Repositório RCAAP

The experiment was conducted to evaluate natural and artificial feeding for piavuçu larvae. Different formulations with raw chicken Tiver and molasse yeast were tested, but soybean meal was used as a partial substitute for molasse yeast at the proportions of 0 % for Treatment 1 (TI), 25 % for T2, and 50% for T3. Also, a fourth treatment (T4) was tested, using T l plus natural food (Artemia fr-anciscana nauplii). The four treatments and four repetitions were arranged in a completely randomized design. According to the obtained data, we concluded that artificial feeding introduced better results, and the use of soybean meal up to the levei of 50 % did jeopardize the larvae growth.

The experiment evaluated the effects of three lipid sources (pork fat, soybean oil, and canola oil) and two leveis of inclusion (5 and 10%) in dry diets prepared with raw chicken liver and molasse yeast on jundia (catfish) fíngerlings feeding. A completely randomized experimental design with a 3 x 2 fatorial arrangement was used with 6 treatments and 4 replications. Data were submitted to variance analysis and test F at 5 % levei of significance, and means were compared through Tukey's test. The estimated parameters were: average weight, daily average gain, survival, condition factor, growth, body composition, fat and protein deposition in the carcass and fat and protein deposition rate in the carcass. Only the body cdmposition and the fat and protein deposition in the carcass showed correlation. among the tested .sources and leveis (P<0.05). The conclusion was that the tested lipid sources and leveis cause variation in the body composition of south american catfish (Rhamdia quelen).

The lack of an adequate feed-budget planning for grazing animais has driven Brazilian farmers to an inadequate farm management. One of the main causes of this problem is related to the fact that farmers do not have a clear objective for their farm production, and because there is a lack of knowledge in relation to the planning and adjustment of animal requirement and forage availability during the year. This paper suggests that feed planning should be done in long, medium and short terms. These three kinds of planning generate different decisions in different periods of the year. The long terra plan determines general farm policies; the medium term plan determines specific decisions on how to adjusi the lack and/or excess of forage (or specific requirements of forage for specific period), and the short term plan is associated with decisions taken in specific moments and is mainly related to environmental conditions (weather, soil etc.) in a particular moment. The objective of this paper is to discuss this subject and help farmers to make decisions in relation to feed planning of grazing animais. The milk production from pasture will be highlighted in this review.

To provide a better use of the soil in the regions where sugarcane is grown, in the state of Rio Grande do Sul, an intercropping study was conducted to identify the best bean type to achieve higher yields. The bean cultivars tested were: determ i nate growth habit, type 1; 'Pampa `, indeterminate. type II; 'Macanudo. indeterm i- nate, type III. The sugarcane cultivar was CB4176. Two simultaneous sowings of the bean and sugarcane cultivara were performed, single and intercropped. The first experiment, from the sugarcane growth season of 1993, was sown in 09/27/91, and the second, of 1994, in 09/22/92. The results showed no interaction among year of sowing and the performance of the cultivars. Best beans plant type behavior were III, of cultivar 'Macanudo', and 11 of 'Pampa' . Sugarcane yield and piam population were affected by intercropping. The treatments sugarcane x `Macanudo' provided the best results concerning culm hight and diameter.

During nine years the economic effects of seven c rop rotation systems were assessed. The following systems were evaluated: system I (wheat/ soybean); system II (wheat/soybean. from 1987 to 1989, and wheat/ soybean and common vetch/corn, from 1990 to 1995); system III (wheat/soybean, black oats or white oats/soybean, and common vetch/corn); system 1V (wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn, from 1987 to 1989, and wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/ corri, from 1990 to 1995); system V (wheat/soybean, wheat/soybean, black oats or white oats/soybean, and common vetch/corn); system VI (wheat/soybean, wheat/soybean, white oats/soybean, flax/soybean, and common vetch/ com, from 1987 to 1989, and wheat/soybean, wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn, from 1990 to 1995); and system VII (winter fallow/soybean, from 1990 to 1995). In the mean from 1987 to 1989, systems IV and VI showed h igher net returns than systems III and V, respectively. In the average from 1990 to 1995, no si gni ficant differences were observed for net return in Ihe systems evaluated.

