Aplicação de fósforo para imobilização química do cádmio em solo contaminado

The objective of the study was to evaluate the effect of phosphorus on the Cd availability to plants of a contaminated soil using 109Cd isotope and chemical extractants. The experiment was set in a randomized block design and the soil was labeled with 222 KBq of 109Cd per pot and received 5 rates of P as triple superphosphate, growing lettuce plants as test crop. The use of phosphorus reduced pH of soil which altered the Cd availability in DTPA and Mehlich extractants. The lettuce Cd content decreased but its accumulation and L value increased in all treatments compared to the control, demonstrating the inefficiency of phosphorus in reducing the Cd availability.

Identification of sources of resistance in sorghum to Peronosclerospora sorghi

The main objective of this work was to identify sources of resistance in sorghum (Sorghum bicolor) to Peronosclerospora sorghi, the causal agent of downy mildew, through the evaluation of 42 sorghum genotypes under natural infection in the field. Genotypes were planted in single row plots between two rows of the susceptible line SC283, planted 30 days before, to act as spreader rows, in two separate nurseries. The experimental design was a completely randomized block design with three replications. Sorghum genotypes CMSXS156, CMSXS157, CMSXS243, TxARG-1, 8902, 9902054, 9910032, 9910296, Tx430, QL-3, SC170-6-17, CMSXS762 and BR304 were classified as highly resistant in both nurseries. Among these, SC170-6-17 and 9910296 showed 0% systemic infection. Results indicated the possible occurrence of different pathotypes of P. sorghi in the two nurseries.

Experimental alternatives for evaluation of progenies and clones in eucalyptus breeding programs

The feasibility of using augmented block designs and spatial analysis methods for early stage selection in eucalyptus breeding programs was tested. A total of 113 half-sib progenies of Eucalyptus urophylla and eight clones were evaluated in an 11 x 11 triple lattice experiment at two locations: Posto da Mata (Bahia, Brazil) and São Mateus (Minas Gerais, Brazil). Four checks were randomly allocated within each block. Plots consisted of 15 m long rows containing 6 plants spaced 3 m apart. The girth at breast height (cm/plant) was evaluated at 19 and 26 months of age. Variance analyses were performed according to the following methods: lattice design, randomized complete block design, augmented block design, Papadakis method, moving means method, and check plots. Comparisons among different methods were based on the magnitude of experimental errors and precision of the estimates of genetic and phenotypic parameters. General results indicated that augmented block design is useful to evaluate progenies and clones in early selection in eucalyptus breeding programs using moderate and low selection intensities. However, this design is not suitable for estimating genetic and phenotypic parameters due to its low precision. Check plots, nearest neighbour, Papadakis (1937), and moving means methods were efficient in removing the heterogeneity within blocks. These efficiencies were compared to that in lattice analysis for estimation of genetic and phenotypic parameters.

Boron influence on concentration of polyols and other sugars in Eucalyptus

Although the functions of the element Boron (B) in plants have not been sufficiently clarified, several hypotheses have been raised. Some of the functions attributed to this element are synthesis and transport of carbohydrates. To evaluate the effect of B on the synthesis of some polyols and sugars in Eucalyptus grandis and hybrids "urograndis", these species were submitted to situations of supply and restriction of B. The experiment was carried out in a greenhouse, arranged in a randomized block design in a 2 x 2 factorial scheme, with 5 replicates of each genotype. The B levels were provided in the form of nutrient solution. No significant difference was observed in the content of mannitol, sorbitol, myo-inositol and scyllo-inositol and sugars α-glucose and β-glucose between E. grandis and hybrids. Arabinose was the only one to present a higher content in E. grandis on restriction of B. The effect of the presence of B was very expressive, but regarding B supply, the plants showed significant increase in the synthesis of the compounds evaluated.

