Photo courtesy of BioWorks

As disease control methods change, more growers are starting to incorporate biological fungicides into their product rotations. Dr. Matthew Krause, product development manager at BioWorks, talks about some of the common plant diseases in greenhouse edible crops and ways to biologically treat them.

Produce Grower: What are some plant diseases that greenhouse produce growers face on a regular basis that they should be aware of?

Dr. Matthew Krause: There are the usual culprits for foliar and fruit diseases of tomato, pepper and other crops: Botrytis cinerea, which causes grey mold; leaf blights and fruit blights and bacterial diseases, which can be caused by Xanthomonas, Pseudomonas and Clavibacter species. Growers may also face Anthracnose on several different greenhouse vegetables as well as gummy stem blight and powdery mildew on cucumber. Also worth mentioning is downy mildew, which is quite difficult to control on crops such as basil.

PG: What are some soil-borne diseases, or root diseases, that affect produce?

MK: There are damping-off diseases caused by Pythium and Rhizoctonia that affect germinating seeds and young plants. Then there are root and crown rots caused by these two pathogens and Phytophthora as well as wilts caused by Fusarium species that may come along later in a crop, usually as the crops are stressed while they grow more rapidly, flower and develop fruit.

PG: How can growers treat plant diseases using biological fungicides?

MK: Biological fungicides and bactericides work preventively against plant diseases. They should be used as early as possible in a crop, along with good cultural and sanitation practices, to minimize disease risks and be re-applied at recommended rates and intervals to maintain low disease pressures throughout crop production. Because most registered biofungicides are not curative and remain on the outside of the plant, they are not effective at high disease pressures. The same principles apply to bioinsecticides used to manage insect pests and mites. You want to use biologicals right from the very beginning because this is usually where the pathogens can be first introduced to plants that are very vulnerable to pathogen attack, especially by those that cause soil-borne diseases.

PG: How can growers fit synthetic chemistries into a disease control program that is biologically focused?

MK: Many growers find that they can minimize the use, or reduce the use, of fungicide chemistries by using biologicals. When they need to use the chemistries, their active ingredients are often more effective because they don’t have the resistance being built up to them by the pathogens. That’s a benefit we see very frequently.

If plant material is received that is suspect for disease, or that is known to come in somewhat contaminated, a conventional grower can apply a tank mix or co-apply a chemical that’s known to knock down the pathogen with a compatible and appropriate biofungicide product. With this approach, a grower gets the quick knockdown of the chemical and the longer-lasting effect and multiple different modes of action of the biological. Growers who treat crops under higher disease pressures with RootShield Plus WP and a fungicide containing Propamocarb or Mefanoxam, depending on the crop situation, frequently get 8 to 10 weeks of root disease control before reapplication of RootShield Plus is needed. — Interviewed by Patrick Williams

With organic products becoming more popular, it’s as important than ever for growers to know the ins and outs of organic production. Below, Jiffy Director of Marketing Roelof Drost shares his insight.

Produce Grower: Organic production has seen an upward trend over the past few years, and companies seem eager to be able to supply organic growers with products that are suitable for organic applications. What is Jiffy’s view on this?

Roelof Drost: Jiffy looks at it this way; at the time the Jiffypot was developed in the mid 1950s, most growers worldwide grew organic without the need of organic certification. Most small farmers would sell their products directly to farmers markets. But times have changed, there are much larger farms today and food is shipped over long distances from farm to store. Most consumers now purchase their food at a supermarket, and much of the food on the market is grown using pesticides. For today’s consumer, to know for sure that the food is grown the healthiest way possible, organic certification is a must.

PG: Why does Jiffy believe offering products suitable for organic growing methods is important?

RD: Jiffy’s products such as the Jiffypot and Jiffy-7 are natural products that have been around for many years now. No chemicals, no gimmicks, 100 percent natural. Today, we still produce most of our products the same way as we did when we first produced them, natural ingredients only. This is why our products are naturally suitable to be used in organic applications. It is a natural fit, and we aim to have as many products as possible we manufacture OMRI listed.

