Curtobacterium flaccumfaciens pv. Flaccumfaciens detection in bean seeds using a semi-selective culture medium

The bacterial wilt caused by Curtobacterium flaccumfaciens pv. flaccumfaciens is currently considered one of the most important bacterial bean disease in Brazil. One of the most effective control methods against this disease is the use of healthy seeds. However, no methods are known that could be routinely used to detect this bacterium in bean seeds under Brazilian condition. The aim of this work was to evaluate qualitative and quantitative detection methods for Curtobacterium flaccumfaciens pv. flaccumfaciens in naturally-infected bean seeds, and the detection of this pathogen in thirty bean seed samples, by sowing onto a semi- selective culture medium the leachate obtained from soaked bean seeds. Both the qualitative and quantitative methods were effective for detecting the presence of the bacteria in the seeds samples analysed. The qualitative method proved more practical for rotine use; of the thirty bean seed samples analyzed by this method, fifty percent were infected with Curtobacterium flaccumfaciens pv. flaccumfaciens.

Effect of fruit maturation stage and light on seed germination of Aiphanes aculeata

Despite their spiny nature, Aiphanes palms are popular as ornamentals. They can be grown in various soil conditions, but achieve fast, luxuriant growth in sheltered positions with plenty of water. Shaded conditions are the best when plants are young. The objective of this study was to evaluate the effect of fruit maturation stage and light on the germination of seeds of A. aculeata. Fruits were collected at three different maturation stages: (1) yellow, (2) red, (3) collected on the ground without the fleshy mesocarp (removed by birds and insects). The fleshy mesocarp was also removed in treatments (1) and (2). All fruits were then treated with thiram and 25 seeds per plot were seeded in trays full of sand. The treatments (2) and (3) were subdivided in two other treatments: (a) 12 h photoperiod, (b) continuous darkness. The temperature was maintained at 30 degrees C. Seed germination began 34 days after sowing. After 160 days, the final germination percentage was (1) 54,67%, (2a) 61,33%, (2b) 65,33%, (3a) 38,00% and (3b) 45,33%. The best treatment was (2) independently of the light conditions.

Épocas de plantio de milho em função das deficiências hídricas no solo em Cambará-PR

The aim of this study was to try the forecast of corn (Zea mays L.) sowing dates, the understanding of the quantitative effect of water deficits on that crop and crop yield decrease on a basis of a climatic model of water deficit forecast. This model was applied at Cambara (lat. 23 degrees 00'S, long. 50 circle 02'WGr, altitude 450 m), PR, Brazil. The model estimates yield decrease, in relation to potential values, as a function of the sowing dates which determine flowering and grain filling dates, highly critical times in relation to water deficit. The estimates were done from expected values of water deficit, at the 80% probability level and accumulated degrees-days, using several climatological data. Results show that the first ten days of November are the best corn sowing date under dry or irrigated conditions. Under these same conditions, the worst time showed to be August. Estimates of total needs of supplementar irrigation get values of 126 e 226 mm, respectively to the corn sowed at the first ten days of November and August.

Effect of pre-imbibition and osmoconditioning on seed-germination in Phaseolus-vulgaris L. under water-stress

The effect of osmoconditioning and controlled water sowing was analysed in seeds of Phaseolus vulgaris L. cv. carioca on germination under water stress conditions. The pre-sowing in water at low temperature to limit germination resulted in the increase in the tolerance to water stress. The osmoconditioning with PEG for 48 hours increased the tolerance of bean seeds to water stress of -0.51MPa. The osmoconditioning or controlled water sowing can be used as a practice to increase the tolerance of bean seeds to water stress before planting in the field.

Effects of plant regulators and potassium nitrate, on Rangpur lime seeds germination

The effects of plant regulators and potassium nitrate were studied on 'Rangpur' lime (Citrus limonia Osbeck) seeds germination. The seeds were removed from ripe fruits, washed, dried and stored at 4 - 5 degrees C, and treated for 24 hours before sowing and the treatments were: KNO3 0,1% and 0,2%; GA(3) 50 ppm, 100 ppm and 250 ppm; GA(4+7)+phenylmethylaminepurine 100 ppm; phenylmethylaminepurine 20 ppm and control. The germination was evaluated begining 13 days after sowing. Best results were obtained with KNO3 0,2%, which proved most beneficial in enhancing percentage and germination rate.

