RCAAP Repository

This paper describes the determination of exchangeable aluminum by the colorimetric method using aluminon (ammonium salt of the aurintricarboxylic acid) and by the sodium hydroxide titration method, using phenolphtalein or brom thymol blue and the potentiometer in order to indicate the end point. Aluminum was extracted from several soil samples with N KC1 solution varying the proportion of weight to volume of solution, and time of extraction. Aluminum was also extracted with N calcium acetate solutions with different pH (7.0, 6.0, 5.5 and 5.0). The data obtained allow to conclude that the two methods (colorimetric and sodium hydroxide titration method, using phenolphtalein to indicate the end point) afforded a good precision. Nevertheless the titration method can give higher values than the colorimetric method, especially when the exchangeable aluminum is low. When the relationship between soil weight and volume of N KC1 solution varied from 1:100 to 10:100, exchangeable aluminum, determined by titration, decreased. Normal calcium acetate solution with pH 7.0 did not extract exchangeable aluminum. When the pH of calcium acetate decreased the amount of extracted aluminum increased.

The experiment described herein was performed in order to establish a completely synthetic medium for growing P. denitrificans cells. In order to obtain in 48 hr. a growth as good as that obtained with the control cultures (with yeast extract), the medium must be formed by micronutrients, the inorganic salts No2SO4, MgSO4 and (NH4)2SO4,and by an amino acid such as sodium glutamate. The KNO3 is for course needed in order to proporcionate the nitrate, and the medium must be buffered with 1M potassium phosphate buffer, pH 6.8. Succinate serves as a substrate. The role of glutamate is under investigation.

Young coffee plants were allowed to absorb radiophosphate via leaves during 30, 60, 90 and 120 minutes and via roots during 24 hours. It was verified that leaf absorption was almost twice more intense than root uptake despite the considerable difference in time of contact which would favour the latter. Translocation of leaf applied material was also more marked.

The contents of micronutrientes in coffee berries of the varieties ""Bourbon Amarelo", "Caturra Amarelo" and "Mundo Novo" grown in three different types of soils, namely, "terra roxa", "massape-salmourão", and "arenito de Bauru", have been determined. Statiscal analysis of the chemical data permits the following conclusions to be drawn: (a) there is no difference in the chemical composition of the three varieties; (b) the average content is as follows (in ppm): (c) one bag of dry, unprocessed coffe, has roughly equal total amounts of micronutrients both in the beans and in the hulls; zinc is an exception, however.

The present paper presents the results of a factorial experiment, Mg/K in hydroponic cultures in order to study the absorption on both elements by citrus trees. The treatments consisted of: Magnesium did not interfer with the content of K in the leaves when K was omitted or present in the nutrient solution at level 2 (704 p.p.m.). Magnesium in the nutrient solution (48 ppm) stimulated K absorption. Magnesium absorption was inhibited when K was present in the nutrient solution at levels 0 and 2. At level 1 (234 p.p.m. of K) there was an increase in Mg content in the leaves. Potassium-calcium antagonism was observed in all cases wheresas Mg-Ca antagonism was observed only the presence of higher levels of K. In the absence or presence 234 p.p.m. of K a quadratic effect of Mg was observed.

No summary/description provided

The present paper deals with studies related to pollination of Cucurbita pepo L. in the State of S. Paulo, Brazil. The following results were obtained: 1.° - The ratio of female flowers to male flowers openig at the same day was 1:17,7. 2.º - The opening of the female flowers and observed to occur before the sun rises. Closing begins at 9 A.M. and is finished by 11 A. M. 3.° - With respect to pollinizating insects, Trigona (Trigona) ruficrus Latr.) and Apis, mellifera L. constitute the most important species. 4.° - Due to the phenomenon of parthenocarpy no frutification was observed. 5.º - The sugar concentration of the nectar was observed to average 39,7% and 40,6%. 6.º - The pollination of Cucurbita pepo L. is only by insects.

The county of São José do Rio Preto, State of São Paulo, Brazil, whose climatic and pedological characteristics are referred in this paper, has a reduced and fragmentary area of natural forests, which is mostly occupied by somewhat savanized and, in less grade, ruderalized formations. From the second half of 1962 to the end of 1963, the authors have found species belonging to five different phytogeographic elements, as follow: the General Element, the Amazonic Element, the Atlantic Element, the Meridional Element, and the Central Element. Though no secure] statement can one make on the climax-formation of the region, we may admit that it might be the semideciduous and somewhat xeromorphic latifoliated tropical forest. The problem of origin of the "cerrado" remains an open question yet.

