Com o objetivo de verificar se o uso contínuo de adubações minerais pesadas, desacompanhadas de adubações orgânicas, poderia prejudicar o solo, foi executado um experimento em vasos "Mitcherlich", com capacidade para 6 kg de terra, nos quais se empregou solo do tipo Podzolizado de Lins e Marília, variação Marília. Nesses vasos foram feitas 10 culturas sucessivas de milho, cujas plantas foram cortadas e pesadas ao atingirem cerca de 80 cm de altura. Os resultados demonstraram que as plantas dos vasos, através dos quais haviam passado quantidades exageradas de adubos minerais, se desenvolveram melhor do que aquelas dos vasos testemunhas.

Although largerly employed for economical reasons, it has been suggested that a continuous and exclusive application of mineral fertilizers is deleterious to coffee plantation. To investigate such a possibility, an experiment was carried out in Mitcherlich pots filled with Podzolized soil on Calcareous Sandstone, Marilia variation, which is one of the most commonly used soil for coffee. Ten plantings of corn, used as indicator plants, were made successively in these pots. Plants were harvested when about 80 cm high, and after each harvesting the soil of individual pot was removed, sifted, replaced and heavily fertilized. Prior to new planting, the soil was well watered, dried, then excess o salts being removed by a generous supply of water. A balanced mixture of fertilizer was applied to the plants, as done normally in field cultures. At the end of the experiment, each pot has received a maximum of 440 g of mineral fertilizer which is equivalent to ca. 880 kg of fertilizer applied to an individual coffee plant, under field conditions, in a period of 10 years. Such amount represents roughly a hundredfold dose usually recommended for coffee crop. Nevertheless, corn planted in soils treated with such heavy excess of mineral fertilizer, grew better than those cultivated in control pots. These received only normal level of fertilizers, and had the soil replaced several times during the experiment.

Tem sido preconizada a aspersão de soluções de uréia na folhagem das plantas, como fonte de nutrição nitrogenada. No presente trabalho são relatados quatro ensaios, cuja finalidade principal foi verificar a capacidade de absorção da uréia por via foliar no cafeeiro, pois são divergentes as opiniões sôbre a eficiência de suas fôlhas no aproveitamento desse produto. A análise foliar íevelou aumento do teor de N total na maioria dos casos em que as fôlhas haviam sido aspergidas com soluções de uréia a 2,5% todavia, cafeeiros com cêrca de 10 anos, no campo, não mostraram reações sintomatológicas correspondentes, enquanto plantas novas, em vasos, recebendo o mesmo tratamento, posteriormente apresentaram folhagem verde normal. A solução de uréia comercia!, aplicada na concentração indicada, foi sempre prejudicial à folhagem, pois induziu invariávelmente a ocorrência de manchas típicas da intoxicação pelo biureto. conforme ilustrado na estampa 1.

Four trials were: carried out to study the absorption of urea by coffee leaves sprayed with 2.5% solutions made from commercial and p.a, chemicals. Young plants growing in nutrient solutions did not absorb urea through the leaves, but plants growing in sand culture or in the field, that showed symptoms of nitrogen deficiency, did absorb this element from urea as shown by the results from leaf analysis made prior and after the treatments. However, the plants potted in sand recovered the normal green color, whereas the treated plants in the field did not do so. Sprayings made with solutions of commercial urea at the indicated concentration induced some injury to the coffee leaves, as it can be seen from plate 1.

Tem sido observada ocasionalmente uma lesão no colo de cafeeiros novos ao nível do solo. .Estudos dc laboratório mostraram que o caule de cafeeiros novos foram danificados quando ao redor dêle se fêz circular água aquecida às temperaturas de 45 o 50ºC. O aquecimento da superfície do solo, compreendendo o colo de cafeeiro vegetando em laminados, com o auxílio de uma lâmpada de raios infravermelhos, resultou em lesão semelhante àquela observada nas culturas. Essa lesão apareceu em tratamentos cujas temperaturas estiveram entre 44 e 51°C. O fato dessas temperaturas serem freqüentemente observadas em solos expostos ao sol, sugere que a lesão do caule do cafeeiro, observada freqüentemente em cafèzais novos, seja conseqüência do aquecimento excessivo da superfície do solo pelos raios solares.