Doses de inoculante e nitrogênio na semeadura da soja em área de primeiro cultivo

The inoculation of soybean crop with Bradyrhizobium bacteria is a widespread practice, due to excellent results achieved in productivity, however, some doubt still arise in relation the need of application of mineral nitrogen at sowing. In that mean, this work aimed to evaluate the response of the doses at inoculant and mineral nitrogen in the sowing of crop soybean in area of first cultivation. The experiments were carried in the experimental field of the University of the Estate of Mato Grosso, Campus of Alta Floresta - MT, Brazil, in the growing seasons of 2006/2007 and 2007/2008. The experimental design was randomized blocks, in a factorial escheme 2 x 4, with four replications. The factors consisted in the inoculation of seeds with Bradyrhizobium japonicum *(3 e 6 mL kg(-1) of seeds), and nitrogen fertilizer at sowing *(0, 10, 20 e 40 kg ha(-1)). The following variables were evaluated: plant height, insertion height of first pod, number of pod per plant, number of grain per pod, mass of 100 grain and grain productivity. In the two growing seasons there was no significant difference for doses of inoculants applied in first year of cultivation with soybean. To nitrogen application at sowing of soybean crop there was quadratic effect to plant height and of insertion height of first pod and growing linear to number of pod per plant in the second year of cultivation, however, without significant increase the productivity.

Efeito da porosidade do substrato casca de pínus no desenvolvimento de mudas de grumixameira

Aiming to evaluate the effect of the pine bark substrate porosity on the development of the grumixama plant (Eugenia brasiliensis Lam.), an experiment was conducted in a greenhouse of the Escola Superior de Agricultura "Luiz de Queiroz"/USP, Piracicaba, Brazil. The treatments were: 100% ground pine bark without separation of particles; 100% pine bark of <= 0,1mm; 75% pine bark of <= 0,1mm + 25% between 0,1-4,0 mm; 50% of pine bark <= 0,1mm + 50% between 0,1-4,0 mm; 25% pine bark of <= 0,1mm + 75% between 0,1-4,0 mm and 100% pine bark of 0,1-4,0 mm. The evaluations (stem diameter, length and average dry weight of seedlings) were performed on the 90, 120 and 150(th) days after sowing. The low water absorption in the early stages and the low aeration of the roots promoted by the substrate, affect the development of the grumixama plant seedlings, that grow best when the total pore space of the substrate is less than 90% (v / v).

Effects of biofertilizer rates on the structural, morphogenetic and productive characteristics of Piata grass

The objective of this study was to investigate the influence of different levels of biofertilizers from cattle and swine manure on the structural, morphogenetic and productive characteristics of Brachiaria brizantha cv. Piata. The experiment was arranged in a completely randomized factorial design with split plots. The plots were defined by eight treatments: two biofertilizers (cattle and swine), four levels (0, 100, 200 and 300 kg N.ha(-1)) and subplots by four different cutting periods. The cutting for plant uniformity was performed at 45 days after sowing at 15 cm above the soil surface. The biofertilizeres were applied in a single level, after the cutting of plants, in rates of 0, 0.23 and 0.19, 0.45 and 0.38, 0.68 and 0.57 liters pot(-1) for the biofertilizers from cattle and swine manure, respectively. These rates were also equivalent to levels of 0, 100, 200 and 300 kg N.ha(-1). There was no significant difference between the types of biofertilizers as there was no interaction between them and the different levels, hence both biofertilizers could be applied without any loss of nutrient intake by the plants used in this experiment. There was a significant difference between the production of green and dry matter, the leaf appearance rate, phyllochron, leaf and pseudostem elongation rates, number of green leaves, final leaf length, number and weight of tillers, according to the increase of nitrogen rates, following linear prediction model. Effect of the cutting periods was also observed, once the plants harvested during the summer presented greater performance of structural and morphogenetic characteristics.

