Anais da Escola Superior de Agricultura Luiz de Queiroz
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13757
Navegar
5 resultados
Resultados da Pesquisa
Item Origem e formação das domácias em Coffea L.(Universidade de São Paulo, Escola Superior de Agricultura, 1960-08-04) Barros, Myrthes Apparecida Adâmoli deNo presente trabalho focalizamos o discutido problema da origem ou formação das domácias, escolhendo, inicialmente, as principais variedades de Coffea arabica L.. Na revisão da literatura, procuramos nos cingir unicamente à bibliografia que trata do assunto em aprêço. Apreciando convenientemente o problema da origem, duas hipóteses foram aventadas pelos autores para explicar a formação das domácias: l.ª) causada por insetos ou por ácaros (LUNDSTRÖEM e outros). 2.ª) caráter hereditário (CHEVALIER). Ambas as hipóteses foram consideradas com o objetivo de aclararmos o problema e concluimos, com CHEVALIER, que se trata de um caráter hereditário. O material constou de sementes, e de ramos com fôlhas de várias idades de cafeeiros que vieram das coleções vivas do Instituto Agronômico de Campinas. As observações morfológicas preliminares foram feitas com o auxílio do microscópio estereoscópico. As estruturas anatômicas foram apreciadas em córtes transversais longitudinais, coloridos com violeta-cristal e eritrosina, com espessura de 18 micra.Item Estudos sôbre a alimentação mineral do cafeeiro. II: Absorção do superfosfato radioativo pelo cafeeiro (Coffea arabica L., var. Bourbon Amarelo) em condições de campo(Universidade de São Paulo, Escola Superior de Agricultura, 1959) Malavolta, E.; Menard, L. Neptune; Lott, W. L.In order to find out the best way to supply phosphorus to coffee plants when growing in "terra roxa misturada", a red soil with a high fixing capacity, tagged superphosphate was applied by the following procedures: (1) topdressed in a circular strip around the trees; (2) placed in the bottom of a circular furrow 15 cm deep; (3) placed in a semicircular furrow also 15 cm deep; (4) sprayed directly to the leaves. In each case 150 gms. of ordinary superphosphate tagged with H3 P32 O4 to give 5 X 10(9) c.p.m. were given to the two and half year old coffee plants. It was found that for the several treatments of the total phosphorus in the leaves the following values, on a per cent basis, came from the applied superphosphates: (1) topdressed 10.2 per cent, (2) circular furrow 2.4 per cent, (3) semicircular furrow 1.7 per cent, (4) sprayed 38.0 per cent; one can see, then, that methods (2) and (3) commonly used by the coffee planters are a very inefficient way to supply phosphorus in this type of soil. The remarkable foliar absorption was checked twice: a water culture experiment was carried out, the radiophosphorus being supplied by brushing it in the upper and lower surfaces of a given leaf; radioactivity was detected all over the plant as a result both of absorption and translocation; on the other hand, leaves collected from the sprayed trees were radioautographed; the radioautographs showed the pattern of distribution of the P32 which indicates true absorption rather than a surface contamination. In another locality, an experiment was caried out with 8 year old plants growing in "arenito de Bauru" which is a sandy soil with much less phosphorus fixing capacity. In this experiment the aim was to compare absorption of tagged superphosphate by trees growin under mulch against plants not receiving this treatment, The uptake of phosphorus was the same for both sets of plants. In both field experiments soil samples down to 15 cm in the profile were collected and its 0.2NHC1 soluble phosphorus was counted; rather significant values were observed mainly in the upper 5 cm layers.Item Nota preliminar sôbre a absorção e a translocação do radiozinco no cafeeiro [Coffea arabica] cultivado em solução nutritiva(Universidade de São Paulo, Escola Superior de Agricultura, 1956) Arzolla, J. Dal Pozzo; Haag, H. P.; Malavolta, E.Two water-culture experiments were carried out to study the absorption and the translocation of radiozinc in young coffee plants as influenced by two factors, namely, concentration of heavy metals (iron, manganese, copper and molybdenum) and method of application. Inert zinc was furnished at a uniform rate of 0.05 p.p.m.; the levels of iron supply were 0, 1.0 and 10 p.p.m.; manganese was supplied in three doses 0, 0.5, and 5 p.p.m.; copper - 0, 0.02, and 0.2 p.p.m.; molybdenum - 0, 0.01 and 0.1 p.p.m. When applied to the nutrient solution the activity of the radiozinc was 0.15 microcuries per plant. In the study of the leaf absorption, the radiozinc was supplied at the level of 0.10 microcuries per plant; in this case the material was brushed either on the lower or in the upper surface or both of two pairs of mature leaves. In both experiments the absorption period was 8 weeks. The following conclusions can be drawn: 1. Among the heavy metals herein investigated the iron concentration did not affecc the uptake of the radiozinc; by raising the level of Mn, Cu and Mo ten times, the absorption dropped to 50 per cent and even more whe compared with the control plant; however, when these micronutrients were omitted from the nutrient solution an increase in the uptake of zinc was registered only in the minus - Cu treatment. The effects of high leveds of Mn, Cu and Mo probably indicate an interionic competition for a same site on a common binding substance in the cell surface. 2. The absorption of the radiozinc directly applied to the leaf surface reached levels as high as 8 times that registered when the root uptake took place. Among the three methods of application which have been tried, brushing the lower surface of the leaves proved to be the most effective; this result is easily understood since the stomatal openings of the coffee leaves are preferentially located in the lower surface. In this treatment, about 40 per cent of the activity was absorbed and around 12 per cent were translocated either to the old or to the newer organs. 3. Data herein presented suggest that leaf sprays should be preferred - rather than soil applications - to control zinc deficiency in coffee plants when growing in field conditions.Item A evolução das máquinas de beneficiar café no Brasil(Universidade de São Paulo, Escola Superior de Agricultura, 1953) Leme, Hugo de AlmeidaNo estudo do histórico das Máquinas de Beneficiamento propriamente dito do café diremos, preliminarmente, que o desenvolvimento dessas máquinas acompanhou o progresso da cafeicultura.Item Variedades de cafeeiros(Universidade de São Paulo, Escola Superior de Agricultura, 1948-07-15) Mendes, Carlos TeixeiraNo estudo das variedades de cafeeiros que povoam o Estado de São Paulo, além de mil outros detalhes correlacionados com sua cultura e sua genética (produtividade, rusticddade etc.) podemos levar em consideração outros dois pontos de vista : o da "bebida" e o do "tipo". Em relação à primeira, não será preciso perder muito tempo para demonstrar que as variedades predominantes em nossas culturas não constituem a causa das bebidas finas ou das menos boas. Ao meio em que vivem é que se deve imputar, mais que a tudo, a razão do fato. As duas variedades que englobam de modo quase absoluto, nossas culturas, são a "Nacional" e a "Burbon", as, mesmas que, de Campinas para o Norte do Estado produzem afamados cafés e que, na Sorocabana te no vale do Paraiba só contribuem com produtos indiscutivelmente inferiores aos daquela zona.