RCAAP Repository

The tropical leguminous olants are known as a high quality protein source and in some cases even as wood producers when dealing with the arbustive types. The leucena (Leucaena leucocephala (Lam.) de Wit cv. Peru) was noticed as a very promising species to the Brazilian cattle production, and this fact leads to the setting of a field experiment in order to know its nutrient demands. The experiment was carried out to obtain data for analysis of growth, concentration and extraction of macronutrients (N, P, K, Ca, Mg, S and the dry matter digestibility in vivo for the leaves relatad to the plant age. From the obtained data it was possible to verify that: The whole dry matter production is the highest when the plant was 360 days old. The largest increase in the leaf production in dry matter was observed from 240 days up to 360 days. The N and P concentrations decreased in leaves and stem along the plant life. An the other hand, the age of the plant did not affect the Ca concentration in the stem leaves not the Ca concentration in the stem. When the plants were 360 days old corresponding to the highest dry matter product ion period, the following contents in the leaves and stem were observed: Plants with 360 days also showed the macronutrients accumulations in the folowing order: N >; K >; Ca >; Mg >; >; S >; P. The digestibility of the dry matter in leaves is in the level of 51.05%, in 360 day old plants.

The tropical leguminous plants are known as a high quality protein source and in some cases even as wood producers when dealing with the arbustive types. The leucena (Leucaena leucocephala (Lam.) de Wit cv. Peru) was noticed as a very promising species to the Brazilian cattle production, and this fact leads to the setting of a field experiment in order to know its nutrient demands. The experiment was carried out to obtain data for analysis of growth, concentration and extraction of micronutriets (B, Cu, Fe, Mn, Zn). From the obtained data it was possible to verify that the Mn concentration decreases in leaves and stem along the plant life. On the other hand, the age of the plant did not affect the B and Fe concentrations in the leaves. When the plants were 360 days old, corresponding to the highest dry matter production period, the following contents in the leaves and stem were observed: Plants with 360 days also showed the micronutrient accumulations in the following order: Fe >; Zn >; B >; Mn >; Cu

The relative efficiency of a partially acidulated and granulated rock phosphate, FAPS, containing 26% total P2O5, 10% citric acid soluble P2O5, 13% ammonium citrate soluble P2O5, 27% total CaO and 7% total S, was compared with that of both simple superphosphate (SS) and ground rock phosphate (FA). The experiment with the sugar cane variety NA 56-79 was set in a red yellow latosol, pH 5.1-5.5, low in P (4 ppm), and with and average available sulphur content (5 ppm as sul fate). The main conclusions were as follows: a) FAPS gave the same yield results provided by SS when used at the same rates based on total P2O5 content; b) sucrose content in the juice was increased by the highest level (16a kg P2O5 of application of FAPS; c) leaf analyses data suggest that FAPS has incre ased yield by supplying both P2O5 and S to the sugar-cane crop.

This work was carried out to determine the effect of plant growth stimulants on the fruiting of tomato plant Lycopersicon esculentum cv. Miguel Pereira. In this trial Cytozyme (biostimulant composed of kinetin, enzimes, micronutrients: Zn, Fe, Cu, Mn, Bo, combined with derivatives of siloxane-etoxil ate and amino acids) and Ergostim (N-acetyl-thiazolidin-4-carboxilic acid plus folic acid) were sprayed as follows: Cytozyme at 5ml/l was sprayed once at 70 days; twice, one at 70 and other 8% days after planting. Ergostim at 1,5 ml/l was sprayed once on the flowers of each cluster, and Ergostim at 3,0 ml/l was sprayed three times, in the flowering, in the time of fruit set of the 2nd cluster and when fruits attained one half of their development. It was verified that Cytozyme 5 ml/l applied 70 and 84 days after planting, increased the number and the length of the fruits and the total number of flowers. Ergostim did affect neither flowering and fruiting of tomato plant nor the formation and germination of seeds.

