INTRODUCTION
Coffee is the most important agricultural commodity with an estimated retail value of 70 billion US dollars. It is also crucial for the economy of more than 60 countries as it the main income earner for more than a 100 million households.
Coffee leaf rust (CLR) is a major disease of the coffee Arabica species. It causes a major adverse economic effect and has been reported in over fifty countries. Coffee leaf rust infestation on a farm causes up to 50% leaf loss and up to 70% berry loss.
Coffee leaf rust is a major disease in coffee Arabica and was discovered in 1970.
APPEARANCE
CLR is characterized by small yellow-orange and powdery spots/lesions. Rust pustules are powdery on the under leaf surface while chlorotic patches are observed on the upper leaf surface later they turn black. Rusted leaves drop so that affected trees are virtually denuded, such trees have a lower yield and quality.
LIFECYCLE
Coffee leaf rust is caused by a fungus hemileia vastatrix. This disease is spread by spores from lesions on the underside of leaves by wind and rain. Under humid conditions hyper-parasitic fungi grow over there e lesions which produce a pale micellial growth.
CLR spreads through the germination of uredospore through germ pores in the spore. These spore attack the leaf and mature within 24-48 hours while sporulation takes place through the stomata within 4-6 days. Suitable temperature for the development of the mycellium is not less than 10 degrees and not more than 35 degrees celcius and presence of free water. Sporulation is influenced by temperature, humidity, and host resistance.
ECONOMIC IMPACT
CLR has both direct and indirect impacts on coffee production. Direct impacts include loss of quantity and quality of harvested crop. Indirect impacts include increased cost to control and combat the disease including stumping diseased plants and replacing them. The most common methods used for controlling the disease include:
1.planting resistance varieties -Ruiru 11 and Batian
2.Fungicide application.
For preventive measures copper based fungicides are used while for curative application of systemic fungicides are used.
Due to in adequate rainfall received this season coffee leaf rust will be a major disease for August, September and October due to climate change . As a partner in coffee farming Greenlife Crop protection Africa limited advice coffee farmers to take caution and treat the disease before it attack their crops.
Greenlife Crop Protection Africa limited offers farmers the best solution to control coffee leaf rust.
- RANSOM
It is a systemic fungicide used for both preventive and curativeand purposes against coffee leaf rust. It contains two active ingredients carbendazim and triadimefon. It’s mode of action is that it binds to a site on the tubulin and suppresses microtubules assembly. It is used both as a protective and curative and product. RANSOM is recommended at a rate of 12g/20l of water plus Integra at 3mls/20l.
- GREENCOP
It is a preventive fungicide against coffee leaf rust.Greencop contains copper oxycloride at 97% thus is the purest in the market, it extra fine and dissolve completely when mixed with water and thus leaving no residual.
Copper has majorly been known as a molecule to control coffee leaf rust and other fungal diseases. Greencop is used at a rate of 70g/20l plus Integra 3ml/20l.
- DEFACTO
This is a systemic fungicide which bears both preventive and curativeand action against coffee leaf rust. It contains two molecules propiconazole and difeconazole. Its mode of action is stopping cellular growth, preventing development of fungus by inhibiting cell membrane ergosterol biosynthesis. It is applied at a rate of 10-13mls /20l and include Integra 3ml/20l
These products are readily available in all stockists and wholesaller shops countrywide.