Repositório RCAAP

In order to evaluate the effect of nitrogen supply in black oat (Avena strigosa) and the quantity of oat straw as a soil cover on initial growth of maize plants, a trial was conducted in greenhouse conditions, in Porto Alegre/Rio Grande do Sul, Brazil. Treatments consisted of three nitrogen level (0, 15 and 40 kg/ha) applied at the beginning of the tillering stage of oat and two amounts of oat straw as soil cover ( 3 and 6 t/ha). One treatment without oat straw was included. Nitrogen fertilization in oat increased dry matter yield and nitrogen uptake by plant and decreased carbon/nitrogen ratio of oat straw. The increase of the nitrogen level applied on oat and the oat straw quantity used as soil cover increased height, dry matter production and nitrogen uptake by com plants. The variables analysed in com plants were higher in the treatments with soil cover than in the check without soil cover.

The objective of this study was to investigate the genetic variability for grain water absorption capability in 219 genotypes of different commercial common bean groups, as an indicator of cooking time. Grains were obtained from the bean crop breeding program at the Santa Maria Federal University, RS, harvested in January 2002 and adjusted to 12,15% grain humidity. The experiment was conducted in a completely randomized design with three replications of 50g of seeds of each genotype. Samples were placed in a recipient with 200 ml of distilled water during 12 hours. Percentages of normal (soft) and hardshell grains were estimated. The majority of genotypes evaluated showed from 95 to 100 % of water absorption by the grains. A minority presented grains without hydration capacity (hardshell grains). The results showed that there is genetic variability for water absorption in commercial common bean genotypes.

This experiment was performed in Lages, Santa Catarina, to determine the moment of wheat tiller emission through the addition of red and far red light. Treatments involved the application of red (R) and far red (PR) light during the day time, at different growth stages (from emergence to emission of the 2° leaf on the main stem; between the emission of 2° and 3' leaf; 3° and 4° leaf; and 4° and 5° leaf ). The definition about the emission of tiller AO was set between emergence and the emission of wheat's second leaf. For A I, A2 and A3, this decision was made between plant emergence and the emission of the fourth leaf.

The objective of this research work was to test two improved populations of alfalfa for tolerance to acid soils, one selected for two cycles in soil and one for two cycles in solution culture, in five levels of pH. The aluminum tolerance was assessed by measuring the plants height and the roots length. Results indicated progress in alfalfa's tolerance to acid soils, evaluated by plants height and roots lenght by both methodologies of selection. The productive potential of the selected populations was not reduced in the absence of aluminum. The solution culture selection was as efficient as the soil selection for alfalfa's tolerance to acidity. Correlation between plants height and roots lenght was positive and significant.

Two experimenta were performed at the Rice Experimental Farm of IRGA, in the county of Cachoeirinha-Rio Grande do Sul, Brazil, in the 1997/98 and 1998/99 growing seasons, with objective to evaluate soybean grain yield grown in flooded soil. In the 1997/98 growing season, 20 cultivars were evaluated, under 774 mm of precipitation and two flooding irrigation at the reproductive stage. The medium grain yield was of 2598 kg/ ha, the cultivar FT-Abyara (3727 kg/ha) produced the highest yield, and did not differ of other 17 cultivars. The cultivar BR-4 had the lowest grain yield (1555 kg/ha). In 1998/99 growing season, were evaluated 30 cultivars, under 346 mm of precipitation and two flooding periods: one of eight days when plants had six developed leaves and another of two days in the seed-formation begin. The medium grain yield was of 1010 kg/ha, with the highest yield in the cultivar FT-2004 (2065 kg/ha), although it did not differ of other 14 cultivars. These results demonstrated the existente of genetic variability in soybean cultivars under excess of soil water.

In order to indicate the most favorable regions for the cultivation of tomatoes in greenhouse, the monthly average of global solar radiation and the number of days with radiation equal and lower than 8,4 MJ.m -2 d-' was measured based on the lower criticai trophic limit of this crop and the probability of monthly ocurrence of averages equal or lower than that value, from April to September in the State of Rio Grande do Sul . Data collected from 24 meteorological stations of the Fundação Estadual de Pesquisa Agropecuária — FEPAGRO/SCT, located at different climatic regions were, utilized considering the1957 - .1997 period. In general the monthly average for the Depressão Central, Campanha, Serra do Nordeste, and Litoral regions was lower than 8,4 Mim -3 d' in June and July and for the Serra do Sudeste, Missões, Planalto, and Vale do Uruguai the average for the winter months stayed above the criticai limit. 