A collar injury of young, field coffee plants at the soil level has been observed occasionally in the summer. The location of the abnormality and the season when it appears .suggested that excessive heating of the soil surface by the sun rays could be its cause. Two experiments were then conducted in the laboratory to investigate this bypothesis. The first experiment consisted in circulating water at the desired temperature around the stem ofyoung coffee plants, using the same apparatus described in a previous paper. In a second experiment the base of the stem and the soil around it was heated by means of a G. E. 250 watts infrared industrial reflector. By changing the distance between the heat source and the plant, different temperatures at the soil surface could be obtained. The results of the first experiment showed that 4 plants out of o that were treated at 45ºC showed injury; the other 2 plants survived without damage. From 5 plants that were treated at 50ºC, 2 showed injury and 3 died shortly after the treatment. All plants subjected to the temperature treatments at 35°C and 40ºC survived without damage, while those treated at 55ºC and 60ºC, died. In the second experiment, 5 plants out of 18 that were treated at temperatures ranging from 45ºC to 51ºC showed injury similar to that observed in the field. All plants treated at temperatures below 45ºC survived without damage with the exception of one treated al 44°C which died. All treatments above 51°C resulted in the death of the plants. It has been observed in the summer that the soil surface temperatures in the field frequently reaches the 45ºC - 51ºC range or sometimes even exceeds it. The results of the present experiments strongly suggest that coffee collar injury at the soil level as observed in the field is caused by excessive sun heating of the soil surface and stem base.

Em trabalhos recentemente publicados. Pereira (9, 10) conclui que os frutos de café possuem enzimas capazes de eliminar a substância péctica que envolve as sementes, quando após o despolpomento são eles colocados em água de cal contendo 0,4% de cloreto de sódio. No presente trabalho mostra-se que aquela substância péctica não é eliminada pelo tratamento descrito, mas apenas torna-se endurecida pela ação do cálcio. Quando sementes tratadas da maneira indicada foram lavadas e colocadas em água pura ou levemente acidulada, a substância péctica se reintumesceu e as sementes tornaram-se novamente lisas ao tato e envolvidas pela camada translúcida de substância péctica. Esta conclusão confirma os trabalhos anteriormente publicados (3, 4), que mostraram ser a eliminação da substância péctica, que envolve as sementes de café despolpado, devida a mícrorganismos.

In papers recently published, Pereira Jr. (9, 10) claimed that coffee fruits have enzimes capable of breaking down the insoluble pectic substance which involves their seeds. This conclusion was drawn from an experiment where freshly pulped coffee fruits were placed in a calcium hydroxide solution containing 0.4% of NaCl as an enzime activator. After this treatment the seeds which were very slimy became apparently clean and could be handled easily. In this paper it is shown that the pectic substance is not eliminated by such a treatment but that it merely becomes herdened by the action of the calcium hydroxide. When seeds so treated were washed and left in water the pectic substance involving the seeds became turgid again giving the seeds the same slimy feeling to the touch that was noticeable prior to the treatment. This process is enhanced by the use of acidulated water after the washing. These results support the conclusions of previous papers (3, 4) showing that the elimination of the pectic substances in pulped coffee berries is due to microorganisms.

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.

Como o milho é freqüentemente cultivado em solo anteriormente ocupado pela cultura algodoeira, achou-se conveniente verificar se o BHC empregado nesta última cultura poderia permanecer no solo e prejudicar aquela planta. Com êste objetivo fêz-se um ensaio em vasos de Mitscherlich, no qual diferentes doses de BHC foram incorporadas à terra. As doses de BHC empregadas foram correspondentes àquelas recebidas pelo solo no fim de 1, 2, 3, 4 e 5 anos de cultura algodoeira, tratada com a quantidade oficialmente recomendada daquele inseticida (108,5 kg/ha/ano, de BHC contendo 2% de isômero-gama). Nos vasos, onde as condições eram as mais favoráveis para o manifestação dos efeitos tóxicas do BHC, a decomposição dêste inseticida na terra foi suficientemente rápida para que os efeitos tóxicos de uma dose três vezes mais forte do que a oficialmente recomendada desaparecessem completamente no fim de dois anos. Nas condições de cultura os efeitos tóxicos do inseticida devem ser ainda bem menos intensos. Não são de se esperar, pois, prejuízos à cultura do milho, causados pelo acúmulo de BHC no solo, quando aquela fôr feita em terreno anteriormente ocupado pela cultura algodoeira, desde que nesta a quantidade empregada do inseticida, não tenho sido muito diferente daquela oficialmente recomendada.