Outflow of phosphorus on rice seeds or seedlings (Oriza sativa L., Batatais). (Preliminary results) The purpose of this investigations was to detect the outflow of phosphorus by rice seeds or seedlings. Two experiments were conducted as following: a) Firts experiment Rice seeds were soaked in water solution containing P32 during 12 hours. After that period the solution was descarded and the seeds washed in a solution of P32. Aliquots from that solution were taken and exposed to a Geiger counter. The seeds were washed until no counts in the solution were detected by the counter. The seed were sowed in crystallizing dishes which contained 200 grams of quartz or 100 grams of quartz mixed with 100 grams of soils. The Neubauer tecnique was employed. The plants were harvested 18 days after the germination. Substrate (soil, quartz) and plant extracted were performed and the activity was measured. Activities were detected in all semples, what prove the outflow of P32 from the seeds or the plants. The outflow of P32 from the plants in show in the follonwing table. Treatments % P32 outflowed and not absorbed quartz 9.60 quartz + savanna soil 32.4 quartz + "terra roxa" 46.2 b) Second experiment Radioactive seeds were obtained by providing a solution containing P32 to rice plants growed in pots. A modification of the Neubauer method was used, as it is described by CATANI & GERBAMIN (1961). The treatments were: quartz, quartz + "arenito de Bauru", quartz + "terra roxa", quartz + "massapé-salmcurão". The experimental techniques were same as in the first experiment. In the same way the outflow was proved, as it can be seen on the following table. Treatments % Pn outflowed and not dbsorved quartz 12.5 quartz + "arenito de Bauru" 13.6 quartz + "terra roxa" 20.7 quartz + "massapé-salmourão" 14.4 The results sugested that there is an outflow of phosphorus from the rice seeds or seedings.

This paper reports the data obtained concerning the determination of pH of acetic acid, citric acid, oxalic acid and tartaric acid solutions from 0,005 M to 0,5 M. There is a linear relationship, between pH and pC log 1/C, where C is the concentration in molarity, of studied acids. On the other hand, the calculation of pH through a quadratic equation, using only the first thermodynamic constant, furnishes data very close to the determinated values. The calculated pH of acetic acid solutions (from 0,55 to 0,0055 M) of citric acid solutions (from 0,25 to 0,025 M) and of tartaric add solutions (from 0,25 to 0,05 M) through an equation of first degree, using only the first thermodynamic constant, gave results which are also very close to the determined pH value. It was possible to establish two equations for the line of regression of pH on pC for each acid. In the first equation the determined pH is the dependent variable and in the second equation the calculated pH is dependent variable. The independent variable in both equations is pC.

The authors present the first list of vascular plants collected by them in the region of São José do Rio Preto county, State of São Paulo, Brazil. This list of 76 species includes 23 ones of cerrado (14 of these exclusively of cerrado), and 20 species of adventitious plants (arvenses or ruderales). The 76 species are distributed in 67 genera and 34 families. The climate of the county is mesothermic, tending to megathermic, corresponding to the Koppen's Cwa type. The predominant soil is a dark-red latosol, originated from decomposition of Arenito de Bauru (Bauru sandy soil of upper Cretaceous).

The present paper, deals with study of the resistance against two antibiotics in a phytopathogenic bacterium Xanthomonas campestris (Pammel) Dowson. Colonies resistant to the vancomycin appeared even in the highest concentration used (256 meg/ml.). For the tylosin in concentrations higher than 128 mcg/ml resistant colonies did not appear. So, the results show that vancomycin follows the "single-step" model and the tylosin follows the "multiple-step" resistant scheme.

In order to know the patogenic behavior of Fusarium oxysporum f. lycopersici, the causal agent of Fusarium wilt of tomato, 48 isolates of the fungus, from different tomato growing areas of the State of São Paulo, Brazil, were tested on the following differential varieties: Bonny Best, Santa Cruz (Kobayashi) and S-34. The inoculation tests were made under gree-house conditions, with partial control of temperature. The results showed that: 1) The fungus may present groups of different patogenicity; 2) 47 isolates belonged to the race 1 of F. oxysporum f. lycopersici; 3)1 isolated showed to belong to the race 2 of the same fungus.

