Coffee is a highly valuable agricultural commodity, estimated to be worth around 70 billion US dollars. It plays a crucial role in the economies of over 60 countries and serves as the main source of income for more than 100 million households.
Coffee leaf rust (CLR) is a significant disease that affects the coffee Arabica species. It has a major negative economic impact and has been reported in more than 50 countries. Infestation of coffee leaf rust can cause up to 50% leaf loss and up to 70% loss of berries.
CLR is characterized by small, yellow-orange, powdery spots or lesions. The undersides of the leaves have powdery rust pustules, while the upper leaf surface shows chlorotic patches that later turn black. Affected trees shed their rusted leaves, resulting in lower yield and quality.
Coffee leaf rust is caused by a fungus called hemileia vastatrix. The disease spreads through spores from lesions on the underside of leaves, carried by wind and rain. Under humid conditions, hyper-parasitic fungi grow over these lesions, producing a pale, powdery growth.
CLR spreads through the germination of spores called uredospores, which attack the leaves and mature within 24-48 hours. Sporulation occurs through stomata within 4-6 days. The development of the fungus’s mycelium requires a suitable temperature between 10 and 35 degrees Celsius and the presence of free water. Sporulation is influenced by temperature, humidity, and the resistance of the host plant.
CLR has both direct and indirect impacts on coffee production. Direct impacts include the loss of quantity and quality of the harvested crop. Indirect impacts involve increased costs to control and combat the disease, including the removal of infected plants and their replacement. The most common methods used to control the disease are:
1. Planting resistant varieties such as Ruiru 11 and Batian.
2. Application of fungicides.
Copper-based fungicides are used for preventive measures, while systemic fungicides are applied for curative purposes.
Due to inadequate rainfall received this season, coffee leaf rust will pose a significant threat in August, September, and October due to climate change. As a partner in coffee farming, Greenlife Crop Protection Africa Limited advises coffee farmers to take precautions and treat the disease before it attacks their crops.
Moiben Connections Limited offers coffee farmers the best solution for controlling coffee leaf rust.
RANSOM is a systemic fungicide that serves both preventive and curative purposes in combating coffee leaf rust. It consists of two active ingredients, carbendazim and triadimefon. The fungicide functions by binding to a specific site on tubulin, thereby inhibiting the assembly of microtubules.
It can be applied as a protective measure or as a curative treatment. For effective usage, RANSOM is recommended to be applied at a rate of 12g per 20 liters of water, along with the addition of 3mls of Integra per 20 liters of water.
Greencop is a highly effective fungicide designed for the prevention of coffee leaf rust. It contains 97% copper oxychloride, making it the purest and highest quality product available in the market. Its extra-fine formulation ensures that it dissolves completely when mixed with water, leaving no residue behind.
Copper has long been recognized for its efficacy in controlling coffee leaf rust and various other fungal diseases. To ensure optimum results, Greencop is recommended to be used at a rate of 70g per 20 liters of water, along with the addition of 3mls of Integra per 20 liters of water.
This particular fungicide is a systemic solution that offers both preventive and curative effects against coffee leaf rust. It consists of two active molecules, propiconazole and difeconazole. Its mode of action involves halting the growth of cells and preventing the development of the fungus by inhibiting the biosynthesis of ergosterol, an essential component of the cell membrane.
For effective application, it is recommended to use this fungicide at a rate of 10-13mls per 20 liters of water, along with the addition of 3mls of Integra per 20 liters.
These products are readily accessible at all stockists and wholesale shops throughout the country.