PG: What other changes might we see in our industry, especially looking at this trend toward certified organic?

RD: We will see organic food growers establishing closer to where the food is consumed. Jiffy plays in on this trend by offering organic Jiffy-7 pellets and Grow Block systems to be used by the future organic farmers, such as organic solutions for hydroponic farming and vertical farming.

PG: How are products you supply to the organic grower different from Jiffy’s regular products?

RD: If we look at a Jiffypot, the original biodegradable pot, then nothing is different. All of our pots therefore are good to be used in organic applications. The pot is made of natural ingredients, peat and wood fiber. It always has been this way. We will not even use recycled paper because the printing ink on the pages might contain something we might not like to have in our pots. So, our Jiffypot has always been pure nature.

For other products, such the Jiffy-7 pellets, we would change to an organic approved lime and fertilizer, or leave the fertilizer out altogether. In the case of our Organic Grow Blocks and Grow Bags, treating the coir product differently is important, still making sure the salts are removed from the product to get the best possible results for the organic application the item is used for. — Interviewed by Chris Manning

Photo courtesy of Atlas Manufacturing

From the question of whether to add insect exclusion rooms or invest in a gutter connected greenhouse, growers have plenty of decisions to make about their structures. Bill Mathis, sales manager at Atlas Manufacturing, breaks it down.

Produce Grower: What are some new developments in greenhouse structures that are conducive to growing produce?

Bill Mathis: Increased size of insect exclusion rooms on ends to make usable space while increasing area of screen, which lessens the restriction of air flow. The demand for taller structures is also increasing to better accommodate vining crops and vertical grow operations.

PG: Is one type of greenhouse structure preferable to another with regard to geography, crop type, etc.?

BM: Geographic location and crop type play a huge role in determining which structure is right for the project. Snow and wind loads have to be accounted for as well as the weight of any equipment or crop that will be supported by the greenhouse frame. A tomato plant may have 10 to 12 pounds of fruit at a given time. If you multiply that by 1,100 plants in a 35-foot by 120-foot greenhouse, you can have over 13,000 pounds of tomatoes that need to be supported. If you live in an area that gets a decent amount of snow, you may have 20 to 30 pounds per square foot of weight on the roof that also needs to be factored into the equation. Because of this we recommend a crop support system that is independent of the greenhouse frame.

PG: How can working with specific bench accessories such as continuous benches, portable benches or rolling benches be of use to growers?

BM: Benches are not normally used in hydroponic greenhouse vegetable production. If growing vegetable transplants, however, there is a need for some sort of bench or T-Rail system to support the seedling trays. A T-Rail system offers a lower cost method of doing this when compared with a traditional greenhouse bench system.

PG: How can growers benefit from shade curtains?

BM: Shade/energy curtains are necessary for controlling temperature, light intensity and also heat retention during winter. There is a tremendous number of climate screen options to help create the specific environment needed. Each crop and geographic location has its own needs and challenges. In addition to shading, today’s screen options can offer light diffusion, heat retention, solar reflection, color spectrum altering, etc.

PG: When does a gutter connect structure become more economically feasible than managing multiple high tunnels and/or free-standing greenhouses?

BM: A gutter connected structure may cost more than a free-standing structure because they are generally taller and often require more structural strength to be able to withstand the weight of snow, ice and rain that accumulates in the gutters. The cost of the gutters alone can add up to a pretty significant amount. The advantage of gutter connected structures, however, is that because of the larger air mass, consistent temperatures are easier to maintain. Gutter connected structures also allow more efficient use of equipment, such as environmental controllers, plumbing and fertigation equipment and material handling equipment. For the small or beginning grower, a free-standing greenhouse is often a good choice because of the lower initial investment required and also ease of installation. — Interviewed by Patrick Williams

When the Kerns, owners of Nova, Ohio-based Bradwood Farm, began growing and selling greenhouse produce in 2015, they focused on lettuce and tomatoes. Since then, they have expanded their offerings to many more crops, including the nontraditional greenhouse offerings of fennel, beets and strawberries.