Técnicas culturais avançadas utilizadas atualmente no cultivo do tomateiro têm levado à aplicação de reguladores vegetais com a finalidade de promover aumentos na produtividade de forma quantitativa e qualitativa. O presente ensaio teve como objetivo determinar a ação do ácido 2-hidroximetil-4-clorofenoxiacético (Trylone) e do ácido para-clorofenoxiacético (Tomatotone) na frutificação do tomateiro (Lycopersicon esculentum cv. Miguel Pereira). Em condições de casa de vegetação efetuou-se pulverização dirigida aos cachos com Trylone a 10 ml/l e 20 ml/l e Tomatotone a 10 ml/l e 20 ml/l, na antese das duas primeiras flores dos três primeiros cachos. Foram coletados os frutos maduros dos três primeiros cachos, em dez colheitas efetuadas no período de 7 de novembro a 9 de janeiro. Foi observado o número, peso e comprimento dos frutos, assim como o número de flores e de flores abortadas. Foi também determinada a classificação dos frutos e a germinação das sementes. Verificou-se que o Tomatotone 10 ml/l e 20 ml/l aumentou o número, comprimento e peso dos frutos de tomateiro; Tomatotone 20 ml/l induziu a formação de frutos de melhor classificação. Tomatotone e Trylone diminuíram o número de flores abortadas. Trylone 20 ml/l aumentou a percentagem de frutos paternocârpicos.

Como nas condições brasileiras a cultura do tomateiro já atingiu um nível técnico bastante avançado, torna-se necessário conhecer os efeitos de reguladores e estimulantes vegetais no aumento da produtividade, pois se tornara muito difícil promover aumentos de produção através de outras técnicas culturais. O presente trabalho teve como objetivo determinar a ação do Atonik (bioestimulante formado de mono-nitroguaiacol sódico e outros compostos aromaticos nitrogenados na frutificação do tomateiro Lycopercicon esculentum cv. Miguel Pereira. Em condições de casa de vegetação, realizou-se pulverização em toda florescência; na antese das duas prímeiras flores do 1º cacho; na antese das duas primeiras flores do 1º cacho mais duas vezes com intervalos de 7 dias, e quando o primeiro fruto do 1º cacho estava desenvolvido mais duas vezes com intervalos de 7 dias. Foram coletados os frutos maduros dos três primeiros cachos, em dez colheitas efetuadas no período de 2 de outubro a 5 de dezembro. Foram observados o número, peso e comprimento dos frutos, assim como o número de flores e de flores abortadas. Determinou-se também a classificação dos frutos e a germinação das sementes. Constatou-se que Atoník, aplicado quando o primeiro fruto do 1º cacho estava desenvolvido, com repetições de mais duas vezes, a intervalos de 7 dias, aumentou o numero de frutos do tomateiro; Atonik na antese das duas primeiras flores do 1º cacho prejudicou a classificação dos frutos e aumentou o número de flores abortadas do tomateiro.

Devido às técnicas culturais avançadas utilizadas atualmente na produção do tomateiro, a aplicação de reguladores vegetais poderá alterar de forma qualitativa e quantitativa a produtividade desta hortaliça. O presente ensaio teve por finalidade determinar a ação do ácido 3-clorofenoxipropiônico (3-CP) na frutificação do tomateiro Lycopersicon esculentum cv. Miguel Pereira. Em condições de casa de vegetação, efetuou-se pulverizações em toda planta de 3-CP nas concentrações de 25, 50, 100 e 200 ppm, 109 dias após a semeadura. Foram coletados os frutos maduros dos três primeiros cachos, em oito colheitas efetuadas no período de 3 de agosto a 18 de setembro. Foi observado o número, peso e comprimento dos frutos, assim como o número de flores abortadas. Foi também determinada a classificação dos frutos e a germinação das sementes. Verificou-se que tratamento com 3-CP não alterou a frutificação e o número de flores abortadas, mas 3-CP 200 ppm diminuiu o número total de flores e aumentou a percentagem de frutos partenocárpicos.

Plantas de pepino (Cucumis sativus L.) var. Aodai, foram cultivadas no município de Piracicaba, SP (LS: 22° 41'31' e LW: 47º31'01''), em solo Terra Roxa Estruturada, série Luiz de Queiroz, devidamente adubado. O delineamento estatístico foi o inteiramente casualizado com quatro repetições, com amostragens das plantas aos 12, 24, 36, 48, 60, 72 e 84 dias após a emergência, sendo subdivididas em caule, folhas do caule, folhas dos ramos, flores masculinas, flores femininas e frutos. As partes da planta foram lavadas e secadas, e atingido o peso constante do material, determinou-se o peso da matéria seca. As seguintes conclusões foram obtidas: a) o crescimento é contínuo, acelerando-se até a maturidade da planta com a incorporação da matéria seca produzida pelos ramos e suas folhas, e pela contribuição dos frutos; b) aos 84 dias da cultura no campo, a quantidade de matéria seca estimada, produzida pela parte aérea, por planta, atingiu: 63,4 g no caule e ramos (25,7%); 88,4 g nas folhas (41,4%); 61,5 g nas flores e frutos (28,8%); sendo o total produzido pela planta de.... 213,28 g.

