Enio Marchezan

Arroz: composição e características nutricionais

Due to the importance of rice in the diet, its composition and nutritional characteristics are related to humans health. This cereal is a source of energy, due to its high starch content, also providing proteins, lipids, vitamins and minerals. The present review aimed at examining rice composition, its nutritional characteristics, and the improvement of these characteristics through genetic modification. Variations in rice composition are observed due to genotype and processing, affecting nutritional characteristics. Rice has a positive effect on the prevention of several chronic diseases due to different constituents, and its composition has been improved through genetic modifications, resulting in grains with more interesting nutritional characteristics.

Monitoring of the herbicide clomazone in environmental water samples by solid-phase extraction and high-performance liquid chromatography with ultraviolet detection

SummaryEvaluation of a simple and rapid method for determination of clomazone in environmental water samples, by high-performance liquid chromatography with ultraviolet detection, is described. After solid-phase extraction with C18 extraction cartridges clomazone was separated on a C18 column with 65∶35 (v/v) methanol-water, pH 4.0, as mobile phase at a flow-rate of 1.0 mL min−1. After optimization of the extraction and separation conditions, the method was used for determination of clomazone residues in rivers and agricultural waters of the central region of the Rio Grande do Sul province. The results revealed that clomazone persists in agricultural water at least for 130 days, and was present in 90% of the river water samples analyzed.

Arroz tolerante a imidazolinonas: controle do arroz-vermelho, fluxo gênico e efeito residual do herbicida em culturas sucessoras não-tolerantes

After several decades searching for tools to control red rice, imidazolinone tolerant rice was developed to selectively control red rice. To better understand this technology An experiment was conducted in 2004/2005, in Santa Maria, Rio Grande do Sul, Brazil to evaluate: 1) red rice control by imidazolinone herbicides in Clearfield™ rice; 2) evaluate the imidazolinone herbicide carryover effect on rygrass and non-tolerant rice (IRGA 417) and 3) evaluate the outcrossing rates between Clearfield rice and red rice. The experimental design was a randomized block design, with 3 treatments and 12 replications. To determine the outcrossing rates between Clearfield rice and red rice, virtually all the red rice panicle was collected and analyzed in the area. The carryover effect was tested using ryegrass and a non-tolerant rice cultivar (IRGA 417). The herbicides tested controlled red rice. Although injury to Clearfield rice was observed, the herbicide did not affect yield. Herbicide carry-over to non-tolerant rice was observed, reducing plant stand on rice seeded 361 days after herbicide application. Natural out-crossing occurred between Clearfield rice and red rice, at rates of 0.065%.

PRODUÇÃO ANIMAL EM VÁRZEA SISTEMATIZADA CULTIVADA COM FORRAGEIRAS DE ESTAÇÃO FRIA SUBMETIDAS A DIFERENTES NÍVEIS DE ADUBAÇÃO

The use of lowland areas in the Central Depression of Rio Grande do Sul State, Brazil is basically limited to irrigated rice. Those areas stay on fallow during the winter due to lack of a good natural drainage. Improvement in drainage can be obtained througth area leveling and microrelief correction associated to the establishment of superficial drains. Therefore, an experiment was conducted in order to evaluate cattle production on a leveled lowland area with several grazing winter plant species under different fertilizer rates. The experiment was conducted at the Federal University of Santa Maria in a soil of the Vacacai mapping unit. The area was leveled with a 0.06% slope gradient and the plant species were ryegrass (Lolium multiflorum), white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus). The fertilizer levels were 50%, 100% and 150% of the official recomended rate and the soil had its pH corrected to 5.5 using limestone. The experiment design was a randomized block with two replications and each experimental unit measured 0.5ha. The beef calves had 8-10 months of age and placed under continuous grazing, with 480 kg ha-1 of live weight for treatment. The parameters evaluated were: individual daily weight gain, animal load, weight gain per area, average dry matter accumulation by the pastures, in vitro digestibility, protein and botanical composition. The dry matter of the pastures was around 1000kg ha-1 and average accumulation for dry matter of the pastures was 19.9kg ha-1 day-1. The average weight gain per animal was 1016g animal-1 day--1, with an average load 738.6kg per hectare and the average weight gain was 469.7 kg ha-1. The total number of grazing days were 98, 121 and 128 for the 50, 100 and 150% recommended fertilizer rates. The NPK fertilizer levels, keeping constant the nitrogen fertilization, didn´t affect the average daily weight gain, animal load and weight gain per area.

ARROZ VERMELHO: CARACTERIZAÇÃO, PREJUÍZOS E CONTROLE

RESUMO O objetivo deste trabalho e caracterizar o arroz vermelho e discutir alternativas de minimizacao do problema. Sao apresentados os principais prejuizos causados pelo arroz vermelho e os metodos de controle abordando os pontos positivos e as restricoes de cada um de modos a utiliza-los mais eficientemente.

