RCAAP Repository

By using data collected from the Brazilian literature, it was possible to derive regression equations 1 linking the Mg and S contents of the +3 leaf to the rainfall within the 2 month period before sampling. For each 200 mm of rain it could be antecipated increases in leaf Mg and S, respectively of 0.027 and 0.055%.

The present study was conducted at the Department of Agriculture and Horticulture, ESALQ, from October 1981 to February 1982. The objective was to determine the susceptibility of pepper crop to tempora y floodings of the root system, in order to quantify yield damages in distinct phases of vegetative cycle. On the other hand, the study tries to establish the drainage coefficient, for projects utilizing pepper crop. The results showed that pepper plants are susceptible to excess of water in the soil, lowering yields through the reduction of number and weight of fruits, when submitted to 2, 4 and 6 days of flooding. The drainage time of the root zone must be less than 2 days.

This work deals with mineral nutrition of Andropogon gayanus var. bisquamulatus (Hochst) Hack. The following parameters were studied: weight of dry matter, concentration of macro nad micronutrients on plants from 20 to 140 days old, and the coefficient of digestitility of the dry matter in relation to the age of the grass. The plants were collected, at intervals, from 20 to 140 days old, from an area of half hectare of "Terra Roxa Estruturada", in Piracicaba, State of São Paulo, Brazil. The dry matter at 80 days was analysed for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn contents. The coefficient of digestibility was determined "in vivo" by using the nylon bag technique. It was observed that the coefficient of digestibility decreased with the aging of the grass, and at 80 days, which corresponds to the maximum production of dry matter (58,000 kg/ha), the coeficient of digestibility for leaves and stems was 71,27% and 66.47%, respectively. When plants were 80 days old the leaves presented the following concentrations of nutrients: N (1.46%), P (0.12%), K (1.79%), Ca (0.27%), Mg (0.16%), S (0.07%), B (11.75 ppm), Cu (4.75 ppm), Fe (236.75 ppm), Mn (74.50 ppm), and Zn (22.25 ppm).

This paper deals with a study of the efficiency of three nitrogen-15N fertilizers: ammonium sulphate, urea, and ammonium nitrate on wheat crops. The fertilizers were applied by throwing and then incorporated to the soil or in the furrows, at the rate of 120 kg N/ha, half at sowing and half at sowing and half by throwing at the tillering stage. The results were as follows: all fertilizers gave similar effects in straw and grain yields, in the percentage of nitrogen derived from the fertilizers and percentage of fertilizer nitrogen utilized. When the nitrogen fertilizers were applied along the seed rows (5 cm apart and 2 cm deep) it was observed higher values in the nitrogen contents of the grains and in the efficiency of the fertilizers. The mean of all results indicated that 23% of the nitrogen applied was recovered by the wheat plants.

This research deals with the effects of exogenous growth regulators on fruiting of tomato plants (Lycopersicon esculentum Mill.) under greenhouse conditions. Applications of (2-chloroethyl) trimethylammonium chloride (CCC) 1,000 ppm, succinic acid-2,2-dimethylhydrazide (SADH) 2,000 ppm, 3-chlorophenoxy propionic acid (3 -CP) 50 ppm, thiazolidin-4-carboxylic acid plus folic acid 0,75 ml/l, and water (check treatment) were performed. It was observed that SADH reduced total weight, number and weight average of tomato fruits, because of flower abscission caused by the timing of the repeated application. Thiazolidin-4-carboxylic acid plus folic acid reduced the total weight and weight average of tomato fruits. Application of 3-CP showed a tendency to increase total weight and number of fruits in the plant.

A series of solution culture experiments designed to simulate some field conditions were carried out with varieties (Carioca, Rico 23 and Venezuela) in order to check the hypothesis that adverse soil factors might affect N fixation. The main conclusions were the following: (1) growth was promoted by increasing the level of combined N; only the starter rates (from 0.3 to 1.3 mM/l), however, promoted nodulation and dinitrogen fixation; (2) higher dry matter production was observed at pH 6.0 to 7.0, whereas poor growth at pH 4.0 could be traced to low N2 fixation; (3) a favourable effect of Ca supply on the parameters under study was observed up to the level of 1.25 mM/l; (4) a linear response to P supply was verified; (5) excess Al and Mn (5-10 ppm; 10-20 ppm; respectively) caused inhibition on nodulation, reduction on root growth and N2 fixation; (6) although the trends were the same, varietal differences were found.

The influence of some anti-browning treatments on the canning of heart-of-palm (Euterpe edulis Mart.) was studied. The results showed that ascorbic acid was, in general, the best treatment to control enzymatic browning for all atributes of quality except for texture, in which blanching was superior. For the first three cuts, in particular, ascorbic acid was better than blanching for all attributes of quality. On the other hand, for the last cuts, blanching presented the best results, except for flavor. This attribute of quality was better preserved in the canned heart-of-palm by ascorbic acid.

