Pest management technologies in Uganda
Truth be told, Uganda is vulnerable to pest and disease attack especially due to environmental conditions that favor availability of crops in most parts of the East African region. The weather also favors the pests and diseases. Virtually every crop is affected by pests and therefore requires some form of pest management during cultivation. Some crop pests have largely been managed for example coffee wilt disease and banana xanthomonas wilt, but new pests keep emerging for example the coffee twig borer.
Certain characteristics of a pest management practice or technology are likely to influence the choice of dissemination method (or methods). Characteristics include:
1. Complexity of the technology and therefore of the messages needed to explain the technology to farmers;
2. Whether the method is relevant for control at an individual farm level – or whether effective control depends on
collective action by all farmers in an area – or centralized action;
3. Whether purchased inputs are required.
The main pest management methods can be clustered as follows:
a) Cultural and physical control
These are applied control practices aimed at altering conditions or pest behaviors or pest populations. These practices include; clearing fields of weeds and host plants to reduce harborage; removing infected plant parts, materials and burning / burying them; mulching; managing manure and other soil amendments to improve crop
Vigor; planting timing; crop rotations; using irrigation and related field measures. Passing on messages related to cultural practices may require relatively more intense dissemination approaches such as extension agent visits or moderate approaches like field days. For management of some pests, collective action is required because if only a few farmers implement field sanitation measures, their crops may still be infected as a result of poor sanitation in their neighbors’ fields. For example in the control of Banana xanthomonas wilt, collective community action was used due to the ease of spread of the disease from infected fields to non-infected fields.
b) Chemical control
Chemical crop protection products (pesticides) are biologically active chemicals that control a range of insect and vertebrate pests, diseases and weeds. Pesticides may be systemic or contact, selective or non-selective, and residual or non-residual. Effective application of pesticides requires that farmer have appropriate knowledge of the type of pesticide in relation to the pest or disease they intend to manage. Use of pesticides is effective, fast and easy but requires proper diagnosis of the pest/disease problem is key, followed by appropriate application.
Responsible use and good handling practices limit potential pesticide residues in crops and the environment as well as help avoid pest resurgence and resistance. To ensure this, there is need for demonstrations and more intensive extension approaches that incorporate follow up and routine check with farmers on usage of chemicals.
c) Biological control
This involves nature’s own methods of pest control. This includes introduction of beneficial insects or predators; applying micro-organisms such as viruses, fungi and bacteria; and using pheromones to lure, trap and kill or interfere with insects’ mating habits.
I. Use of natural enemies: This involves mass rearing of the pest natural enemy and its periodic release into the
environment. An example is mass rearing and release of T. aripo against cassava green mite and cassava
mealy bug in Uganda. The natural enemy was obtained from IITA (West Africa) and currently managed by the
Bio-Control Unit at the NARL in Kawanda. Deployment of the natural enemy is
II. Considered easy, even farmers can do it once given the biocontrol agent by research. Once released, the enemy
sustains its self for long in the habitat though a post release monitoring is required to ensure pest populations
do not build up.
III. Bio-pesticides: Involves the mass rearing and use of bacteria, fungi, nematodes or viruses to control some
pests. The most common and successful is Bacillus thuringiensis (Bt), a naturally occurring bacterium,
which has been used to control several important pests (e.g. caterpillar pests in vegetables, vineyards and
IV. Sex pheromones baits and traps: This involves the development and use of insect sex pheromones and other
behavior-modifying chemicals to trap and kill pests. Some pheromones disrupt mating thus slowing down
population build-up of insect pests. Often use of traps requires collective action and messages are relatively
complicated. Sometimes farmers operating traps for monitoring are perceived to be rearing and releasing the
d) Use of resistance
This involves use of planting materials that have levels of resistance or tolerance to pests and diseases. Two approaches are commonly used:
I. Pest or disease resistant varieties. NARO and other research institutions have developed various crop varieties
with resistance to pests and diseases. Farmers need to be aware of these varieties and associated costs of
acquiring seed/planting materials. Raising awareness of new varieties is likely to involve relatively simple
messages – explaining what the advantages are and indicating where to buy a variety. To enhance further
learning and observations, intermediate approaches such as farmer field days and demonstrations may be
undertaken so that farmers observe first had the difference between their own varieties and resistant ones, and
possibly associated agronomic practices.
II. Grafting or budding is also used to enhance resistance of plants by selecting a resistant root stock on which a
desirable plant material (high performing but susceptible) is grafted. Grafting has mainly been used in the
management of pests and disease in fruits and vegetables. The technique is quite complex and therefore
requires more intensive extension approaches, combined with demonstrations for farmers to be able to
understand and effectively adopt it.
e) Regulatory pest management
The objective of regulatory pest management is to prevent the introduction and/or spread of pests through the application of various pest management techniques such as pest exclusion, detection, eradication, mitigation, and public education. Achieving this objective requires limiting movement of commodities and materials, and treating commodities, materials, and the environment. This requires regulatory authorities to efficiently and effectively identify pest harm, assess pest risk; and manage pest risk.
Two approaches are commonly used:
I. Quarantine: The primary strategy to exclude pest entry is through the use of quarantines. Quarantine inspection
programs at ports of entry are designed to prevent the introduction and establishment of pests into the country.
Quarantine can be effective at reducing the incidence of pest introduction and reduce any incidents of pest
introduction to a manageable population that can be eradicated.
II. Eradication: If prevention is not successful and an introduction occurs, there is need for the control program to
institute eradication measures. Eradication generally means using all available viable options, which often
includes the application of pesticides or destruction of plant materials. Eradication programs require
participation of farmers and communities who must first be sensitized especially if losses to farmers are
anticipated. Farmers require adequate knowledge of such pests and implications for noncompliance.
Moderately intensive measures such as field days can be used for farmer education, or lighter methods such as
mass campaigns through radio and TV.
f) Integrated pest management (IPM)
IPM means considering all available pest control techniques and other measures that discourage the development of pest populations, while minimizing risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms. IPM requires a combination of cultural, biological and chemical measures to manage diseases, insects, weeds and other pests. It takes into account all relevant control tactics and methods that are locally available, evaluating their potential cost-effectiveness Implementation of IPM lies with farmers who adopt practices they view as practical and valuable to their activities. Ultimately, IPM is a site-specific strategy for managing pests in the most cost-effective, environmentally sound and socially acceptable way. Using IPM is rather complex and require intensive extension measures to ensure that farmers learn and adopt IPM
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