Repositório RCAAP

This study aims to understand the rationality that orients a large part of familial producers, who are involved in the production of milk, that adopt Mis technological standard in their production systems. A mathematical programming model was devised for feeding systems considering forages with low, medium and high contents of energy and protein. It was verified that the milk production which optimize the economic results for the farmers vary from 10 to 15 liters of milk per cow/day. h was observed that the milk production obtained by the optimization of the feeding systems was always lower that 18 liters per cow/day:Based on the simulations that were carried out, it can be concluded that the adoption of less intensive technological standards is more the result of a deliberate economic rationality of the farmers Man an eventual posture against the adoption of technical progress.

This paper reports the first isolation in Brazil of Escherichia coli in broi ler chickens with lesion of cellulitis. In addition, histopathological examination of the skin to characterize the lesion was also carried out. No significant changes occurred on the epidermis .However,the dermis was infiltrated by lymphocytes,macrophages,eosinophi Is and heterophils. 

Com is the main cereal used in Brazil for pigs and poultry feeding. Its price variation in the last years has led to contemplate the use of other alternatives to its substitution. There is little information in Brazil regarding technical and economic viability of winter cereais use as an alternative feeding for animais. Therefore, knowledge of the chemical composition is of paramount importance in the feeding.formulation for different animal.species. This study aimed to verify the chemical composition of the grains of the main winter cereais produced in the country (white oats, black oats, rye, barley, triticale and wheat). Winter cereal grain samples of a field trial planted in Embrapa Trigo, Passo Fundo, RS, under a randomized block design with three replications were analysed in Embrapa Suínos e Aves, Concórdia, SC, relatively to dry matter, crude.protein, fat, crude fibre, ash, non-nitrogenous substancesand crude energy. The results obtained with the different w inter cereais were advantageous comparatively to corn in animal feeding formulation, suggesting that they show potentiality to be used as a viable alternative. 

The objective of this study was to obtain models to estimate the leaf area of cucumberthrough linear measurements of its leaves. Also, existent models in literature obtained from other placeswere evaluated. The study was carried out during the fali and spring of 2000. The hybrid "Marinda" wasgrown inside a plastic greenhouse in the spacing of 25x 100cm, with plants in a single stem sustained bya plastic thread. The maxim width (L) and the length (C) of leaves were measured, and the leaf area(AF) was determined through the disks method. The models with determination coefficient (R') above0.980 were obtained by the regression analysis. Only some of the existent models in literature showedan acceptable performance. The conclusion was that the leaf area of cucumber may be estimated fromleaf length only.

This work was carried out during the growing season of 1993/94. ft aimed to assess the total extraction of nutrientes and consequently obtain useful information for fertization prescription. Twelve representative of Cabemet Sauvignow( Viris vinifera L.) vineyards in the Serra Gaúcha region in Rio Grande do Sul, Brazil were chosen. Leaves, clusters and branches were picked, counted, weighed and dried, thus supplying dry matter. This material was analysed and its contents in chemical elements were determined. The total extraction of nutrients was the following in decreasing order: K>N>Ca>Mg>P>S>Cu>Mn>Fe>Zn>B. With regard to the parts of the plant, the total extraction obeyed this decreasing order: blade>berry>branch>petiole>angace. The leaf blade extracted all nutrientes in major quantities, except for K, which the berry extracted most. 

Nutritional status of Cabernet Sauvignon vineyards in the Serra Gaúcha region was evaluated, according to the methods developed in Califomia, Michigan and South Africa. The Californian method, using leaf petiole sampled at flowering, identified no nutritional troubles for P, K, Mg, Mn and Zn, but B was deficient in 83.3% of the vineyards. The Michigan method, using leaf petiole sampled during "véraison", identified no nutritional troubles in the vineyards for B, Fe and Mn. For N, 58.3% were below normal nutritional class, and the others were normal; for P 25.0% were normal and 41.7% above normal; K was excessive in 58.3% and above normal in 25.0%; Ca and Mg were normal or in excess for all vineyards; Zn above normal in 75.0%. For the South African method P and B were normal in all vineyards; N in 83.3%; K, Ca, Mg, and Mn were above normal in 91.7% of the vineyards, and Zn in 75.0%. Differences found among methods were probably dueto the phoenological state when samples were taken and tissue analysed.

