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Registros recuperados: 230 | |
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Zamith,Adiel Paes Leme; Lordello,Luiz Gonzaga E.; Boock,O. J.. |
Irish potato tubers imported from Holland and Germany were planted at the Instituto Agronômico Experiment Station, Campinas, in April, 1955. At digging time, in July, 1955, the tubers were found to be injured by nematodes belonging to the genus Ditylenchus. No visible symptoms were found on the plants during the growing season, since the nematodes did not attack the stems. However, prevailing weather conditions from April to July were not favorable for nema activities, with low temperature and rain precipitation. Therefore, it does not seem safe to assume that, as a rule, the nemas do not attack buds and stems, for further observations may reveal such an occurrence, as it has been reported in the literature. The injury was characterized by spots consisting... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100017 |
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Simão,Salim. |
The author carried out an experiment of watering of lettuce (Lactuca sativa L.) in the vegetable garden of the Escola Superior de Agricultura "Luiz de Queiroz", with soil of the type know as "terra roxa". Eight treatments, with 4 replications, were used, divided into 3 groups, as follows: Group A - Watering once a day, late, in the afternoon, with 5, 10 and 15 liters per square meter; Group B - Watering twice a day, with 10 and 15 liters per square meter, one half in the morning, one half late in the afternoon; Group C - Watering as in group A, but with a 0.1% Chilean nitrate of soda, every 3 days. The size of plots was 2,0 x 2,0 meters. The means obtained, with their respective standard errors, were the following: Group A- (4295 ± 53 gm.) 5 lit./sq.m.... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100015 |
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Accorsi,Walter R.. |
1 - Os estudos sôbre o órgão cupuliforme datam de 1941, ocasião em que observávamos os "seedlings" de Eucalyptus tereticornis e Eucalyptus citriodora, com o propósito de colher material para estudos anatômicos comparativos das citadas espécies (1). 2 - Examinámos, a seguir, "seedlings" de outras espécies de Eucalyptus, comprovando em tôdas a existência do órgão cupuliforme. 3 -BRIOSI e WARMING, ambos mencionados por HABER-LANDT (4), assinalaram a presença de longos pêlos absorventes, no limite entre radícula e caulículo, respectivamente de plantas aquáticas e de Eucalyptus e outras Myrtaceae, sem contudo se reportarem à existência de qualquer órgão na região considerada. 4 - Revendo a bibliografia especializada, entre as quais a "A Critical Revision of the... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100001 |
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Lordello,Luiz Gonzaga E.. |
Tomato roots heavily disfigured by root-knot nematodes were throughly mixed with soil. At various time intervals, samples were taken from the mixture and treated in closed containers by each of the folio wing nematicides: D.D., E.D.B. and M.B. The efficacy of the treatment was tested by setting indicator plants in the treated soil and by examining their roots for the presence of galls two months later. In other words, the ability of the three nematicides to penetrate nematode galls after various periods of rotting, which varied from 5 to 30 days was studied. The main conclusions drawn are as follows: a) no nematicide among the three listed above showed the ability for complete destruction of the nematodes protected inside the roots, for a number of small... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100011 |
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Gurgel,J. T. A.; Mitidieri,J.. |
The present work deals with the study of the effects of selfing and crossing in pures lines of okra inbred for five generations and the methods of breeding in this plant. This work is party of a large program of this Dept. to study heterosis in plants naturally self pollinated. The technic of selfing consists of tying with a string the floral bud before anthesis. To make controlled crosses, it is necessary to emasculate the flowers removing the anthers with small forceps, and to cover the flowers with a bag and wait for 1 or 2 days until the blooming. Also, the male parents are covered with paper bags prior to flowering. Finally, the pollen is brushed lightly over the stigma of the emasculated flowers and the females unit rebagged. The authors have tried... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100008 |
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Jardim,W. R.; Peixoto,A. M.; Silveira F°,S.; Gomes,F. Pimentel. |
This paper deals with the estimation of milk production by means of weekly, biweekly, bimonthly observations and also by method known as 6-5-8, where one observation is taken at the 6th week of lactation, another at 5th month and a third one at the 8th month. The data studied were obtained from 72 lactations of the Holstein Friesian breed of the "Escola Superior de Agricultura "Luiz de Queiroz" (Piracicaba), S. Paulo, Brazil), being 6 calvings on each month of year and also 12 first calvings, 12 second calvings, and so on, up to the sixth. The authors criticize the use of "maximum error" to be found in papers dealing with this subject, and also the use of mean deviation. The former is completely supersed and unadvisable and latter, although equivalent, to... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100009 |
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Gomes,Frederico Pimentel. |
