Integrated Pest and Disease Management through Agroforestry in Arid and Semi-Arid Environments

Arid and Semi-Arid Lands (ASALs) are prone to pests and diseases due to high temperatures, long dry spells and low moisture contents. These conditions favour the survivability of many pest and disease pathogens and vectors which affect both crops and animals. ASAL environments are also fragile, and in this case, their biodiversity has been influenced by biotic (human, livestock and wildlife) through clearing, burning, dislodging and overgrazing; physiographic (including erosion and other land-forming processes) and climatic factors including rainfall and temperature. These factors have led to ecological imbalances, and hence the prevalence of more disease causing pathogens, vectors and pests, than other species that can control them.  

Certain tree and herbaceous species have proven to be important in ameliorating climatic, soil and moisture conditions for crop growth in arid and semi arid environments. Some of the tree species are Melia volkensii and Azadirachta indica which we have been grown for the past 8 years in our agroforestry systems at Africa Wood Grow- The trees repel pests and diseases. Annual crops viz. green grams, pigeon peas, cow peas, maize and sorghum are grown in between the rows of trees. Fruits including bananas, pawpaws, and passions are also grown. The trees protect the crops from pest and disease attacks. They also ameliorate the climate and soil moisture regimes for the good growth of crops in the arid environment where rainfall is erratic. In this case crop yields are increased.

Extracts of Melia volkensii, Azadirachta indica, hot pepper, tagetes minuta, Mexican marigold, Solanum incanum (Sodom apple) and tobacco either solely or in combination are applied to crops to repel pests and diseases. Powdered/crashed leaves, barks, roots or fruits of these plants
are dusted on cereals in stores against pests. Although other storage technologies have been developed, they have posed a lot of challenges including

a) The use of Agro Z bags is an efficient way of storing dry cereals; a technology that cuts off air from entering the bag. This kills every living thing in the bag. Seed germination of the stored cereals deteriorates with time. Tastes and hardness of the cereals are affected too.

b) The use of chemicals (pesticide and insecticide) in the field and stores pose many threats to human life and biodiversity.    

How I want to do it

While Melia volkensii and Azadirachta indica agroforestry is a good system for protecting crops in the field, not all crops can grow under shade after 5 years of tree growth. After every 5 years of growth, a new system has to be established. At Africa Wood Grow, we have established over 60 acres of Melia volkensii and Azadirachta indica agroforestry systems with over 30,000 trees. The forests produce several tonnes of fruits and leaves that can be extracted to make organic pesticides/insecticides/fertilizers. The immediate beneficiaries will be the local communities who spend a lot of money seasonally to buy the chemicals. Oils from neem and Melia seeds make good organic chemicals for crop protection. The seed cakes left are mixed with crop residues to make organic fertilizers. The success of this project is measured by the number of tonnes of raw materials and other products obtained seasonally. The agro-processing industry established from this system will create employment, increase household incomes, eradicate poverty and ensure food security in the region. New technologies will be transferred to the local communities.

My motivation is based on the establishment of a localized solution in far remote areas of the country where no industries are available to offer job opportunities to the communities. The system also offers a solution to food losses due to crop diseases and pests. It also increases nutritional and food security in the region. The system will increase incomes by sale of products, create employment and increase biodiversity in the degraded lands. New knowledge and skills will be developed and transferred to the local communities in the region.

In short:

  • The idea is to collect fruits and leaves from the already existing forests to make agrochemicals for the farmers who use inorganic chemicals on their farms.
  • This project is practical, realistic and hands-on since most of the raw materials are available and renewable every season. What is remaining is to add value to the raw materials to produce agro-chemicals. There is a large population of farmers around who will benefit from the project and willing to buy products that are safe to handle and environmentally safe.
  • The innovation is self sustaining since the raw materials are available, customer-base for the products is large and the products are environmentally friendly.
  • The results of the innovation are concrete and tangible within a year since the raw materials are readily available and the process requires a short time to implement.

Daniel Musyoka Muvali, Kenya