Designing Efficient and Effective Greenhouse Trials (Greenhouse Grower)
First it was toilet paper. Then it was cleaning supplies. Now, it seems like there’s a new shortage of materials announced almost every day, and it’s no longer just affecting consumers. Each grower our team at HydraFiber talked to this year has experienced a disruption to their supply chain, whether it was soil, plastic, or even plants.
At a time when the horticulture industry is flourishing with record-breaking sales growth, behind the scenes, growers are scrambling to keep supplies in stock and operations running smoothly. In fact, many of you may be questioning if there are alternatives, new innovations, or workarounds to avoid these hurdles. That’s where a good trial can save the day.
The question then becomes, “How does one find time to trial when things are screaming busy like they are this spring?” For Kyle Carboni, Production Manager at Green Lake Nursery in Seagoville, TX, he says it all comes down to timing.
“Scheduling trials to start immediately after Mother’s Day is a great time,” he says. “You can still get some experience growing under spring production conditions, but the peak of the season is starting to wind down and you start to get more breathing time to follow the trials through.”
The way in which trials are prepared, conducted, and recorded can vary greatly from facility to facility. Within the HydraFiber research and development greenhouses, our head grower, Ryan Knauer, has spent time determining ways to streamline the trialing process without compromising on its integrity. Here’s his top tips and best practices to ensure a high level of success in your evaluation process. The good news for growers is that some of this may already be common practice at your facility.
Identify a Point Person
Assign a single point of contact to oversee the data collection and have them develop a written protocol to ensure consistency throughout a trial.
Identify a Measurable Objective
Write down what you want to accomplish with the trial. Set specific, measurable goals like improving crop yield by 6% using a new seed variety or reducing irrigation by 20% using a different substrate material. Also, identify what data points are most important to capture for measurement; these could include plant height, number of flowers, moisture content in the soil, tissue color, etc.
Invest Time in Planning
Consider each of these stages prior to starting a trial.
- Treatments: What treatments will be used and how many replications (number of plants per treatment). Having multiple plants allows for a better idea of how the treatment will perform in a real-life growing situation.
“Start with a trial of just a few pots, and if you like it, expand to a larger section,” suggests Ron Van Der Hengst, owner of South Central Growers. “For example, when we trialed with HydraFiber, we went through three different crops before making the switch.”
It’s important not to go overboard, though. In trials, growers will often grow hundreds or thousands of replications because they don’t want to lose the trial. However, if they are going to collect data, it would be worthwhile to identify five to 20 plants out of the entire lot from which measurements will always be collected. Growers aren’t realistically able to capture data from hundreds of plants but could identify a small sub-set to track and measure.
“If you’re in a time crunch and the trial is mainly for plant growth comparison, then side-by-side images of treatments may be the quickest and most helpful thing to collect,” Knauer suggests. - Scheduling: Establish start and end dates. Identify, for example, the sow date/plant date; the length of time for the trial (i.e. flower initiation/forcing dates, harvest); and the method and frequency of data collection. Ideally, data should be collected at the same time of day and the same interval of time throughout the trial, such as every three days at 11 a.m.
- Details: Things like container size, plant material, fertility, temperature, irrigation cycles, and light should be qualified up front and kept consistent across all plant material throughout the trial.
- Genetics: If you are testing a new product, then it would be a good idea to select a range of genetics that you have issues with or exhibit the problem you are experiencing. For substrate trials, select crops that commonly provide a challenge, along with crops that do well. This will provide a fair comparison as to the effect of the substrate.
Establish a Control Treatment
It can be tempting to just rely on past experiences and skip identifying a control. However, if a control treatment is left out, then it is harder to objectively evaluate the results of the various treatments against a baseline measurement.
Pay Attention to Maintenance
During trials, it’s important to keep in mind that the treated plants may require different maintenance practices than the control. For instance, when Carboni trialed with HydraFiber, an engineered fiber substrate designed with greater moisture availability, he needed to pay closer attention to his watering practices to ensure the plant wasn’t overly hydrated. It’s important to make sure the control is also maintained effectively and does not fall prey to things like pests, poor environmental conditions, underwatering, etc.
Randomize Treatments
Randomization helps remove biases from the study. For example, if all of one treatment has a specific microclimate, the results may be biased for that one climate. If the plants are randomized, this can provide a more accurate picture of how the item on trial will perform.
Document Everything
Photographs and notes can be incredibly helpful when reviewing trial data at a later time. You never know what questions will be asked, so the more information you capture, the easier it will be to address questions. Be sure to date and timestamp notes to correlate with the images you’re capturing. It is also helpful to label everything to prevent misplacing or confusing different treatments. You can use a paint pen on containers or color-coded tags. There are also trial tracking apps for growers that want a digital companion. Keeping data collection as simple and targeted as possible will go a long way for efficiency and success.
Evaluate
Examine the data across all of the replications to identify any outliers and ensure that your conclusions are supported by factual data rather than assumptions. The final stage should be a report summary outlining the key conclusions and drawing upon the data for support.
Usually the hustle and bustle of a grower operation shortchanges some of the trial details such as data collection, documentation, and evaluation. While it’s best to follow the trial through the full plant production cycle, growers can speed up results by choosing crops with a shorter crop time or conducting multiple repetitions.
Following these simple steps can vastly improve the process of research trials and data collection, ensuring that you can reach scientific conclusions that can shape the future of greenhouse production at your facility.
Original article written by Jennifer Broersma-Neujahr for Greenhouse Grower. View the online version.