Corn is frequently cultivated on soil previously used for cotton. Cotton plantings usually receive heavy applications of BHC for insect control, what might lead to an accumulation of the insecticide in the soil. An attempt was made to verify whether varying amounts of BHC added to a sandy soil in Mitscherlich pots would injury corn plants. The amounts added were calculated on an area basis to correspond to those received by the land at the end of 1, 2, 3, 4 and 5 years of cotton cultivation when BHC is applied at the yearly rate of 108 kg per hectare. Other types of soil were not used in this experiment because the toxic effects of this insecticide seem to be more serious on sandy soils. Other techniques employed in this work were exactly the same described in a previous paper (1). The experiment was terminated one month after sowing and the weights of the plant tops and roots were determined. The soil from the pots was passed through a sieve after harvesting, returned to the pots and left undisturbed for one year. Corn was then planted a second time on the same soil. In the first planting, dose 1 had no injurious effect on plant growth, but the heavier doses depressed it severely. In the second planting only doses 4 and 5 showed injurious effects, but injury was less severe than that in the first planting. The results seem to indicate that there is practically no risk that residual BHC in the soil from a previous cotton planting that received standard applications of the insecticide will injury corn plants raised on the same land the following year.

Com o objetivo de investigar se o estrangulamento do caule de cafeeiros novos, observado em alguns anos de inverno rigoroso, poderia ser conseqüência do acúmulo de camadas de ar frio nas proximidades do solo, tratou-se com temperaturas baixas a haste de plantas com cêrca de seis meses de idade. O tratamento consistiu em se fazer circular salmoura refrigerada ao redor do caule, sem, entretanto, entrar em contato com êste. Obteve-se o estrangulamento com o emprêgo de vários tratamentos que incluiam temperaturas de - 2 a - 6º C. Uma planta tratada com temperatura de - 5 a - 7º C morreu duas semanas após o tratamento. Plantas tratadas por duas horas com as temperaturas de 0 a - 2º C não exibiram estrangulamento nem qualquer outro sintoma de anormalidade.

A strangulation of the stem of young coffee plants a few inches above ground has been observed in some years after a cold winter. To know if this strangulation could be caused by the action of a layer of cold air that had settled over the surface of the soil as has been suggested (1), an experiment was carried out wich consisted of circulating cold water around the stem for a certain period of time. To accomplish this a special apparatus was mode using plexiglass. To obtain temperatures below the freezing point, pre-chilled salt water was used. To avoid an injurious direct contact of brine with the stem, this was wrapped with aluminum foil which was made waterproof. Two plants subjected to temperature treatments of 0° to - 2° C survived without damage. All treatments with temperatures below - 2° C resulted in strangulation and in the case of the coldest treatment used (- 5 to - 7° C) in the death of the plant.

A fim de verificar o efeito do acúmulo de inseticidas no solo, fêz-se um ensaio em vasos de Mitscherlich, empregando-se os inseticidas BHC, toxafeno, lindano e DDT, incorporados ao solo. Os três últimos foram experimentados também na forma de emulsão, enquanto que o BHC entrou no ensaio apenas na forma de pó. As quantidades de inseticidas empregadas foram correspondentes àquelas recebidas pelo solo no fim de 1, 3 e 7 anos de cultura algodoeira, tratada com as quantidades recomendadas para cada um dêles. Em terra arenosa, do tipo arenito Bauru, a dose de BHC correspondente à recebida pelo solo em um ano de cultura com o algodoeiro (108,5 kg/ha) já causou um decréscimo de produção de 20%; a dose correspondente a 3 anos produziu um decréscimo de 56% e a correspondente a 7 anos anulou a produção. Entretanto, após ter o solo permanecido sem cultura durante um ano agrícola, os efeitos tóxicos do BHC decresceram, a ponto de mesmo a dose correspondente a 7 anos de cultura ter permitido alguma produção. Dos outros inseticidas sòmente o toxafeno em emulsão e quando empregado em dose 7 vêzes mais forte do que a recomendada, que é de 18,6 l/ha de emulsão a 50%, causou algum prejuízo à produção, reduzindo-a de 30% na cultura feita logo após a sua aplicação no solo. Em conseqüência de um acidente ocorrido e mencionado no texto, não se obtiveram dados de uma segunda cultura com êste inseticida, após ter o solo "descansado" durante um ano agrícola. Em terra-roxa os efeitos tóxicos do BHC foram menos intensos. Neste tipo de terra a dose correspondente à recebida pelo solo no fim de um ano de cultura algodoeira não prejudicou em nada o algodoeiro. As doses correspondentes às recebidas pelo solo no fim de 3 e 5 anos de cultura algodoeira causaram sensíveis decréscimos de produção. Na segunda cultura, entretanto, feita nos mesmos solos após terem êstes permanecido sem cultura durante um ano, não houve nenhuma diferença entre as plantas tratadas e testemunhas, quer quanto ao desenvolvimento ou à produção, o que mostra que na terra-roxa os efeitos tóxicos do BHC, nas doses estudadas, desapareceram completamente do solo no fim de dois anos.