A commercial cucumber plantation was set in Piracicaba (SL: 22º41'31" and LW: 47º38'31"), State of São Paulo, Brazil, in a soil classified as "Terra Roxa Estruturada (Alfissol), série Luiz de Queiroz". Plants (4 replications) with 12, 24, 36, 48, 60, 72, and 84 days from emergence were collected and divided into roots, stems, stem leaves, shoot leaves, masculine and feminine flowers, and fruits. The material was dried at 80ºC and analysed for macro and micronutrients. The results were as follows: - the nutrient concentrations are unstable and vary with the plant aging; - the concentration of N, P, K, S, and Fe decrease whereas the concentrations of Ca, Mg, and B increased with the plant aging; the elements Zn, Cu, and Mn diddid not show concentration tendencies in the different parts of the plant; - the young fruits present higher nutrient concentrations that decrease during the ripening period.

A commercial cucumber plantation was set in Piracicaba (SL: 22º41'31" and LW: 47º38'01"), State of São Paulo, Brazil, in a soil classified as "Terra Roxa Estruturada (Alfissol) séries Luiz de Queiroz, in order to study the accumulation of nutrients by the plant and its parts. Plants (4 replications) with 12, 24, 36, 48, 60, 72, and 84 days old from emergence were collected and dovoded into stems, leaves of stems, leaves of the shoots, masculine flowers, feminine flowers, and fruits. The material was dried at 80°C and analysed for macro and micronutrients. The results indicated that at 84 days from emergence the serial plant parts have accumulated: 10.8 g-K; 6.1 g-N; 5.6 g-Ca; 1.5 g-Mg; 0.69 g -P; 0.44 g-S; 37-5 g-Fe; 25.0- g-Mn; 10.7 g-Zn; 10.3 g-B; and 4.5 g-Cu.

A commercial cucumber plantation was set in Piracicaba (SL: 22°41'31" and LW: 47°38'01"), State of São Paulo, Brazil, in a soil classified as "Terra Roxa Estruturada (Alfissol) séries Luiz de Queiroz", in order to study the fruit development and the nutrient exportation by harvesting. Plants (4 replications) with, 12, 24, 36, 48, 60, 72, and 84 dayz old from emergende were collected and divided into roots, stems, leaves of the stems, leaves of the shoots, masculine flowers, feminine flowers, and fruits. The material was dried at 80º C, and analysed for macro and micronutrients. The results indicated that the nutrient exportations by ton of harvested fruits at the ripe stage were: K- 1.617 g; N -1.05 g; P - 200 g; Ca - 174 g; Mg - 139 g; S - 58 g; Fe-1.9 g; Zn - 1.2 g; Mn - 1.0 g; B - 0.9 g; Cu - 0.5 g.

A comparision was made of the efficiency of a rock phosphate from Catalão, Goiás, Brazil (FG) with that of concentrated superphosphate (ST) in a Dark Red Latosol (LEa) from the same region. Four rates of were used in presence and absence of liming. Residual effect was followed in two successive crops. Main conelusions were the following; ST was a better source of P2O5 than FG; liming increased the effect of FG to the extent of circa 50 per cent of the efficiency of ST when the three crops were considered together; the method of application, placement against mixing, did not influence dry matter yield; P uptake was positively influenced by liming, especially in the second and third crops; there was a significant, positive correiation between residual P in the soil, evaluated by bicarbonate extraction, and dry matter; better correlations, however, were found between soil exchangeable Ca and yield.

Information on karyotypes and types of parthenogenesis for 10 species of Brazilian spider mites In the subfamily Tetranychinae is presented. Oligonychus ilicis was found to exhibit both types of parthenogenesis, thelytoky and arrhenotoky.

Uma lista de novas referências e ocorrências para ácaros tetraniquídeos da mandioca é apresentada.

Rice, varieties IAC-165 and IAC-165, both upland, were grown in nutrient solution (Hoagland's nº 2) complete, with deficiency of N, P, K, Ca, Mg, S, B, Cu and Zn, and with excess of Al, CI, and Mn. Symptoms od feficiency and toxicity were observed according to the treatments. Dry matter production by var. IAC-164 was affected by the treatments in the following order: - N, -K, -P, -Mg, -B, -Ca = -Zn, -S, and -Cu; in the case of var. IAC-165, the sequence was -B, -N, -P, -K, -Mg, -Ca, -Cu, -S, and -Zn. There was no grain yield in treatments -Ca and -B. The toxicity of Al, CI, and Mn significantly decreased dry matter formation; Mn was more detrimental than Al. Variety IAC-164 was more sensitive to the toxic levels of Al and CI. At full tillering the following tissue levels in the freshly mature leaves are considered as adequate, respectivelr the varieties IAC-164 and IAC-165. N - 2.32-2.70%, P - 0.28-0,49, K - 2.83-4,21, Ca - 0.94-0,94, Mg - 0.73-0.88, S - O.13-0.16%.

