Aphids are little insects that can make a big impact on produce yields, sucking out crops’ vitality and spreading plant viruses. Hard to spot until it’s too late, they’re one of the most destructive pests on cultivated crops.

“Aphids are a pest because they develop very quickly,” says Hugh Smith, assistant professor of vegetable entomology at the University of Florida. “They have a complex lifecycle. … It’s a really accelerated production, and in some cases some species don’t even need to mate; the females produce babies on their own. So they’re very well adapted to build up quickly … and when you’re in a greenhouse, they’re protected from a lot of their natural enemies.”

The key to protecting your production is to take steps to catch an aphid threat as early as possible and mitigate impact. Knowing what to look for and how to respond will make a difference to your operation’s bottom line.

Identifying a threat
There are many different types of aphids, which are known as plant lice. Some are plant-specific, while others attack a wide array of plant material. Color for these pear-shaped pests varies, including green, yellow, orange, brown and black. Common species affecting produce growers are green peach aphids, potato aphids and bean aphids.

At low population levels, warning signs are few and far between. Yellow sticky insect cards can be used to detect the aphids’ winged form if present, and you can train your team to look for the pest in key spots on crops. They’re attracted to new growth cells, such as topside growing spots or shoots off the side. They are also common on the underside of leaves.

“Implement as rigorous a scouting program as you can to detect as early on as you can,” Smith says. “Have a good scouting program looking twice a week, with a trained crew.”

As an aphid population builds up, you’ll spot a sugary, sticky excretion called honeydew on your plants. This honeydew often promotes sooty mold growth. Because the aphids suck sap from plants and distribute poisonous saliva (as well as often carry viruses), crops typically show signs of stunted growth, wilted and curled leaves, and discoloration in a bad infestation case.

Key risk factors
First and foremost, realize that if you’re a greenhouse grower, regardless of region, you are going to get aphids. Aphids will get in from the outside, and there’s no way around it.

“There’s no way you can really keep aphids or other pests out,” Smith says. “You may raise the walls on your structure or have a porous roof structure. Even if you have a tightly sealed operation, they can still sometimes get in through ventilation openings and things like that.”

You can reduce your risk for contracting this insect by diligently avoiding contamination from new material.

“If you’re getting your material and seedlings from somewhere else, you want to be in communication with your supplier and make sure your supplier is someone who follows good practices in terms of giving you the cleanest material possible,” Smith says.

Identifying how prevalent ants are in your operation can also alert you to your risk level. Some ant species actually farm aphids, a mutualistic relationship in which the ants provide protection for them on leaves to reap the dietary benefits of aphids’ honeydew excretion. The more ants you have, the more encouraging an environment aphids may find.

Mitigation and management
There are several measures you can take to manage an aphid infestation among your crop yield. In addition to your human scouting crew, employ a cavalry of beneficial control insects. Lady bugs, lacewings and parasitic wasps (they don’t sting humans) are common predators of aphids.

Insecticides can also be effective, particularly newer systemic insecticides taken up by the plant roots or from foliage.

“(Aphids) have this sucking, piercing mouth like a couple straws put together that they use for sucking the sap out of a plant,” Smith says. “So when aphids are actually sucking on the plant’s sap or juice … they’ll be sucking up the insecticide.”

But Smith warns that many insecticides can be too harsh for greenhouse use, particularly with food crops.

“There are protection issues; you don’t want to spray something toxic in an enclosed area,” Smith says. “Switch to more selective, softer insecticides if that’s what you’re going to use.”

Some growers support organic alternatives to synthetic insecticides. Such options include insecticidal soap, pyrethrin, and neem oil, although opinion on effectiveness varies.

You can also take a simple, hands-on approach by wiping off or removing leaves with aphid colonies by hand and spraying down plants with pressurized water to dislodge clingers.

Keeping your food crops clean of aphids is key to maintaining fruitful stock and providing pest-free plant shipments, which is critical to maintaining a positive bottom line.

“They’re a very common pest,” Smith says. “In vegetable production, people need to be concerned about them just about everywhere. Any grower should get familiar with what pests they’re expecting.”

Jessica Hanna is a frequent contributor to Produce Grower magazine.

Every now and then, something comes along that is truly innovative. The automobile and smartphone come most readily to mind. In the world of gardening and agriculture, it may just be the grafted vegetable.

Grafting vegetables is nothing new. It’s been done in Asian and European countries for centuries. It has only been practiced in the United States for about the last five years, however. Tomatoes are getting most of the attention at the moment, but other vegetables are starting to be grafted and sold to gardeners and market growers alike.

Building a case
Grafted vegetables not only create an opportunity for growers, seed suppliers and retailers; they may actually become a necessity as growers everywhere struggle with soil-borne pathogens such as verticillium, fusarium wilt, corky root rot, root-knot nematodes, bacterial wilt and southern blight.

