Repositório RCAAP

The use of copper based phytossanitary products in viticultura is being done for long years. In Rio Grande doSul the Bordeaux mixture (with 1% CuSO4 ) is, always, part of the production system for grapes. High leveis of soil and leafcopper are being detected in vineyards where it is used. Up to now, no symptoms of copper toxicity on vines have beenreported, except for vineyard replanting. Aiming to avoid future damage to vines, soils and subterrancan water, new forms ofapplication of the product sbould be adopted, like low volume application and with lower concentration. Liming and massivemanure applications are practices that might be used to minimize the problem. In some cases, quit or reduce applications ofcopper based products might be necessary.

The objective of this study was to verify the viability of using crop residues as ground cover, in addition to traditional methods, as a way to control spontaneous plants in pineapple cultivation. The experimental design was a randomized complete block design with three replications, and eight treatments were used between the rows of pineapple: (1) herbicide; (2) mowing; (3) hand weeding; ground cover with (4) caete leaves and stalks; (5) corn crop residues; (6) bean crop residues; (7) sugar cane leaves and (8) banana leaves. Each plot consisted of four rows of pineapple in 1.0 x 0.2 m spacing; each row consisted of 12 plants, totaling 48 per plot. Morphometric and qualitative characteristics of pineapple fruits were evaluated, besides the production of spontaneous plants. The results indicated that the highest dry mass yield of spontaneous plants occurred in herbicide and mowing treatments in contrast to that produced by beans. The most promising soil cover with banana leaves was similar to the traditional weeding and herbicide treatments for pineapple yield, fruit size, crownless fruit mass and fruit quality, as well as control of spontaneous plants.

Probable negative effects of high pH and of salts present in spray solution on herbicide activity may be overcome through addition of substances such as acids and/or nitrogenous compounds. The objective of this research was to evaluate the effect of waters from different origins, and of addition of ammonium sulphate, on herbicide action of glyphosate. Treatments consisted of glyphosate rates of 90 and 180 g/ha a. e., with and without ammonium sulphate (1.25% p/v), that were diluted in mineral waters Fonte Azul, Fonte Ijuí, Fonte Sarandi, and distilled water, and applied over oat plants. Phytotoxicity was evaluated at 5, 11, and 19 days after applications. As resulta, it was observed for the three evaluations that glyphosate rate of 180 g/ha caused higher toxicity than did 90 g/ha, what was repeated for oat dry manar. Also, two evaluations indicated that addition of ammonium sulphate to spray solution increased herbicide activity. Only at the latest evaluation Fonte Sarandi water originated higher glyphosate action on oats than Fonte -Azul and distilled waters. It is demonstrated that herbicide activity of glyphosate is not greatly affected by the type of diluent employed, but that addition of ammonium sulphate increases its phytotoxicity.

A field experiment was carried out in Eldorado do Sul, RS, during the 1994/95 growing season, in order to evaluate the influence of weed classes (grasses and broadleaves) in reducing soybean yield, as a function of time of their control. Soil preparation and soybean seeding were performed in the conventional way. The experimental design was randomized blocks; where check treatments consisted of one weedy check and another in which soybean plants were pulled out 14 days after emergente (DAE) and Alexandergrass (Brachiaria plantaginea) was chemically controlled. Additional treatments consisted of chemical control of Alexandergrass alone or of general control of weeds, performed chemical or mechanically at 14, 21, or 28 DAE. Soil covering by weeds and dry matter produced were evaluated two times. The highest values of soil covering and of weed dry matter production were obtained where soybean and Alexandergrass were eliminated. As time progressed, weeds showed reduction in soil covering; nevertheless, dry matter production increased. All treatments that included weed control overcame the weedy check in grain yield; however, they did not differ among them. Results show that weed control applied between second and fourth week after soybean emergency preserve crop yield, that Alexandergrass is the main responsible by yield decrease, and, also that the presence' of broadleaf weeds is reduced by Alexandergrass occurrence, causing disappearance of some species.

