Produce Grower: What are the most common insect and mite problems fruiting vegetable growers face?

JB: Whether growing heirlooms, cherry, tomatoes-on-vine or peppers, fruiting vegetable growers routinely battle spider mites and whiteflies, with aphids singing backup chorus. Thrips can be a problem in some ranges, and even caterpillars make an appearance from time to time. In wetter ranges, fungus gnats may be a nuisance pest — we’re still working out how much of a vector we think these might be for plant diseases.

PG: What’s new in products for managing these pests?

JB: You’ll see more targeted chemistries coming to the market — manufacturers hear that demand from the market and growers loud and clear. Those are materials that target pest groups while preserving beneficials and non-targets. BASF introduced Sultan® miticide, a spider mite-specific product that is so targeted you can use it with predatory mites, and it only has activity on the pests (Tetranychids). Then we brought Ventigra® insecticide to fruiting vegetables and cucurbits, and this active ingredient targets piercing and sucking pests like aphids and whiteflies. You’ll also see more biological insecticides and miticides, like Velifer® fungal contact insecticide and miticide, the BASF proprietary Beauveria that has activity on aphids, whiteflies and thrips, and unlike other Beauveria strains, spider mites and broad mites as well.

PG: Experienced growers know about Integrated Pest Management — what’s new in IPM?

JB: At BASF, we’ve been talking about some new ways to work with IPM: that is making programs by choosing products across functional groups. This is an easy way to make sure you have all the heavy lifters in your programs, and it automatically rotates your applications across multiple modes of action. Growers include products from each of the following functional groups: 1) oils and soaps, 2) insect or mite growth regulators, 3) biological insecticides, 4) targeted conventionals, and 5) broad spectrum conventionals. Some growers only use the last group as a rescue. This approach helps ensure you don’t skip important resistance management tools, like growth regulators and horticultural oils (don’t be scared: modern oils, like Ultra-Pure® Oil horticultural insecticide, miticide and fungicide from BASF, are much more predictable than they used to be!).

PG: How can growers stay ahead of pest populations during the hottest times of the year?

JB: Since the crop is perennial in greenhouse fruiting vegetable production, running solid programs makes a difference in pest pressure. If you’re also running beneficials alongside these programs, it will help them be successful. In the heat of summer, biologicals can struggle to keep up with pests — your intervals may tighten up, and rescue applications might be needed. That’s not a failure in pest management, it’s population dynamics at work.

PG: Does BASF have resources and other tools for growers?

JB: We do; we have a portfolio of fungicides and specialty greenhouse products, guides, and rotation resources, and our technical and sales teams are at the ready to help. Also, many of our labels are available in Spanish and we make webinars and technical resources available in Spanish and English. Get in touch with us, we’d love to work with you.

Always read and follow label directions. Sultan, Velifer, Ventigra and Ultra-Pure are registered trademarks of BASF.

Produce Grower: Why is a healthy transplant so critical?

Jeena Andrews & Pierre Marc de Champlain: Moving from the greenhouse to the field, even after hardening off, is stressful for the plant. Young plants with healthy roots will establish more successfully when transplanted in the field. They can more rapidly overcome transplant shock as the roots spread out quickly and have access to give access to more nutrients. Healthy transplants are also less susceptible to pests and diseases. This translates to better stands and earlier harvests which can increase profits to offset the additional production costs associated with transplanting itself. Corrective measures are more difficult to implement outside of the controlled environment.

PG: How can using a quality substrate contribute to producing a healthy transplant?

JA & PMC: A quality substrate is the foundation for healthy plants. It is essential to use a consistent growing media with uniform physical and chemical characteristics that provides the ideal environment for the transplants. With our BM2 series, overall management of production is more efficient and less labor intensive with greater crop uniformity. Differences in growth will inevitably require adjustments to the irrigation and fertilization strategy, which can quickly become very challenging and expensive. Using a substrate from a reputable supplier like Berger will help youget a uniform stand, predictable results and better field success.

PG: What are the characteristics you look for in a growing media for veggie transplants?

JA & PMC: This is a critical step as seedlings are very susceptible to diseases. A well-balanced substrate contains components that provide porosity for air space and drainage while also giving adequate water holding capacity. Growers want a substrate that allows them to develop a strong root mass which maximizes transplant success. The fertilizer starter charge should be well balanced, but low enough to prevent stretching. The growing mix should have a finer particle size than traditional horticultural products since you want to maintain uniform moisture around the seed throughout the germination process. However, too much moisture can also be problematic. Fine or coarse grade perlite can be added to give additional drainage. Recent research we have done with fine grade wood fiber has shown tremendous results and has led to the creation of our new BM2 NF Wood products. The combination of fine grade peat moss and wood fiber promotes phenomenal root development and helps produce stalky transplants.