Efeito do pisoteio bovino em algumas propriedades físicas do solo de várzea

The objetive of the work was to evaluate effects of bovine stepping on the physical proprieties of a lowland soil where a mixture of winter pastures were grown. The plant species were italian ryegrass (Lolium multiflorum), white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus). The soil is classified as an albaqualf, previously leveled with a 0,06% gradient. The experimental design was a randomized block in which each plot measured 0,5ha forming six experimental units under continuous grazzing. The soil treatments were the occasions in which the samplimg were taken; T1 = just before entrance of the animals, T2 = immediately after their exit and T3 = six months later. The animals were 8-10 months old calves with an initial load of 480kg/ha-1 of live load and the residual pasture mass was about 1000kg/ha-1. Animal stepping caused an increase on soil density and a reduction in total porosity. An increase on soil density occurred at the first 5cm soil depth. Six months with no stepping were not sufficient for plant roots to decrease soil compactation.

Dinâmica do banco de sementes de arroz-vermelho afetado pelo pisoteio bovino e tempo de pousio da área

An experiment was conducted in a commercial lowland rice-producing area, adopting the minimum tillage system of rice production, followed by two years of fallow, managed, during this time, by cattle production, in order to evaluate the influence on red rice seed bank dynamics. The experimental design was randomized complete blocks, with three replications, in a bifactorial design. Factor A consisted of rice post-harvest management of the area: [T1] - fallow with cattle trampling and [T2] - fallow without cattle trampling. Factor B was the sampling time: [A1] - 1999, [A2] 2000 and [A3] - 2001. The red rice seed bank estimation was made using 12 soil samples by plot, in April 1999, April 2000 and April 2001, using a 10 cm diameter cylinder soil sampler. The sampling depths were 0-1 cm, 1-5 cm, 5-10 cm and 10-15 cm. After being extracted from the soil, the grains of red rice were counted and submitted to a tetrazolium test to estimate seed viability. Cattle trampling did not affect seed distribution in the soil profile and the dynamics of the red rice seed bank. Fallow duration affected the seed bank of red rice; the regression equation fit that best explains the correlation between number of viable seeds and fallow duration in months was the exponential equation: y = 1382.15 exp (-0.1988*x) p<0.05, showing a decrease in the number of seeds within 12 months, from 1,448 to 151 (90% reduction), and 38 (98% reduction) viable seeds per square meter in 24 months of fallow. Regarding the red rice seed burial depths, seed bank reduction was greater on the soil surface in 2000, with no difference between the depths in 2001. The seeds located on the soil surface lost their viability rapidly, with an average of 99% within one year fallow with or without cattle trampling. It can be concluded that cattle trampling does not affect red rice seed bank dynamics in fallow areas. Soil fallow, with or without cattle trampling, reduces in the red rice seed bank.

Controle de arroz-vermelho em dois genótipos de arroz (Oryza sativa) tolerantes a herbicidas do grupo das imidazolinonas

Red rice (Oryza spp.) is one of the main limiting factors to rice (O. sativa) yield. An experiment was carried out to evaluate red rice control and the behavior of two rice genotypes tolerant to the imidazolinone herbicides in response to imazethapyr (75 g L-1 ) + imazapic (25 g L1 ) application rates and timing. The experiment was conducted in Santa Maria-RS, Brazil in 2004/2005 and was arranged in a factorial scheme, in a randomized block design, with four replications. Factor A included the two rice genotypes tolerant to the imidazolinones, a cultivar (IRGA 422 CL) and a hybrid (Tuno CL); and factor D included the treatments for red rice control, which was a combination of rates and herbicide application timing. The hybrid was found to be more tolerant to the herbicide only than the cultivar. Application rates up to 200% on the hybrid genotype could be done without affecting rice yield. It is important to state that increasing the rate of herbicide application can create carryover problems to non-tolerant crops. Red rice control was total with split application of imazethapyr + imazapic in PRE and POST emergence with the total rate above 125%. The most efficient treatment was application of 75% in PRE followed by 50% in POST, which was the lowest rate promoting 100% control, with relatively low toxicity to the cultivar and without affecting rice yield.

Análise de coeficiente de trilha para os componentes de produção em arroz

Eighty eight rice genotypes were evaluated during four years aiming to study the relationship among yield components. In each year, the experimental design was a completely randomized block design with four replications and the variables studied were: plant height, seed yield, spikelet sterility, number of seeds per panicle, 1000 seeds weight and head grains. The estimation of correlations and the path coefficient analysis were conducted with the GENES software. The genotypes showed significant variability for all the variables analyzed within each one of years. It was concluded that variable selection must be carried out among the cultivars that are more similar and using a greater number of variables allows better inferences about rice yield components. Grain weight was the yield of component that most affected seed yield rice plants.

MANEJO DO PALHIÇO DA CANA-DE-AÇÚCAR. 1. EFEITO NA PRODUÇÃO DE COLMOS INDUSTRIALIZÁVEIS E OUTRAS CARACTERÍSTICAS AGRONÔNICAS

A field experiment was conducted at Federal University of Santa Maria, RS, Brazil, with objective to study different methods of handling sugarcane trash and its effects on productivity and other agronomic characteristics. It was tested five treatments of sugarcane trash, in four consecutive harvests. Treatments of burning the sugarcane plant before harvest, harvesting and burning the remaining trash and remove the trash from plots behaved the same way in relation to industrialized culms production. Aligning it in alternate rows and triturate and redistribute in the field showed less productivity. In relation to brix % juice, it could be suggest any one method of handling the trash studied, because all them presented brix % juice above 18%. The production of green matter from the upper immature part of the stalk, diameter, mean weight of the culm and internode number was not affected by methods of handling the trash.