Grain yield was used to perform a phenotypic stability analysis in maize. The yield data were obtained from a group of maize trials classified as very early, early and normal cycles. Data were analyzed within each maturity group and phenotypic stability was done using the unbalanced discontinuous bi-segmented model (STORCK, 1989). A total of` 18, 20, and 19 environments (1994/95 and 1995/96 growing seasons) and 34, 44, and 19 cultivars were used in the analysis for very early, early and normal maturity groups, respectively. Cultivars were ranked from intermediate, maximum, higher than intermediate, diverse and lower environment to not recommend. The cultivars Agromen 3050. C 969. AGX 6272, Dina 170, Dina 771, P 3063, AG 672 and AG 9023 are those that performed well in a diverse environmental conditions. The cultivars AG 9012, AG 9014, Dina'766, AG 521 and AG 951 are only recommended for environmental conditions relatéd to high yield expectation.

 Populational dynamics of Geophagus brasiliensis (Quoy & Gaimard, 1824) was studied from September/ 1995 to August/1996, through bi monthly samples at the Águas Belas reservoir, Viamão, Rio Grande do Sul, Brazil (30°02'22"S and 51°01'11.5'W). Individuais were captured using a beach reine 10 m long, 2 m high and a circular fishing net, both with 5 mm of mesh size. The reproductive period begins in October, with maximum reproduction activity in November and February, ending on march. The absolute fecundity was estimated 566 ± 142 oocytes, in females ranging from 7.28 to 13.17 cm. The size at the first maturation was between 8 and 9 cm. 

This experiment was carried out in order to determine physical injuries caused by artificial drying of corn kernels using drying air temperatures of 40oC, 70oC and 100oC) and harvested at moisture contents of 18%, 25% and 35% and to correlate them to breakage susceptibility. A stationary fixed bed drier with an air flow of 15 m3/min/ m2 was used. Lots of 1,400 kg, using three replications, were dried for each combination of harvest moisture content and drying temperature level. Hectoliter weight, 1,000-kernels weight, percentage of kernels with one, two and multiple cracks, stress cracks index and breakage susceptibility were evaluated. Stress cracks index of corn kernels increases when harvest moisture and driyng temperature increase in a stationary fixed bed drier. Occurrence of broken kernels during pre processing is affected by stress cracks severity. Stress cracks index and percentage of kernels with multiple cracks are fairly correlated to breakage susceptibility.

The seasonal variations and composition of the diet of Leporinus obtusidens in Lake Guaíba were studied. Specimens were captured between August/1994 and August/1995 with gill nets and trotlines in several different placas of Guaíba Lake. A total of 187 stomachs was examined for fullness and the diet composition of 68 individuais with full or partially full stomachs was investigated. Frequency of occurrence and an index of diet importance were used to analyze the data. Plant matter and sediments were the most abundant items, so that L. obtusidens can be considered a herbivorous-geophagus species. Other less frequent and abundant items included bivalves, gastropods and insect larvae. The large number of empty stomachs (63.6 %) may be an indication that this species regurgitates the contents in its stomach when submitted to stress due to the sampling procedure or that the period of feeding activity is not coincident with the sampling period.

Feeding is omnivorous type. The gonadotrofic hormones existing in commercial forms (Pregnyl) or in carp hypofisis were employed to induce spawning in L. friderici, Lpiau, L obtusidens and L elongatus females. Hormonal dosage were between 0,25 mg/kg and 5.0 mg/kg for females and 0,25 and 3,3 mg/kg for males. L elongatus females were crossed with Schizodon fasciatus males. The Liou for the genus was 12 until 21 cm. L friderici youngs was catched in reservoirs. This denotes the possibility for species of genus spawn in closed environment.

