O presente estudo foi executado com o objetivo de pesquisar a possibilidade de aumentar a produtividade de cafèzais velhos, sem emprêgo de matéria orgânica trazida de fora. Foram estudados N, P, K, micronutrientes (zinco, cobre e boro) e adubação verde. Utilizou-se um delineamento fatorial 3² X 2², em blocos de 18 canteiros com nove plantas cada um, com bordadura de uma planta entre os canteiros. O ensaio foi instalado na Estação Experimental de Ribeirão Prêto, em um cafèzal com mais de 40 anos de idade, em terra-roxa-legítima, e cuja produção média nos quatro anos anteriores foi de 24 sacos de café em côco por mil pés. Obteve-se grande aumento de produção com o emprêgo de nitrogênio, devido não só às quantidades aplicados, mais elevadas do que as até então recomendadas, mas principalmente à sua aplicação parcelada. Os aumentos devidos ao nitrogênio na dose de 360 g de N por planta, na forma de sulfato de amônio, corresponderam a 6, 11, 13, 16 e 34 sacos de café em côco por mil pés, nos anos de 1954 a 1958. A dose mínima de potássio empregada foi de 120 g de K(2)0 por planta. A dose de 240 g de K(2)0 por planta ainda proporcionou um aumento de produção de 9% em relação à anterior. Não houve reação ao fósforo nem à adubação verde. A aplicação de micronutrientes (zinco, boro e cobre) fêz desaparecer os sintomas de deficiência de zinco, mas resultou em decréscimo significativo da produção. A aplicação do nitrogênio melhorou a coloração e o desenvolvimento da folhagem. Não houve influência dos outros fatôres sôbre o aspecto vegetativo das plantas.

It has been believed in Brazil that it is not possible to maintain coffee plantings profitably without the use of organic matter. Consequently it has been routine to recommend yearly applications of manure or compost. The present experiment was carried out to study the possibility of increasing the yield of a coffee planting and maintaining it at a high level by the exclusive use of mineral fertilizers. A coffee plantation of the "Bourbon vermelho" variety about 40 years old grown on "terra-roxa-legítima" soil was used. A factorial experiment 3² X 2² was installed in 1953 with 9 plants per plot. The treatments used were: ammonium sulphate 0 g, 600 g and 1800 g per plant, superphosphate 0 g, 500 g and 1500 g per plant and potassium chloride 200 g, 400 g and 800 g per plant, microelements (Zn, Bo, Cu) and green manure. Until 1957 the phosphate and the chloride were applied in furrows once a year and the ammonium sulphate was applied three times a year as top dressings. Starting in 1958 all the fertilizers were applied four times a year as top dressings. The microelements were applied as foliage spray of the following solution: zinc sulphate - 6 g, copper sulphate - 1 g and borax - 3 g per liter of water. Soybean was used as green manure until 1955 and jack bean (Canavalia ensiformis, D. C.) in the later years. The response to nitrogen application was highly significant and kept increasing every year as shown by the percentage of yield increases for the years 1954 through 1958. These were 8.4%, 60.7%, 30.9%, 50.3% and 63.1%. In previous experiments doses of KCI of up to 200 g per tree had already been used. For that reason in this experiment the minimum dose of that fertilizer used was 200 g per tree. An application of 8OO g per tree of KCI gave only 9% of yield increase in relation to the 200 g per tree application. No reaction was obtained to the application of phosphorus. The microelement spray cured the zinc deficiency symptoms which were evident prior to its application, but decreased the yield significantly, the highest decrease being 39% in 1955. No reaction was obtained to the use of green manure. The results obtained seem to show that it is possible to increase substantially the yield of a coffee plantation through the use of mineral fertilizers only.

No plantio de um cafezal em terra de derrubada recente usa-se plantar as sementes no fundo das covas abertas com 15 a 30 cm. Em terras já anteriormente cultivadas, o emprêgo de mudas é indicado, julgando-se oportuno também o plantio profundo nas covas. A fim de verificar qual a melhor profundidade de plantio foram feitos três ensaios, nos quais se observaram as quantidades de falhas ocorridas e as produções dos cafeeiros. Notou-se que em Campinas a ocorrência de falhas foi a mesma nas diferentes profundidades de plantio, enquanto em Mococa foi maior para o plantio ao nível do solo. Quanto à produção, analisada durante os 4 a 6 primeiros anos, notou-se que as colheitas aumentaram à medida que as mudas foram plantadas a menores profundidades. A maior produção ocorreu no plantio ao nível do solo, em dois dos ensaios analisados. No ensaio instalado na Estação Experimental de Mococa observou-se pequena diferença entre o plantio na superfície e a 10 cm abaixo. Embora os resultados apresentados sejam de caráter preliminar, o bom desenvolvimento vegetativo e as melhores produções, além da facilidade de trabalho de plantio, aconselham o emprego da plantação das mudas ao nível do solo ou a 10 cm de profundidade, nas regiões estudadas.

