Algumas variedades interessantes de mandioca (Manihot esculenta Crantz) da Amazônia ()

Over 150 varieties of cassava have been collected from indians and small holders during the last 3 years. Initial experiments already have identified some with interesting characteristics. 1 - A yellow variety (IM 171) with 3,2 mg carotenoids/100g of root. 2 - IM 097 capable of yielding more than 5 kg of root/m2/year when well fertilized on a yellow Latosol. 3 - IM 159 capable of yielding 7 kg of root/m2 in only 7 months on the fertile varzea. 4 - IM 176 with some tolerance to Root Rot (Phytophthora drechsleri).Durante os três últimos anos, foram coletadas mais de 150 variedades de mandioca entre os índios e pequenos agricultores. Experimentos preliminares já identificaram algumas com características interessantes. 1 - I M 171, uma variedade amarela com 3,2 mg caroteno/100 g de raiz. 2 - IM 097 capaz de render mais de 5 kg de raiz/m3/ano quando fertilizada em latossolo amarelo. 3 - I M 159 capaz de render 7 kg de raiz/m2 em apenas sete meses em várzea fértil. - 4 IM 176 com alguma tolerância à podridão de raiz (Phytophthora drechsleri)

Considerações sobre a produção de alimentos por árvores e florestas

Trees and forest contribute little to most diets. This is surprising as some species seem capable of producing much more food per area than the many annual crops that supply the bulk of our food. It is suggested that this yield potential coupled with agricultural e ecological advantages should lead to research into Increasing food production from all forms of forests and the design of "food forests".Arvores e florestas contribuem com pouco alimento para a maioria das dietas humanas. No entanto, algumas espécies, aparentemente, são capazes de produzir mais alimentos por área do que muitas das culturas anuais que nos fornecem a maioria de nossos alimentos. Este trabalho sugere que esse potencial de alto rendimento dos alimentos de origem florestal, junto com outras vantagens agrícolas e ecológicas, devem estimular pesquisas sobre o aumento na produção de alimentos de todos os tipos do florestas e o planejamento de "florestas de alimentos"

Estudos sobre o caroteno em algumas variedades amazônicas de mandioca (Manihot esculenta Crantz)

The carotenoid content of cassava roots varies with variety, age and the cross section of the root. Large losses occur during the processing of roots into the fermented flour eaten in the region. These losses can be reduced if the roots are well fermented and the flours are stored in good conditions. About 30% of the carotenoides is Beta carotene and the consumption of 100 g of flour could provide about 20% of the daily adult recommended intake for vitamin A.Foram conduzidos experimentos com raízes de mandioca nos quais foi verificado um efeito da variedade, idade e corte transversal, sobre o conteúdo de caroteno. Notaram-se grandes perdas ocorridas durante o processamento das raízes na farinha d'água consumida na região. Essas perdas podem ser reduzidas se as raízes forem bem fermentadas e a farinha armazenada em boas condições. Constatou-se que dos carotenóides 30% era Beta caroteno e o consumo de 100 g de farinha pode fornecer 20% das recomendações diárias de vitamina A

A preliminary study of the agronomic factors affecting the yield of extractable leaf protein

Abstract Several species have been selected for their ability to synthesise protein rapidly. The main factors influencing their protein production were nitrogenous fertiliser, age at harvest, seed rate and climate. Some of the best species were grown either alone or in sequence at optimum rates of seed and N, and harvested to make maximum use of the growing season. The annual yields of extracted protein reached 2000 kg/ha in a good year with winter wheat followed by two crops of mustard or fodder radish. The grasses have not extracted well in the past; however, with recent improvements in agronomy and machinery, cocksfoot yielded 1670 kg/ha in a very dry year and can be expected to yield 2000 kg/ha regularly in wetter parts of the British Isles. It is hoped that similar knowledge will lead to much higher yields in the wet tropics

Traces of 2:1 layer-silicate clays in Oxisols from Brazil, and their significance for potassium nutrition

SUMMARY The recuperation of the soil during bush fallows after a period of cultivation is an important part of the success of shifting cultivation in the lowland humid tropics. However, the sources of the nutrients which enable the observed rapid growth on apparently exhausted soils has never been satisfactorily explained. Some soils from the Manaus region of Brazil have been examined in an attempt to identify reserves of potassium. X-ray diffraction, physical and chemical analyses, and microcalorimetric measurements of K-Ca exchange show that small reserves of K occur in 2:1 clay minerals which exist in trace amounts in the soils. The results suggest that the clay fraction of the soil may play a more important role in nutrient supply than previously realized. The reserves are considered in terms of the land use of the area