Repositório RCAAP

Antibodies to Bovine Leukemia Virus (BLV) were determincd by the agar gel immunodiffusion test in serum samples from dairy cattle imported from Uruguay to Brazil. From 19,774 samples tested during 1992-1997, 3,225 (16.30 %) had antibodies. These results suggest the necessity to import only negative cattle to BLV and to implant control measures in Brazil. 

The pre-germinated rice growing system demands genotypes with a higher capacity of initial development in an anaerobic environment. Having in mind the need for better knowing the characteristics of the cultivars El Paso 144, BR IRGA 409, BR IRGA 410, IRGA 416, IRGA 417 and Bluebelle, this paper reports a comparative study of the enzymatic activity of glutamate oxaloacetate transaminase (GOT), esterase (EST), and malate dehydrogenase (MDH), in the rice seedling shoots through electrophoresis. The treatments consisted in germination and development of the seedlings during 14 days at the temperatures of 20, 25 and 30oC under both aerobic and anaerobic conditions. The analysis of the electrophoresis gels leads to conclude that: a) The IRGA 417 seedlings stands out against the other cultivars because of its higher level of activity of the enzymes studied under the anaerobic treatment at the temperature of 20o C; and b) The great variability found in the enzymatic systems studied for the different genotypes and treatments used allow to recommend that studies of genotype x environment interaction use biochemical systems, in order to assist in the search for genotypes that are able to overcome environmental stress. 

This trial was conducted to determine the value of soybean hulls as a replacement for com grain in finishing beef heifers diets. Dietary treatments consisted of four substitution levels (0, 25, 50 and 75 %) of com grain by whole soybean hulls. Hundred and eight beef caule heifers were used in a randomized complete block design, with four treatments, three replications, with nine animais in each pen. Animais were fed twice a day with a com silage based diet, plus whole soybeans, mineral supplement and a variable amount of ground com grain and soybean hulls. No differences were detected among levels of soybean hulls substituting com grain upon final weight, daily weight gain or feed conversion.

This essay was established at the Fundação Estadual de Pesquisa Agropecuária Experimental station in Maquine in the northeastem Rio Grande do Sul state coastland, Brasil. From august 1997 to october 1999 were evaluated in a pineaple experiment the effect of soil management techniques (conventional, strip- tillage and no-tillage, planting tecniques (furrow and spear), on biomass yield and its nutrient contents. Fruit quality and productivity were also evaluated in this pineaple cv. pérola second harvest. Results showed that soil management techniques did not affect biomass production and nutrient concentration on pineaple leaves. In the conventional tillage, biomass productivity (green and dry) and that of fruits was 45.6; 7.4; 14.4 t/ha and its contents of N; P; K; Ca and Mg amounted 99; 10; 238; 10 and 10 kg/ha respectively. Mantained the due proportions of biomass yield and its nutrients in the higher technological levei (MODEL, 1999) the fertilization needs would be 587 kg of N and 946 kg of K O. Productivity and percentage of harvest in conventiohal ti Ilage (14.35 t/ha and 51.2 %) were higher than in no :tillage (8.61 t/ha and 31.2%) respectively. Length of fruit and crown diameter in the conventional-tillage were higher than in no-tillage, but fruit lenght and total degree of soluble solids showed to be not affected by treatments.

Considering the increasing application of horticultural substrates and the fact that soil is still usedby producers in their mixes, it was conduced an experiment aiming to verify the viability of a Haplumbrept soil as acomponent of horticultural substrate mixes, along with organic conditioners. The soil was chosen due to their hightotal porosity, high level of organic matter and low capacity to agricultural use. In the experiment, the soil wasmixed, in volumetric proportion 1:1, with water hyacinth [Eichhornia crassipes (Mart.) Solms], rest of sugar cane,sawdust of Pinus sp and carbonized rice hulls. The mixes were submitted to physical (bulk density, total porosity,water availability and aeration) and chemical characterization (pH and total soluble salt concentration). Except tothe mix with sawdust, all mixes improved physical characteristics, providing lower bulk density, higher porosity andmore water availability. All conditioners, but water hyacinth, increased the mixes pH, and all of then increasedsoluble salts contents.

