Hybrid poplars are among the fastest-growing trees in North America and are well suited for the production of bioenergy (e.g., heat, power, transportation fuels), fiber (e.g., paper, pulp, particle board, etc.) and other bio-based products (e.g., organic chemicals, adhesives). Because poplar trees have so many economic, environmental and agricultural advantages, it is important they are protected.
John Brown, WSU professor, scientist and extension specialist, is leading an award-winning team that is completely revamping the pattern of insecticides used to protect poplar trees. A driving force for this effort is to have the lumber sold under a Forest Stewardship Council certification program.
“When we started our Integrated Pest Management program, poplar growers were relying on broad spectrum insecticides,” Brown explained. “Now they use sex pheromones, insect growth regulators, and systemic nicotine mimics which are delivered through a drip line.” These methods are more environmentally friendly and won’t hamper biological control.
The research team started with a basic laboratory discovery of the pheromone for the Western Poplar Clearwing Moth and developed an EPA-registered insecticide in just four years that disrupts the mating process. The pheromone is aerially sprayed in microcapsules over the poplar trees each month from April to September so that the male moths cannot find the females.
Brown says that his team also is developing a modified Attract-and-Kill strategy where the males of a specific insect species are lured to a synthetic pheromone. When the male insect approaches the pheromone source, it comes into contact with a killing agent.
Insect growth regulators are another method used to protect poplars. “We use insect growth regulators that prevent insect larvae from successfully molting but are not toxic to adult insects, so beneficial insects such as parasites and predators are not harmed,” Brown explained.
Currently, the team is experimenting with tree injection technology to introduce insecticides directly into individual trees. This method is labor intensive but could provide multiple year protection to the trees.
Brown’s research team received both regional and national IPM Team Awards for their Poplar Protection Program in 2006.
Tree Fruit Genomics: Developing a Stress-free Future
It takes the new science of bioinformatics to find the needle of knowledge in the haystack of information created by a genome map.
In search of the needles that will guide tree-fruit breeders, WSU bioinformaticist Dorrie Main is combing through the haystack of the rosaceae family. Rosaceae includes the rose but, more importantly, Washington’s largest crop–apples–as well as cherries, peaches, berries and nuts. In terms of economic volume, rosaceae is the third most important family in the U.S. and other temperate regions of the world. Its aggregate wholesale value in the United States is approximately $7 billion.
“We take all of the known genes in the public gene bank and analyze them based on function,” said Main, associate professor of horticulture and a scientist in the WSU Agricultural Research Center. “We are looking at 250,000 gene fragments and pulling out what’s meaningful.”
A self-identified “data miner,” Main uses a 128-processer computer to store and evaluate the international Genome Database for Rosaceae, the repository for the rapidly growing haystack of genetic information about the family.
The meaningful needles pulled from the haystack are then turned over to horticultural genomicists Amit Dhingra and Cameron Peace, both assistant professors and scientists in the WSU department of horticulture.
“Tree-fruit genomics,” said Dhingra, “is dedicated to the task of developing useful new varieties based on a large body of knowledge. It’s so large that we need bioinformaticists like Dorrie and her computers to narrow the search.”
The two genomicists work with growers to identify desirable traits. “Growers are the real scientists,” said Dhingra. “They have all sorts of knowledge gained in the fields and orchards that guide us in our research. Basically, though, what we’re all looking for are new varieties that can resist stress—the stress from pests, diseases, climate, and so on. The growers know what they want. We want to help them get there.”