There are many other benefits to grafting vegetables besides the incredible disease resistance that wild rootstocks provide, according to Alice Doyle of Log House Plants in Cottage Grove, Ore. In the case of tomatoes, grafting results in increased vigor, enabling the plants to start better in cool climates and grow well into fall, she says.

Chelsey Fields, vegetable product manager for W. Atlee Burpee, agrees. “One of the benefits is you can go into a little cooler soil, start them a little earlier,” she explains.

Grafted tomato plants also do well during the heat of the summer, still setting fruit when the temperature hovers around 90 degrees, Doyle says. This is unlike seed-grown tomatoes, which stop initiating flowers at 86 degrees. Grafted plants also tend to bounce back after a drought, while seed tomatoes continue to languish from the heat. Heirlooms, which are particularly susceptible to soil-borne disease and struggle to ripen in the northern climates, will particularly benefit from being grafted, Doyle says.

One thing everyone will love about grafted tomatoes is their incredible crop yield, says John Bagnasco, president of GardenLife and co-host of a national radio show that offers gardening advice and introduces new vegetable varieties.

“We do trials all over the country,” he says. “We trialed Indigo Rose, a variety developed by Oregon State University.”

Indigo Rose is a tomato highest in antioxidants and is traditionally bred with a wild species from the Galapagos Islands. “We grafted the Indigo and had great results, three times the weight and three times the fruit,” Bagnasco says, adding that grafted tomatoes will produce at least double the amount of tomatoes as seed-grown plants.

The grafting process
Grafting vegetables is a process that involves joining a scion to a hardy rootstock. This is done in a clean, environmentally controlled greenhouse or in a lab. Many growers, like Joelene Jebbia of Gathering Together Farm in Philomath, Ore., say they use inexpensive covered chambers to trap in the humidity while the graft union forms. Jebbia’s farm grows grafted tomatoes in the ground in high tunnels for the fresh vegetable markets it serves.

“We started out not knowing anything about grafting tomatoes,” says Jebbia, who is now producing 6,000 to 8,000 grafted plants per year. “Read everything you can about it. YouTube offers some good videos on grafting vegetables.” Among other things, the YouTube videos show different types of grafts, such as the side veneer and splice, and options for clips to hold the scion and rootstock together until they fuse.

All the tomato varieties we enjoy eating in the United States, be they hybrid, heirloom or open pollinated, are of the same species, says Doyle. The rootstocks currently being used for grafting are hybrids of wild species that can’t produce an edible tomato but do have important innate disease and soil-borne pest resistance. What’s more, they can be grafted to any type of tomato.

Growers have differing opinions on what the best variety of rootstock is for grafting vegetables, but all agree it should be a generative rootstock — one that produces prolific buds and fruit — as opposed to a vegetative rootstock that produces a lot of foliage and fewer buds. The latter can be a particular problem for greenhouses and high tunnels (as well as the home gardener), so it is particularly important to use generative rootstock in these growing situations.

Mark Willis of Harris Seeds grafts plants for his company’s mail order business. He says they’ve tested the Maxifort and Beaufort, two popular tomato rootstocks that may be too vegetative for the home gardener. Right now, he is grafting with the RST-04-105-T tomato rootstock. He says he allows the grafted plants to fuse in a clean lab that is equipped with the usual environmental controls found in a greenhouse.

A rock star rootstock
The rootstock that appears to be sweeping the country is SuperNatural, which is the choice for Plug Connection’s 39 grafted varieties that comprise the Mighty ‘Mato line of tomatoes. SuperNaturals Grafted Vegetables LLC/Plug Connection is the largest producer of grafted young vegetable plants in the United States, says Bagnasco. They also graft other plants that carry the Mighty Veggies label, so be on the lookout for grafted eggplant, peppers, cucumbers and melons. Growers and gardeners can also purchase SuperNatural rootstock and seed from www.territorialseed.com and www.awhaley.com.

Retail opportunity
Bagnasco says he is convinced that the market is there for grafted vegetables, but the problem may be availability — at least in the short run.

“You don’t have to create a market yourself, look and see what is going on around the world,” he says. “A billion grafted plants were grafted in 2011. It is something that is catching on here.”

Doyle says retailers need to educate consumers on the advantages of grafted vegetables and why they should pay more (up to $8 a plant for the home gardener) than they would for plants grown from seed. When ordering liners, retailers should make sure they’re ordering vegetables that have been grafted to a desirable rootstock and that the plants are packaged properly.

The finishing of the plants can take place in any greenhouse with the desirable conditions for good growth. When transplanting to pots, keep the graft line as high as possible so that the gardener can easily keep it high. If the scion should root, the benefits of using a souped-up rootstock will be compromised, adds Doyle.

Other vegetables are being grafted, but they may not be as high-yielding as the grafted tomatoes. For instance, grafted peppers have about a 30 percent yield right now over seed-grown peppers, according to Bagnsco. Though this is a smaller increase of yield than tomatoes, he says a 30 percent increase in production is still significant for any grower, and it may improve as the technique is perfected.

