June 1998, Volume 19 No. 2
- Editorial
- General News
- Biorational
- Internet Round-Up
- New Books
- Proceedings
- Conference Reports
- Training News
In this new section we welcome all your experiences in working directly with the end-users of arthropod and microbial biocontrol agents or in educational activities on natural enemies aimed at students, farmers, extension staff or policymakers.
Farmer Field Schools
One of the most successful methods in promoting the use of natural enemies as the keystone of IPM in farmers· fields in developing countries has been through the Farmer Field School training approach. Through regular observations of their crops and discovery-learning exercises on pests and beneficials, participating farmers are able to understand the role of natural enemies and the effects of pesticides on these. They can then use the agro-ecological knowledge and skills acquired through group experiments and discussion to make better informed decisions on pest and crop management in their own fields. The following account describes a pilot training project to tackle the problem of whitefly resurgence due to excessive insecticide use in cotton in Pakistan.
Stepping Off the Cotton Pesticide Treadmill
Pesticide use on cotton has increased dramatically in recent years in Asia and more pesticides are applied to cotton than to any other single crop in the continent. In Pakistan, the majority of cotton farmers are smallholders with less than 5 ha of land and their growing dependence on pesticides (mainly organophosphates) has had serious consequences for the health and livelihoods of rural families. Ten years ago a quarter of smallholder cotton farmers in Pakistan were able to produce their crop without spraying pesticides at all. By 1997 the minimum number of applications was four per season with nearly half of all farmers spraying at least seven times. Yet these increases in pesticide use have not solved pest and disease problems nor led to higher yields. In most cases smallholders· income has fallen as they are spending more and more on pesticides. Aggressive marketing of agrochemical products and fear of pest outbreaks have caused cotton farmers to become trapped on a pesticide treadmill of more frequent applications, which, in fact, is the root problem of the current crisis.
In Pakistan the whitefly Bemisia tabaci is by far the most serious insect pest problem on cotton since it is the vector for cotton leaf curl virus (CLCV). Whitefly infestations have become progressively worse since 1992 and farmers are now spraying two or three times in the early season alone in an attempt to control it, unaware that whitefly has now developed resistance to many of the commonly used insecticides. Research carried out by PARC-IIBC in Pakistan1 showed that whitefly may be kept under good control by a natural enemy complex composed of five species of parasitic wasp, lacewing and ladybird predators and a fungal pathogen similar to Paecilomyces spp.2 National and international cotton researchers agree that whitefly outbreaks in Pakistan are a direct result of the elimination of these key natural enemies in cotton fields by increased and early insecticide application in cotton. In addition, the shift to earlier spraying also reduces populations of the predators which usually keep bollworm pests in check later in the season. The challenge is to convince the cotton farmers that it is in their economic interest to abandon calendar spraying of insecticides and to place their trust in natural enemies.
On-farm research and demonstrations in an earlier project had indicated that it is quite feasible to reduce farmers· current insecticide applications by at least 50%, while maintaining or even increasing yields. However, for farmers to gain the confidence to abandon preventative calendar applications, considerable understanding of agro-ecological processes is required, particularly the role of natural enemies of cotton pests and cotton plant physiology and compensation for damage. The traditional top-down model of IPM implementation, based on threshold scouting, has simply not worked in Pakistan; there are too many farms and too few extension staff for traditional extension methods to be effective. For these reasons, the Farmer Field School (FFS) approach to IPM training and technology development was chosen for a pilot training project in Vehari District, Punjab, in Pakistan, drawing on technical insights gained through an earlier regional cotton project and from several years of FFS experience in Asia.
Cotton IPM Training Curriculum
A 14-week Training of Trainers (TOT) course was held in 1997 for the 21 B.Sc.-level agricultural officers responsible for extension activities in Vehari. A key element of the training is non-formal education methods and group dynamics so that extension staff gain the confidence to become facilitators of a learning process with farmers, rather than conveyors of messages and providers of advice. The technical part involves planting and tending experimental plots and weekly agro-ecosystems analysis (AESA) observation throughout the crop cycle. The curriculum included whitefly parasitization studies; natural enemy action thresholds for adults and larvae of pink, spotted and American bollworms; natural boll shedding studies; impact of bollworm and bollworm predators during square shedding and early boll formation; yield loss studies for bollworms and defoliators; and -insect zoos· to study predation and parasitism of whitefly and jassids. Experiments included: cotton varieties resistant to CLCV; whitefly population growth studies; pesticide effects on livestock and natural enemies; and defoliation and desquaring experiments.
Achievements
The TOT trainees set up ten FFS groups of 25 farmers each and facilitated at fortnightly intervals with each FFS group starting around 20 days after planting, when the first whitefly begin to appear. Each FFS set up two 0.5-ha plots in the fields of one of the participants to compare their current chemical control (farmers· practice (FP) plot) with decision-making based on observation of pest and natural enemy numbers in the crop (IPM plot).
No insecticide applications were made on any of the IPM plots in the first eight to ten weeks after planting, thus allowing natural enemy populations to build up. In contrast FP plots had already received one or two sprays of organophosphates over the same period. The results were striking: the average number of applications in the IPM plots was 1.4, compared to 5.2 in the FP plots. Two FFS groups succeeded in reaching the end of the season without a single application of synthetic pesticides on their IPM plot, compared to three or seven applications under FP. The other groups applied one to three sprays under IPM and four to seven under FP. Rich complexes of beneficial arthropods were found in all IPM plots (spiders, predatory bugs, whitefly parasites, ants, ladybird beetles, lacewings) and the absence or greatly reduced application of pesticides allowed these natural enemies to exert effective control of whitefly, jassid and bollworm pests. At seven of the ten sites, IPM plots gave higher yields than the FP plots, including both sites where no pesticide applications at all were made under IPM decision-making. Of equal importance to the participating farmers and the FFS facilitators is the saving in input costs; the FFS groups involved translated IPM as Increased Profit Margins! The IPM plots reduced input costs by an average of 68%. At all sites facilitators and FFS farmers were able to observe the role of predators and parasites in controlling whitefly, jassids and bollworm in their IPM plots. In addition to small insect zoos in plastic bags, all sites also set up field cages to observe spider predation on jassids. After experimenting, one FFS group even demonstrated whitefly resurgence as the result of unnecessary insecticide application to local agro-chemical salesmen, Department of Agriculture officials and neighbouring farmers. Further refinement of the curriculum and expansion of the TOT and FFS programme will take place over the 1998 season to build on the national enthusiasm generated by the Vehari experience.
1 The -Management of Cotton Leaf Curl Virus, Pakistan· project and the subproject -IPM Implementation though Training of Trainers and Farmer Field Schools· are funded by the Asian Development Bank (ADB). The project was executed by the PARC-IIBC Station at Rawalpindi, (now renamed CABI Bioscience Centre Pakistan) in collaboration with the Ministry of Food, Agriculture & Livestock, Islamabad; the Department of Agriculture, Punjab (Extension), Lahore; and the Regional Agriculture Economic Centre, Vehari District.
2 IIBC Annual Report 1996. Wallingford, UK; CAB INTERNATIONAL, pp.69-70.
For a detailed report of this project or further information on FFS training methods contact: Stephanie Williamson, CABI Bioscience (Ascot), Silwood Park, Buckhurst Road, Ascot SL5 7TA, UK
E-mail: s.williamson@cabi.org
Fax: + 441344 875007