The inoculation with vesicular mycorrhizal fungi (VMF) increase of the quality seedling and yield crops. The objective this study were to evaluate the influence of VMF and soil pH in the seedling formation and leaf yield production of flue-cured tobacco. The seedling formation in soil with three levels of pH (4.7, 5.0, and 5.4) and with and without VMF. Eight seedling was conducted by treatment. In four seedling, root morphology, mycorrhizal infection and dry matter was evaluated. The other four was transplanted to pot contend 7 kg of soil with three levels of pH (4.7, 5.0, and 5.4). The planta was cultivated until leaf maturation. In the nursery, the raise of soil pH improved quality of tobacco seedling production. The inoculation of mycorrhizal increase the root length, root surface area, and dry matter of the seedling in lower soil pH, and leaf dry matter when transplanted by lower soil pH. Seedling growing in sói' without exchangeable Al produced highest leaf dry matter, independent of mycorrhizal or field soil pH. Seeding inoculated with VMF in high soil pH, decreasing leaf dry matter when transplant to lower field soil pH.

Tissue culture technique is been used to generate useful genetic mutation for breeding program. In this work it was evaluated the third generation of in vitro callus regenerated plant (R 3 somaclones). The assay was established in experimental field. It were seeded 19 somaclones of UPF 12 cultivar, 2 somaclones of CTC 2 cultivar as well as the controls. The experiment was carried out randomized with 3 repetitions of 1m 2 parcels with 250 seeds (5 rows with 50 seeds/row). It were analysed days to flowering, plant heigth, growth habit, test weight, 1000 seeds weight, grain yield and groat percentage. It was observed positive (useful) variation to these seven traits valued from UPF 12 tissue culture derived lines coMpared to the control. There were only negative variation for four characters. Hundred percent of evaluated UPF 12 somaclones showed . variation at least in one measured trait. The CTC 2 somaclones showed positive variation on three traits (days to flowering, test weight and 1000 seeds weight) and did not showed negativo alterations.

Twelve wheat (Triticum aestivum L.) genotypes were assessed, in vitro and in vivo, for resistance to spotblotch induced by Bipolaris sorokiniana, with the objective of verify correlation between calli and seedling responses. Toxicfiltrates were obtained from two fungai isolates and added to the culture mediam where the wheat callus developed; sporesuspensions were also produced and applied to wheat seedlings. The callus reaction was quantified by the difference betweengrowth of those exposed to the filtrates and the untreated cheks. The response of the seedlings was measured by the percentageof necrotic lesions present on the leaves. A smaller callus growth corresponded to a higher percentage of lesions on theseedling leaves.

The sanity of maize in Santa Catarina has deserved more attention due to its important as a component of animal ration and for human feed. The "grão ardido" is one of the symptom complex of fungi presence that can reduce the quality of maize. In Campo Erê — SC, 32 hybrids werc evaluated for intensity of infected grains and they presented a gradient that varied from 5.29% to 41.74%. E moniliforme (53.25%) and D. maydis (56.75%) were the principal fungi found infecting the kemels.

The objective of this experiment was to evaluate the accumulation and exportation of nitrogen (N), phosphorus(P) and potassium (K) in drybean shoots and grains in response to irrigation, fertirrigation with N and seed micronutrientapplication. The experiment was conducted on a loam Podzolic soil, in Santa Maria, RS. A complete randomized blockdesign was the experimental layout with six treatments and six repetitions. The accumulation of N, P and K was determinedat 49 (anthesis) and 71 (physiological maturity) days after emergency. The exportation and accumulation of N, P and K werehighly influenced by irrigation. The use of irrigation resulted in a exportation of 92.8 kg/ha of N, 15.9 kg/ha of P and 60.9 kg/ha of K by crop grains. The cummulative nutrient exportations through grains and shoots were of 117.6 kg/ha of N, 18.7 kg/ha of P and 87.0 kg/ha of K.