The objective of this research was to evaluate the effect of both continuous and sequential defoliation on soybean BRS 66 yield. The treatments were evaluated during the vegetative and reproductive stages by using the injury leveis recommended for the management of soybean defoliating pests. The study was conducted at the Univer- sity of Passo Fundo, in Passo Fundo-RS, from December 1999 to May 2000. The experimental design was complete randomized blocks with six treatments and four replications. The following treatments were tested: (i) 33% of continuous defoliation at stages V4 to V9 and of (ii) 17 and (iii) 33% at stages RI to R4 (1-tHR & CAVINES, 1977, stage); sequential defoliation of (iv) 33+17% and (v) 17+33% from stages V4 to V9 and from stages RI and R4; and (vi) control (no defoliation). Independent of the defoliation levei applied and the fenologic growth stage, the treatments did not de- crease the grain yield per area and per plant. The sequential defoliation of 17%+33% increased the number of grains and the normal pods per plant. However, this treatment decreased the grain weight. This latter effect was also observed with the sequential defoliation of 33%+17% and the continuous of 33% (reproductive stage). The sequential defoliations of 33+17% or 17+33% at the vegetative and reproductive stages, respectively, are more indicated for the control of leaf- feeding insects for the soybean variety BRS 66.

A greenhouse experiment was carried out in order to evaluate the residual effect of triple superphos- phate, magnesium thermophosphate (Yoorin), North Carolina rock phosphate and Arad rock phosphate on the rice yield, to determine the efficiency of five soil P extractants, and to test the "Y" leaf as a diagnostic leaf in the phosphated nutrition of rice. On the previous study, four P rates (0, 50 100 and 200 mg/dm 3) were applied to alfalfa grown in a Oxysol (dystrophic Red Yellow Latosol). The residual effect of P was observed by an increase in grain yield and P accumulation in the plant. Resin, Mehlich-1 and Mehlich-3 soil P extraction methods were similar indicators of available P. Soil P extracted by isotopic dilution and by the Bray extractant presenled lower correlation coefficients with the P accumulated in the plant tops. The "Y" leaf was a good indicator of the P nutrition of rice.

The mite Brevipalpus phoenicis (Geijskes, 1939) (Acari, Tenuipalpidae) is the vector of the "citrus leprosis virus" which provokes damages on fruit, leaves and branches, reducing the production and compromising the trees. To study the environmental influente on the population fluctuation of th is pest in the Western region of the State of Santa Catarina, Brazil, two citrus orchard of "Valência" cultivar with six year old were evaluated every two weeks from 1997 to 2000. During the evaluations, the number of mites was counted on the surface of three fruits or branches portions from the internai part of the canopy of 20 trees of each orchard. Infestai ion of leprosis mite were observed during all the studied period, with lower populations during the cold months and with increasing infesta- tions at the end of winter and the beginning of spring. Higher popualtions of B. phoenicis were observed during the worm months. Correlation analyses between the number of observed mites and the monthly maximum (tma) and minimum mean temperatures, rainfall, percentage of air humidity, insolation and wind speed accused "r" values of 0.55; 0.48; -0.17; -0.20; 0.24 and -0.23, respectively. Third order polynomial regression analyses with "F" test and probability of 0.05 resulted the equation y = 1257.5 -195.2tma + 8.35tma 2 -0.11 tma3, with R2 = 0.44.

The assessment of the hydraulic properties of soils is an important aspect to consider when dealing with the soil-water phenomena, particularly its behavior at field sente when data coverage is needed for the feeding of integrated modeling purposes, or if any aspect of water management is treated. At field scale, it is importam to knowyhe spatial behavior of water transfer/retention conditions and related soifparameters as well as the ones that should be sampled for soil-water description. Difficulties for "in situ" determination brings simulation of hydraulic parameters as a natural choice for data coverage in large arcas (at least approximated data, since they have, in most cases, a complex behavior). An experiment was carried out in Angatuba, Sao Paulo, Brazi I (23°33'S; 48°.18'W; 670m) and intensive soim sampling was done in a regular grid, covering a 40 ha field, in order lo study spatial contrasts of hydraulic properties and related easy-measured soim parameters. Simulations for soil-water were done based upon the pore size distribution model and pedrotransfer functions. Results from the field scale observations have shown poi nt-by-point differences in the characteristics of soil permeability, particularly near saturation. Spatial anal ysi s h as shown low coefficient of variation values and lack of strong spatial autocorrelation, for ali soim properties analyzed.

