by Grace Dannemiller, Agribusiness and Applied Economics major

What is Late Blight?

Late blight is a pathogen that affects green and ripe tomatoes when the weather is cool and humid by blighting the part of the plant that is visible. Late blight is most commonly found in potatoes, but is also having a major impact in the tomato industry.

How does it survive?

The pathogen survives primarily from infected abandoned, volunteer, and culled tomatoes. Late Blight can easily be dispersed by the wind and can infect a large area in a short amount of time. Once a plant is infected, it must be culled to prevent the disease from spreading to neighboring plants.

How can it be prevented?

Studies done at Michigan State University have been testing fungicide products to manage late blight. Results of these tests have shown a nearly 66% decrease in the diseased leaves as a result of treatment. In addition, the treatment also reduced the amount of rotted fruit.

Recommendations?

As the test above has shownn with treatments the disease can be managed quite well if applied following recommended guidelines. It is important to be aware of what diseases are happening around your area so that you can start treatments before the disease runs its course. Late Blight products that could be used for prevention include Ranman, Revus, Gaval, and many more (Late blight threatens Michigan tomates).

To learn more please visit Michigan State University’s website:
msue.anr.msu.edu/news/late_blight_threatens_michigan_tomatoes

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This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

by Nate Detweiler, Sustainable Plant Systems major

Xanthomonas Bacterial Wilt (XBW) is a disease that is severely effecting banana production in many East African countries. Originally observed in Ethiopia in 1968, Xanthomonas has spread to most of the Great Lakes region and has been observed in Uganda, Democratic Republic of Congo, and Rwanda to name a few of the countries affected.

XBW is important because no banana cultivar has shown resistance to this disease. Banana is a staple source of both food and also income for many poorer farmers in this region. Many farmers and land holders are aware of XBW but do not necessarily take precautionary disease prevention steps until the disease is present in their immediate area.

One study conducted by Kawanda Agricultural Research Institute in Uganda, found that it is important to insure that farmers are receiving a single clear message about how to control and prevent XBW. The study also indicated that the most effective method of disseminating XBW control measures was by personal instruction/ local support from sub county leaders.

Promising research on breeding transgenic banana cultivars that are resistant to XBW is currently be conducted by the International Institute of Tropical Agriculture in Uganda. A gene from sweet peppers has been introduced in to several banana cultivars. This gene is responsible for a hyper-sensitive response in peppers. Basically the hypersensitive response is where a plant senses an invading disease and responds by programed cell death in the local area of of the disease entrance.

Xanthomonas Bacterial Wilt is very interesting and also extremely important because of the millions of farmers and people who rely on banana as a core part of their diet.

Sources

Bagamba, F., Kikulwe, E., Tushemereirwe, W., Ngambeki, D., Muhangi, J., Kagezi, G.H., Ragama, P.E. and Eden-Green, S.J. 2006. Awareness of banana bacterial wilt control in Uganda: 1. Farmers’ perspective. African Crop Science Journal 14(2):157-164.

Kubiriba J. et al. 2014. Strategies for rehabilitation of banana fields infested with Xanthomonas campestris pv. musacrearum. J. Crop Protection, 3 (1): 21-29.

Tripathi, L., Mwaka, H., Tripathi, J.N. and Tushemereirwe, W. 2010. Expression of sweet pepper Hrap gene in banana enhances resistance to Xanthomonas campestris pv. musacearum. Molecular Plant Pathology, Nov 11(6):721-31.

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This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.