Maximum benefits of no-tilled summer crops are obtained when winter species are used to cover the soil with straw to prevent soil erosion. Forage oats is the main species utilized as cover crop in Rio Grande do Sul State, Brazil. One experiment was conducted at Experimental Estation of UFGRS, in Eldorado do Sul, RS, during 1996/97, with the objective to evaluate com yield and development when established on forage oats plant parts and with nitrogen fertilizing systems. Treatments consisted of four cover systems established before com seeding (com seeding on whole oats plant straw, oat roots, oat shoots, and bare soil); as well as four nitrogen fertilizer systems (0/0, 30/90, 60/60 and 0/120 kg/ha of N at start/ dressing, respectively). Com seeding on oat plant parts or on whole oat plants reduced corn emergente, com dry matter at 15 days after emergency (DAE), and corn height at 15 and 28 DAE. The best results for dry matter and height of com plants at 15 and 28 DAE were obtained with 60/60 kg/ha of N, as averages of all cover systems. For the variables com height at harvesting, leal area, and grain yield there were no differences between nitrogen fertilizer systems, with best results obtained with nitrogen application, as compared to the treatment without nitrogen. It is concluded that the presence of different oat plant parts decrease inicial development of corn plants, but do not reduce grain yield when the crop receives nitrogen.

With the objective to recommend varieties with different ripening times, a collection of tangerine trees at the Agronomic Experiment Station of the Federal University of Rio Grande do Sul, RS, southem Brazil (30°39'S — 51°06W) has been under evaluation over a five-year period. Fruit samples were picked every two weeks and analysed for total soluble solida (TSS), titratable acidity (TA), the TSS/TA ratio and the percentage of juice. Resulta indicate that the best periods to harvest was concluded highest quality that 'Lee' fruits tangerines of the evaluated should be tangerine harvested varieties not earlier are as than follows: April after 15 over 2' and a five-year not later than period lune of evaluation 302'; 'Cravo' it between May 15" and July 31'; cv. 'Facket' should not be harvested before lune 1° and after August 31' and 'King' tangerines, between October 1° and 31". 'Clementine' tangerines, sampled for four years, should be harvested fiem Arpil 1' until May 31', while 'Oneco' and 'Montenegrina' sampled only for three seasons, have been recommended to be harvested between -lune 1' and July 31', and between July 15 2' and October 15', respectively. 

A percentagem de produção de gemas vegetais e florais, a percentagem de queda de gemas e a produção da ameixeira híbrida 'Shiro' foram avaliadas em pomar do Colégio de Postgraduados de Texcoco — México, no período de janeiro a julho de 1995. Foram aplicados, logo após a poda de inverno, no estágio de gema dormente, os seguintes tratamentos: 1) Cianamida Hidrogenada (CH) 0,245%; 2) CH 0,245% + Óleo Mineral (OM) 2%; 3) CH 0,245% + Extrato de alho (EA.) 3%; 4) CH 0,245% + E.A. 4%; 5) E.A. 3% + O.M. 2%; 6) E.A. 4% + O.M. 2%; 7) E.A. 3%; 8) E.A. 4%; 9) O.M. 2% e 10) 'Tratamento testemunha, com aplicação de água. A aplicação foi realizada com pulverizador costal manual, gastando-se em média 1,25 litros de calda por planta. A percentagem de geMas vegetais brotadas foi significativamente superior, no tratamento de CH 0,245% + O.M. 2%, em relação a todos os tratamentos. Houve uma antecipação média de 20 dias na brotação das plantas submetidas a este tratamento, em comparação ao tratamento testemunha. A percentagem final de floração foi maior nas plantas que receberam tratamentos com a cianamida, que também apresentaram menor percentual de gemas caídas e a maior produção por planta. Houve uma antecipação de colheita de 15 dias para os tratamentos com a cianamida e de 4 dias para os demais, exceto nas plantas tratadas apenas com O.M. 2%. O óleo mineral sozinho não diferiu da comparação com o tratamento testemunha. Os tratamentos com extrato de alho, aplicados isoladamente ou associados ao O.M. 2%, não foram efetivos para estimular brotação das gemas vegetativas e florais, assim como não reduziram a queda de gemas, resultando em uma produção similar à testemunha. 