The objective of this paper was to study the influence of pretreatment solutions and processing times on the quality of canned heart-of-palm (Euterpe edulis Mart.). The results showed that, in general, the best processing method was the pretreatment solution 5% NaCl + 1% k2s2o5 combined with thermal processing times of 50 minutes for the first three cuts and 60 minutes for the last ones. For the first three cuts, in particular, the pretreatment solution 5% NaCl + 1% citric acid combined with 45 minutes of thermal processing presented the best results for all attributes of quality, except for flavor, in which the pretreatment solution 1% citric acid + 0,25% ascorbic acid with 40 minutes of thermal processing was superior.

To improve the quality control conditions of the processed product, the influence of some parameters on the attributes of quality of canned hear-of-palm (Euterpe edulis Mart.) was studied. The results showed that, depending on the treatment used, some attributes of quality may have important variations during processing and storage of the canned product.

An experiment was carried out to investigate the germination and initial growth of Cucurbita L. seedlings under several environmental conditions and on different substrata. The best results were obtained by using sand or vermiculite as a substratum and greenhouse conditions as environment.

Trials were carried out to test the effects of Atonik 1:2000 (sodium mono-nitroguaicol and other aromatic nitro compounds) on fruiting of chillies and three egg-plant cultivars. The plant stimulant did not affect significantly chillies yield, but Atonik 0,5 ml/l applied after fruit set and twice again after 7 day intervals showed a tendency to increase the total weight and the number of fruits in the plant. Total weight, number and weight average of eggplant fruits were unaffected or reduced by Atonik application at the flowering, at the flowering and twice again after intervals of 7 days, and after fruit set.

Foram conduzidos em solos arenosos de nove municípios do Estado de São Paulo, localizados na área de produção de amendoim, dez experimentos de grande área, tipo "Ensaio de Confirmação", objetivando estudar o efeito da calagem sobre o rendimento de dois cultivares de amendoim. A calagem aplicada com antecedência ao plantio, na dose de 1,230 kg/ha aumentou a produção de vagens no amendoim, cultivar Tatu (tipo vegetativo Valência), em dois dos dez experimentos. O cultivar Tatuí (tipo vegetativo Spanish) não reagiu à aplicação de calagem. Não houve diferenças entre os rendimentos semente/casca dos diferentes tratamentos, nem entre as local idades onde foram conduzidos os experimentos.

A pot experiment was carried out with treatments consisting of applications of solution of 65 ppm phosphorus labelled with 32p, when the plants had 6, 9, 12 and 14 leaves. These plants were harvested respectively when they had 9, 12 and 14 leaves and 21 days after last application. The phosphorus contents were determined in the different parts of the plants, such as lamine, petiole, stem and inflorescences and the absorption of this element was followed through the determination of radioactive phosphorus in these samples. According to the data the following conclusions can be drawn: - the application of phosphorus fertilizer has increased the phosphorus content, aided plant development, and stimulated the primary inflorescence emissions; - 32p showed that in soils, with low phosphorus content, the application of the phosphorus fertilizer at the emission of the primary inflorescence will not affect its development, since the inflorescence is formed at the expense of phosphorus previously accumulated in the petiole and in the lamine; - phosphorus applied later will not increase the yield of primary racemes which represent at least 30% of the total yield of castor bean.

A greenhouse experiment was carried out on podzolic soil of Lins and Marilia, with the aim of studying the effect of two calcium sources: gypsum and lime, on peanut, cv. Tatu (valencia vegetative type). The gypsum application at flowering and the application of lime at planting plus gypsum at flowering increased the peanut yield.

This research was carried out in order to study the symptomalogical chart of macronutrient deficiencies and verify the analytical level of the macronutrients. in lettuce plants under mineral deficiency conditions. Lettuce seedlings were cultivated and irrigated with nutrient solutions in the greenhouse. The treatments were: complete solution and solutions lacking N or P, K, Ca, Mg and S. Whenever the plants showed evidency and clear deficiency symptoms, they were harvested and analysed for the respective elements. The nutrient deficiencies were observed and easily identified, except for S, The macronutrient concentrations in the leaves of cv. Brasil 48 were: Normal plants: N (3-37%), P (0.44%), K (5-54%), Ca (0.97%), Mg (0.35%), and S (0.16%); Undernourished plants: N (1.86%), P (0.16%), K (1.32%), Cu (0.20%), Mg (0.05%), and S (1.16%). The concentration of the macronutrients in the leaves of cv. Clause's Aurelia were: Normal plants: N (3-02%), P (0.71%), K (7-70%); Cu t(1.47%), Mg (0.43%), and S (0.24%); Undernourished plants: N (2.68%), P (0.19%), K (1.54%), Mg (0.10%), and S (0.24%).

