wagner at Future Forest Nurseries in Kailua-Kona on the Island of Hawaii. These are good seedlings. The root to shoot ratio is appropriate, about that much root for about that much shoot. In Hawaii we always plant containerized seedlings, so these are grown in root trainers dibble tubes. On the tubes here the seedlings come out easily for planting. They also train the roots, so the roots go straight down. And you can see the tree comes out in a solid plug here, this makes it easy to plant. Koa is a nitrogen fixing tree and the bacteria that fixed the nitrogen live in nodules attached to the roots of the seedlings. If you cut open one of these nodules you should see a healthy pink inside as in this photo. If the nodules are white inside, or brown or black, then they’re either dead or not actively fixing nitrogen. This site turned out to be pretty rocky, so we’re digging our holes with the oʻo this time. I put a piece of tape on this oʻo bar to gauge how deep to thrust it into the ground so my holeʻs not too deep and it’s not too shallow. So I’m just gonna thrust it down here, I hit a bit of a rock, so I’ll just move over a couple inches and Found a soft spot it went in just the right depth up to my tape line That holeʻs ready, and I can move on to the next one. I’ve marked my oʻo with this tape so I can thrust it into the exact depth. It’s the same depth as one dibble, the dibble that I’m planting, to make sure that my hole is not too deep and not too shallow. Also to gauge the hole sometimes I just insert a stack of dibble tubes to see if I’m at the right depth, and it also helps to form the hole a little bit rounder to match the exact shape of my root ball when we drop it into the hole. When we’re planting the tree, in this project we’re using about five grams of fertilizer. Here we have an osmocote triple 14, so it’s coated slow-release. Put it in the bottom of the hole. I like to knock a little soil on top of that so the roots aren’t directly in contact with it. Form the hole again with the old dibble tubes Ease the seedling out of the dibble tube. So these, since they’ve been soaked in water here, they came out quite easily. Slide it in the hole. When we slide it in the hole, we want to firm up the soil around the dibble tube, use a trowel I like using the hori knife We just jam it in to close up the bottom of the hole. The important thing is to make sure there are no air pockets in the bottom of the hole, and that the roots have good contact with the soil. The other important thing is to make sure the roots are straight down in there and don’t J-root so they don’t bend around as they hit the bottom of the soil. You want to plant the seedling so the soil surface and the root collar of the seedling are at the soil surface where you’re planting. You don’t want it down too far or up too high, so this seedlings planted at exactly the right depth. This seedling was planted too shallow, not deep enough in the soil, so this top portion of the roots that are sticking out, these will dry out quickly and that will kill the seedling, so this seedling won’t survive. This hole was dug too deep. You can see here the stem of the tree would be covered by several inches of soil. If this happens the stem will be rotten, and the seedlings will die, so this hole needs to be filled in somewhat more. Here we put a little more soil in the hole, and there it’s just at the right depth. At planting we give each seedling about a liter of water to get it started. Here we are back in Kaiholena in February. That’s three months after we initially planted the trees. It’s been a good rainy three months. You can see that the grass is nice and green, however our weed control has worked well, and in this plot we have good weed control, the koa trees are off to a healthy start, and we’ve had 85% survival so far. For the weed control on this plot, we’ve used a combination of the herbicides glyphosate and imazapyr. Glyphosate gives you a quick takedown of grasses but the effects usually wear off after about six months. If this had just been sprayed by Glyphosate, the grasses would have started coming back by now. Imazapyr is a slower-acting but longer-acting herbicide, and you can see six months after application, the weeds are completely dead, and we have no competition for our koa trees. We’re applying three ounces of a coated triple 13 with micros fertilizer to each tree. The coated fertilizer is a slow release. Three months after planting here, these trees are off to a good start, and we’re broadcasting fertilizer. We’re not worrying about the fertilizer helping the grass grow in promoting weeds, because the herbicide treatment has kept the grass competition down. So we’re just broadcasting three ounces of our fertilizer on each tree here. What’s going to happen now is that the trees are going to hit the summer with a lot of fertilizer with no weed competition, we expect they’ll take off. Acacia koa, 3 months growth Acacia koa, good weed control (3 months growth) Acacia koa, 3 months growth Acknowledgements
Steve Coffee, Educational Solutions Inc
Jill Wagner, Future Forests Nursery
The Nature Conservancy, Hawaiʻi
Jody Smith, CTAHR, Video Editing
Dr. H.C. Skip Bittenbender for his rendition of Papakolea Funding provided by USDA Forest Service
Reforestation, Nurseries, and Genetic Resources Program USDA NRCS Conservation Innovation Grant to Dr. Liba Pejchar
Dept. of Fish, Wildlife, and Conservation Biology, Colorado State University For more information contact:
Dr. J.B. Friday, Extension Forester
875 Komohana Street, Hilo HI 96720 Telephone: 808-981-5199 FAX: 808-981-5211
email: [email protected]
https://cms.ctahr.hawaii.edu/forestry This “video log” is a project of the College of Tropical Agriculture and Human Resources, University of Hawai‘i at Mānoa. The editors, authors and publisher intend the information to be reliable but they do not assume any responsibility for consequences of using the information provided.
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It is an amateur production made possible with support from the RREA program of USDA-NIFA.
June 2012 USDA National Institute of Food and Agriculture, Renewable Resources Extension Act (RREA), Sponsored by USDA-NIFA University of Hawaii Logo