At the family farm, Katy Kern grows the produce, and her husband, Douglas Kern, performs maintenance. They work in a 5,000-square-foot, two-bay greenhouse and use both NFT and bato bucket hydroponic systems. Both the structure and the hydroponic systems are provided by CropKing.

While turning heads with their more traditional crops (Bradwood Farms recently won a “top tomato” award at a farmers market in Ohio), the Kerns are producing those less common crops, such as the Chinese cabbage bok choy and nasturtium.

“[Nasturtium] is an edible flower,” Katy explains. “You eat the whole flower. It’s sweet at first, and then it has a radish kick at the end — a little bite at the end.” She adds, “I also sell a ton of watercress.” An aquatic plant, the aptly-named watercress also goes by the botanical name Nasturtium officinale. Nasturtium (from the genus Tropaeolum) and watercress are in the same order, but not in the same family.

A fitting background

Although the greenhouse business is relatively new to the Kerns, they have farmed at Bradwood Farm since 1999. “I had a huge herd of sheep years ago,” Katy says. In the past two decades, the Kerns have raised beef cattle, chickens and hogs, and produced hay on their 130 acres. They have also produced maple syrup, tapping maple trees from the sizable forest on their property.

Katy and Douglas come from a construction background, having ran a company in that industry for 23 years. For a year and a half, they performed double duty, running the construction business while setting up the greenhouse operation. Their construction background suited them well in building their greenhouse. Other than pouring some concrete, Katy and Douglas built the structure themselves.

Since the Kerns’ greenhouse became fully operational, Douglas has continued to use his technical skills to advance the business. “He’s done some interesting things because we have oil and gas wells here on the property, but it likes to go down,” Katy says. “He put in a wood burner, and he did these heat exchangers to integrate with the CropKing system so I can have backup heat for my greenhouse. He also did a heat exchanger technique for my water, so in the wintertime when I change my nutrient tank, it can heat up my water before it goes in the nutrient tank. He’s always coming up with neat ideas on how to improve.”

Growing methods

In CropKing’s nutrient film technique (NFT) channels, Katy grows crops such as lettuce (varieties include Bibb, oakleaf, Salanova and romaine), leafy greens, basil, herbs, strawberries, beets and fennel. In the company’s bato bucket systems, she grows tomatoes, cucumbers, hot peppers and green beans.

The two systems, as well as different crops within a single system, require separate nutrient mixes. “The tomatoes call for a totally different nutrient mix than my NFT channels, and then the beans and the peppers have a separate nutrient tank also,” Katy says. “I have three different nutrient tanks here in the greenhouse.”

The NFT system is Katy’s major system and is set up to a 1,200-gallon nutrient tank. Meanwhile, she uses a 100-gallon tank for her tomatoes, and a separate 100-gallon tank for her cucumbers, beans and peppers.

Katy regularly rotates her crops throughout the year. “[This winter], I’m doing spinach, which I can only do in the wintertime because it gets too hot in here in the summer and it bolts,” she says. “I primarily do green beans in the wintertime also because it’s harder to get them. And tomatoes — I start those in January, and then I end up pulling them in November.” She grows cucumbers, basil and lettuce year-round.

Catering to customers

Bradwood Farm sells to some grocery stores near her in Ashland County, as well as stores in Northwest Ohio. She also sells her product at farmers markets in Northeast Ohio and works with a community supported agriculture (CSA) program in Central Ohio.

Throughout the year, customer demands change. “It does slow down in the wintertime, because, to me, people like to eat comfort food more than salads,” Katy says. However, a base of her customers emails her with specific orders and she delivers their orders to a drop-off location. “There is that group of people that like to eat fresh salads all year-round,” she says.

Katy produces herbs for customers in the winter because they cook more at that time of year. “I do rosemary and thyme, and I also do cilantro in the wintertime,” she says. She also grows parsley year-round because she is in a good market for the crop.

“I just started with lettuce and tomatoes,” she says. “[But] I really expanded into a lot of Asian greens like Tatsoi, Carlton, Tokyo [Bekana] — just a bunch of different ones. They have different flavors and different colors — lighter greens, darker greens.”