Documento(s) 13 de 14

The Centro International de la Papa (CIP), based in Lima, has extensive experience in promoting integrated pest management (IPM) to combat the Andean potato weevil. CIP's IPM research and technology transfer efforts have contributed to the enhanced welfare of small farm and poor urban households. Building on earlier research, CIP and the Instituto Nacional de Investigación Agraria (INIA) began an on-farm research project to manage the Andean potato weevil. Two high-altitude Andean communities (altitudes of 3 500-3 800 metres) were selected for the project. Huatata, Cusco began participating in the 1991-92 cropping year, while Chilimpampa, Cajamarca became involved the following year. Farmer participation was built into the project work in each community, which included undertaking  both entomological and socioeconomic studies. 

The primary difference between the two communities is that Huatata grows potatoes commercially, using moderately intensive management while Chilimpampa's potato production is more subsistence-oriented and less intensely managed. Based on a survey of 30 farmers in each community, the following differences were found: 

• Huatata's average farm size is 1.5 hectares (ha) versus 0.5 for Chilimpampa;

• 60% of Huatata's farms use chemical fertilizer versus 10% in Chilimpampa;

• Use of pesticides is more prevalent in Huatata (95% of farmers use insecticides and 70% use fungicides), versus 30% and 15% in Chilimpampa;

• Huatata produces more than twice the yield of Chilimpampa (12.5 tonnes/ha versus 6.0).

Diminished potato harvest weights and a lower sales price are direct results of weevil damage. Potato merchants in Cusco sell moderately damaged tubers for about 50% less than undamaged ones. Farmers who process potatoes according to traditional methods to make chuño and moraya, (which involve washing, sun drying, and freezing potatoes), are especially vulnerable to crop weight loss. A seed-producing farmer who experiences 10% crop damage may find the loss devastating, while a subsistence farmer can often cope with 20% damage. 

Integrated pest management is information intensive, and its effectiveness depends on each farmer's knowledge, management practices, production and storage systems. Men, women, and children in both Huatata and Chilimpampa received instruction in the Andean potato weevil's biology, as well as options for management practices, including: 

• Chemical control - currently the primary method of weevil management in commercial potato production; used much more extensively in Huatata than in Chilimpampa. 

• Timely harvesting - project information reinforced the desirability of this practice. 

• Chickens - useful for eating larvae, although only as one component of an overall strategy. 

• The fungus Beauveria - a parasitic fungus, native to the Andes, which is mixed into the soil where potatoes are stored on the ground. It attacks weevils as they emerge from tubers to pupate in the ground. Farmers adopted this method at a rate of 90% during the Huatata project's first year. Once it is established, annual introduction of the fungus is no longer necessary. 

• Stirring up soil in storage areas - a manual practice using simple implements in infected areas where damaged tubers are stored. By turning the soil, pupating larvae are exposed to light and chickens. 

• Stirring up soil in the field - less widely accepted in Chilimpampa, owing to larger harvests, a wider distribution of potatoes and the difficulty of stirring up soil manually during the dry season. 

• Dry-season tillage of harvested fields - also designed to expose larvae to light and chickens; however, this practice is often unfeasible because the ground is too hard. 

• Traditional covers for selection and transport - mantas, or blankets, have traditionally been used; also useful in capturing weevils to be killed. Since larvae that fall to the ground pupate and become adults in the next cropping year, plastic sheets were introduced, but were not adopted. Farmers prefer smaller woolen covers or bags which can also be used for other purposes. 

• Nocturnal manual collection of adults - has become a widely accepted practice in both communities, although it is viewed as more effective in Chilimpampa, because fields are smaller and closer to homes. An important development involves educating farmers and their families to understand the biological link between larvae and the adult weevils. 

• Ditches around storage areas - viewed as impractical and not accepted by farmers, who believe that this particular technique does not augment other IPM practices such as using parasitic fungus, chickens, or stirring up soil. 

• Ditches around fields - using wet straw in the ditch to trap the insect. 

• Vegetative barriers - to impede the migration of adult weevils to potato fields; accepted in Chilimpampa, where fields are worked manually and lupine is often planted as a border crop. 

• Diffused-light storage - now used by a minority of farmers in each community, particularly those who sell seed. Although simple, such storage structures are still relatively costly. Furthermore, this practice is not well adapted to high-altitude regions prone to severe frost. 

