1. Catherine N. Kibunja, Senior Principal Research Officer-Integrated Soil Fertility Management, Kenya Agricultural and Livestock Research Organization-Kabete, P.O. Box 14733-00800 Nairobi, Email:
  2. Ruth Amata, Senior Research officer-Plant Pathologist, Kenya Agricultural and Livestock Research Organization-Kabete,P.O. Box 14733-00800 Nairobi,;
  3. Monica Olala, Research and Extension Specialist-ASDSP, Ministry of Agriculture, Livestock & Fisheries, P.O. Box 30028-00100 Nairobi, Email:;;
  4. Susan Moywaywa; Ministry of Agriculture, Livestock & Fisheries, P.O. Box 30028-00100 Nairobi, Email:
  5. Adul Ochieng; ASDSP, Ministry of Agriculture, Livestock & Fisheries, P.O. Box 30028-00100 Nairobi, Email:
  6. Dr. Orodi Odhiambo


Horticulture industry is one of the most vibrant sub sectors of agriculture in the Kenyan economy. It contributes 8% of the Country’s GDP and 36% of the agricultural GDP. Tomato (Lycopersicon esculentum mill) is among the promising commodities in horticultural development in Kenya grown either on open field or under greenhouse technology. The crop plays an important role in meeting domestic and nutritional food requirements, income generation, foreign exchange earnings and employment creation. Despite this critical role to the economy, pests and diseases especially soil borne pathogens, pose a great challenge to tomato production causing huge losses, thus impacting on food security. In addition to food security there is an increased demand for food safety and better quality by the growing populations and international trade. This therefore calls for judicious implementation of Integrated Pest Management that integrates various control measures without harmful effects on the environment, occupational and public health.

Soil treatment is one of the Integrated Pest Management approaches to management of soil borne pests and diseases. Currently, many farmers rely on chemical pesticides as a method of protecting crops against soil-borne pathogens. However, use of chemical pesticides may not be desirable due to the potential risk to the environment as well as human and animal health and therefore should be used as a last resort. As a result of these risks, increased restrictions have been imposed on a variety of chemical pesticides in Kenya for example use of Methyl Bromide as a soil fumigant. Some of the promising alternatives or IPM approaches for the management of soil borne pathogens include soil solarization, soil heat treatment and fumigation.

Soil solarization is a method of disinfecting soil by covering it with a clear polythene sheet to trap solar energy for management of soil borne pathogens and weeds. Soil heat treatment is the use of heat in various forms (either steam or dry heat) to control soil borne pests. Fumigation is the application of pesticides/biopesticides that may be in liquid or solid form but form a gas (fumes) when applied to soil. This gas controls pests that live in soil.

This booklet explains in details how to conduct these three soil treatment methods for management of soil borne pathogens in tomato. The technology is a useful tool for large and small-scale producers, homeowners (kitchen gardens) and organic growers, with limited opportunity for crop rotation;

Phoebe Odhiambo (Mrs.)
National Program Coordinator