Black Rot Disease Hits Uganda

A photograph of a cabbage leaf showing symptoms of black rot. Image by USDA Forest Service via Wikimedia Commons (CC-BY 3.0)
A photograph of a cabbage leaf showing symptoms of black rot. Image by USDA Forest Service via Wikimedia Commons (CC-BY 3.0)

Vegetable farmers in the Kayunga and Mukono districts of Uganda are reporting crop losses due to black rot disease. One farmer, Twaha Kahooza of Kyampisi village, Kayunga Sub-county, says he had planted four acres of cabbages and was expecting about Shs18m (about £4,500 or US$7,000) from the harvest, however he only managed to get Shs5m (about £1,200 or US$2,000).

Black rot is caused by the bacterium Xanthomonas campestris pv. campestris and is one of the most destructive diseases of cabbage and other crucifers such as  broccoli, brussels sprouts, Chinese cabbage, collards, kohlrabi and mustard. The disease is usually most prevalent in low lying areas where plants remain wet for long periods. The disease is characterized by a yellow V-shaped lesion at the leaf margin which turns brown as the leaf area expands. The disease can also affect seedlings and can enter the plant through insect feeding or injury to the plant. Management of black rot in crucifers includes obtaining certified, pathogen free seed, ensuring there is enough space between plants and crop rotation.To read more about black rot and black rot management visit factsheets on the Plantwise Knowledge Bank.  

To read a Plantwise Factsheet for Farmers written in Uganda click here. 

To find out more about Plantwise plant clinics running in Uganda, click here

References:

‘Farmers count losses over black rot disease in cabbage’, Fred Muzaale, April 2013, Daily Monitor 

Maize Lethal Necrosis Disease Spreads To Uganda

Maize plants showing Maize Lethal Necrosis disease © CIMMYT via Flickr (License CC-BY-NC-SA 2.0)
Maize plants showing Maize Lethal Necrosis disease © CIMMYT via Flickr (License CC-BY-NC-SA 2.0)

Maize Lethal Necrosis disease, which was first reported in Kenya and Tanzania, has now spread to Uganda, raising concerns for food security in the country. The Ministry of Agriculture has warned that Maize Lethal Necrosis has been reported in districts in eastern Uganda, including Busia and Tororo.

A spokesman for the Agriculture Research Organisation, Robert Anguzo, has said that Ugandan scientists are working in collaboration with the International Maize and Wheat Improvement Centre (CIMMYT) to find management solutions to the disease.

More information about the pests and viruses associated with Maize Lethal Necrosis and the management of the disease can be found on the Plantwise Knowledge Bank

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Plantwise Photo Of The Month- April

Participants at the first Plant Health Rally to take place in Santa Cruz, Bolivia © CABI UK
Participants at the first Plant Health Rally to take place in Santa Cruz, Bolivia © CABI UK

To read more about the work Plantwise is doing in Bolivia follow this link. To read Spanish factsheets specific to Bolivia on the Plantwise Knowledge Bank click here.

Plantwise launches in Ghana

Workshop opening ceremony included words from (l-r): Dr Victor Clottey, Dr Entsua-Mensah, Dr Samuel Kojo Dapaah and Morris Akiri © CABI
Workshop opening ceremony included words from (l-r) Dr Victor Clottey, Dr Entsua-Mensah, Dr Samuel Kojo Dapaah and Morris Akiri © CABI

Plantwise, a global initiative run by CABI, was launched in Accra, Ghana last week. The initiative involves establishing plant clinics, which farmers can attend to get advice on plant health from trained plant doctors. In addition to the knowledge they acquire through the training programmes, these plant doctors can make use of the Plantwise Knowledge Bank which provides up-to-date information to best advise the farmer.

Following the launch, a review and planning workshop took place for stakeholders in the agricultural sector.  The event attracted policy makers, extension workers, plant protection officers and researchers as well as private sector and non-governmental agencies who were all keen to share their knowledge and ideas on how to develop Plantwise activities in the country. Continue reading

Monitoring and Management of Desert Locusts in Africa

An adult Desert Locust © AtelierMonpli via Wikimedia Commons (License CC-BY-SA-3.0)
An adult Desert Locust © AtelierMonpli via Wikimedia Commons (License CC-BY-SA-3.0)

The United Nations Food and Agriculture Organisation (FAO) has this month warned that Desert Locust (Schistocerca gregaria) swarms are invading cropping areas of northern Sudan. The swarms originated from winter breeding areas on the Red Sea coastal plains and subcoastal areas in northeast Sudan and southeast Egypt. The situation requires close monitoring as more swarms are expected to form in the coming weeks that could move into parts of  Sudan and southern Egypt. If no further rains fall and the vegetation dries out, some of these swarms could move into the interior of both countries and also cross the Red Sea to the coast of Saudi Arabia.

Locusts belong to the Acrididae family (in the order Orthoptera which includes grasshoppers and crickets) and when triggered by certain cues such as increased crowding with other locusts have the ability to change their morphology, behaviour and physiology over several generations. This phase change occurs from a solitary to a gregarious phase, eventually causing the locusts to form dense hopper bands and swarms. One of the most serious locust pests is the Desert Locust.

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New Type of Invasive Whitefly Recorded In South Africa

The whitefly Bemisia tabaci (USDA image PD USDA ARS via Wikimedia Commons)
The whitefly Bemisia tabaci (USDA image PD USDA ARS via Wikimedia Commons)

A species of whitefly that transmits cassava mosaic virus has been detected in South Africa for the first time. The whitefly, Bemisia tabaci is a cryptic species complex containing some important agricultural pests and virus vectors. The term ‘cryptic species complex’ means that Bemisia tabaci is considered to be a complex of at least 24 different species that look almost identical but are in fact genetically different.  Researchers from a range of organisations including the University of Johannesburg, the University of Witwatersrand and ARC-Vegetable and Ornamental Plant Institute conducted surveys to investigate the diversity and distribution of Bemisia tabaci species in 8 provinces in South Africa. The study aimed to update the information regarding the different Bemisia tabaci types present in the country.

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Parasitic Witchweed defeated in Kenya

Striga Weed in a rice field © AfricaRice (License CC-BY-NC-ND 2.0)
Striga Weed in a rice field © AfricaRice (License CC-BY-NC-ND 2.0)

Striga, a parasitic weed (also known as Witchweed,) has long been a problem in African nations; causing farmers to lose billions of dollars’ worth of crops annually. To make matters worse, the weed flourishes in conditions that characterise that of poor farming communities (small plots, mono-cropping, lack of oxen and natural manure and lack of agricultural inputs.)

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