Navegando por Autor "Inforzato, Romeu"

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Estudo comparativo do sistema radicular dos cafeeiros Bourbon amarelo e Mundo novo
(Instituto Agronômico (IAC), 1963-11) Inforzato, Romeu; Reis, Antônio Junqueira
São apresentados resultados de determinações do desenvolvimento do sistema radicular do cafeeiro, variedades Bourbon Amarelo e Mundo Nôvo, em solo tipo terra-roxa-legítima. Os sistemas radiculares atingiram as profundidades médias de 3,70 m e 3,10 m, respectivamente, para Bourbon Amarelo e Mundo Nôvo. Em ambos os casos, cêrca de 90% das raízes foram encontradas na primeira camada de 50 cm de profundidade. Maior densidade de raízes finas foi encontrada nas proximidades dos troncos, dentro de um círculo de raio de 75 cm.
Quantidade de água transpirada pelo cafeeiro cultivado ao sol
(Instituto Agronômico (IAC), 1950-09) Franco, Coaraci M.; Inforzato, Romeu
In determinations made with a porometer it was verified that the stomatal opening of coffee leaves increases in size immediately after the leaves are detached from the plant (fig. 1). This fact indicates that the method of rapid weighings of detached leaves is not suitable for studies on the transpiration of the coffee plant. The transpiration of coffee plants has been determined by the weighing potted plant method. Pots with a capacity for 51 liters were used. They were made of galvanized iron plate and had no drainage hole. When the moisture content of the soil approached the wilting point water was added to bring all the soil mass to fiel capacity. In order to avoid oxygen depletion the pots were not sealed. To decrease the direct evaporation at the soil surface a two-centimeter layer of rice hulls was used as mulch, and a celotex cover was placed on top of the pot. Three similar pots with the same type of protection, but without plants were used to measure the direct evaporation from the soil surface. The weight losses of these pots were subtracted from the weight losses of the pots with plants. Two to throe-year old plants of Coffea arabica var. bourbon were used. Three plants were employed each month and after this time their leaves were picked off, and the total leaf area was determined. The tests were carried out for a whole year. The transpiration rates were calculated in g/dm2/day. The total leaf area of an adult coffee plant was found to be 3,146 dm2 (average of seven trees). Based on this average and on the transpiration rate of the experimental plants it was possible to calculate approximately the amount of water that an adult coffee plant would transpire under the same conditions. Since the plants submitted to the experiment did not suffer water shortage at any time, the present results show the approximate amount of water lost by the coffee plant under optimal soil-water conditions. The data are presented in table 1. The figure 1 shows the monthly amount of water lost by transpiration in a coffee* plantation compared with the monthly rainfall during a year. The environmental factors that influence plant transpiration vary much less between the same months of different years than between the different months of the same year. Hence the results obtained should not be far from the average; that would be obtained if the transpiration had been measured during a number of years. Comparing the water lost by transpiration of coffee trees with the average rainfall in'Campinas, State of São Paulo, Brazil, it is seen that from October to March rainfall exceeds water consumption. In April, June, and September the excess is small, and in May, July, and August the amount of water transpired exceeds the average rainfall (fig. 2). Since the rainfall distribution is variable, this figure may be different in a given year. The highest daily rate of transpiration encountered was 17.6 mg/dm2/m (over twelve; hours). Previous results obtained by the writers showed 18.2 mg/dm2/m to be the rate of transpiration in a very sunny and hot day. Nutman working in Africa (2) found a maximum daily rate of 20.67/dm2/m (over nine hours). These data are comparable and must represent approximately the maximum rate of transpiration of the coffee plant. The average daily transpiration encountered was 6.20 g/dm2/day and the total amount of water transpired by a coffee tree in one year was found to be 7,273 liters.
Quantidade de água transpirada pelo cafeeiro sombreado e pelo ingazeiro
(Instituto Agronômico (IAC), 1951-04) Franco, Coaraci M.; Inforzato, Romeu
The present paper discusses the amount of water lost by the soil through the transpiration of coffee plants and shade trees in shaded coffee plantation. All methods and techniques employed in the study of transpiration of the shade tree Inga edulis Mart, were exactly the same as those described in a paper recently published (4). It was determined previously (3) that a shaded coffee plant receiving 55% of full sunlight transpired 80% as much as when in 100% full sunlight. The amount of water transpired by a coffee plant was calculated by taking 80% of the amount transpired in unshaded plantation (4). Comparing the water lost by transpiration of shaded coffee plants and shade trees with the average rainfall in Campinas, São Paulo, Brazil, it is seen that from April to September the amount of water transpired exceeds the average rainfall. This finding seems to agree with our previous conclusion (1, 2, 5) that water competition between shade trees and coffee plants is the factor that controls the success of growing coffee under shade in the State of São Paulo, Brazil. The highest daily rate of transpiration encountered, for Inga edvlis was 36.7 milligrams per square decimeter per minute. The average daily transpiration was found to be 9.90 grams per square decimeter per day. The total amount of water transpired by an Inga tree was calculated to be 71,140 liters per plant per year. Since the plants submited to the experiment did not suffer a water shortage at any time, the present results show the approximate amount of water lost by the Inga tree and shaded coffee plant under optimal soil-water conditions.