Outplanting performace of eucalyptus clonal cuttings produced in different containers and substrates

The objective of this work was to evaluate the outplanting growth of Eucalyptus grandis e E. saligna clones, produced by cuttings in tubes (50cm³) and in pressed blocks (40x60x07cm) - 175 cm³/ seedlings, with different substrates (BT - sugarcane bagasse+sugarcane filter cake; AR - carbonized rice hull + eucalyptus bark; TF - peat). The experiment was arranged in a randomized block design, in a 2x7 factorial (2 clones and 7 treatments), with four replicates with 25 plants. Survival was evaluated two months later. Plant growth was monitored through height and ground level diameter at 20, 40, 60, 120 and 180 days after outplanting. To evaluate the effect of the containers on stem and root biomass in both clones, 180 days after outplanting, the cuttings grown in BT substrate with fertilizer were selected. One plant per plot of each clone, grown in tubes and in pressed blocks was selected. The E. grandis and E. saligna cuttings grown in pressed blocks with sugarcane bagasse+sugarcane filter cake presented greater height and diameter after out planting. Both clones presented larger root, bark, log and branch biomass production in plants produced in the block system. Cuttings of E. saligna grown in pressed blocks showed 80% most wood biomass 180 days after outplanting, compared to that grown in tubes. In E. grandis, the differences in diameter and height, in function of the cutting production system, decreased along time, while in E. saligna these differences increased along the evaluation period.

Propagation through cutting technique of species ocurring in the Lower São Francisco River in Sergipe State with different concentrations of indolbutiric acid

The objective of this work was to evaluate the feasibility of vegetative propagation through cutting technique of seven tree species with strong occurrence in the riparian forest of the Lower São Francisco River in Sergipe State, under different concentrations of indolbutiric acid at 0, 2500, and 5000 mg.L-1, for potentialization of its use in soil bioengineering technique. It was used a complete random block design with three replicates, and a total of twenty-one treatments. The evaluation period was 120 days for each species, and the data collection was made in intervals of fifteen days, in a total of eight evaluations for each species. The evaluated parameters were: Survival Rate, callus formation, and Root Dry matter Weight. Among the studied species, Schinus terebinthifolius Raddi presented the best results related to cutting technique mainly under the indolbutiric acid concentration of 2500 mg.L-1.

Planting density and initial growth of two tree species adapted to the semi-arid region

Planting densities influence several aspects of forest formation, including management practices, timber yield, quality, and extraction, and consequently its production costs. The objective of this study was to evaluate Mimosa caesalpiinifolia and Gliricidia sepium growth as a function of planting density (400, 600, 800, 1000, and 1200 plants ha-1) and plant age. The species were evaluated every 90 days for plant height (PH), crown diameter (CD) and root collar diameter (RCD) (10 cm above the ground), with the first evaluation performed at 90 days and the last at 720 days. When plants were one year of age and beyond, evaluations were conducted also for stem diameter at breast height (DBH) (1.30 m above the ground). A randomized block design with split-plots and three replicates was adopted. Species were assigned to plots, planting densities were assigned to subplots, and evaluation ages were assigned to subsubplots. The four traits in both species had their values decreased as planting density increased, but continually increased as plant age increased. For PH and RCD there was an alternation between species superiority, with gliricidia being superior to sabiá at some ages, while the opposite occurred at other ages. As to CD the species only differed in the last measurement, gliricidia being superior. With regard to DBH, gliricidia was superior starting from the second measurement. There was an effect of the species × ages interaction for the four traits and also an effect of the densities × ages interaction for CD and DBH.

Soil salinization and maize and cowpea yield in the crop rotation system using saline waters

