Summary of “Survey of Agricultural Practices and Alternatives to Pesticide Use to Conserve Water Resources in the Mojanda Watershed, Ecuador”
by Lukas Schütz
Agriculture in the Mojanda Watershed is facing rainfall reductions caused by climate change. Reductions of water availability in the Watershed are further strengthened by constant extension of the agricultural activities into the páramo ecosystem above 3000m a.s.l., with this ecosystem having immanently important functions in the local water balance. The application of pesticides threatens the quality of water and with less precipitation contaminations will further concentrate in the outflow. To analyze problems associated with agricultural practices in the area a questionnaire about agricultural practices (28) was conducted and fields (20) were surveyed for pests and diseases with a focus on potatoes (Solanum tuberosum L.) as a traditional crop with good marketability, tree tomatoes (Solanum betaceum Cav.) as a newly introduced cash crop and peas (Pisum sativum L.) as a legume with minor marketbility. Potatoes were infected to a low degree with Phytophthora infestans and according to the farmers the Andean potato weevil (Premnotrypes spec.) caused biggest losses. To combat the weevil the soils are disinfected with highly toxic Carbofuran (WHO Class IB) and fungicides are sprayed on a regular basis against late blight. Tree tomatoes showed symptoms of various fungal diseases. Most important was Fusarium solani causing the branches to rot and Anthracnosis (Colletotrichum gloeosporioides) causing the fruits to rot. Fungicide applications were correspondingly high. Peas were only minorly affected by Ascochyta blight (Mycosphaerella pinodes) and an unidentified root rot. Overall 19 active ingredients were applied of which fungicide Mancozeb (WHO class table 5) and insecticide Carbofuran (WHO Class IB) were applied the most. IPM methods like the economic threshold of each pest to time application of pesticides, the planting of resistant varieties and a proper crop rotation are promising to reduce pesticide use. For tree tomatoes regular cutting of branches infected with F. solani and regular collection and disposal of infected fruits with Anthracnosis are advised. For potato plastic barriers around the fields, as published by Kuschel et al. in 2009, limit the movement of the Andean potato weevil and prevent them from laying eggs at the base of the plant thus reducing infestation with the larvae in the tubers.
Local bioinsecticide “Biol”, composed of several herbs, is regarded as effective by the farmers and without harm to the environment. It is however used by only a few farmers. A decrease in soil fertility was identified by the farmers. Increasing the application of organic fertilizers promises reestablishment of soil fertility, increase in water holding capacity and reduction of erosion. Traditional adobe walls reduce erosion as well and are a habitat for wild bees, however they are not being constructed anymore. As the slope can be quite high, the construction of terraces is another strategy to increase the water retention. Resources and programs which allow for IPM principles and water management strategies to be implemented need to be made available to the farmers. The newly established extension service programs of the Ecuadorian Government, “Schools of the Agrarian Revolution” (ERA) are aimed at reaching smallholders and reducing poverty, and should focus on IPM methods for improving agricultural practices to solve local environmental problems. The here presented study seeks out alternatives and strategies to reduce pesticide use and manage water resources, which pose an opportunity to conserve the water resources of the region.
Read full research paper at http://fofj.org/index.php/journal/article/view/42
Uniform Resource Name Code urn:nbn:de:hebis:34-2014062645593
Photo credit:- FAO - ALC