This paper proves the following theorems on the gamma function: Theorem I The integral ∫O∞ t u e-t dt = Γ ( u + 1 ) , where u, real or complex, is such that R (u) > -1, will not change its value if we substitute z = Q (cos φ + i sen φ) for the real variable t, being jconstant and such that - Π/2 < φ < Π/2 , Theorem II The integral ∫-∞∞ w2u + 1 e -w² dw = Γ ( u + 1 ) , where 2u + 1 is supposed to be a non negative even integer, will not change its value if we substitute z = w + fi, f being a real constant, for the real variable w. The proof of both theorems is obtained by means of the well known Cauchy theorem on contour integrals on the complex plane, as suggested by CRAMÉR (1, p. 126) and LEVY (3, p. 178). |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100006 |
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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... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100003 |
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Coury,T.; Torres,A. P.; Ranzani,G.. |
Kikuio grass (Pennisetum clandestinum Hochst) is beyond any doubt, a pasture very important for farm animals; since its chemical composition is very similar to that of alfalfa, the present field trial was carried out; a randomized block design with 8 treatments was selected as follows: 1 N - P - K - Ca - Mg (complete manuring) 2 N - P - K - Ca----- (without Mg) 3 N - P - K-------Mg (without Ca) 4 ----P - K - Ca - Mg (without N) 5 N------K - Ca Mg (without P) 6 N - P - Ca - Mg (without K) 7 organic matter (without mineral fertilizers) 8 control Nitrogen was applied as NaN03 (topdressed) and as ammonium sulfate; P2O5 was given as superphosphate associated to bonemeal; K2O was applied as muriate, CaO as "sambaquis" (oyster shells); MgO was given as MgSO4... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100004 |
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Leme,Hugo de Almeida. |
A aradura é a principal das operações agrícolas para o desenvolvimento das diversas culturas. A sua importância é conhecida desde as mais remotas eras. Assim, os romanos já tinham sua teoria sobre aradura. Desta forma o arado, a mais antiga das máquinas agrícolas, foi sempre motivo de atenção dos agricultores, fabricantes e técnicos em mecânica agrícola. A sua evolução foi bastante grande. O estudo do arado sob o ponto de vista agrícola e econômico, para exata aplicação da máquina, nas diversas condições de solo, é de máximo interêsse para a mecânica agrícola. Assim sendo, para orientar a correta aplicação do arado, o que constitui a presente tese, foi experimentado num solo arenoso, de características mecânicas (areia total 75,7%, argila 13,5 e lôdo... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100010 |
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Gomes,Frederico Pimentel. |
This paper deals with the estimation of the residual effect of fertilizers through the use of Mitscherlich's law. The formulas and reasonings now presented are a further development of those introduced previously by PIMENTEL GOMES (2). The new formulas allow the estimation of the residual effect h in cases where the experiments are carried out in the same plots for two or three subsequent years (or crops). In an experiment analysed as an example, the residual effect of calcium hydroxide was estimated to be h = 0.423, that is, about 42%, so that one should advise the use of frequent application of small amounts of lime instead of heavy quantities used at long intervals. |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761956000100005 |
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Verdade,F. da Costa. |
Os solos do Estado de São Paulo possuem, predominantemente, argilas do tipo caolinita, de baixa capacidade de cations permutáveis, o que leva a atribuir à matéria orgânica uma grande parte da capacidade de troca de catíons dêsses solos. Para avaliar a capacidade de troca de cations da fração orgânica, é esta destruida pela H2O2 a 12%, dosando-se, pelo processo de acetato de amónio, a C.T.C, no solo original e no solo tratado. Dos trabalhos efetuados, verificou-se que nos solos argilosos as primeiras frações da matéria orgânica destruidas possuem pequena capacidade de troca de catíons, enquanto as mais resistentes têm essa propriedade em maior escala. Nos solos arenosos, todas as frações orgânicas parecem apresentar a capacidade de troca com a mesma... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051956000100004 |
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Verdade,F. da Costa. |
Ao se procurar estudar a capacidade de troca de cations (T) da matéria orgânica do solo, verificou-se que o método mais adequado para êsse estudo era o do acetato de amônio. Para êsse processo procurou-se adaptar a percolação, como é utilizada na Seção de Agrogeologia, verificando-se que o emprêgo da relação 1 (pêso de solo) : 5 (volume de solução de acetato de amónio) é adequada para deslocar as bases e os Hidrogênios substituíveis. Após lavagens do solo com quatro porções de 25 ml de álcool etílico a 95%, o deslocamento do amônio adsorvido é feito com uma solução N em NaCl e 0,005N em HCl, na relação de 1 (pêso de solo) : 5 (volume do extrator). Verificou-se que o manuseio da amostra, quando se empregam os tubos percoladores é pequeno e o inconveniente... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1956 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051956000100029 |
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Registros recuperados: 230 | |
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