The use of saline water and the reuse of drainage water for irrigation depend on long-term strategies that ensure the sustainability of socio-economic and environmental impacts of agricultural systems. In this study, it was evaluated the effects of irrigation with saline water in the dry season and fresh water in the rainy season on the soil salt accumulation yield of maize and cowpea, in a crop rotation system. The experiment was conducted in the field, using a randomized complete block design, with five replications. The first crop was installed during the dry season of 2007, with maize irrigated with water of different salinities (0.8, 2.2, 3.6 and 5.0 dS m-1). The maize plants were harvested at 90 days after sowing (DAS), and vegetative growth, dry mass of 1000 seeds and grain yield were evaluated. The same plots were utilized for the cultivation of cowpea, during the rainy season of 2008. At the end of the crop, cycle plants of this species were harvested, being evaluated the vegetative growth and plant yield. Soil samples were collected before and after maize and cowpea cultivation. The salinity of irrigation water above 2.2 dS m-1 reduced the yield of maize during the dry season. The high total rainfall during the rainy season resulted in leaching of salts accumulated during cultivation in the dry season, and eliminated the possible negative effects of salinity on cowpea plants. However, this crop showed atypical behavior with a significant proportion of vegetative mass and low pod production, which reduced the efficiency of this strategy of crop rotation under the conditions of this study.

Behavior, performance and physiological parameters of pigs reared in deep bedding

An experiment was conducted to evaluate the behavior, performance and physiological parameters of pigs in different production systems. Twenty four animals in the growth phase were distributed in a randomized block design in three treatments: T1 - concrete floor, T2 - deep bedding with wood shaving, and T3 - deep bedding with coffee husks. The behavioral study was carried out by observing the animal behavior for an uninterrupted period of eight hours throughout seven weeks. The proportions of time spent in each behavior were characterized using the frequency histogram composition. Environmental (IBGTH), physiological (rectal and skin temperature and respiratory rate) and performance (weight gain, feed intake and feed conversion) parameters were measured in animals during the period. The production systems of deep bedding showed higher values of IBGTH. There was no effect of production systems evaluated on the performance parameters. Rectal temperature was higher in animals reared on deep bedding with coffee husks in relation to the concrete floor. The use of deep bedding benefited the behavior of piglets in the growth phase and it reduced the agonistic behavior among individuals.

Comparison of metering mechanisms of corn seed

It was compared the performance of the metering mechanism of corn seeds (Zea mays) in direct seeding in an area of ​​200 ha, a property in Piraí do Sul, State of Paraná - PR, in Brazil. It was seeded 4 maize hybrids, 50 ha of each, with seeds of different sieves. The experiment was conducted in a randomized block design (RBD), with 3 treatments and 9 repetitions for each corn hybrid. The treatments were the pneumatic seed of metering mechanisms, horizontal perforated disc with and without ramp®. The plots were 40 m² and were distributed at the early, middle and late sowing. The variables analyzed in each corn hybrid were initial population, faulty spacing, multiple spacing, acceptable spacing, and yield components. As there were no significant differences in the variables, it was concluded that the quality of seeding with different systems of distribution was similar in the different sieves of distributed corn seeds.

Sowing depths of brachiaria in intercropping with corn in no tillage planting

The forage production in crop-livestock integration is critical both for formation of straw for no tillage planting and food for livestock farm. The experiment was conducted in the autumn/winter of 2009 and 2010, in the city of Selvíria -state of Mato Grosso do Sul -MS, Brazil, at Experimental Station of FEIS/UNESP. The objective was to evaluate the optimal depth for deposition of seeds of two Brachiaria species intercropped with corn with emphasis on grain yield and straw. The experimental design was a randomized block design in a factorial scheme 3 x 3, with four replications. The main treatments were two species of Brachiaria (Urochloa brizantha "Marandú" and Urochloa ruziziensis), which seeds were mixed with corn fertilizer and a control treatment (without intercropping). Secondary treatments consisted of three depths (8; 10 and 16 cm) in the deposition of fertilizer (in the consortium and the control treatments). The intercropping corn with Brachiaria produced similar amounts of straw. The straw total production was higher when intercropped and decreased with depth. The consortium with U. ruziziensis provided higher grain yield of corn in relation to U. brizantha, in 2010. The sowing depth of forages did not affect corn yield.