Os autôres, utilizaram as variedades de tomates Santa Cruz e S-34 como variedade sdiferericiais, para determinar raças fisiológicas de Fusarium oxysporum f. lycopersici (Wr) Sny & Hans. Testaram 7 isolamentos do patógeno, retirados de material proveniente de Pernambuco, em condições de casa de vegetação com contrôle parcial de temperatura e concluiram que todos os 7 isolamentos reagiram como sendo da raça 1, e que houve variação na patogenicidade entre eles.

The authors studied the selection of nine tomato varieties, 10 progenies and plants of L. pimpinelilfolium specie (P.I. 126915-1-8) to one new isolate of F. oxysporum f. lycopersici (Wr) Sny & Hans, under controled green-house condition. The selection observed during the experiment were the following: 1 - The commercial varieties with resistance to races 1 and 2 of F. oxysporum f. lycopersici were susceptible to the new isolate of the fungus. 2 - The plants of L. pimpinellifolium were resistant to the isolate test. 3 - The authors suggest that the isolate of the fungus studied be regarded as race 3 of F. oxysporum f. lycopersici (Wr) sny & Hansen.

Sugar cane stalks were stored in a shaded gree-house under dry or sprinkled conditions. Three-bud cuttings were inoculated with Ceratocystis paradoxa prior to planting, The following conclusion can be drown: 1) Storage may improve the rate of germination depending upon the variety and the season of the year. 2) ''Wet" storage is as good or better than "dry" under the conditions used. 3) Storage increases the susceptibility of cane to C. paradoxa. 4) Storage reduces the auxin level in some varieties as manifested by a reduce curvature of whole stalks.

This paper deals with the variation of Colletotrichum lindemuthianum (Sacc. et Magn.) Scrib., the fungus of bean anthracnose, one of the most serious diseases of bean in Brazil. Nineteen cultures of C. lindemuthianum were isolated from different regions of the State of São Paulo and were tested on the differential varieties Michelite, Dark Red Kidney and Perry Marrow, and on local varieties. The differential varieties were obtained from Cornell and Beltsville. The Hark Red Kidnety variety from Cornell behaved differently than that from Beltsville when inoculated with cultures C-12, C-13 and C-18. It was therefore impossible to say if these cultures belonged to race delta or to a new race not yet reported. For the culture C-3 and C-15 the Dark Red Kidney variety behaved similary, independent of its origin. Therefore these cultures belong to race alfa. For the other cultures the race is unknown. Local varieties were for the most part susceptible to all isolates tested. Some were variable in their reaction to isolates of the alfa race. Variety 54 was resistant to 18 isolates and variety 131 was resistant to all isolates in a single trial.

The pathogenicity of one isolate of Xanthomonas malvacearum (E. F. Smith) Dowson was tested under greenhouse conditions on the cotton varieties Stoneville-20, Nu-16, Gregg, Mebane, RM2 and IAC-12 and under field conditions on Stoneville-20, Nu-16, RM2 and RM4 varieties. Stoneville-20 and Nu-16 varieties showed a high degree of resistance when tested either under greenhouse or field conditions. The varieties RM4, Gregg, Mebane an IAC-12 showed to be susceptible to the isolate tested. The variety RM2 was found to be composed of resistant and susceptible plants. Only 20% of the progenies of RM2 plants selected as resistante plants when artificially inoculated under field conditions, showed to have a high degree of resistance when artificialy inoculation under greenhouse conditions.

No summary/description provided

This paper deals with the transpiration of Spathodea nilotica Seem (Bignoniaceae), a small tree native in tropical Africa and cultivated in the State of São Paulo, Brazil, for arborization of streets and ornamental. Transpiration was determined by the so called "cut leaf" method and observations were made on the daily march of total and cuticular transpiration, on the saturation deficits of the leaves used in the determination of the transpiration and on the hydroactive movements of the stomata. Comparation of the daily march of total transpiration curves to the saturation deficits ones of the same leaflets, showed that the two restrictions of total transpiration which the plant presented during the day were caused by lack of water supply in the leaflets. Cuticular transpiration was measured by covering the stomatal (abaxial) face of the leaflets with a layer of vaseline and weighing the cut leaflets in the torsion balance. The daily march of cuticular transpiration compared to the one of total transpiration showed the same results, that is, the restrictions of transpiration during the day were due chiefly to the lack of water supply in the leaflets.