• Acceptance of IPM techniques - The acceptance rate of various integrated pest management methods by farmers and their families in each of the communities varied. Approximately four to six practices were ultimately accepted by farmers at each site. However, it is significant that initial acceptance was enhanced by diffusing information, in turn assimilated as knowledge, about the life cycle of the weevil. As a result of this effort to educate farmers, a majority understood the weevil's life cycle during the project's second year, enhancing their ability to control the pest. Very few possessed this knowledge at the outset. Similarly, the farmers also became knowledgeable in a more extensive range of IPM practices. 

• Education - Research of this type reveals that integrated pest management techniques are fairly location-specific and knowledge-intensive. Accordingly, a key component of IPM is the ability to impart basic information on the life cycle and behaviour of the pest. In turn, such basic information is essential in helping farmers to understand and participate in technology design and innovation. In fact, CIP has concluded that educating farmers about IPM is often more important than doling out recommendations about specific practices. 

• Reduced crop damage, additional family income - By using a range of IPM practices, the incidence of damaged tubers sharply declined, resulting in direct economic benefit. For example, it is estimated that the IPM techniques outlined above contributed to an average incidence of damage of 15% in Chilimpampa, in 1993-94, (versus a pre-project rate of 50%). For commercial farmers in Huatata, the average incidence of damage declined from 31% in 1990-91 to about 10% in 1993-94. These figures translate into savings of $241/ha (net benefits per hectare from the early acceptance of IPM practices), or approximately $360 in additional family income for an average-sized farm in Huatata. Unfortunately, cost savings in pesticide use cannot be attributed to the project. While insecticide use is uncommon in Chilimpampa, most farmers in Huatata apply insecticides. They believe that chemical control plays an important part in weevil management. Because the cost of chemical control is not considered prohibitive, at $60-$70/ha, market-oriented farmers prefer to incur this cost to reduce risks. Farmers have become more selective with respect to chemicals that are used for weevil control. As a result, the use of the more toxic chlorinated hydrocarbons and organophosphates has declined. 

• CIP's success - At the institutional level, CIP is an example of an organization which exhibits "institutional impact", based on the networks it has cultivated and a decentralized regional structure, along with its research and training activities in national agricultural research programs. In 1992, CIP was awarded the King Baudowin award in recognition of its innovative IPM program and for creating a pest-resistant hybrid population (the "hairy" potato). Work on integrated weevil management is of great interest to a variety of NGOs in Peru. CIP and CARE-Peru are now involved in a three-year project to transfer weevil management practices tested and evaluated in Huatata and Chilimpampa to 3 500 families in 114 communities located in the Peruvian departments of Puno, Ancash, La Libertad, and Cajamarca. 

MacMillan, Neale. 25 September 1995. ANDEAN FARMING FOR PRESENT AND FUTURE.
Reports. 

Otiz. O. et al. 1996. Economic impact of IPM practices on the Andean potato weevil in Peru, In,Walker, T.; Crissman, C. Case studies of the economic impact of CIP-related technology. International Potato Center, Lima, Peru. pp. 95-110. ISBN 92-9060-181-7. 
US $25.00 (add US $8.00 to cover the registered airmail postage). 

Selected references on pesticides and pest management. 

Related projects: 

Sustainable Andean Development Consortium (CONDESAN); IDRC PROJECTS ON BIODIVERSITY (September 1996). 

International organizations: 

Cooperative Research Centre for Tropical Pest Management 
The University of Queensland 
QLD, 4072, AUSTRALIA 
Tel: +61 (0)7 3365-1851 
Fax: +61 (0)7 3365-1855 
E-mail: Enquiries@ctpm.uq.edu.au  
Web site: http://www.ctpm.org/ 

Consortium for International Crop Protection 
N.Y.S. Agricultural Experiment Station 
Geneva, New York 14456-0462 USA 
Tel: (315) 787-2252 
Fax: (315) 787-2418 
E-mail: CICP@cornell.edu  
Web site: http://www.IPMnet.org/ 

IPMnet 

The System-wide Programme on IPM (SP-IPM) - Consultative Group for International Agricultural Research (CGIAR). 

info@idrc.ca | February 6, 1998

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Documento(s) 13 de 14

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