World Coffee Research says fighting coffee leaf rust through genetic resistance via F1 hybrids ‘is an effective tactic’ but won’t be enough to protect farmers from significant crop losses.
In a presentation at the 2018 ASIC event in Portland, Oregon, World Coffee Research Scientific Director Dr Christophe Montagnon said some coffee varieties’ rust resistance has been proven to break down, with the latest example being the Lempira variety from Honduras’ IHCAFE.
Dr Montagnon told attendees that researchers believe it is only a matter of time before rust resistance in most resistant varieties is going to break down, perhaps in as soon as 5-10 years in many countries.
This development highlights the need for farmers to focus on plant health no matter the variety of their coffee.
Secondly, those traveling between origin countries must develop a heightened sensitivity and awareness for appropriate phytosanitary practices to prevent spreading fungi and other diseases from farm to farm or region to region.
Thirdly, the coffee industry needs to prioritize ongoing research and development. New sources of rust resistance can be found and must be discovered to foster sustainable coffee production.
Coffee’s scientific community, led by World Coffee Research in collaboration with coffee-producing countries, and with the support of the broader coffee industry, must seek to produce new solutions, new technology, and new ways of combating plant disease, Dr Montagnon said.
A crucial part of rust-control strategies going forward, according to World Coffee Research and others in the scientific community, is the promotion of plant health in coffee production, which has been overlooked in the past.
Just as humans are more likely to be healthy if they exercise well and eat good food, coffee is better equipped to defend against rust when it is in good health. Factors contributing to plant health include good maintenance, soil conservation, adequate plant nutrition, and adequate shading.
A recent study from World Coffee Research and CIRAD recently showed that good fertilization can be as effective as spraying fungicide in protecting a genetically susceptible coffee to rust. Furthermore, it is acknowledged that one of the main reasons for the 2012 rust crisis in Central America was farmers’ reduced maintenance of their trees, itself due to low prices of coffee.
A plant’s health, or inherent vigour, is also dependent on the plant’s genetics and maintenance. F1 hybrids are inherently vigorous due to ‘hybrid vigour’ and are hence benefiting from their plant health to defend against rust, even if they don’t bear the rust resistance genes.
Beyond promoting plant health, World Coffee Research is committed to R&D work to develop new solutions, which will be described in the November 2018 issue of Coffee & Cocoa International.