About the Genus Phakopsora

Introduction

The Genus Phakopsora is a plant disease that is caused by fungi and generally affects legumes. This fungal disease has been known to have a devastating effect on crops in the humid regions of South America, Asia, Africa, Australia and some parts of the United States of America. The disease caused by this disease is also commonly known as Asian soybean rust and is caused by two types of the fungi, namely Phakopsora phachyrhizi and Phakopsora meibomiae. The latter is weaker than the first and has not been known to cause as widespread damage as its cousin. The Genus Phakopsora has been kept in check by the fact that it does not thrive in cold areas like the North where the winters are unforgiving.

History

The origin of the Genus Phakopsora can be traced from far as the two genera of the fungi came from different parts of the continent. The devastating Phakopsora phachyrhizi originally came from Asia- Australia while the more docile Phakopsora meibomiae came from Latin America. The spread of the aggressive strain can be documented as recently as 1990s when it entered Hawaii, into South America in 2002 and finally found its way into the United States of America. What helped the Genus Phakopsora to spread so rapidly was the fact that it is propagated by wind borne spores and these were aided by the constant Caribbean hurricanes. This is suspected to be the case with spores carried from Venezuela to the United States on Hurricane Ivan winds in 2004.

Features

The Genus Phakopsora has been known to affect other types of legumes apart from the soy bean. The most effective way of preventive an attack of the crop is by treating the seed with prothioconazole , a salt or an adduct. If the bean is treated before planting or the crop sprayed with fungicide upon presentation of the disease, then its prevention and treatment are found to be effective. A popular herbicide used for this treatment is called Glyphosphate.

When a plant is infected, brown lesions appear on the leaf and they may appear to have characteristics of chlorosis that may also look like small volcanoes. The lesions usually appear on the lower leaf but may appear on the upper side in extreme cases of Genus phakopsora infestation. The lesions enlarge fast and within five to eight days, the disease is fully manifested. Uredia then develop and release uredospores once the ostioles open leading to a new cycle of life.

Comments

Most Recent Articles