Natural Crop Protection in the Tropics: Zambezi Valley Organic Cotton Project

by Sam Page PhD, AfFOResT

Background

This project is based in the Dande communal area, situated along the northern edge of Zimbabwe. This is a hot, dry, forested region, plagued by malaria and sleeping sickness, which occupies the flood plain of the mighty Zambezi River. Here the Tonga people have practised shifting cultivation, alongside herds of elephant and other wild animals, for thousands of years. It is of interest to note that these farmers were amongst the first to domesticate Gossypium herbaceum var. africanum, which is considered to be the precursor of modern Deltapine cottons.

In recent years the EU has funded successful research which has led to the decline of sleeping sickness in Dande. As a result of this decline the Zimbabwe government has been able to resettle hundreds of new farmers and their cattle in the area. These resettled farmers and their families have each been allocated 12 acres (4.9 ha) of virgin land and advised to grow cotton as their main cash crop. The local extension service has stressed the importance of cutting down all the trees on the arable land and the routine use of pesticides to control the myriad of pests that attack the cotton monocultures.

Cotton growers on communal land in particular are advised to spray up to nine different organophosphate and up to five different pyrethroid pesticides to control American, red and spiny bollworms, aphids and red spidermites, at two weekly intervals. The resettlement programme and, in particular, conventional cotton production in Dande has resulted in massive environmental degradation and brought the resettled farmers into conflict with the indigenous farmers, whose traditional farming methods had, hitherto, been in harmony with environmental conservation.

Motivations and expectations of the farmers

Farmers are motivated to join the organic cotton project primarily by the promise of savings on input costs and the possibility of obtaining a cash premium for their harvest. Organic farmers also experience lower labour requirements – our research has shown that conventional cotton growers spend an average of 15 hours per week on tasks associated with procuring and applying pesticides. In an organic system the farmers spend one to two hours per week scouting their own land and another two hours attending their local FFS (farmer field school). Many farmers are aware of the toxic effects of pesticides and see the creation of a pesticide-free environment as an added benefit provided by the conversion to organic agriculture. Lower labour requirements and lower production costs have also attracted many AIDS widows to the organic project. These women are generally resource-poor, constrained by labour shortages and inexperienced in financial and farm management. The community-based FFSs have become support groups in which these issues can be addressed sympathetically.

Research and extension approach of the project

The project was initiated by a group of 40, mainly women farmers, who were too poor to buy pesticides. These farmers had also expressed concerns regarding their health and the health of their environment as a result of repeated pesticide applications. During this early stage of the project the farmers had simply substituted home-made remedies, such as fermented cow urine, ground chilli peppers and Datura stramonium, for the conventional pesticides. The results were disappointing in terms of the quality of the ”pesticide-free” cotton, as these remedies had not reduced pest pressure. The following season one of the field officers who had been working with these farmers approached African Farmers’ Organic Research and Training (AfFOResT) for assistance.

AfFOResT training is based on the ”Farmer Field School” (FFS) approach that was pioneered by the FAO in Asia during the 1980s. AfFOResT has adapted this training for local conditions and for organic agricultural production. The initial intensive training for up to ten farmers lasted for 4 weeks. The first 30 Farmer Field Workers (FFWs) were trained in 1997. The second group of 27 farmers were trained at the Eco-Lab of AfFOResT over a period of 12 weeks, between June and September 1998, in natural pest management and organic farming methods. The new FFWs were selected by their peers and will be active during the 1998/99 season. Unfortunately, we have discovered that the farmers are selecting their relatives to be trained as FFWs, in the hope that they will benefit from any allowances which may accrue, rather than choosing someone who is committed to serving his or her community. AfFOResT is planning to improve the selection process next season by nominating several hard-working farmers as candidates amongst whom the farmers can vote.

During their training at the Eco-Lab, the farmers learn basic soil science, botany and biological control of pests through a series of simple experiments. They learn about insect life cycles, pest-predator relations, disease transmission and development, and the way natural and synthetic pesticides work, through a series of in-field and 'jam-jar' experiments. As these trained farmers will also be responsible for the project’s internal control system, they are familiarized with the IFOAM (International Federation of Organic Agriculture Movements) regulations and spend time developing expertise in the drawing of farm maps and the planning of rotations and intercropping systems to reduce pests and encourage foraging by natural enemies. The training is carried out in a spirit of 'sharing ideas' and the FFWs learn techniques which enable them to become keen observers and innovators in both a scientific and creative way.

On returning to their communities, the FFWs share their new knowledge and ways of learning with the ten farmers who originally selected them. At the same time they should continue to receive support from AfFOResT staff. The FFWs conduct regular FFSs, and ensure that individual farmers adhere to the agreed guidelines for organic production. During the FFS, the farmers' groups scout for pests and predators, discuss control strategies and carry out simple experiments on insect life cycles. They also examine the efficacy of local natural pesticides, and the comparative susceptibility of crop varieties to pests. AfFOResT's role during these FFSs is to support the FFWs in their job as facilitators and to offer advice when asked to do so.

Once the organic crops are established, the FFWs facilitate weekly FFSs for ten other farmers who have registered to join the project. During these FFSs, the organic farmers follow a 'learning through discovery' programme which has been specially developed by the FFWs and AfFOResT scientists to support their conversion to organic agriculture.

The weekly FFSs begin with group scouting of cotton plants for pests and natural enemies (termed ”agroecosystem analysis” by FAO). The results of this exercise are displayed pictorially and reported in terms of the numbers of pests in relation to the numbers of their natural enemies which were found in a representative sample of the crop. Pest management strategies are discussed and spot treatment using herbal remedies (botanicals) may be used, but only as a last resort. Farmers soon learn not to despair when aphids are present on the immature cotton plants as these pests will attract large numbers of natural enemies, such as lace-wing larvae, predatory ants and parasitoid wasps, which will also attack the more serious bollworms later in the season. During the FFSs the farmers also conduct simple experiments to study the properties of healthy soils, life cycles of pests and their natural enemies and the effects of herbal remedies on these insects. AfFOResT is responsible for providing follow-up support of the FFWs and their farmers throughout the season.

The organic cotton farmers follow production guidelines which encourage the retention of some indigenous trees and shrubs, both within and bordering their fields, to stabilise the soil and provide a refuge for natural enemies. They are also advised to plant live fences of Jatropha and other goat-proof bushes. Once these are established the farmers can mulch their land with grass, leaves and crop residues and introduce zero or minimum tillage in order to prevent soil erosion. The farmers are supposed to rotate their cotton with a legume and a cereal crop to break the life cycle of pests, for the maintenance of soil fertility and the promotion of food security. Some farmers are using sunnhemp as a green manure to add organic matter, improve the nitrogen content of the soil and as to act as a trap crop for phyto-nematodes and witch-weed. The production guidelines seek to establish a 'closed system', eliminating the need for external inputs, as set out in the IFOAM basic standards.