The importance of this research work results from the fact that relatively few studies on crop rotation systems involving com crop are avalilable. In a trial conducted from 1987/88 to 1995/96, in Passo Fundo, RS, Brazil, the yields of com and sorghum grown in different crop rotation systems were studied. The following systems were evaluated: system I (wheat/soybean or wheat/soybean and common vetch/com or sorghum); system II (wheat/soybean, black oats or white oats/soybean, and common vetch/com or sorghum); system III (wheat/soybean, white oats/soybean, flax/soybean, and common vetch/com or wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/com or sorghum); system IV (wheat/ soybean, wheat/soybean, black oats or white oats/soybean, and common vetch/com or sorghum); and system V (wheat/soybean, wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn or wheat/ soybean, wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn or sorghum). An experimental design of randomized blocks with three replications and plots measuring 30 m 2 was used. The means obtained from 1987/88 to 1989/90 for systems III (7,547 kg ha') and V (7,739 kg ha -') showed higher yields of com, as compared to systems II (6,923 kg ha') and IV (6,890 kg ha'). The means from 1991/92 to 1992/93 and from 1994/95 to 1995/96 showed no significant differences between com and sorghum yields in the systems under study. Com and sorghum may be grown in crop rotation with common vetch, wheat, soybean, and white oats without negative impact on grain yield. 

Trials were conducted in field conditions in Passo Fundo (1984/89) and in Coxilha (1996/97), RS, and in Guarapuava (1984/90 e 1990/94), PR, Brazil, to study the effects of winter crop residues on soybean grown in succession, under no-till system. Winter crops were white oats knife rolled for mulching purposes, white oats, barley, rapeseed, flax, and wheat for grain yield. In these cropping systems, soybean was grown in the summer in monoculture and in rotation with com and pearl millet. A randomized complete block design with four replications was uséd. Soybean grown after flax and rape showed lower yields and lower plant heights than soybean after barley and wheat. Yields of soybean grown in monoculture were in intermediate position, between yields of soybean grown in crop rotation and soybean grown after rape or flax. Soybean grown after barley and wheat may be included in the different systems studied without yield losses. Volunteer white oat seeds may reduce soybean yield and plant height.

The effects of soil tillage methods and winter crop rotation on soybean yield were assessed over a ten-year period. Four soil tillage methods — 1) no-tillage continuous; 2) minimum tillage in winter and no-tillage in summer; 3) conventional tillage with disk plow in winter and no- tillage in summer; and 4) tillage using a moldboard plow in winter and no-tillage in summer—and three crop rotation systems [system 1 (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum)] were compared. An experimental randomized blocks design with split-plots and three replications was used. Soybean yields under conventional soil tillage with disk plow'minimum tillage, and no-tillage were the highest. The yield of soybean grown after wheat, in system II, was higher than soybean grown afier black oats or white oats, after wheat, in system III, and after wheat, in system I. The lowest soybean yield was obtained in monoculture . 

The experiment was conducted in Ituporanga, SC, Brazil for a period of three years, and it aimed to evaluate perennial grasses. The climate in the region is humid subtropical — Cfa, and the soil is the Distrofic Alie Cambissol type, which was limed and fertilized. The species tested in completely experimental design with two replicates were: Hemarthria altissima (fifleen entries); Axonopus sp (five entries); Paspalum notatum (three entries); Paspalum notatum (one cultivar); Cynodon sp. (one cultivar). The most productive treatments were: Paspalum notatum entrie EEL 10162 (CP 13,9%, IVDOM 49% and 20559 kg/ha DM); Axonopus sp. entries Missioneira Gigante (CP 12%, IVDOM 61,8% and 18469 kg/ha DM) and Taió (CP 14,5%, IVDOM 53,1% and 19077 kg/ha DM); Hemarthria altissima entries IAPAR — 35 — Roxinha (CP 10,8%, IVDOM 44,8% and 17068 kg/ha DM), PI 349798 (CP 11,7%, IVDOM 56,9% and 16273 kg/ha DM), PI — HM — 365509 (CP 11,4%, IVDOM 55,5% and 15466 kg/ha DM), and IAPAR — 36 — Flórida (CP 11,2%, IVDOM 60,2% and 14659 kg/ha DM); Cynodon sp. cultivar Tifton 85 (CP 14,1%, IVDOM 50,2% and 19784(CP 13,9%, IVDOM 49% and 20559 kg/ha DM) kg/ha DM). 

The objective of this study was to develop a micropropagation protocol for maté, which included the following experiments: I) Exam of culture medium contamination by microorganisms and in vitro development of explants; II) Pre-treatment of donor plants with the fungicides mancozeb and benomyl, amendment of ANA culture medium with various leveis of benomyl and rifampicin; III) Development of erva-mate explants in culture medium with different rates of cytokinin (BAP); IV) Mass propagation and root development of explants in two culture media (with agar + IBA or vermiculita + IBA). The fungi Alternaria sp. and Colletotrichum sp. were identified contam inating micropropagated explants and causing plant death. Bacteria were also found but they did not affect explant development. Pre-treatment of donor plants with fungicide reduced in vitro contamination by 90%. The use of 0.2 to 0.8 mg BAP in the culture medium did not stimulate shoot formation and did not influence leaf number. The rooting medium with IBA and vermiculita was more efficient on elongation and subsequent root emission.