PG: What services does Berger offer to help support growers?

JA & PMC: Berger has a technical services team to assist professional growers that includes grower advisors available to assist throughout the production cycle to help improve yield and simplify operations. Berger’s ISO 9001 certified lab can perform a wide range of chemical and physical analysis including media analysis, water analysis, plant tissue analysis and complete characterization of the growing media. Our technical services team is available to help interpret the results. Our lab also conducts thorough testing of all our products throughout production to ensure quality and consistency. A final inspection report is available for each bale or bag of mix we deliver.

Produce Grower: Why should growers look to a company traditionally known for its petunias for advice about fruit and vegetable crops?

Kevin Hurd: We’ve taken our expertise of finding exceptional ornamental plants that perform for the consumer and expanded it into fruits and vegetables. As with annuals, there is a flood of food crop varieties on the market. We want to help simplify the consumers’ choices to make it easy for them to find the very best plants to help nourish their loved ones.

PG: What does Proven Winners look for when selecting new Proven Harvest varieties?

KH: First and foremost, we select for flavor. If it isn’t the most delicious fruit, vegetable or herb we’ve tasted, it doesn’t make the cut. Beauty is a secondary, yet important, trait. Proven Harvest varieties combine both ornamental and edible attributes into one.

For example, one might grow Berried Treasure® strawberries for their delectable fruit, but their bright, double flowers carry equal merit. That makes them easy to showcase in container recipes like the one pictured here called Strawberry Fields. It combines Berried Treasure Red strawberries and Amazel Basil® with Superbells® Holy Cow!™ calibrachoa and Rockin’® Fuchsia salvia.

PG: Are Proven Harvest varieties trialed as rigorously as annuals before introduction?

KH: They are put through even more intensive testing than our annuals. In addition to container and landscape trials at locations across the U.S., each trial site has a tasting panel comprised of everyone from professional fruit/vegetable breeders to casual vegetable consumers. Yield, vigor and disease pressure as well as flavor, texture, mouth feel and additional qualities are tallied across all locations and voted on by Proven Winners members.

GM: How does branding work to the advantage of growers and grower retailer?

KH: The Proven Winners brand name means quality to consumers — it assures them that what they are buying is going to perform exceptionally. Even if they know nothing about growing tomatoes, they know that if they plant a Proven Winners tomato, it is going to be amazing. Plus, margins are far more generous on Proven Winners branded varieties than generics, making them a wise use of greenhouse space.

PG: What’s new in the Proven Harvest line for 2022?

KH: In addition to our strawberries, tomatoes, pepper and vegetatively produced basil, we are adding two new herbs for 2022. Pesto Besto™ is a sweet Italian seed grown basil that comes from the same highly respected breeder as Amazel Basil®. And AlliYum!™ garlic chives is both ornamental and edible, carrying a blend of onion and garlic flavors throughout its attractive foliage and flowers.

Seeds and liners are available for all Proven Harvest varieties with the exception of Amazel Basil which is sterile, so is offered as URCs and liners. Contact your preferred Proven Winners propagator for further details.

As a producer of fresh-cut basil, what is your main production goal? It is most likely to produce a quality crop with the highest possible yield while minimizing production time and input costs. Similar to produce, basil is sold by mass, so yield equals profitability. We know that we can steer plant growth, development and yield to meet our targets by manipulating environmental parameters such as light intensity, quality and photoperiod, as well as temperature and carbon dioxide concentration. However, crop quality parameters must also be preserved. Basil quality consists of many parameters including its appearance (color, blemishes, turgid vs. wilted, etc.), leaf-to-stem ratio, leaf size, shelf life, aroma and flavor. Without great aroma and flavor, basil would be no different from lettuce.

Flavor compounds

We often think of flavor as only taste, but it is actually a combination of taste and aroma. Take basil as an example: What is the characteristic smell you associate with basil? How does that compare to its taste? This is a strong example of how taste and aroma work in concert. It also helps illustrate how volatile compounds, or compounds that can be airborne, are integral to the quality of certain crops.

When investigating basil flavor, we have to quantify specific compounds. How do we decide which ones to focus on? There are many compounds that make up the characteristic flavor of basil, but we will focus on four compounds that contribute the most: eugenol, methyl chavicol, 1,8 cineole, and linalool (Fig. 1). Eugenol and methyl chavicol are the main flavor compounds in cloves and anise, respectively, contributing to the clove- and anise-like aroma of basil. 1,8 cineole, also known as eucalyptol, contributes a eucalyptus-like flavor and is a main component of eucalyptus. Finally, linalool contributes a flavor that is described as “floral with spiciness” in the literature, but we think it smells like Fruit Loops. Together, these compounds, along with several others, make up the basil flavor profile we love.

