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close this bookAbstracts on Sustainable Agriculture (GTZ; 1992; 423 pages)
Open this folder and view contentsAbstracts On Traditional Land-Use Systems
Open this folder and view contentsAbstracts on farming systems research and development
Open this folder and view contentsAbstracts on integrated systems
Open this folder and view contentsAbstracts on cropping system
Open this folder and view contentsAbstracts on agroecology
Open this folder and view contentsAbstracts on agrometeorology
Open this folder and view contentsAbstracts on agroforestry
Open this folder and view contentsAbstracts on homegardens
Open this folder and view contentsAbstracts on seed production
close this folderAbstracts on plant protection
View the documentAcknowledgements
View the document1. Designing integrated pest management for sustainable and productive futures.
View the document2. Biotechnology's bitter harvest: herbicide-tolerant crops and the threat to sustainable agriculture.
View the document3. Chemistry, agriculture and the environment.
View the document4. Mise au point de techniques appropriées de lir qui seront utilisés par les petits agriculteurs traditionnels d'Afrique tropicale.(developing appropriate ipm technology for the traditional small-scale farmer in tropical Africa).
View the document5. Biological control in developing countries: towards its wider application in sustainable pest management.
View the document6. Transforming plants as a means of crop protection against insects.
View the document7. Utilization of va-mycorrhiza as a factor in integrated plant protection.
View the document8. Activity of four plant leaf extracts against three fungal pathogens of rice.
View the document9. A useful approach to the biocontrol of cassava pathogens.
View the document10. Evaluation of the biological activity of flax as a trap crop against orobanche parasitism of vicia faba.
View the document11. Insect pest management.
View the document12. Economic contributions of pest management to agricultural development.
View the document13. The effects of intercropping and mixed varieties of predators and parasitoids of cassava whiteflies (hemiptera: aleyrodidae) in Colombia.
View the document14. Prospects for traditional and cultural practices in integrated pest management of some root crop diseases in rivers state, Nigeria.
View the document15. Studies on cowpea farming practices in nigeria, with emphasis on insect pest control.
View the document16. Effect of various fertilizers and rates on insect pest/pearl millet relationship in Senegal.
View the document17. Insect pests of intercrops and their potential to infest oil palm in an oil-palm-based agroforestry system in India.
View the document18. Using weather data to forecast insect pest outbreaks.
View the document19. Insect pest management and socio-economic circumstances of small-scale farmers for food crop production in western Kenya: a case study.
View the document20. Rodent communities associated with three traditional agroecosystems in the San Luis potosi plateau, Mexico.
View the document21. Grain storage losses in Zimbabwe.
View the document22. Controlling weeds without chemicals.
View the document23. Weed management in agroecosystems: ecological approaches.
View the document24. Manual on the prevention of post-harvest grain losses.
View the document25. Evaluation of efficient weed management systems in pigeonpea (cajanus cajan l.)
View the document26. Weed management in a low-input cropping system in the Peruvian Amazon region.
View the document27. Poblaciones, biomasa y banco de semillas de arvenses en cultivos de maiz zea mays l. Y frijol phaseolus vulgaris l. Efecto de m+todos de control y rotaciones. (Weed population, biomass, and seed bank in maize and bean crops. Effects of control methods and crop rotations).
View the document28. Effects of groundnut, cowpea and melon on weed control and yields of intercropped cassava and maize.
View the document29. Intercropping and weeding: effects on some natural enemies of African bollworm, heliothis armigera (hbn.) (lep., Noctuidae), in bean fields.
Open this folder and view contentsAbstracts on water management
Open this folder and view contentsAbstracts on soil fertility
Open this folder and view contentsAbstracts on erosion and desertification control
Open this folder and view contentsAbstracts on potential crops for marginal lands
 

26. Weed management in a low-input cropping system in the Peruvian Amazon region.

Trop. Agric. (Trinidad), 69, 3, 1992, pp. 250-258

A weed-control study in a five-crop sequence (rice-rice-cowpea-rice-cowpea) following forest clearing in the Peruvian Amazon was carried out.

Previous work has established that continuous cropping systems in the Peruvian Amazon are viable alternatives to shifting cultivation if appropriate amounts of lime and fertilizers are supplied. Herbicides have provided effective but costly weed control in these intensively managed (high-input) systems.

Low input systems are based on acid-tolerant cultivars and rely on moderate amounts of fertilizers and careful recycling of crop residues to maintain soil fertility. But weed control in this management system poses special problems. Complete reliance on herbicides is unacceptable because of the cost, and hand labour is often unavailable.

Weed control in a low-input system must focus on cultural practices that increase the crop's ability to compete with weeds and thereby eliminate some of thecostly control measures needed to maintain yields.

The results of this study revealed that tilled plots had more weeds than untilled in the first crop but fewer in the fifth. Mulching residues had little weed-controlling effect, and crop yields were always higher when residues where incorporated. High planting density reduced weed levels and increased crop yields. Herbicides were as effective as hand weeding in controlling weeds, but herbicide costs sharply limit their use in low-input systems. Rice yields fell by 54-100% in the absence of weed control but were reduced by less than 30% for cowpea. Sedges comprised 84% of the weeds in the first crop following forest clearing, but grasses dominated (79%) in the fifth crop.

As has been shown in other environments a practical and effective weed-management programme for continuously cropped systems must combine cultural practices with chemical and manual methods of control. The observations suggest that a similar integration of control measures is needed during this transitional period that bridges the time-span between forested land and the cultivatable fields of a permanent agriculture.

1220 92 - 10/147

Plant protection

Latin America, Mexico, weed control methods, crop rotations, maize, bean, intercropping

CHAVEZ, C.M.

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