Pasture arborization with nodulating legumes trees represents the most economic and ecological strategy to add nitrogen to the system plant-soil. However, for introduction of trees in pasture it is necessary to identify grass species that are able to grow under the trees where ligth intensity is lower. The present study was conducted at Embrapa Agrobiologia, Seropédica/RJ, Brazil, to test three grass species (Coast cross 1, Pennisetum purpureum cv. Cameron and Brachiaria brizantha cv. Marandu) and three leveis of shadowing (25, 50 and 75 %). All leveis of shadowing decreased the root biomass of ali the three grass species tested while B. brizantha and P. purpureum showed that their shoot was I ittle affected by shadowing. B. brizantha produced more root biomass than the other two species in ali leveis of ligth intensity tested. 

The adoption of soil tillage systems compatible with the soil, climate characteristics found in southern Brazil is an indispensable procedure for soil amendment and to maintain the commercial fields economically iMe- grated in the agricultura' production system. The effects of soil tillage systems on the yield of white oats (Avena saliva L.) were compared over a eight-year period in a crop rotation of wheat/soybean, commom vetch/corn, and white oats/soybean. Four soil tillage systems were evaluated: 1) no-tillage, 2) minimum tillage, 3) conventional ti Ilage using disk plow plus disk harrow, and 4) conventional tillage using moldboard plow plus disk harrow. An experimental design of blocks at random, with three replications were used. The main field plots (4 x 90 m) were formed by soil management systems, while the subplots (4 x 10 m) consisted of crop systems. The average yield of white oats grown under no-tillage from 1990 to 1997 (2,959 kg/ha) and under minimum tillage (2,938 kg/ha) was higher than the yield obtained for white oats grown under conventional tillage using either disk plow (2,709 kg/ha) or moldboard plows (2,682 kg/ha). Higher contents of soil organic matter, extractable P, and exchangeable K were ohserved in the 0-5 cm layer for the conservation tillage systems (minimum tillage and no-tillage), as compared to the conventional tillage systems (disk plow and moldboard plow). The no-tillage and minimum tillage system should be preferred for white oats cropping.

Genetic dissimilarity measures are commonly used by plant breeders to identify dissimilar parents to get desired segregant populations. Multivariate techniques were utilized to evaluate the genetic dissimilarity among 53 genotypes of the carioca bean (Phaseolus vulgaris L.). Six traits were evaluated in a field experiment using a randomized block design with four replications. Canonical variable analysis and cluster analysis using Tocher's agglomerative method and hierarchical method (nearest neighbor) were applied. Generalized Mahalanobis distance (D2) was used to measure dissimilarity. Genotypes comprised twenty six distinct groups by Tocher's method. Thousand seed weight was the most important trait to the total genetic dissimilarity. The obtained results allowed to characterize dissimilar genotypes to be strategically used in artificial hybridizations.

With the objective to anticipate the harvest period and to enhance fruit size in peach c v. Diamante, in the two auxins: acid (3.5.6-TPA) and 2,4-diclorofenoxipropionic acid (2.4—DP), a citocinine (pheni I urea) and girdling of the main branches werc applied on trees located in the Depressão Central of Rio Grande do Sul, at the Estação Experimental of the Federal University of Rio Grande do Sul, in Eldorado do Sul, latitude 30°39'S and longitude of 5I °06'W. The following treatments were applied at phase II of fruit development, in a randomized block design: 1) 10 ppm 3,5,6 TPA; 2)20 ppm 3.5,6 TPA; 3) 10 ppm 3.5,6 TPA plus girdling of branches; 4) 20 ppm 3,5,6 TPA plus girdl ing of branches; 5)25 ppm 2,4 -DP; 6)50 pppm 2,4-DP; 7)25 ppm 2.4-DP plus girdling of branches; 8)50 ppm 2,4-DP plus girdling of branches; 9) 10 ppm pheni turca (CPPU); 10) girdling of branches; and II) control. ALI the chemicals were applied directly to the fruits, spending about 1,25 lítree. Fruit diameter, of 10 fruits per troe, was measured weekly, from thinning to harvest. The number of fruits and total prodution per tree was determined. The percentage from the total number of fruits at each harvest was determined at the end of the harvesting period. Aux i n treatments and girdling of branches did not increase total number of fruits/tree and did not increase average fruit weight. However, auxin treatment, specially 20 ppm 3,5,6- TPA with or without girdling of branches, resulted in anticipation of about 15 days in begining of harvest. Fruit quality was not affected by any of the treatments.