Grafting Resources

Sources for grafted liners for tomatoes and other grafted plants:
www.plugconnection.com; Burpee Home Garden Bumper Crop, www.ballseed.com

Sources for wholesale grafted vegetable plants:
www.loghouseplants.com; www.harrisseeds.com; see www.mightymato.com for retail locations and contact Plug Connection for local wholesalers

Sources for individual grafted plants to trial:
www.gardenlife.com; www.territorialseed.com; www.jungseed.com

Sources for rootstock seed and clips:
www.johnnyseeds.com; www.territorialseed.com; www.awhaley.com

For information on grafting tomatoes and other plants, visit http://cals.arizona.edu/grafting/home

Neil Moran is a horticulturist and regular contributor to Produce Grower. Visit his website at www.neilmoran.com.

All photos courtesy Log House Plants (www.loghouseplants.com)

Postharvest Technology Short Course
When: June 17-28
Where: Davis, Calif.
The University of California, Davis will offer a two-week course focused on the biology and technologies of handling fruits, vegetables, nuts and ornamentals in California. The lecture and field trip is open to 55 participants, and the lecture-only course is open to 25. Enrollment will be treated as first-paid, first-enrolled.
postharvest.ucdavis.edu

Produce Marketing Association Foodservice Conference and Exposition
When: July 26-28
Where: Monterey, Calif.
Providing the opportunity to meet with foodservice leaders throughout the industry, the Produce Marketing Association Foodservice Conference and Exposition will offer attendees an environment in which to network with one another, learn about new products and services and much more. The annual event reportedly has a 93 percent exhibitor approval rating.
fsc.pma.com

The Packer’s Midwest Produce Conference & Expo
When: August 10-20
Where: Chicago
Bringing together leading produce growers, suppliers, wholesalers, distributors, retail executives and more, The Packer’s Midwest Produce Conference & Expo is intended to fill a niche in the region by merging a conference program, networking events and a retail tour with an industry expo.
midwestproduceexpo.com

Produce Inspection Training Program
When: Sept. 10-14
Where: Fredericksburg, Va.
In partnership with the USDA-AMS, the United Fresh Foundation is offering three produce inspection training courses in 2013. Attendees will have hands-on instruction from USDA expert and learn about quality control standards, inspection grading, USDA produce procedures and requirements, and more. Developed into two courses, participants will first take Fundamentals of Produce Inspection and then Commodity Labs.
unitedfresh.org/programs

PMA Fresh Summit International Convention & Exposition
When: Oct. 18-20
Where: New Orleans The Fresh Summit is an opportunity for growers, retailers, processors, suppliers, wholesalers and more to meet and stay up-to-date on the global supply chain. More than 20,000 industry professionals from more than 60 countries convene to obtain information about global connections, consumer insights and more.
freshsummit.com

Spending in 2013 depends on your point of view

Retailers and consumer packaged goods experts gauging consumers’ spending prospects see a divided America whose financial expectations for 2013 vary with the camp they’re in.

On one hand, stockholders and homeowners with high-equity positions in their property feel a wealth effect from recent gains in stock and home prices and may be more optimistic and inclined to spend more.

Consumers like these who want to create distance between them and the recession could shift from comfort foods to more extreme, experimental behaviors that embody “risk taking, playfulness, courage and vulnerability,” says a new Culinary Tides report titled “Top 10 Trends Analysis – Shifting Sands 2013.”  

On the other hand, much of the nation continues to spend cautiously because they struggle financially. The impact of the 2% payroll tax on national spending figures has been dulled so far by Federal Reserve monetary support driving the recovery. Yet BNP Paribas economist Yelena Shulyalyeva told Reuters she expects “a significant decrease in real consumer spending in the first half” of 2013. Retailers tell The Lempert Report they believe the same due to the lack of real wage growth, high unemployment rates (7.7%), and rising food, gas and healthcare costs.

For instance, many elderly make tough choices everyday between buying food and medicine. A new University of Georgia study documents that nearly half (48.7 percent) of food-insecure Medicare patients also don’t adhere to their medication regimens.

Moreover, parts of the nation beset by natural disasters — among them fires in the West and Hurricane Sandy floods in the East — hurt residents who are attempting to rebuild, often on their own.

It isn’t surprising then that 28 percent of Americans aren’t confident about saving enough money for retirement, and only 13 percent are “very confident,” according to the Employee Benefit Research Institute (EBRI). This is the highest anxiety level in the 23 years EBRI has tracked this.

And a new Pew Research Center study says 32 percent of U.S. moms with children under 18 would prefer to work full-time, up from 20 percent in pre-recession 2007 — a probable sign of the urgency they feel to make ends meet.

Source: The Lempert Report/Supermarket Guru

Did you know?
Only 13 percent of Americans are “very confident” about saving enough money for retirement. (source: Employee Benefit Research Institute)