Light = Flavor

How do our production practices influence basil flavor and the concentration of these compounds? We grew sweet basil ‘Nufar’ seedlings in a growth chamber under 100, 200, 400 or 600 µmol·m^-2·s^-1 for 16 hours each day to create daily light integrals of 6, 12, 23 or 35 mol·m^-2·d^-1. After two weeks, we harvested the seedlings. Overall, concentrations of three of the four compounds tended to increase as light intensity increased (Fig. 2).

The bigger question is, how did altering the light environment impact consumer perception and preferences? After all, while lab tests are important, at the end of the day, what really matters is whether a customer likes how the product looks and tastes. We conducted a sensory panel where samples were prepared, randomized and supplied one at a time along with water and saltine crackers to consumer panelists through a sliding door (Fig. 3). The panelists answered a series of questions regarding their perception of the basil they consumed. What we found was that overall liking (green line) was greatest when young basil was grown under 200 µmol·m^-2·s^-1 compared to lower or higher light intensities (Figure 4). But why is this the case? Trends in plant color, texture and flavor mirror the overall liking trend. Panelists described a deeper green coloration of leaves grown under lower light intensities compared to those grown under 400 or 600 µmol·m^-2·s^-1 of light (purple line). While plants grown under 600 µmol·m^-2·s^-1 appeared normal when harvested, bruising occurred when leaves were rinsed gently for consumption (Fig. 4). Additionally, the texture (blue line) of the leaves grown under 600 µmol·m^-2·s^-1 was more frequently described as “wilted” or “chewy.” Besides the discoloration and texture differences, flavor (red line) was a large contributor to overall consumer liking. Basil grown under 100 µmol·m^-2·s^-1 did not have a strong flavor, but those grown under 200 µmol·m^-2·s^-1 had the characteristic basil flavor panelists expected. However, as light intensity increased up to 400 and 600 µmol·m^-2·s^-1, the flavor was too intense. Panelists described the basil grown under high intensities as “bitter” and “spicier.”

We often think of flavor as only taste, but it is actually a combination of taste and aroma.

Aroma preferences (yellow line) had an interesting trend where plants grown under 100 µmol·m^-2·s^-1 had the lowest rating because the aroma was not strong enough. As light intensity increased to 200 to 600 µmol·m^-2·s^-1, aroma preference leveled off because it is more difficult to saturate aroma in a large room compared to a sample having too strong of a flavor.

Additionally, the participants preferred the larger leaf size (pink line) of plants grown under higher light intensities. Again, these were two-week old seedlings; the plants grown under 100 µmol·m^-2·s^-1 had fairly small leaves. The positive aspect to small leaves, as some panelists suggested, is that entire leaves could be used to garnish a dish.

What implications do these insights have for production?

There are some limitations to this study. Young basil plants were used in the analysis and consumer sensory study, where basil is often transplanted and grown longer before harvesting. Additionally, panelists tasted the basil as a whole leaf by itself, not in pasta, caprese salad or any other delicious dish. However, there are still some important takeaways from this work. We know that light intensity has a large impact on the concentration of flavor compounds in basil, and we know that consumers can perceive the difference. If the basil you are growing is not flavorful enough, consider adding more light. If it is too flavorful, consider shading the crop. Keep in mind that altering the light environment will not only influence flavor, but yield as well. Additionally, for greenhouse-grown basil, light differences across seasons may influence the flavor and overall quality of your crop. To produce a crop with year-round flavor consistency, supplemental lighting or shading will mostly likely be needed. Finally, if your goal is to produce basil for different purposes, the “light” level is an effective tool to manipulate to produce low-flavor intensity basil for fresh eating, such as in caprese salads, and high-flavor basil for freshly processed foods, such as pesto.

Kellie Walters is a former graduate student at Michigan State University (MSU) and is now an assistant professor of controlled environment plant physiology in the Department of Plant Sciences at the University of Tennessee. Roberto Lopez is an associate professor and controlled environment/floriculture extension specialist in the Department of Horticulture at MSU. The authors gratefully acknowledge Sean Tarr and Nate DuRussel for assistance, JR Peters for fertilizer, Grodan for substrate, Hydrofarm for hydroponic production systems, LS Svensson for shade cloth, and MSU AgBioResearch and Project GREEEN, MSU Graduate School, and the USDA-NIFA for funding.