What started in the 1960s as a vegetable farming operation, Tagawa Greenhouses has evolved into one of North America’s top young plant producers. Set up by five Tagawa brothers, its core values remain the production of high quality plants, excellent customer service, honesty and integrity. The company also enjoys a reputation for innovation − holding several patents for greenhouse growing and manufacturing processes. Today, working with Biobest, Tagawa Greenhouses leads the way implementing biocontrol in North American ornamental plant production. Using careful scouting and preventative introductions of the right biocontrol agents (BCAs), the team has demonstrated IPM can be successful in shorter spring crops.
Charlie McKenzie is the site manager at the company’s 20 acre New Mexico site, one of three Tagawa growing facilities. In addition to an acre of geranium mother stock for cuttings production, he oversees bedding plant, pot mums and poinsettias production at the site.
An enthusiastic young grower, Charlie is also passionate about entomology. “As a grower you can control light, moisture, temperature, nutrients and growth but insect pressure is one variable that is very difficult to control,” he says. Early on in his career an aphid outbreak devastated part of a pot mum crop, even though it was thoroughly sprayed with chemical pesticides. This proved a turning point. Convinced there had to be a better approach, Charlie began to take an interest in biocontrol.
Charlie started out with a bio programme for the 2014 mum crop, which typically has high pest pressure. In the first year this was quite a struggle. Towards the end of the season, the team resorted to spraying part of the crop with chemicals. But Charlie was determined to succeed and, with the owner’s approval, set out to implement an ambitious full biocontrol programme on a quarter of the greenhouse.
A timely call from Biobest’s technical representative Emiel Vanderwel saw the two join forces. “Emiel’s knowledge, growing experience and enthusiasm impressed me and we have developed a strong working relationship,” says Charlie. “For biocontrol to work you have to look at programmes on a crop-by-crop basis taking in to account factors such as when it is being grown, where, how and the likely insect pressure.”
“Each crop type requires a different biocontrol programme which must be fine-tuned as the pest pressures constantly evolve and change,” says Charlie. Successful programmes have been implemented across the full range of crops to control pests including whitefly, two-spotted mite, thrips, various aphid species, fungus gnats, shorefly and Lepidoptera.
“Thorough pest monitoring and scouting is the key to success,” says Charlie. “As our former CEO Ken Tagawa told me, if you pay attention to the details, all the bigger things work out – this couldn’t be more true for biological control.”
“Charlie employs rigorous methods involving sticking traps and physical scouting of the crop at least once a week,” says Biobest’s Emiel Vanderwel. “Pots are turned over, leaves shaken and a sample examined under the microscope. Employing a highly disciplined approached, all the data is collected and inputted in to the Greenhouse Scout app.”
“As to beneficials, where possible we take a preventative and programmed approach. Good examples include Californicus-Breeding-System to control two-spotted spider mite; Swirskii-Breeding-System to control thrips and whitefly and Eretmocerus-System and Encarsia-System for whitefly control.
“Should we still detect any pest hotspots, then we release other biocontrols with “curative” action in the programmes. Here good examples are Delphastus-System for whitefly, Chrysopa-System for aphid and Phytoseiulus-System for two-spotted spider mite control."
“It is impossible to argue against biocontrol if it works as well, or better, and is competitive in cost compared to traditional pesticide use,” he says. “There are really many benefits: better staff health and safety, more vigorous and healthier plants and, a reduction in environmental impact. Switching to biocontrol has also increased employee interest in the crop. In the end, the most important benefit is that customers are very enthusiastic and love the idea of residue free plants – we see it as a useful point of difference and a strong marketing and sales tool for the future.