At a recent Kona Coffee Farmers Association meeting, researchers from the Pacific Basin Agricultural Research Center brought new information to a crowd of coffee farmers and concerned citizens about ways to diminish the impact of the coffee berry borer on
At a recent Kona Coffee Farmers Association meeting, researchers from the Pacific Basin Agricultural Research Center brought new information to a crowd of coffee farmers and concerned citizens about ways to diminish the impact of the coffee berry borer on Kona’s coffee crop.
The beetles enter coffee cherries as they develop and consume the bean inside. The damage they cause diminishes the quality of Kona coffee, marring its appearance and taste. This critter is plaguing the Kona coffee industry, affecting almost every farm in Kona’s prime coffee belt.
At the meeting, Tracie Matsumoto from the center reported on her research into ways to create synchronous flowering in coffee. Using two Organic Materials Review Institute-approved compounds, she has been able to combine the multiple coffee flowering rounds into fewer, larger rounds with increased yields. The first and last rounds, which are often small and uneconomical to pick, are combined into larger rounds in her tests. This means that the final round where the raisins, or old unpicked cherries, are removed could be a more cost-effective round. If her technique proves affordable, it could certainly make it worthwhile to clean the trees of borer breeding sites. For more information on her work, contact her at 959-4358 or Tracie.Matsumoto@ars.usda.gov.
Lisa Keith and Robbie Hollingsworth reported on their research into the efficacy of the commercial fungus Beauveria bassiana currently being used against the borer, which is very similar to our naturally occurring fungus. Keith and Hollingsworth are researching the ideal conditions for the fungus to remain effective. They have found that fungus populations vary widely based on weather conditions and amount of sunlight on different farms. B. bassiana seems to live longer on farms at higher elevations where the ambient conditions are often cooler and wetter. Spraying once per month seems to be adequate under ideal conditions. You can contact LisaKeith@ars.usda.gov or Robert.Hollingsworth@ars.usda.gov for more information on their research.
Another speaker, from the U.S. Department of Agriculture, reported on his research into bait compounds for traps. Although prior research indicated the current bait compound being used for berry borer traps draws and captures some beetles, it is not effectively reducing the beetle population. USDA researchers are examining a variety of volatiles from coffee trees in an attempt to identify a substance that will draw and destroy more beetles in traps.
Studies conducted by a committee including members of the Kona Coffee Farmers Association; Andrea Kawabata from the University of Hawaii College of Tropical Agriculture and Human Resources; Rob Curtiss, a state Department of Agriculture entomologist; and representatives from other organizations have resulted in additional new information.
The committee advises coffee farmers to increase the amount of B. bassiana fungus they apply to 32 ounces per acre in order to maintain an effective amount in the fields. This is based on USDA tests done in Keauhou showing that dosages of more than 21 ounces have an effective kill rate that lasts at least 30 days. A forum on mixing rates can be found on the association’s website.
The group also reported finding that the most effective way to reduce coffee berry borer populations is to strip the trees at the end of the harvest before pruning or the first flowering. Removing all cherries and spent cherries at this time seems to be the best way to reduce borer breeding sites. Their studies also indicated that although traps do not effectively reduce borer populations, they do serve as helpful devices in monitoring spikes in beetle population.
Although the committee found little borer activity in raisins that have fallen on the ground, some farmers reported spraying to contact fallen raisins can help control ground-based breeding sites.
An accurate way of determining the size of an infestation and the best time to spray is to use the 30 tree sampling method taught by Luis Aristizabal at a KCFA workshop last August. Suzanne Shriner from KCFA recently offered a refresher course on this method at the April Coffee Talk. If you missed her course you can download Aristizabal’s original presentation from the KCFA website at konacoffeefarmers.org/wp-content/uploads/2012/08/Monitoring-CBB-making-decisions-PRESENTATION.pdf. Using it can help maximize the efficacy of the fungal spraying program for individual farms.
This pest’s arrival has had severe consequences for Kona coffee farmers and, by extension, the economy of the region. It is important for our community to have the latest information on this pest. Everyone’s help and support is important in getting the pest under control. The KCFA keeps a constant update on cbb developments on their website konacoffeefarmers.org. Check it out. Stay informed.
Tropical
gardening helpline
Kathy asks: I like growing Genovese basil for my pesto, but it seems to struggle here. I noticed in a local nursery herb garden that the tulsi and Thai basil were thriving. Why is my Genovese so scrawny and sensitive by comparison?
Answer: Most of the 40-plus basil varieties can trace their heritage to distant relatives native to various parts of India.
Genovese basil is a cultivar that was derived from Ocimum basilicum, or sweet basil. It is best known as a culinary herb prominently featured in Italian cuisine. It has been cultivated in Italy for centuries and has become acclimated to the dry, temperate climate of the area around Genoa. Genovese basil probably struggles to adjust to our nearly year-round warmth and humidity. Its fleshy leaves are particularly vulnerable to diseases that wet, rainy weather encourage.
Tulsi, or holy basil, Ocimum tenuiflorum, is native to the tropical areas of India and of other Eastern world countries. With centuries of cultivation in the tropics, holy basil is much heartier in climates like ours. This plant grows well here and can grow into a beautiful shrub with small pointed leaves on long graceful stems topped with lovely purple flower racemes. The plant is of spiritual importance in its native cultures and also has many culinary and medicinal uses.
Thai basil is another tropical variety, Ocimum basilicum var. thyrsiflora. It is actually a type of sweet basil that is native to Southeast Asia and has been cultivated to encourage particular traits including its distinctive flavor. It is nearly ubiquitous in Thai soups, stews and curries, adding a hint of flavor reminiscent of licorice and clove. Thai basil exhibits small, narrow leaves, purple stems and a light purple flower.
If you want the flavor of Italian or sweet basil in an attractive and somewhat heartier plant that seems to do well in our climate, look for Pesto perpetuo, Ocimum basilicum x citriodorum. It is a variegated form of Greek columnar basil. It’s sterile, so it doesn’t produce flowers or seeds. Pesto perpetuo is a superb culinary plant and its light green and cream variegation makes it an eye-catching specimen. In ideal conditions it can grow to a small upright shrub 3 or more feet tall.
All basil plants have slightly different flavors but most can be enjoyed in pesto or to flavor stews or soups. Grow several varieties to find one that grows well in your microclimate and has a flavor you enjoy.
Email plant questions to konamg@ctahr.hawaii.edu for answers by certified master gardeners. Some questions will be chosen for inclusion in this column.
Diana Duff is a local organic farmer, plant advisor and consultant.
