What is the basic knowledge of leaf rust coffee

Coffee leaf rust was discovered in Central America as early as 40 years ago, but recent outbreaks in Central America (Colombia, Costa Rica, El Salvador, Guatemala, Nicaragua) and Mexico are by far the most serious, and Guatemala, Honduras, Costa Rica and other countries have declared national emergencies.

Guatemala's president says leaf rust will reduce coffee production by 40 percent in Guatemala's 2013 - 14 season. Guatemala accounts for 14 per cent of global green coffee production, so rising coffee prices are inevitable.

During the past 20 to 25 years, global demand for green coffee beans has been strong. In order to increase production, many coffee farmers in Central America abandoned traditional shade-growing techniques and adopted the "sun exposure" method to grow coffee. The loss of canopy protection reduces biodiversity, and pest control relies more on the use of pesticides and fungicides, which not only disrupts the complex ecological network, but also reduces or even disappears the white-half fungus that controls insects and coffee leaf rust, resulting in widespread outbreaks of leaf rust.

More seriously, the deterioration of the ecological environment and ecosystems may lead to more complex problems.

The unanswered question is: Is this massive leaf rust outbreak a single event or the debut of a new normal?

Leaf rust is the most serious coffee disease. It first appeared in the Victoria Lake coffee producing area of East Africa in 1861. It ravaged Sri Lanka in 1867, causing the destruction of the coffee industry in Sri Lanka. It soon spread to many parts of Southeast Asia and finally affected the coffee producing areas of southern, central and western Africa.

Until 1970, leaf rust had not been found in the Western Hemisphere until an outbreak in Bahia, Brazil, and since then leaf rust has been found in all coffee producing areas worldwide.

Leaf rust mainly infects coffee leaves, buds and newly produced coffee berries, which in turn causes coffee trees to die; coffee rust spores spread lesions on the underside of leaves through wind and rain.