The probability of occurrence of low values of solar radiation, which are harmful to cucumber, was calculated in thel3aixo Vale do Taquari Region, Rio Grande do Sul State, Brazil. Daily data of solar radiation from 1963 to 1999 obtained in the meteorological station of Taquari (Latitude: 29° 48' S, Longitude: 51° 41W, Altitude: 75 m) were used. The following threshold values were used in this study: 8.4, 7.5 and 6.3 MJ/m 2.day. The first value was the threshold levei for growth and development of cucumber, and the other two leveis were the cause of serious yield tosses. The results showed that during the second and third decades of July the probability of occurring these threshold values of solar radiation is high: up to 9 days in each decade can be expected to have solar radiation lower than 8.4 and 7.5 MJ/m2.day.

Predatory coccinelids were surveyed in citric plants fortnightly at orchards in Viamão for 4 months (from August to November, 1998) and in Porto Alegre for 5 months (from December, 1998 to April, 1999), Rio Grande do Sul state. The research was conducted at private properties where insecticides were not used in the orchards. Baiting trays were used randomly to catch the specimens. Thirteen species of 13 genera totaling 276 specimens were collected, with the predominance of lady beetles Coccidophilus citricola Bréthes, 1905, which feed preferentially on scale insects of the family Diaspididae.

The State of Rio Grande do Sul, southem Brazil has 10 million hectares of native pastures and soils with high acidity and phosphorus deficiency, requiring liming and fertilization to improve productivity. An experiment was carried out at Centro de Pesquisas em Forrageiras, in São Gabriel county, Rio Grande do Sul, Brazil, aiming to study the residual effect of superficial liming and fertilization on dry matter yield of native pasture and on some soil chemical characteristics. A split-plot experimental design with randomized blocks and three replications was used. Treatments were limestone (zero, 4,3 and 8,6t.ha') with annual fertilization (45 kg.ha' de N, 110 kg.ha' de P2O5 e 60 kg.ha-' de K2O) and without fertilization and two depths (0-3cm and 3-6cm). The limestone was applied on February, 1994 and fertilizations were annual since February, 1994 until February, 1996. Soil and forage samples were collected by October, 1997. Fertilization showed a residual positive effect, increasing dry matter yield of native pasture. On the other hand, limestone application decreased exchangeable AI ¨3  and increased pH and  availability of soil Ca" and Mr.

The sowing date is, probably, the cultural practice singly more important for the soybean [Glycine max (L.) Merrill]. The best sowing date for this oleaginous depends, mainly, on soil temperature for germination and emergency, air temperature during the whole growing cycle of the plant, photoperiod after the emergente and soil moisture on the sowing date, along fiowering and grain filling. This study aimed to define an adjustment of sowing dates for the soybean in the State of Rio Grande do Sul, Brazil taking into account the meteorological elements referred above, stages of soybean plant development and the agronomic behavior of the cultivars presently recommended for seeding in the State. The new calendar presents an amplification of the sowing period for all areas of the State. The soybean can be sowed since the end of September Iate to December 25, in Rio Grande do Sul State. However, the largest yields are obtained with November sowings.

The goal of this study was to determine the probabilities of low air temperature for cucumber in the Taquari valley. Daily data of minimum air temperature from 20 Jan 1963 to 31 Jan 1999 measured in Taquari State of Rio Grande do Sul, Brazil (latitude:29°48'S, longitude:51°49'W and altitude:75m) were used to calculate the probability of temperatures lower or equal than 0°C, 3°C, 4°C, 5°C, 12°C and 15°C. Such values were chosen because 0°C is a reference for frost, and 3°C, 4°C, 5°C are the lethal values for the crop during night time conditions of weak, moderate and strong inversion temperature profile, respectively, and 12°C and 15°C are values used as base temperature for the crop. The minimum number of days with the temperature supra cited was well described by a negative binomial distribution for the majority of the periods (decades = 10 days) used in the computation. Therefore we used this probability distribution to calculate the probabilities. For the periods that were not well described by that distribution, the probabilities were calculated using the Poisson distribution. The probability of lethal temperatures is higher from decade 2 in April to decade 1 in October which varied from 1 to 78% and from decade 2 in September to decade 2 in May in which this probability is lower than 20%. Minimum temperatures lower than 12°C and 15°C may occur ali year long, but the frequency is lower from the beginning of Decernber to the end of March.

