A Farmer’s Guide to Conducting a Successful Variety Trial

Success in farming often hinges on the choices made long before harvest — choices like which crop varieties to grow. With shifting climates, changing markets, and evolving pest pressures, the right variety can distinguish between a thriving and challenging season. A well-planned variety trial allows you to test potential options under your farm’s specific conditions, helping you make informed decisions rooted in observation, data, and experience. This guide offers a step-by-step approach to designing and evaluating variety trials so you can grow confidently, adapt with insight, and cultivate the best outcomes for your farm.

Choosing which varieties of crops to grow is one of the most critical farming decisions. Each variety has its own unique advantages and disadvantages. To sort out which variety is best for your farming system, doing a variety trial can help you make that decision. Choosing the right variety for the local climate and field conditions can minimize crop and time loss and increase your success. It can help you maximize yields, minimize crop loss due to pests, fill key market and production niches, and identify the best seed sources.

The first step is planning your variety trial. What do you want to learn from the trial? Is your goal to measure how your favorite variety compares to newer varieties, do you need a variety for a specific market or customer base, or are you trying to replace a particular variety? These are all important things to consider. It is recommended that you grow varieties that you know, along with the new varieties. These will be your controls and allow you to have a side-by-side comparison of the characteristics of the new varieties with your standard varieties. 

Field size is also something you need to consider. Ideally, you need three replications of each variety you are testing. The replications need to be randomized. This helps account for any differences caused by variation throughout the field. Each replication should have a minimum of six plants for fruiting crops and six to 10 feet of row for root and leafy crops. 

You should also account for border rows around the entire experiment. These border rows will minimize edging effects. Plots without borders tend to be more productive because they lack competing plants around them, but edge plots can also suffer from increased wind and sun. Calculate the total width of the experiment to make sure the chosen field is large enough to accommodate the trial. Ideally, you would like the entire trial to be planted in one contiguous block. When selecting the field, choose one that is uniform in slope, drainage, fertility, and where the soil type is representative of your farm. Avoid having the plots border a fence line, road, or the field edge to avoid favoring or penalizing one variety over another.

The next step is planting your variety trial. Use flags or stakes to mark each plot. Use a permanent marker or a horticultural marker to label each variety clearly by name or number on the stakes or flags. Researchers recommend labeling varieties by number or letter to avoid bias in favoring one variety over another. Once the labels are placed in the field, create a field map. Stakes and flags are easily lost, stepped on, run over by a tractor, or faded in the sun. On the field map label where you planted everything. Put the map in a safe place to ensure that all your effort isn’t wasted. Treat all varieties equally. Plant on the same day and throughout the season, use the same production practices such as watering, fertilizing, and weed management schedule for the entire trial.

Randomized Block Design Example

Evaluating Your Variety Trial

How you evaluate your variety trial will depend on the goals you identified in the planning process. Evaluation criteria can be extensive or very focused, depending on the intent of the trial and how much time you have available. Most farmers are very busy, so it is important to narrow the list of evaluation criteria to those that are most important to you. Variety evaluation can occur throughout the season to capture traits during different stages of growth, but each variety should be evaluated at harvest maturity. This ensures that the data collected represents the variety accurately. Often, all varieties in a trial will mature at the same time, but keep in mind that sometimes different varieties mature at different times, so you may have to do multiple evaluations. There are a few ways to evaluate or make assessments on your trial. One is measurement. This could be things like measuring yield in pounds or measuring plant height. While this is time-consuming, it is very precise. A second option, which is less accurate but faster, is scoring each plot for a particular trait by judging your assessment on a 1-5 or 1-9 scale. The third method of assessment is ranking the plots from best to worst. When ranking the most productive plot in the block would get a 1and the least productive would be ranked last.

By planting a variety trial on your farm, the process should leave you with answers to your questions and leave you with a few new favorite varieties and increase the success of your farm.

Beyond the practical benefits, variety trials also foster a deeper connection with your land. As you observe the growth and development of different crops, you become more attuned to the nuances of your environment, leading to a more sustainable and harmonious farming practice. Sharing your findings with other farmers can further enrich the agricultural community, promoting collaboration and innovation.

As you move forward with your variety trials, remember that agriculture is both an art and a science. Embrace the journey of discovery and take pride in the knowledge that you are contributing to the advancement of farming practices that will benefit not only your operation but also the broader agricultural landscape.