The establishment of coffee plantation in new deforested lands is usually made sowing about 20 seeds very deep in the holes and protecting with wood the lateral and upper sides of the holes in order to secure to the germinating seeds an environment similar to that found in nurseries. In land already cultivated with other crops the coffee plantation is established using seedlings developed in nursery. At our conditions four individual seedlings are planted in each hole. It is usually believed that these one year old seedlings must also be planted 20 to 30 cm below soil surface in the same way as the seeds are planted in new land. There are however indications that the seedlings can be planted only a few centimeters below the soil surface or at the soil level, saving a great deal of time in the preparation of the hole. In order to study the effects of depth of planting on the development and yield of the coffee plants, three experimental trials were planted in three coffee regions of the State of S. Paulo, using three to four different depths of planting. Seedling failures were the same for the depths of 0, 10, 20, and 30 cm in the trials from Campinas and higher at soil level in Mococa. The yields for the period of four consecutive years increased as the seedlings were planted at lower depth at the three localities. The highest yield was observed when seedlings were planted at soil level or at 10 cm depth. For clay soils (where the trials were established) it can be stated that seedlings may advantageously be planted at soil level. Other experiments will indicate which will be the best depth of planting for the coffee seedlings in sand soil, since it is a common practice in this type of soil to plant seedlings very deep in the hole.

Realizaram-se contagens de frutos novos de café logo após o florescimento, em novembro, e de frutos completamente desenvolvidos, em fevereiro do ano seguinte, a fim de calcular as porcentagens de "pegamento" dos frutos, em alguns canteiros de um. ensaio de adubação, que haviam recebido combinações de adubo mineral e orgânico. As determinações foram feitas para as posições alta, média e inferior de cada planta, e o resultado médio foi correlacionado com os elementos usados na adubação e também com a produção das plantas. Os resultados obtidos indicaram que o fósforo, combinado com o estêrco, contribuiu para aumentar 3,5% à porcentagem de pegamento em relação à adubação sòmente com estêrco, e que o potássio também contribuiu com um aumento de 8,1% em relação às plantas que não receberam êste elemento. O pegamento dos frutos na. parte superior das plantas mostrou-se maior do que nas partes média e inferior. Verificou-se, ainda, que a porcentagem de pegamento geral, a qual é de cerca de 50%, é independente da produtividade das plantas.

Determinations of fruit setting were made in a fertilizer trial that is being carried out at the Estação Experimental de Ribeirão Prêto. This experiment is a factorial 2(4) with four replications, the basic treatments being 10 kg of "estêrco" (e), 0.2 kg of ammonium sulphate (n), 0.2 kg of bone meal (p) and 0.1 kg of potassium chloride (k). Fruits were counted in November of 1953 and 1954, soon after flowering, and also in February of the following years, when the fruits were already well developed. By fruit setting it is meant the ratio between fruit numbers in November and February, although counting was made at 15-day intervals between these two dates. In 1953/54 the percentage of fruit setting was determined for one plant in each of the four replications of treatments e, en, ep and ek. One plant in each replication of treatments np, en, enk and enpk was studied in 1954/55. For each plant in both seasons, six flowering branches were used, two at the higher part of the coffee plant, two at the base and two in intermediate positions. From the results obtained it is concluded that chemical fertilizers may contribute significantly to increase the percentage of fruit setting. Together with "estêrco" (stable manure), phosphorus showed a 3.5 per cent increase over "estêrco" alone. Comparing treatments with and without potash an increase of 8.1 per cent was found for plots receiving this fertilizer in 1954/55. It is also concluded that significant differences were observed in fruit setting at different levels of the plant, in favor of the higher branches. Fruit setting showed no correlation with total yield of ripened fruits.