It was determined probability to occur equal or superior pluvial precipitation 100% and 60% of themaximum evapotranspiration (ETm) of the common bean, in different sub period and sowing dates, for threelocalities in Rio Grande do Sul State, Brazil. With the daily pluvial precipitation data, determined the accumulationof pluvial precipitation (TPP) in each sub period, sowing date and locality. The adjustment of the data of TPP wasevaluated in each sub period, sowing date and locality, to the distributions normal and gama, using Lilliefors’ testfor first and Kolmogorov-Smirnovs’ test for second. It was verified that the probability the pluvial precipitation beequal or superior of the ETm for common bean in complete cycle were minor in Julio de Castilhos, intermediary inCruz Alta and superior in Passo Fundo. However, between studies localities, Passo Fundo is the local of minorproduction risk. The lesser probabilities had occurred during the sub periods most critical of the culture, understoodbetween the beginning of the flowering and the physiological maturation, when the probabilities are lesser than50%, considering the total ETm. The three sowing dates considered, the lesser probabilities during the completecycle of the culture occurred in October and November, being that in the critical period, the sowing of Septemberpresented the higher probability

The experimental work was carried out at the Estação Experimental da Faculdade de Agronomia, UFRGS, in Eldorado do Sul, Rio Grande do Sul, Brazil. The objective was to evaluate the effect of fertilizer treatments (with and without N, P and K) and lime leveis (0; 1,5 and 3,0 ton/ha) on a Plintossolo, on the yield and botanical composition of a nature pasture sodseeded with white clover (Trifolhan repens L.). The climate is Cfa, according to Kaeppen's classification. The experimental design was a split-plot arranged in randomized block with three replications. The fertilization on the first year was 22,5 kg N/ha, 180 kg P205/ha and 120 kg K 20/ha. On the second and third year the amounts were of 90 kg P 205/ha and 48kg K20/ha. On the fourth year were of 24 kg N/ha, 84 kg P205/ha e 63 kg K20/ha. Fertilization with N, P and K increased the forage dry matter yield and changed the botanical composition of the natural pasture. Such variables were also affected by the year .

An analysis of genotype x environment interaction was perfomed on grain yields of twenty-fourgenotypes of bean (Phaseolus vulgaris L.) grown at five different locations in Rio Grande do Sul. The stabilityparameters were estimated by the linear regression model of EBERHART & RUSSEL (1966). In addition, theenvironmental index of the model was obtained through wheather variables and disease index. The best estimatorof the environment was the usual environmental index, whereas the weather variables and disease index failled toprovide a good estimation.

This study had as objective evaluates the potential behavior of eight cultivars of melon plants, hybrid and varieties, seeking your indication for cultivation in polyethylene greenhouse, in the region of the Serra do Nordeste of Rio Grande do Sul State, Brazil. The experimental design was randomized blocks, with three replications for treatment. The yields varied from 8,22 kg m-2 to 5,20 kg m-2.The cultivars Galeão, C.A.C. and Jumbo were the more fruitfull, while the Gaúcho cultivar was the most productive in function of the largest medium weight of fruit, 1,412 kg. C.A.C. cultivar presented the smallest fruit size, 0,798 kg. The standardization of fruits for the size showed the need to establish, through pruning fruits, the number of fruits ideal for plant for each variety. The largest uniformity in the maturation of fruits was presented by cultivar RML-2704.

Aiming to delimit areas showing climate aptitude for growing com, an agroclimatic zoning based on growing degrce-days and water deficit as agroclimatic indexes, at different sowing dates, was generated for the State of Rio Grande do Sul, Brazil. The zoning was established for sowing dates 8/1, 9/1, 10/1, 11/1,12/1, and 1/1, and six maps (1:750,000), which are presented in a reduced forre in this papei, were obtained. The zoning areas were classified as Preferential I and II. Tolerable. Marginal, and Not Recomended for com. Planalto, Serra do Nordeste, Serra do Sudeste, and Alto Vale do Uruguai are the regions showing higher potential for com in the state. Additionally, Médio and Baixo Vale do Uruguai, Missões, Depressão Central, Litoral Sul, and Campanha regions, though also showing potential for com, have the highest values of water deficit and, by using irrigation, are clssified through the temperature index. The main limitation to high com yields in the state is linked to water deficit that normaly occurs in southwestern and southeastern state arcas and in part of Depressão Central region in 9/1 to 1/1 sowing dates. Low temperaturas and frost occurrence are the most limiting factors in the sowings centered in 8/ 1. The results obtained show that climate aptitude for com in Rio grande do Sul varies according to the sowing date and region, evidencing the importante of carrying out the zoning by sowing dates. 