Dry matter production and accumulation of macronutrients were studied by growing plants in nutrient solution and taking samples at given physiological intervals. It was found that curves describing dry matter production and uptake were sigmoidal in tendency. Maximum rate of uptake was observed within a 2-month period starting at full tillering and ending at the stage of panicle formation. Leaf levels of N, P, and K decrease as the plant grows older; the opposite is true in the case of the other elements.

Rice plants were grown in nutrient solution till the end of their life cycle. At given stages of development plant samples harvested for the determination of dry matter and micronutrient contents in the various organs. The following conclusions were drawn: only Fe accumulation showed some degree of positive relation with dry matter production; the pattern of distribution of the elements among the plant parts was essentially the same, for both varieties; B, Cu and Fe tend to concentrate in the root system; no clear cut pattern of variation in leaf composition could be described throughout the plant life cycle; maximum rate of uptake took place between full tillering and panicle formation.

Vermiculitic and kaolinitic materials were used to determine the effects of these clay minerals on the phosphorus fixing capacity of two sandy soils, a Podzolic and a Latosol, both occuring in the Piracicaba municipality. Quantities varying from 1.25% to 25% (weight basis) were thoroughly mixed with samples taken from the Ap horizon of the two soils. Two groups of treatments thus prepared received an application of soluble phosphorus at the rate of 50 and 100 ppm, and were incubaded for two different periods, 10 and 20 days. The clayed materials and soils were analysed as to their mineralogical characteristics. The chemical characteristics and particle size distribution of the samples were also determined. The results obtained were statistically analysed. The following condusions were drawn: 1. The vermiculitic material and the Podzolic soil had a greater phosphorus fixing capacity than the kaolinitic material and the Latosol soil, respectively. 2. Percentage of phosphorus fixed by the soils increased with the percentage of vermiculite approaching the fixing capacity of the pure clay-mineral. This effect was attibuted to the nature of the clay (vermiculite) and to a high magnesium concentration in a pH range favorable to the precipitation of phospho-magnesium compounds. 3. Amount and percentage of fixed phosphorus increased with time of incubation for all treatments, but approximately 90% or more of total P fixation occurred after 10 days, indicating that the phosphorus fixing processes stabilized between 10 and 20 days of incubation. 4. For a given incubation period (10 or 20 days), the amount of phosphorus fixed (ppm) increased with rate of P added, but the % of phosphorus fixed decreased, indicating that the samples were probably saturated with the phosphate ion.

The experiments here in described were carried out in a podzolic soil, in the Sate of São Paulo, Brazil, with the double hybrid corn HD-6999 B. The aim of the work reported in this paper is to determine the critical N, P, K levels or percentages associated with the fertilizer rates that give the maximum yield and the maximum profit. To arrive at a critical nitrogen, phosphorus and potassium economical level in the corn leaf, it was calculated the maximum economical yield attainable under the conditions presented in this study by using the Mitscherlich and Pimentel Gomes and Malavolta equation. The foolowing results have been found: Rates of fertilizers (kg/ha): 228(N), 80(P2O5), 50(K2O) - 100(N), 253(P2O5), 50(K2O) - 100(N), 80(P205),61,7(K2O); Maximum economical corn yield (kg/ha): 11,000 - 6,877 - 9,252; Critical nutrients level: 3,27% N - 0,293% P - 2,07% K

Rice plants, varieties IAC-164 and IAC-165 weree grown in number 2 Hoagland's solution, full strength, and with excess of Al and Cl. Nitrate reductase (RNO3) activity was assayed in the leaves one month before harvesting. When the grains were already dry, plants were harvested, the mineral contents of the organs was determined, and crude protein in the grains was also determined (semi micro Kjeldahl). Statistical analyses of the data thus obtained showed that enzymatic activity decreased when the plants were deficient in N, P, and K, as well as when the plants were deficient in N, P, and K, as well as when they had excess Al and Cl. Sulfur deficiency depressed RNO3 activity in variety IAC-164 only. Lack of Mg had the same effect in variety IAC-165. Crude protein in the grains decreased due to lack of N, P, Cu, and S, and to excess both of Al and Cl. In both varieties, however, the deficiencies of K and Mg had apparently the opposite effect. By putting together data from all treatments (except -K and -Mg) a positive correlation between leaf RNO3 activity and grain protein was found to exist.