Apomixis is a method genetically determined of reproduction in plants, in which embryo is formed without the union of male and female gametes. There are three basic mechanisms of apomixis: apospory, diplospory and adventitious embryony. In most apomictic species, the pseudogamy is necessary for the endosperm development and consequent embryo viability. Apomixis can be detected through several techniques as embryo sac cytological analysis, progeny tests, callose deposition analysis in cell walls, auxin tests, among others. Apomixis represents an advantage for plant improvement because it allows the fixation of superior genotypes by succeeding generations. The available information about the genetics of apomixis suggests that this characteristic is controlled by few dominant genes, which favors the manipulation of this characteristic in breeding programs.

This study was conducted at the Santa Terezinha do Salto district (Lages, SC, Brazil) during the 1998/1999 growing season. The main objective of this trial was to evaluate the effects of increasing rates of nitrogen (0, 50, 100 and 200 kg/ha) fertilization (Urea form) in combination with com (Zea mays) hybrids (AG 12, AG 28, AG 303, and AG 9012) on the incidence and severity of common rust (Puccinia sorghi) and stalk rots (Gibberella zea and Pythium sp.). The experimental design was a completely randomized block (four replications) with split-plots. Hybrids were located on the main plots and nitrogen rates on the split plot of each block. The results showed that common rust severity increased with the increasing rates of nitrogen. The hybrids AG 303 and AG 9012 were more affected by rust than the hybrids AG 12 and AG 28. The hybrids AG 28 and AG 303 presented more incidence of stalk rot than the other hybrids. Despite of being one of the most affected by the diseases, the hybrid AG 9012 was the most productive. 

 Soil fertility and yield was evaluated on a typical dystrophic Red Latosol (Typic Haplorthox) located in Passo Fundo, State of Rio Grande do Sul, Brazil, after eight years under mixed production systems (1993 to 2000). Five production systems were evaluated: system I (wheat/soybean, common vetch/corn, and white oat/soybean); system II (wheat/soybean, grazed black oat + grazed common vetch/corn, and white oat/soybean); system III [perennial cool season pastures (fescue + white clover + red clover + birdsfoot trefoil)]; system IV [perennial warm season pastures (bahiagrass + black oat + rye grass + white clover + red clover + birdsfoot trefoil)]; and system V (alfalfa as hay crop), which was established in replicated plots in an adjacent area in 1994. The treatments were arranged in a randomized complete block design, with four replications. Exchangeable Al, exchangeable Ca + Mg, organic matter, extractable P, and exchangeable K levels displayed differences among crop production systems, whereas the production systems raised the corresponding contents, chiefly in the 0-5 cm layer. Organic matter, exchangeable Al, extractable P, and exchangeable K levels decreased from the 0-5 cm soil layer to the 15-20 cm layer, while the opposite occurred with the pH and exchangeable Ca + Mg contents. 

This work presents a part of the results of an investigation carried out with tropical fruits Brazilian exporter firms. Research aimed to characterize such companies with the purpose to know its structures, its sate, growth and product's promotion strategies, its marketing plans, main importers markets and the problems faced to export, among other factors. Starting from the results, looked for to diagnose which aspects that play against a better exporter performance to sector and to point to some solutions. Little time of performance in the fruit's market, reduced size of the companies, export's concentration to an market only, consignment sale, lack of forecast of safes and of a marketing program, little importance to market studies, marketing and product's support and the faulty government support are some of the factors that hinder the exports of tropical fruits to European Union markets.

The ornamental plant Portulaca grandiflora Hook is very diffused mainly in the north coast of Rio Grande do Sul. Was founded a large attack of scale insect Pulvinaria ficus Hempel, 1900, in this plant, cultivated in stonecutter. The prepare and determination of scale insect was made on Laboratory of Entomology FEPAGRO, Porto Alegre, RS, been the permanent microslides deposited in collection of Coccoidea, Prof. Ramiro Gomes Costa Museum, of this Institution. The characterization is followed by pictures of adult female in stereomicroscope, optic microscope and scanning electronic microscope. The pictures were made in FaBio and CEMM of PUCRS. P. ficus over there ornamental plants, attacks other economic important plants, as fruit plants. Your recognition is important, a time that presents potential as plague, that be can adopted adequate rules if your control been necessary. Realized, also, the increase of host-list and geographic distribution.