The effects of increasing amounts of insecticides added to the soil on the growth of cotton plants were studied. This was an attempt to verify whether or not a possible accumulation of insecticides in the soil might become detrimental to plant growth. The experiment was carried out in Mitscherlich pots with two types of soil: one sandy (arenito de Bauru) and the other clayey (terra-roxa). The amounts of insecticides added to the pots were calculated on an area basis to correspond to those applied to cotton plantings at the end of 1, 3, and 7 crops, and are called in this paper doses 1, 3, and 7, respectively. The amounts of insecticides as recommended for cotton in the state of São Paulo are as follows: BHC, 108 kg; Toxaphene, 14.5 k; Lindane, 0.4 kg and DDT, 3.6 kg. In the sandy soil, doses 1 and 3 of BHC caused 20% and 56% reduction in yield, respectively; dose 7 inhibited the production completely. Dose 7 of Toxaphene (72.24 kg/ha) when applied in emulsion form showed some toxicity. The same insecticide applied at the rate of 101.5 kg/ha in powdered form did not have any toxic effect nor did the emulsifier (15 ml of tritton 177 + xilol q.s.p. 100 ml) when applied alone. Lindane, emulsified Lindane, and DDT did not have any adverse effect on the cotton plant0 growth and yield. After the first crop the soil in each pot was passed through a sieve, returned to the pot and left undisturbed for one year. Cotton was then planted again. The development of the plants in this second planting was very irregular. This was due to aluminum toxicity, because the protective painting of the aluminum trays of the Mitscherlich pots came off in many spots and the metal wos attocked by the salts used as a fertilizer, forming aluminum salts that were detrimental to the plants. It wos possible, however, to see that toxic effects of the BHC added to the soil decreased fast enough after two years to allow even the plants in pots which received dose 7 of the insecticide to come to bearing. In the experiment with clayey soil only BHC was used since it was the only insecticide that showed a dangerous level of toxicity. The doses employed were 1, 3, and 5. Here too these numbers mean that the omounts of BHC added to the soil correspond to the omounts applied to cotton fields after 1, 3, and 5 years of cultivation, respectively. In the clayey soil, dose 1 of BHC did not decreose the yield nor caused any other toxicity symptom. Doses 3 and 5 decreased the yield in 14 % ond 27%, respectively, but the analysis of variance did nat show a significant difference between the two results. The growth and yield of the plants sown offer the soil had been left undisturbed far one year did not show any difference between the control ond treated plants, thus indicating that the toxic effects of the BHC had completely disappeared.

Submetendo-se cafeeiros novos à ação de temperaturas baixas, pouco acima de zero, determinadas fôlhas apresentaram áreas despigmentadas, de forma e extensão variáveis. Êstes sintomas se assemelham muito aos que ocorrem em certas ocasiões nas culturas, o que sugere que a temperatura muito baixa de algumas noites de inverno seja a causa dessa ocorrência.

Coffee plants growing in the field may sometimes exhibit a peculiar type of whitish or yellowish discoloration in pairs of leaves of the same age. The discolored areas are not uniform throughout the affected leaves, and in less severe cases only a strip along the leaf margins shows the symptoms. Leaves severely affected are usually smaller than normal, and may become mottled and distorted. Symptoms identical to those observed in the field were reproduced when coffee seedlings were submitted to low temperatures in the laboratory. Treatment for six hours at 3°C was enough to induce leaf discoloration, but it was noticed that conditions to which the plants had been submitted on the day prior to treatment had some influence on symptom expression. Severity of symptoms seems to be increased when coffee seedlings were treated after a clear sunny day.