The probabilities of maximum temperatures harmful to the growth and development of cucumber crop and the thermal time occurring from transplanting to end of harvest of this crop were calculated for the "Baixo Vale do Taquari" Region, Rio Grande do Sul State, Brazil. Maximum and minimum temperature data during the period 20 January 1963 through 31 March 1999 measured in a meteorological station at Taquari (29°48' S Latitude, 51 °49' W Longitude and 75 m altitude) were used in this study. For the analysis of maximum temperature, the probabilities of occurring values greater or equal to 30°C, 32°C, 34°C, 36°C and 38 °C were calculated. It was assumed that temperatures greater than 30°C are harmful to the plant. In order to determine a planting date schedule for the crop, the thermal time above 12°C during the phenological phase from transplanting to end of harvest period was used in the calculations. Results showed that temperatures greater than 30°C may occur even during the winter months, when growing cucumber is not recommended in this region due to the risk of low lethal temperatures. Also, it was found that there is a probability of occurring temperatures greater than 32°C from the third decade of August to the third decade April, greater or equal to 34°C from the third decade of August to the first decade of April, greater or equal to 36°C from the third decade of September to the third decade of March and greater or equal to 38°C from the second decade of November to the second decade of February. Based on thermal time, the duration of the phenological phase from transplanting to end of harvest period was shorter during January and February (as short as 45 days) and longer during August, September and March (as long as 100 days). 

The experiment was conducted on a native pasture in Santa Maria, Rio Grande do Sul State, Brazil. The soil is a Red Yellow Podzolic. The climate of the region is Cfa, subtropical umid. Treatments were the introduction by sodseeding of oats (Avena strigosa) and annual ryegrass (Lolium multiflorum) into native pasture, with and without dosis of paraquat. The seeding and fertilization were made with a sod-seeder drill, after herbicide aplications on 04/21/98. The experimental design was a randomized complete blocks with Eive replications. It was evaluated dry matter yield (DM), botanical composition, plant and tiller populations of sodseeded species, crude protein content (CP), in vitro organic matter digestibility (IVOMD) and seed yield for natural reseeding. No significant differences were found for all the parameters studied. Pasture average DM yield was 4784 kg/ha. CP content and IVOMD were 13% and 58%, respectively. Ryegrass average seed yield was 287 kg/ha.

With the objective to evaluate the effects of non-selective herbicides, utilized for crop desiccation at its maturity phase, on flooded rice (Oryza sativa L.) progeny, there were conducted experiments at field, laboratory, and greenhouse conditions, during the growing seasons of 1997/98 and 1998/99. Treatments tested were the herbicides glyphosate, glufosinate, and paraquat, applied at two rates and at two times, the growth regulator maleic hydrazide was used as a standard, besides a check without chemical applicátion. The rice reagent cultivar was IRGA-416. The remainder management practices applied were those recommended for the crop, which developed in the presence of a red rice infestation. It was evaluated the following variables: rice seed viability and germination, and emergence, height, and dry weight of seedlings. In general, applications of the herbicides glyphosate, glufosinate, and paraquat, at physiological maturity of flooded rice, do not affect seed viability and germination, or seedling emergence. The non-selective herbicides, used for crop desiccation showed effects equivalents to those of the growth regulator maleic hydrazide in relation to the characteristics of rice progeny. High infestation of red rice affects negatively the germination of flooded rice seeds, but does not affect initial growth of the seedlings of its progeny.

Fruit-flies are considered "key" orchard pests because their laying and their worms cause damages in the fruits. To study the attractiveness of flies by associating attractive feed, pesticide and pigment it was installed one experiment in a peach orchard, thiripa' variety, in Chapecó, SC, South Brazil. The design was established in a factorial structure with four replicates in time and three factors combined: with and without trichlorfon 1 %; with and *without food yellow pigment 0,625 %; and four attractive feed, totaling 16 treatments. The feed used were: inverted glucose 10 %, hydrolysis protein 5 %, dyed vinegar 25 % and di-ammoniac phosphate 1,25 %. The trap flasks with 200 ml of ingredients were put in the canopy. Five days after the formulations were changed and the samples were brougth to Fitossanity Laboratory of Research Center for Small Farms of Epagri, where the flies were counted. Results showed that insecticide with no repellent action and yellow pigment were favourable in capturing tefritids. Inverted glucose 10 % was the most efflcient attractive food to fruit-flies, with prominence in the atractiveness of Anastrepha fraterculus.