From 1986 to 1995, in Passo Fundo, RS, Brazil, the effects of soil tillage systems and crop rotationwere assessed. Four soil tillage systems 1) no-tillage, 2) minimum tillage, 3) conventional tillage using disk plow,and 4) conventional tillage using moldboard plow and three crop rotation systems [system I (wheat/soybean),system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, black oats orwhite oats/soybean, and common vetch/corn or sorghum)] were compared. An experimental design of blocks atrandom with split-plots and three replications was used. The main plot was formed by the soil tillage systems, whilethe split-plots consisted of the crop rotation systems. Energy conversion (energy produced/energy consumed)and balance (energy produced - energy consumed) during a tem-year period is presented in this paper. For energyconversion and balance, no-tillage (6.38 e 16,252 Mcal/ha) and minimum tillage (6.53 e 16,434 Mcal/ha) presentedthe higher rates, while conventional tillage using disk plow remained in an intermediate position (6.27 e 17,578Mcal/ha) and tillage using moldboard showed the lowest rate (6.06 e 14,987 Mcal/ha), respectively. The croprotation for wheat was more efficient in energy than the monoculture of this cereal. Corn presented the higherefficient in energy.

This paper shows recommendations for controlling the pineapple mealybug and gives suggestionsto adapt to the season, the number of treatments and the volume of the mixture according to the conditions of theRio Grande do Sul, as well as considerations about the comparative costs of the insecticides recommended,destiny of the mixture used, the managing of the contaminated biomass, sanitary situation and longevity of thecrops and needs of research in the State with the objective of reducing losses due to the plagues which, in otherregions, are controlled through of treatment of plants and/or preventive pulverizing of the crops 60, 150 e 240days after the planting, applying, respectively 30, 50 and 70 ml of solution/plant. However, these recommendationsare based on research made in and for areal climatically different from those which prevail in Rio Grande do Sulwhere observations of crop and the behavior of the temperature, precipitation and humidity of the air during theyear indicate that the population of the mealybugs grows from September to May and decreases in the winter. Infunction of this, and taking in account that in Rio Grande do Sul the pineapple shows a slower growing rate, alonger cycle and less productivity of biomass, it is recommended that the crops receive from two to four treatmentsyearly, preferably in the period of the bigger growth of the plague and of the crop (September to Mai), using 70%of the volume of the mixture of the recommended products in other regions. The treating or not of the plants and the choice of the most adequate treatment depends onthe type of scion, preparation of the ground, the gradeof contamination and the season of the year.

They were appraised in the summer and winter of the year of 1991, the incidence of endoparasites in 21 pig farms of the Southwest of Paraná. In each herd were evaluated the diarrhoea in the suckling, weight variation coefficient (VC) at weaning and average daily weight gain (DWG) in the period. The samples of collected feces of the sows and her litters were appraised for the flotation method. In the period of the summer, the Coccids and Strongilids they were the parasites more frequently found in the feces of sows and her litters. In the winter period, the larger occurrence was of Coccids, so much in sows as her litters. DWG and VC were respectively 38g/ day lower and 12% higher in farms where Coccids were demonstrated in piglets feces in comparison to negative farms. 

The effect of Nicotiana glauca and Chrysanthemum vulgaris leave extracts on the humoral response in cattle vaccinated with an inactivated vaccine to bovine Herpesvirus type 5 (BHV-5) were examined. Two inactivated oil-adjuvanted BHV-5 vaccines were prepared with an infectious titre (pre-inactivation) of 10 84DICC/ ml, inactivated with binary ethylenimine (BEI) and emulsified in oil adjuvant. Nicotiana glauca and Chrysanthemum vulgaris extracts were added . (5mg of each extract per dose) as a coadjuvant to one of the vaccines (vaccine B). Two groups of nineteen calves were vaccinated with 3 doses (3 ml) at four week intervals between doses. Neutralizing antibody leveis in sera were determined at different time intervals after vaccination. Thirty days after the administration of the third dose the mean neutralizing antibody titre was 96 for vaccine A and 80 for vaccine B. There was no significant difference between the antibody titres induced by the two vaccines (p>0.05). These results indicate that extracts of these plants had no adjuvant effect on the inactivated BHV-5 vaccine .