Coccoidea is a homogeneous group of insects commonly called scales. They are highly specialized plant parasites and can cause serious damage to agricultural economy by their potential pest condition. The classification of this group is based almost exclusively on morphological characteristics of the adult female. The aim of this work was to update the species records of the Coccoidea Colletion of Prof. Ramiro Gomes Costa Museum. There are 88 species distributed in 8 families of which 16 are type-material, 7 new records for Rio Grande do Sul and one for Brazil.

Genotype x environment interaction analysis was performed on grain yield of twenty-two commonbean (Phaseolus vulgaris L.) genotypes grown at tive different locations in Rio Grande do Sul, during two growing

Genotype x environment interaction was perfomed on grain yield of twenty-two genotypes of common bean (Phaseolus vulgaris L.) grown at tive different locations in Rio Grande do Sul, during two years. The stability parameters were estimated by linear regression model of EBERHART and RUSSEL (1966). In addition, the environmental index of the model was obtained by weather variables and disease index. The best estimator of the environment was the normal environmental index, whereas the weather variables and disease index failled to provide a good estimation.

In the State of Rio Grande do Sul, the losses of spring-summer crops by drought events has showed the necessity of specific studies about local water deficit regarding the irrigation practice. Depressão Central lowlands, specifically the Arroio dos Ratos soil, are usefitl alternative to wet rice and are suitable for irrigation. So, the water deficit occurrence in the spring-summer period in Eldorado do Sul, with Arroio dos Ratos soil, were studied, adopting a soil water-storage capacity of 67.71 mm. The homogeneous serial dates of the 1967-1993 period were used to evaluate the referential evapotranspiration, and to compute the average water balance and the serial water balance for ten-day periods. The deficit and water indexes frequency were calculated. The results showed that water deficit occurs from November through March, however December, January and February were the months with the most frequent and severe water deficit. 

The main objective of the experimenta carried out in August 12, 1993 and in October 6, 1995 at the Estação de Pesquisa e Produção de Viamão, Rio Grande do Sul, Southern Brazil was to compare the effect of organic manure on yield and quality of carrot cultivars. In the first experiment the cultivars Nantes Forto, Flakkese, Fuyumaki, Nantes Superior and Harumaki Kinko were evaluated. In 1995 `Nantes Superior' and `Harumaki Kinko' were replaced by 'Brasília' and `Tin Ton'. For the manuring treatments, chicken and quail manure were used in two leveis. In the first experiment results showed a h igher yield for Nantes Forto' for the commercial roots. The materiais differed in number of roots, weight, diameter and lenght. In the second experiment, results did not show significant differences among cultivars. However, there were differences in the average weight (better with 'Brasília') and in average length (better with `Tin Ton'). In 1 993. organic manure provided an increase in ali the factors evaluated, except in the number of roots. In the second one, the organic manure provided an increase in average root weight, average root diameter and average root length.

The fluctuation of the citrus flat mitc Brevipalpus phoenicis (Geijskes, 1939) Sayed, 1946 (Acari, Tenuipalpidae) population was surveyed in Taquari, Rio Grande do Sul, froni December 1996 to October 1997. This study was carried out in a 'Valência' orange orchard. The experimental design was arranged in a randomized complete block with four replications. Plants were divided in quadrants, and the samplings were taken in three fruits per quadrant, in five points of the fruit (one at style end and four in arcas with citrus scab lesions). Results showed significant difference in the occurrence of the citrus flat mire. Relative humidity and rainfall significantly affect the occurrence of the citrus flat mite.

The choice of an adequate soil management system and planting techniques increases pineapple yield and lowers the production costs as well. To estimate the effect of different soil management systems (conventional tillage, strip-tillage and no-tillage), and two planting techniques (furrow and spear) on productivity, fruit characteristics, percentage of sprouting, and seedling production, a field experiment was carried out from August/1997 to January/1999 at the Estação de Pesquisa e Produção of FEPAGRO, Maquiné, Rio Grande do Sul, Brazil. The soil type was a clay loam Argiudoll. Results showed that productivity and harvest percentage were higher in conventional tillage (1 1.94 ilha and 52%) than in no-tillage (5.67 t/ha and 27.7%). The productivity and harvest percentage in furrow and spear plantings did not differ statistically. Fruit diameter and length, crown size, brix degree, number and average weight of sprouts were not affected by the different treatmcnts.