Produtividade do milho safrinha e modificações químicas de um latossolo em sistema plantio direto em função de espécies de cobertura após calagem superficial

Modern agriculture is undergoing profound changes, with demands for more efficient management practices in the production systems used in each area. The objectives of this study were: to evaluate the effect of different covering species on a no-tillage system; to find the results of lime application on soil surface after sowing those forage species; measure the effects on soil chemical properties and subsequent effect on corn yield; and to determine the dry matter produced by each species used. The experiment was conducted on November, 2002, in the town of Palotina, Parana State, Brazil. A randomized block design was used, with 4 repetitions, in a 2x6 factorial scheme -two depths of soil sampling (0-10 and 10-20 cm) and six types of forage covering on the soil (Mucuna deeringiana, Crotalaria juncea, Setaria incana, Pennisetum glancum and Eleusine gracilis, as well as a mix of all these species). 3 t ha(-1) of dolomitic limestone were applied in total surface area, without amending. The covering species associated with the surface limestone application showed improvement in soil fertility, mainly in the layer of 10-20 cm, with prominence to Elensine gracilis, Crotalaria juncea and Setaria incana. Eleusine gracilis and Crotalaria juncea featured the largest dry matter production; however, the great amount of straw of Eleusine gracilis damaged the productivity of corn. Grain and corn straw productivity was higher when previously cultivated along with Setaria incana and the mix of forage species covering

INTERAÇÃO ENTRE BACTÉRIAS Azospirillum brasilense E Herbaspirillum seropedicae COM ADUBAÇÃO NITROGENADA, VISANDO O FORNECIMENTO DE NITROGÊNIO PARA O MILHO

This study aimed to investigate the interaction between the bacteria A. brasilense and H. seropedicae associated with nitrogen fertilization, aiming to supply nitrogen for corn crop. The experimental design was randomized blocks, in 4 x 3 factorial design with four replications. The first factor was formed by the treatments: no inoculation, inoculation H. seropedicae and A. brasilense in isolation and combination of the two strains. The second factor referred to nitrogen levels, 0, 60 and 120 kg ha-1 of N. Each experimental plot consisted of six corn lines of 3.5 meters, where the evaluation of yield components was performed: number of rows grain and number of kernels per row, thousand grain mass, average mass of grains per spike and productivity. Isolated inoculation with the bacteria A. brasilense (AbV5) and H. seropedicae (SMR1) resulted in gains especially for thousand grain weight, which can be observed that for less than the maximum dose of nitrogen doses, remained the same yield. There were no gains in productivity with respect to the use of corn seed inoculation with rhizobacteria of the genus A. brasilense (AbV5) and H. seropedicae (SMR1) in relation to nitrogen fertilization

Influence of physical protectors with different filters on the initial development of Peltophorum dubium (Spreng.) Taub seedlings

The use of physical protectors has been considered as an efficient technique for tillage farming of different species, mainly native ones. Based on the importance of the species, Peltophorum dubium for revegetation of degraded areas, this study evaluated the emergence, survival and initial development of P. dubium seedlings under the influence of physical protectors with different filters. Thus, the following treatments were adopted: absence of physical protector (APP), transparent physical protector (TPP), transparent physical protector + blue cellophane (BPP) and transparent physical protector + red cellophane (RPP). The evaluated characteristics were: emergence velocity index (EVI), seedling survival and emergence percentage, plant height, leaf area and root collar diameter. All of these physical protectors increased the mean values of EVI and survival. In conclusion, the emergence speed and initial development of P. dubium (Spreng.) seedlings grown in the interior of physical protectors, independent on the filters, presented positive results. The reduction on the light intensity interferes positively in the initial growth of these plants

Production of Lettuce Seedlings with Association of Diazotrophic Bacteria and Humic Acids

The objective of this work was to verify the responses in agronomic and physiological characters of lettuce seedlings when submitted to different doses of humic acids and the presence or absence of inoculation of the bacterium Azospirillum brasilense. The experiment was carried out at the Protected Cultivation Station and Biological Control Teacher Mário César Lopes, belonging to the Experimental Stations Nucleus of the State University of the West of Paraná. The experimental design was a randomized block design, in a 5 × 2 factorial scheme, with four repetitions, totaling 40 plots. The first factor consisted of five solutions containing humic acid (100%, 75%, 50%, 25% and 0%) and the second factor was the presence or absence of the diazotrophic bacterium Azospirillum brasilense obtained by commercial product. Germination tests were carried out in addition to the determination of agronomic characters such as the number of fully expanded leaves, plant height, stem diameter, main root length, shoot dry mass, root dry mass, total dry mass, and Dickson quality index. The association of diazotrophic bacteria and humic acids did not influence the emergency rate, mean emergence time, mean speed of emergency, emergence speed index, plant height, and root length of lettuce seedlings. The dilutions of humic acids, regardless of inoculation with bacteria diazotrophic favored the development of the number of leaves, stem diameter and Dickson quality index. Inoculation of lettuce seeds with diazotrophic bacteria associated with the addition of humic acids, favored the development of the dry mass of root and total dry matter