This research was carried out in Chapecó, western of Santa Catarina, Brazil, to study the atractiveness to Gyropsylla spegazziniana (Lizer, 1917) (Hom., Psyllidae) to colourful traps in three-year-old flex paraguariensis orchard. The design was randomized blocks with six replicates in time. The five treataments consisted of trays painted with Eive different coloras of "Coral" sintetic oil as follows: white (001); yellow-dark (016); yellow-light (01679); green-light (01862); and red (019). Colourful trays filled with water and detergent were installed between trees on a wood support with 1.30 m high. After 24 hours samples were collected and brougth to laboratory of Epagri-CPPP. Psillids were counted under sterioscopic microscope adjusted to forty times magnificent. The red and yellow-dark traps showed more atiactive than others and can used for monitoring of this kind of insect pest.

Most of the cultivated species (crops and forrages) is damaged by the lack of or low availability of oxigen in the soil, a consequence of the water filling of the macropores. The arca of the low plains of Brazil Southem Region (Rio Grande do Sul, Santa Catarina and Parana States) is approximately 6.8 millions hectares and most of these soils is dedicated to irrigated rice crop. The main characteristic of these soils is hydromorphism. The excess of humidity is associated with a water table neer the soil surface, as a result of the plain relief and of an impermeable B horizon, both impairing natural drainage atter excessive rainfall. Reaction of maize planta to water excess in the soil have already been evaluated and breeding methods are being employed to develop tolerant germplasrn. This work presents a simple methodology, easy to carry out, that is useful to select maize plantlets (20 days old) tolerant to soil waterlogging, through the examination of their root systems. The determinations of density and of volumetric and gravimetric humidities on 160 cm' of soil contained in plastic cups, compared with field collected data (Albaqualf) allowed to infer that the "cups method" is adequate to be used in screening young maize planta tolerant to excessivo soil water. 

Sediment particle size is a characteristic that affects the particles transportability and deposition in theerosion process. It is necessary to know the particle size distribution in order to build a model to predict the sedimentyield during an erosion process. Two field experimenta were conducted at the Forest and Soil Conservation ResearchCenter, from FEPAGRO, in Santa Maria, State of Rio Grande do Sul, Braz on a Paleudult sandy loam soil, to determinethe partido size distribution, from interrill and rill erosion processes. In the first experiment, residues of whcat and corowere applied as a surface cover on small interrillplots of 0.50 x 0.75 m, at amounts of 0.00, 0.05, 0.10, 0.20, 0.40 and0.80 kg/mi, in four replications on freshly tilled soil, with an average land slope of 0.17 m/m. A simulated rainfall withintensity of 67 mnifh was applied during 90 minutes, when runoff samples were taken to determine the sedimentparticle size distribution. In a second field experiment, concentrated flow rates of 10, 20, 30, 40 and 50 dm 2/min were applied during 40 minutes, on four replications of preformed 5 m long rills in a freshly tilled soil with an average landslope of 0.116 mim. The median size of the sediment yielded in the interrill soil erosion process decreased exponentiallywith the increase of the soil surface cover by crop residues. In the rill erosion process, the median size sediment particlesdecreased with the time from the beginning of the flow application. However, it was not observed any statisticallysignificant difference in the median size of the particle sediment with the increase in the flow rates. The median size ofsediment partido given by the Dsoíndex was 0.250 mm in the interrill erosion process and 0.325 mm in the rill erosionproccss.

