can take it. If you need to hold them, you can irrigate with clear water or reduce the ppm N. Remember the goal of producing controlled growth that meets your specs at time of transplant.
growth to achieve our finished liner spec so we’ll produce the best product at this stage. The hardest part of providing the best environment is that not all plants have the same needs, so you’ll have to hit the middle of the road for what you’re producing and you may need separate zones for the warmest crops (think angelonia, lantana, sweet potato vine) and a different zone This is the first opportunity to fully recharge our liners with the nutrients they’ve lost since being removed from the stock plants. Again, the environment will play a key role, so we need to make for the rest of your liners. Fertility in Stage 3 sure our plants are “active” so we can push nutrients into the soil and into our liners. Stage 3 is often only two to three weeks long, so there isn’t much time to recharge our plants and a good fertility plan is necessary. Choosing the best formulation of fertilizer is important in this stage, especially because of the high density of the plants in your liner tray. A well-balanced fertilizer with calcium and magnesium, along with a higher percentage of nitrate to ammoniacal nitrogen, is best. This will help to promote controlled growth but provide the plants with everything they need. In this instance, a 14-4- 14 is superior to a 20-10-20. Many growers will use a constant fertilizer strategy in this stage, but will keep their ppm N lower, like 75 to 150 ppm N, in an effort to better control the growth. Remember that most complete fertilizers will deliver 1 ppm Fe at a 200 ppm N rate, so if you’re using a lower ppm N, then it’s advisable to increase your micronutrient package to deliver a 1 ppm Fe constantly to your liners. If you feel that your liners are behind schedule, don’t be afraid to push them with higher rates – they
finished container after transplant. This means timing it correctly before the transplant date. Sanitation is a big part of any pinching process and shouldn’t be taken lightly. Build this into your pinching process and be sure to communicate it properly to your crews; it should be a priority. Whether we pinch liners with scissors or shear them with a machine, there’s always the opportunity to rapidly transmit disease, and we want to minimize this risk with the correct sanitation protocols. Pick a sanitizer that provides control of fungi and bacteria as well as viruses. This is especially important for solanaceous crops like petunia and calibrachoa. Choose an appropriate concentration of sanitizer and be sure to give your cutting tools the appropriate contact time before reusing. Many growers will give their pinching crews two pairs of scissors, and they’ll have one soaking in the sanitizer while using the other pair to trim a tray. Once the tray is finished, they’ll switch scissors. Please don’t skip this step of the pinching process! PGRs and Controlled Growth Stage 3 is the phase of liner production where tone and controlled growth is most often lost, so having a plan or controlled growth strategy is important. Ideally, we can use environmental factors, moisture management and proper fertility to produce a toned liner that meets our specs, but sometimes that’s not enough. As all propagators know, growth regulators are one of the most useful tools in your toolbox; however, over-regulation is one of the fastest ways to ruin a finished crop and should always be on your mind when formulating your controlled growth strategy. Know the genetic potential of the plants
Pinched liner
Pinching Stage 3 is where most crops that need a pinch in the liner will get their pinch. As with all aspects of liner production, start this with the end in mind – in other words, what should the finished liner look like when it’s time to transplant? Do we want four, six or eight breaks on the liner? How many leaves or nodes should remain on the plant after pinching to achieve that? How tall should the plant be after pinching? How much space do we want between nodes or leaves when we pinch? These are all important questions to answer before you stick your cuttings and should be a part of your finished liner specifications. Once you know how many breaks you need and how developed you want the breaks at the time of transplant, you can put a date on the pinch. This date will then become your target date for the plant to be ready for a pinch. You should have a size and number of leaves as part of the expectation or spec of your plant on this pinch date. Ideally, your pinched liner has breaks emerging and starting to develop, and unfolded leaves so your finished liner is ready to quickly fill out the
16
Powered by FlippingBook