Eliminating potato blight disease by producing disease free seed

At an early age I had a keen interest in the field of agriculture especially with small holder farmers. In 2009 I graduated with a Bachelor of Science in Agriculture with bias in Agriculture Economics from Makerere University (Uganda). 

My quest for knowledge saw me enroll for a MSc. Agro ecology degree from Uganda Martyrs University (UMU). This interaction with my lecturers saw me develop keen interest in Integrated Crop Pest and Disease Management using good agronomic practices coupled with mainly traditional organic methods.

It was this background that the government of Uganda, in its process of formulation and operationalization of plant clinics to be run all over the 9 potato growing sub counties that comprise Rubanda District, selected me as the District Agricultural Officer, a post I have held since September 2018. The plant clinics are a good platform for me to work with small holder farmers, especially potato farmers in curbing potato blight disease using mainly traditional and sustainable organic methods.

The potato crop growing enterprise has been immeasurably ravaged by potato blight disease (phytophthora infestans). Management of this disease has increased the cost of potato production leaving some small holder farmers to abandon potato farming yet they depend on potato as a staple food. This poses a threat to food security in my District. I just can’t let this happen under my nose! Reason: Potato growing is the main economic activity and thus farmers livelihood depends on this crop for subsistence and commercial gain.

The government has tried to produce potato breeds that are resistant to potato blight disease but the seed is very expensive and still not affordable to most farmers.

Potato Blight is still one of the most infamous diseases in agriculture, causing the Irish potato famine. The potato crop, which is grown by about 300 000 smallholder households, is important in Uganda both as a food crop and a cash crop. Potato Blight disease alone is responsible for 60 percent of crop loss in potato production. Together with a group of local farmers I embarked on a process of producing potato blight disease free seed propagated from direct seeding, stem and leaf cuttings and grown on organically sterilized soils and distributing the planting materials to farmers at very low prices.

We use stem and leaf cuttings (use of organically concocted rooting hormone rooting hormone or even sometimes seradix which is an inorganic powder). Using a rooting hormone to propagate plant cuttings increases the chance that the new plant will thrive and can escape disease attack. Stem cuttings are the most commonly used on our farm, but plants can also be grown from root cuttings and leaf cuttings.

We have made it possible to produce from direct seeding. While potatoes grown from tubers or seed potatoes produce an exact genetic clone of the mother plant, those grown from true potato seed are not clones and will have different characteristics (usually very small) from the parent plant. We re-grow them 2-3 times (2nd and 3rd generations) to come up with clean seed of desirable size. We have made it possible to grow potatoes from the true potato seed. This is the most efficient and cheap way a local farmer can produce clean potato seed on his own.

Not to put my efforts to waste I am complementing my efforts with safe and efficient storage facilities and post-harvest handling methods. My main aim is to utilize some simple organic methods of pest and disease management leading to production of healthy plants by even the smallest of all small holder farmers at almost minimum cost. The aim is to make it extremely cheap and easy to protect crops especially potatoes. We are only grappling with ways to market the strategies across the whole district.

Compost manure made using indigenous knowledge like composting kitchen refuse and crop residues help to reduce susceptibility to disease attack from pathogens that may be existing in the soils.  Use of some of the high nitrogen sources like phytolacca dodecandra for composting to manure gives the new plants a nitrogen boost to survive disease attack. These are just some of the organic means of plant protection we use instead of the soil sterilization procedure.

With further support from IUPAC, any disease occurrence can easily be identified through sophiscated crop field monitoring and subsequent potato blight disease control using drone technology (covers a wide area and avoids persistent chemical usage and sometimes wastage in addition to efficiently controlling the disease).

I have introduced the growing of healthy potatoes with onions as protective measure against pathogens because onions are known to release allopathic chemicals (allelopathy is a biological phenomenon by which an organism produces one or more bio chemicals that influence the germination, growth, survival, and reproduction of other organisms) into the soil to help protect against pathogens. Coupled with the growing of tobacco on a manure-soil mixture on which seeds are to be grown as a sure way of protecting crops using organic methods.  We have registered success in this specific method as an organic measure to reduce disease infection since tobacco is known to release chemicals that kill soil pathogens.

Conclusive remarks: With the help of IUPAC 2019 I hope to extend these technologies to all farmer groups who will be able to produce clean seed, subsequently distributing it among themselves and using it as clean planting materials every other season.

Roland Mwebesa Mugumya, Uganda


  1. Thanks Ronald, with the increasing world populattion, pollution, climate change, gene pool loss and biodiversity extiction. Players in the agric sectors worldwide need to put much emphasis on sustainable agric innovations that can paramountly increase yield with no impact on the enviroment, or affect interactions in the ecosystem


  2. Nice project. Well organized. I support the idea of bringing more genetic diversity into local potato population as the way to fight with its natural diseases.
    It can be universal stabilization approach in fact for many other crops intended for use by small farmers.
    They will be substantially less productive because of that biodiversity but more predictable in harvest. So the farmer will know that even without any special care and agro-chemicals he will get something from his field and it is possible to rely on expectations.
    That is not the case for modern industrial cultivation of monoclonal plants. They are going to lose almost all yield in case of serious infection. And the soil very often becomes the source of such infections for several years after the first case if the all plants were not fast enough destroyed. It needs tons of agro-chemicals and lots of work to get those commercially viable high yields. Good Luck with your idea, it makes sense to bring more bio-variety to the small farmers with traditional agrotechnical protocols also for sustainability.


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