Knowing the amount and size-distribution of sediments transported in the runoff water is important for bota erosion studies and farm planning. The effect of type and amount of crop residues, mulch cover, surface roughness, and runoff rate on the size-distribution of eroded sediments, as evaluated by the 13 50 index, was investigated in a field study using simulated rainfall, in Eldorado do Sul-RS, Brazil, during the period of 1992 to 1994. The soil used in the experiment was a red-yellow podzolic, clay loam in texture, with 0.066 m/m slope. Treatments consisted of no-till, chisel plow, and plow-and- disk all of them in the presence and absence of cornstalk and wheat straw. The D50 index increased with runoff discharge up to a given size of eroded sediments and decreased thereafter, regardless of mulch cover and surface roughness. This was explained in terms of amount of sediments readily available for transport and in terms of available runoff energy to deteach new sediments. For a given runoff rate, the 13 55 index values decreased with mulch cover and surface roughness. 

foram analisadas 8752 amostras de leite bovino, sendo 7902 e 850 provenientes de vacas com mastites subclínicas e clínicas, respectivamente. As amostras foram cultivadas em agar sangue bovino e agar McConkey, incubadas a 37°C por 96 horas e examinadas macroscopicamente a cada 24 horas. Isolou-se Candida albicans em 3,6% e 4,03%, Candida krusei em 1,59% e 1,91% e Geotricum candidum em 1,51% e 1,09% dos casos de mastite subclínica e clínica, respectivamente. A prevalência destes agentes foi similar (P>0,02), nos casos subclínicos e clínicos. Estes resultados ressaltam a importância das leveduras na gênese da mastite bovina.

The purpose of this work was to get informations about quality of bean seeds (Phaseolus vulgaris L.) used byfarmers in growing season 1990/91 in Sobradinho-RS, South Brazil. Seventy seven samples were analized in the seedingperiod (August and September). Vigor (field emergency and rapid aging), germination, humidity, purity (physical and varietal)and infestation by bean weevil (Acanthoscelides obtectus) were analized. Dealings followed by fanners in yield and maintenanceof seeds were observed. The seeds presented high humidity proportion, in average 14.7%. In 62.3% of samples the índex ofphysical purity was at the least 98%, that by convention was settled for inspected seeds to Brazil, just 33.7%, of it, werefulfilled the standard of varietal purity. The samples presented high germination, in average 80.4%, and low vigor: theaverage rates of field emergency and rapid aging were 49.2% and 36.1%, respectively. Just 3.1% of seeds analized wereattacked by bean weevil. The seeds, in 85.7% of the cases, were of own crop, that were gotten in little fields (81.9% up to 5ha) and low technological levei, characterized by reduced mechanization use, manures, correctives, herbicides, fungicidesand insecticides.

 The maximum yield (Ym') of sunflower obtained on basis of efective temperature and on the photosyntheticaly active solar radiation absorved accumulted (PARaa) and that based on the highest sunflower yield reached in 53 environments of the State of Rio Grande do Sul, were penalized in function of the relative water consumption or crop specific dryness index (CSDI), according to the Jenssen multiplicative model. The results show that the adjusted and validated model, based on the relative water consumption in the reproductive subperiod, explain about 80 % of the variation in the sunflower yield in Rio Grande do Sul. The model showed good perpormance in the yield prediction (r = 0.926; b = 0.993). The sunflower grain yield may be predicted with four weelcs bef ore the harvest time, using the multiplicative model in which the Ym he the maximum yield estimated in function of the PARaa (Ym'). 

Carrot seeds lots (Daucus carota L.) cultivar Brasília were collected during four consecutive years processed, analyzed, for the moisture content and germinability. Thereafter seeds were stored with 6% moisture content at 15°C and 45% of relative humidity. The seed quality was evaluated by germination and vigor tests. (field emergence, accelerated ageing for a period of 24, 48 and 72 hours and electrical conductivity an half hour and 4 hours of solutes leaching). This paper discusses some procedure for germination and vigor tests, which could be adopted as altemative methods. The germination test using the rolled towels as substrate and evaluated at the 4 4 day shows significant correlation with field emergence and electrical conductivity. Significant leveis of correlation were also observed among accelerated ageing 48 hours and electrical conductivity an half hour (r =0,97); field emergence and accelerated ageing 72 hours. (r =0,83). The electrical conductivity test is most indicated to estimation of seed vigor due to the practical use, objectivity and rapidity for its performance.