Influences of two CO2 concentrations and water availability on bean crop

This study was carried out to determine some physiological and phenological responses of the bean under high [CO2] and drought stress. The experiment was conducted from April to July 2009 in Viçosa, Brazil. The open-top chambers were used to enrich the air with CO2, whereas the drought stress was applied between the flowering and the ripening. The randomized block design was used, with four replicates in the subplots. The following plots were [CO2] at 700ppm (F1) and [CO2] environmental (F2) and the subplots were well watering (S1) and drought stress (S2). The results were subjected to Anova and the Tukey test (P < 0.05). For the treatments F1S1 and F1S2 the photosynthetic rate showed increments of 59% and the transpiration reduction of 12%. The yield, leaf temperature and stomatal conductance were not significant different to high [CO2], different from the dry matter, who showed increment of 20% (F1S1) and the water use efficiency who showed increase of 90% for high [CO2]. The osmotic potential was lower in plants under drought stress (F2S2 and F1S2), followed by plants under high [CO2] (F1S1). Despite the increment in photosynthesis, high [CO2] does not guarantee higher yield.

Trickle irrigation: effects on papaya crop

The objective of this study was to evaluate growth and yield of papaya cv. Sunrise solo under trickle irrigation system configurations. A random block design was used with six treatments and four replications. Treatments were: T1- a 32 L h-1 micro sprinkler; T2 - a 43 L h-1 micro sprinkler and T3 - a 60 L h-1 micro sprinkler for four plants; T4 - Drip system with four emitters per plant on one lateral line per crop row; T5 - Drip system with eight emitters per plant on two laterals line per crop row; T6 - Drip system with four emitters per plant on one lateral line distributed as pig tail. The dripper flow rate was 4 L h-1and they were apart each other 0.50 m. Crop growth variables were measured every two weeks. Production variables were evaluated during harvest. The treatment that presented superiority was irrigated by micro sprinkler system with flow rate of 43 L h-1.

Sweet grape mini tomato grown in culture substrates and effluent with nutrient complementation

The objective of this study was to evaluate production of Sweet Grape mini tomato (Lycopersicum esculentum Mill.) using culture substrates and nutrient solution sewage effluent, applied by drip irrigation (fertigation). The experiment was conducted at the University of Goiás State (UEG-UnUCET), from June to November 2011 in Anápolis-GO, Brazil. The experimental design was a 2 x 3 factorial arrangement in a randomized complete block design with four repetitions. The plots were made by combining two nutrient solutions, effluent supplemented with mineral fertilizers (EcS); conventional nutrient solution (SnC); in addition three cultivation substrates: 60% of fine sand washed + 40% substrate composed by 20% coconut fiber plus 80% pine bark (S1); 20% coconut fiber and 80% pine bark (S2) and natural coconut fiber (S3). Sewage effluent were determined nitrate, calcium, potassium, manganese, total phosphate, total iron, magnesium, chloride, sulphate, boron, zinc and molybdenum. We evaluated average mass and average number of fruits per bunch, total fruit and total yield per plant. Statistical difference absence among tested solutions indicates sewage effluent can be used as an alternative source of nutrients in growing mini tomatoes in hydroponics.

Corn production for silage intercropped with forage in the farming-cattle breeding integration

Corn cropping for silage, due to the plant material exportation, intercropping with forage provides greater ground cover and straw formation for the Direct Planting System (DPS) continuity. The objective of this study was to evaluate corn production for silage in DPS intercropped with four forages (Urochloa brizantha cv. Marandu, U. ruziziensis cv. Ruziziensis, Panicum maximum cv. Tanzânia and P. maximum cv. Áries). We applied three sowing methods (in row together with corn fertilizer; by no-till sowing simultaneously to corn sowing and at V4 corn stage) and corn without intercropping. The experiment was conducted in autumn/ winter of 2010, in Selvíria - MS, in a randomized block design in factorial arrangement (4 x 3 + 1) and 4 replications. For corn, we evaluated plant height, basal stem diameter, initial and final stand and silage production and for forage dry matter production. Morphological characteristics and corn yield were not affected by intercropping when compared to sole corn crop. Forage dry matter production sown in corn row with fertilizer is a highlight, which in addition to providing greater productivity, harnesses the operation during sowing.