This paper deals with allocative changes in the production of rice in the State of Rio Grande do Sul, Brazil, during the period 1970-1996. Therefore, it was possible to obtain, through a descriptive statistical method, that involves interconnected analyses of proportions of land use, among other indicators, the Dislodgement Index (DI) and the Rice Allocative Effect (RAE). Results, that embody recent structural changes surveyed in the agricultural census of 1995-96, support either basic and specific hypotheses formulated in this paper. The Dislodgement Index (DI), a proxy indicator for agricultural output growth rate, decreased along time, a movement apparently of pro- cyclical content. Although, it has to be put in perspective with yield increases in agricultural production as well as with changes of relative weights in all the links of the production chain, that must have been increasing participation of processing industries, services sector and so on. Therefore, rice production has been increasingly nettcd by agribusiness links and by systems of institutional support that made it possible to generate changes, in an environment that helped increase scale, complexity and scope for rice production in Rio Grande do Sul. The trends observed for results obtained regarding RAE in the analysed periods reflected allocative changes. once farmers privileged investment decision in favour of rice, making that activity one of important specific weight in the economy of State of Rio Grande do Sul, and stabilizing the original impacts of soybeans, that has "migrated" to midwestern region, on a very concentrated farm size structure. The expansion of rice in State of Rio Grande do Sul was, for its turn, highlighted as a phenomenon occurred largely on biggcr farms. Mass production, found in Europe and in the United State.% canal "fordism", that consists in a increasing concentration in a reduced number of agricultural and processing units, on larger scale of operation, has been a new tendency for rice production in State of Rio Grande do Sul. However, even larger scales cannot avoid the increasing segmenting trend in demand, patterns that have been observed more recently, as opposed to the mass production. It is the so-called demand-pull influente, that may significantly alter the conformation of rice production in State of Rio Grande do Sul.

Exploitation of heterosis has been the main point to increase maize productivity in this century. However, the varieties use this phenomenon in a different way. This work was designed to compare the performance of open pollinated populations, their crossings and commercial hybrids in two different locations. The results demonstrated that the environment is important for the expression of the genetic potential of the plants. In the favorable environment the crossings performed better than the populations and the commercial hybrids outperformed both. In the unfavorable environment ali genotypes presented low grain yield. This fact demonstrated that superior genotypes could not express their genetic potential in environments with limitations for plant development. As a consequence, the choice of the commercial variety to be acquired by the farmers should take into account the environment and the management level that will be adopted in the crop.

Cultivation in plastic greenhouses is an incipient activity in the State of Rio Grande do Sul, in the south of Brazil, specially for melon. Studies in adaptation of cultivars, period of cultivation and greenhouse management are essential to the improvement of this activity. In order to evaluate the productivity, in protected environment, of four cultivars of melon – Hy Mark, Acclaim, AI-522 and Sunrise – an experiment was carried out, in four seedling periods, in the region of Serra do Nordeste, in the State of Rio Grande do Sul, Brazil. The treatments were laid out in a randomized block arranged in a split plot design with three replicates, where seedling period was assigned to the main plot and cultivar of melon was assigned to the sub-plot effect. The cultivars Hy Mark, Acclaim, AI-522 and Sunrise productivities varied from 36,7 to 77,3 t of melons per hectare. The cultivars Hy Mark and Acclaim presented the more stable productivities among the periods of seedling. The cultivar Sunrise is the most prolific and productive, while AI-522 shows the lowest productivities and the most extensive period of conservation after harvest.

The research evaluates the vegetative and productive behavior of five cultivars and one selection ofpersimmon cultivated in Veranópolis, RS, Brazil. In general, the flowering of persimmon cultivars and selectionoccurred in October, while the fruit’s ripening began in March and finished in April or May. ‘Kaoru’, ‘Rama Forte’,‘Micado’ and ‘Regina’ showed the longest cycles (period between the beginning of the flowering and the beginningof the ripening), while ‘Fuyu’ and ‘Chocolate 3’ the shortest cycles. The cvs. Fuyu, Kaoru and Micado exhibitedalternation of production. Regina persimmon was the best, with an average yield of 83,10 kg/plant; ‘Kaoru’ and‘Fuyu’ also showed good yields. The cv. Micado showed the highest mean fruit weight (368,43 g), while the cv.Rama Forte showed the lowest (140,25 g).

This work was designed to investigate the possible existence of genetic variability for speed of germination in bean seeds. Hundred and one genotypes, three of them green beans and the remainder dry beans, were evaluated in greenhouse. Greenhouse produced seeds were sowed in plastic boxes at depths of 2.5 and 8.0 cm. A randomized complete block design with two replications and six seeds per plot, was performed. Analysis of speed of germination, evaluated through an Emergente Index, indicated significant differences for seed placement depth and no significant differences for seed placement depth x cultivar interaction. A superior group comprised 98 genotypes. whereas the inferior one, comprised the three others, two of which are green bean types. The conclusions are: low variability was detected for the character germination speed within this germplasm; green beans might be improved; germplasm collected from different locations presented different • behavior suggesting that natural selection might act differently in different environments.

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.