Excised roots obtained from 8 varieties of rice (IAC-164, 165 and 1246, Batatais, Caqui, Dourado Precoce, 90 Dias and Senbon) were used to study the kinetics of P uptake. Three cultivars (IAC-164, 90 Dias and Senbon) were employed in an experiment designed to compare root and leaf uptake and to evaluate the long distance transport. The main conclusions were as follows: a) after 180 minutes of contact with the external solution the uptake reached a maximum in the case of varieties IAC-164 and 165 , 90 Dias and Dourado Precoce; the same took place with the remaining cultivars after 240 minutes; b) the best fitting for individual varieties was obtained by using eiter potential or exponential models of adjustment wherein time was the independent variable and rate of uptake was the dependent one. c) IAC-164 and IAC-165 showed the highest efficiency of absorption while Dourado Precoce and 90 dias showed the lowest one. d) some evidence for the operation of a dual uptake mechanism was obtained when data from all varieties were put together; e) root absorption was usually higher than foliar uptake.

Two upland rice varieties, IAC-164 and IAC-165 were grown in full strenght nº 2 Hoagland's solution untill their life cycle was completed. Dry matter production and both macro and micronutrient contents were then determined. Accumulation of macronutrients obeyed the following decreasing order: IAC-164 - K, N, Ca, Mg, P, and S; IAC-165 - N, K, Ca, P = Mg, and S. Exportation of macronutrients followed the same order for both varieties namely: N, K, P, Mg, Ca, and S. Percentwise P was the element exported in the grains in higher proportion. The requirement for micronutrients showed the following decreasing order: IAC-164 - Cl, Fe, Zn, Mn, Cu, B, and Mo; IAC-165 - Cl, Fe, Mn, Zn, Cu, B, and Mo. The extremely high Cl content was tentatively explained by luxury consumption. Both varieties presented the same trend in the exportation of micronutrients: Cl, Zn, Fe, Mn, Cu, B and Mo. Variety IAC-165 showed a higher efficiency of utilization of elements for yield formation, only P and Ca being exceptions.

Two sweet sorghum cultivars, Brandes 501 and CMS-616, were grown in the presence of the following treatments: Control (T), Maintenance fertilization (Am), Corrective fertilization (Ac) and Am+Ac. There was a significant effect of treatments on the results of the first cutting, in terms of yield of stalk. No residual influence, however, was observed in the ratoon. In both cutings cv. CMS-616 gave higher yields than cv. BR-501. Fertilization decreased total solids in the juice of cv. BR 501 in both harvests; positive correlations were found to exist between leaf P and Ca in the case of the cv. CMS 616 only; adequate levels of these elements were, respectively, 0.33 and 0.29%.

This paper was carried out in order to determine and analyse the growth rate and the concentration and amount of nutrients required by the lettuce cultivars. Plants from a commercial field were collected at the age of 20, 30, 40, 50, 60 and 70 days old, and the dry matter production, as well as the concentration of N, P, K, Ca, Mg, and S, were determined. Although the growth rate and the nutrient extraction were slow at the beginning, they have increase from the 30th day on and then maintained in a oermanently intensive rate, not reaching the point of highest accumulation until the harvest time. The growth was similar for both varieties, being the dry matter production of 12.75 g/pl for Brasil 48 and 12.52 g/pl for Clause's Aurélia. Percentages above 59% of dry and between 43 and 69% of the nutrients were accumulated by both varieties during the 20 days before harvesting. The amount of nutrients quantitatively accumulated at the end of the period by the two varieties were: Brasil 48 - 469 mg N, 99 mg P, 1,017 mg K, 161 mg Ca, 47 mg Mg, 21 mg S; Clause's Aurélia - 410 mg N, 100 mg P, 759 mg K, 200 mg Ca, 52 mg Mg, 20 mg S. It was observed that one plant of the cultivar Brail 48 has accumulated 469 mg N, 100 mg P, 1,017 mg K, 161 mg Ca, 47 mg Mg, and 21 mg S, at the harvest time.

This research was carried out in order to determine the concentration and the amount of micronutrients extracted by to varieties of lettuce plants during a life cycle. The lettuce plants were collected at the age of 20, 30, 40, 50, 60 and 70 days old from a commercial field and separated into new and old leaves and stems; then the concentrations of B, Cu, Fe, Mn and Zn were determined. There were differences in the nutrient concentrations between the two varieties, and the cultivar Brasil 48 has presentend the highest levels. The amount of Fe 6,800 µg, Mn 3,534 µg, Zn 4,462 µg; Clause's Aurélia: B 958 µg, Cu 165 µg, Fe 5,446 µg, Mn 1,025µg, Zn 2,425 µg.