CONTROLLED ENVIRONMENT AGRICULTURE Tip #1: Start with good seed. Poor quality seed can lead to bad germination, increased risk of disease and inconsistent seedling growth - all of which will make grafting much more difficult. Tip #2: Always run a small trial before using a cultivar for the first time. Sowing a few seeds and growing them to grafting size can help to determine the cultivar's germination rate, growth rate and consistency. Tip #3: Seed the rootstock variety two days after the scion variety. Rootstock cultivars have vigorous growth and, therefore, grow faster and reach sufficient stem diameter for grafting earlier than scion varieties. PHASE 2: GRAFTING Twenty days after sowing the scion cultivar the seedlings of both the scion plants and rootstock plants should have a stem diameter of approximately 2 mm (although there will likely be some variation) and are now ready to graft. While it is possible to graft older plants, younger plants heal faster and have a higher likelihood of surviving. The first step in the grafting phase is to choose a scion plant and a rootstock plant with compatible stem diameters (Figure 2). It is important to graft plants with very similar stem diameters to achieve the best success. Stem diameter measurements should be taken below the cotyledons for both the scion and rootstock plants. Figure 2. A rootstock (left) and scion (right) seedling with compatible stem diameters for grafting. Vested in Your Success The next step is to cut the rootstock below the cotyledons (Figure 3). Cutting below the cotyledons eliminates advantageous shoots from growing out of the rootstock. The cut can be done using a razor blade at a 45- to 60-degree angle with a deeper angle allowing for greater surface for the graft to take hold. Then, a transparent silicon channel grafting clip should be slipped onto the freshly cut rootstock stem so that the top half of the channel is left empty (Figure 4). Next, the scion seedling should be cut at the same angle as the rootstock seedling was cut (Figure 5). The top part of the grafting clip should then be pulled open slightly so the scion stem can slip in. The cut surfaces of the two stems should now be in perfect contact with each other with no gap between them (Figure 6). We're Hiring. 26 OCTOBER 2020 GPNMAG.COMhttp://www.GPNMAG.COM