Hypsiboas raniceps in a crop plantation of guava. (Maike Guschal)
Irrigated crops attract various pest species. Farmers usually address crop pest and disease problems through the use of agrochemicals. Especially bees, birds, and amphibians, which fulfil important functions in agroecosystems, are affected by high use of agrochemicals. The combination of inappropriate irrigation practices, incorrect application rates of agrochemicals, and low producer prices often lead, however, to poor income from smallholder irrigated agriculture and to further problems such as poor health, loss of biodiversity, and soil and water contamination. Amphibians are themselves proven biological pest control agents of arthropod pest species (predators of e.g. larvae of butterflies, beetles, termites, bugs and others) and the incorrect use of agrochemicals, as well as the removal of vegetation along field margins hampers this useful function. The technology described here aims to support and utilise the potential of amphibians (such as frogs and toads) as biocontrol agents –as an alternative to agrochemicals in crops.
Purpose of the Technology: Establishing habitats for amphibians is crucial in order to increase and secure their numbers: for example encouraging shrubby vegetation next to water bodies for arboreal frogs, and installing additional water ponds inside and around plantations for ground-living frogs. First, the local species pool of amphibians needs to be determined by visual and acoustic observations. Amphibian species do not need to be determined precisely, but it is important to detect whether they are arboreal and/or ground-living amphibians, as these two groups have different roles as biocontrol agents. Pests that feed on the main cultivated species should be characterized by (a) collecting plant material to determine the type and quantity of pests and (b) by comparing observations with neighbouring farmers and extension agents. Pest species can be determined also by installing traps and using nets. Inspection should be done at least every 15 days to once a month during the whole rainy season to detect possible mass reproduction of arthropods after rainfall events. Once amphibians and pest species are detected, decisions on management strategies can be made. Such a strategy is to create habitats for amphibians with additional sources of income, e.g. by planting pomegranate or guavas as shrubby vegetation structure for arboreal frogs. If pest species can't be reduced solely by amphibian species, the use of agrochemicals has to be reconsidered. Preference shall be given to chemicals which do not harm amphibians. Organic, self-made pesticides based on the extract of manioc roots (manipoera) seem promising. Twenty litres of manipoera, the bark of manicoba tree (Manihot pseudoglaziovii), a cup of American wormseed (Dysphania ambrosioides), a cup of yellow tagetes (Tagetes sp.), a cup of malagueta pepper (Capsicum sp.), garlic and a little bit of bleach have to be chopped, mixed and fermented for 10 days. Application of the final product (25 ml of organic pesticide diluted in 20 l of water) should be done every 8 to 15 days depending on crop species.
Natural / human environment: Increasing habitat heterogeneity stimulates the diversity of amphibians and so a greater number of pest types will be controlled. Combined control by safeguarding natural amphibian habitats and application of organic pesticides is an innovative alternative to the overuse of toxic agrochemicals.
Lieu: Brazil, Pernambuco, Floresta, Itacuruba, Petrolandia, Brésil
Nbr de sites de la Technologie analysés:
Diffusion de la Technologie: répartie uniformément sur une zone (approx. 0,1-1 km2)
Dans des zones protégées en permanence ?:
Date de mise en oeuvre: il y a plus de 50 ans (technologie traditionnelle)
Type d'introduction
| Spécifiez les intrants | Unité | Quantité | Coûts par unité (sans objet) | Coût total par intrant (sans objet) | % des coût supporté par les exploitants des terres |
| Main d'œuvre | |||||
| Constructing of large ponds | ha | 1,0 | 36,0 | 36,0 | 100,0 |
| Constructing of small ponds | ha | 1,0 | 1,8 | 1,8 | 100,0 |
| Planting 100 Guava tree/ha | ha | 1,0 | 11,25 | 11,25 | 100,0 |
| Equipements | |||||
| Rent of machine for pond or drainage ditch excavation | ha | 1,0 | 100,0 | 100,0 | 100,0 |
| Knapsack sprayer | ha | 1,0 | 90,0 | 90,0 | 100,0 |
| Matériel végétal | |||||
| Fruit tree seedlings (100) | ha | 1,0 | 75,0 | 75,0 | 100,0 |
| Coût total de mise en place de la Technologie | 314.05 | ||||
| Coût total de mise en place de la Technologie en dollars américains (USD) | 314.05 | ||||
| Spécifiez les intrants | Unité | Quantité | Coûts par unité (sans objet) | Coût total par intrant (sans objet) | % des coût supporté par les exploitants des terres |
| Main d'œuvre | |||||
| Monitoring of frogs | ha | 1,0 | 27,0 | 27,0 | 100,0 |
| Monitoring of pest species | ha | 1,0 | 18,0 | 18,0 | |
| Production and application of organic pesticide | ha | 1,0 | 720,5 | 720,5 | |
| Pruning and fertilizer application | ha | 1,0 | 56,25 | 56,25 | |
| Coût total d'entretien de la Technologie | 821.75 | ||||
| Coût total d'entretien de la Technologie en dollars américains (USD) | 821.75 | ||||
high number of livestock will decrease favourable vegetation structure for predators
loss of land
Reduced pesticide toxic effect on human health
Less use of agrochemicals