Vermiculita como substrato para o teste de germinação de sementes de barbatimão

The objective of this research was to evaluate the use of vermiculite as a substrate for the germination test of 'barbatimao' seeds and to establish what would be the best granulometry and the best moisture intensity to germinate 'barbatimao' seeds. Four replications of 50 seeds were previously scarified with H(2)SO(4) for 60 minutes. Afterwards, the following germination substrates were evaluated: paper rolls moistened with water equivalent to 2.5 times the weight of the dry paper (control); micron, super thin, thin and average sized vermiculite moistened with 0.5, 1.0, 1.5 and 2.0 times the weight of the dry paper. The germination temperature was 30 C. The percentage of normal seedlings was obtained seven days after sowing (first count) and, then, weekly (up to 28 days). Average time and relative distribution of germination were calculated. It was concluded that the germination of 'barbatimao' seeds can be carried out with either fine vermiculite moistened with water equivalent to 2.0 times the weight of the dry paper or average sized substrate moistened with water equivalent to 0.5 to 2.0 times the weight of dry paper. These treatments resulted in higher and faster germination (21 days), similarly to the paper roll method.

Weed-soybean interference studies in Brazil

Recently, a notable shift in weed patterns has occurred in some soybean growing regions, as a result of tillage system change and herbicide use. The weed communities are very diversified and strongly interfere with soybean growth and productivity, especially when the shading of superior leaves of the canopy occurs. Some changes to certain agricultural practices, such as cultivars, row spacing and sowing density, were studied and were considered suitable for the establishment of an integrated weed management system under Brazilian conditions. -from Author

Avaliação da silagem de milho das variedades granífera e forrageira no desempenho de bovinos das raças nelore e cachim em regime de confinamento

The experiment was carried out to evaluate corn grain and corn forage varieties productivity and nutritive value for silage comparing to the performance of Nellore and Canchim cattle in a feedlot. A completely randomized design was used with a 2 x 2 factorial arrangement based on two breeds (Nellore and Canchim) and two corn varieties (grain and forage). Harvest was made after 120 days sowing, when plants showed more than 2/3 of dry. leaves and grains were in dough stage. The silage was stored in a 400 tons. The experimental diet consisted of grain and forage corn silage, 7,2 liters of liquid yeast (1,5 kg of dry yeast/ head/day) and 1,1 kg of ground corn (1,0 kg of dry matter/head/day). The experiment duration was 110 days, with a 20 days adaptation period and 90 days for data collection. Animals were regularly weighted every 28 days. It was concluded that corn grain was more appropriate for silage than corn forage, and in the same stage it showed a higher dry matter content and a 41.3% higher grain yield, promoting higher weight gain and better feed/gain ratio in the feedlot beef cattle.

Inhibitory effects of jackbean (Canavalia ensiformis L.) leaf residues on germination and vigour of crops and weeds

The effects of jackbean leaf residues incorporated in the soil on germination and seedlings growth of cucumber, radish and some weeds was examined. Trials were carried out under greenhouse conditions to (a) determine the amount of incorporated residue that is inhibitory to two test plants, (b) to determine if decomposition time changes the inhibitory levels of jackbean residues on test plants and (c) to determine the amount of residue that is inhibitory to the weed species. Jackbean leaf residues incorporated in soil at concentration of 2% or higher and allowed to decompose for a period of 0 to 2 weeks before sowing, reduced the initial growth of cucumber and radish and at different concentrations, reduced germination and growth of three weed species. These results suggest the presence of allelopathic components in Jackbean leaves that could affect seed germination and seedling development.

An alternative field method for screening soybean genotypes for resistance to Heterodera glycines

The soybean cyst nematode (Heterodera glycines) has become an increasingly severe problem in soybean production areas in Brazil. The development and use of resistant cultivars is the most efficient method of minimizing losses due to this pathogen. Our objective was to test the efficiency of an alternative method for screening soybean genotypes for resistance to H. glycines in field plots. The alternative method was compared to the standard method of sowing the test genotypes in fields found to be infested during the previous crop season. In the alternative method, the test genotypes are sown in the furrow following the uprooting of 45-day-old infected plants. The alternative method resulted in twice the cyst population and fewer escapes, and more consistent results than the standard method. The major advantage of the alternative method is that it permits screening in a more homogeneous distribution of H. glycines in the soil.

Seed production of species belonging to the palm collection of the FCAV-UNESP, Jaboticabal, state of Sao Paulo, Brazil

The seed production of fully developed specimens belonging to the palm collection of the Experimental Nursery of the FCAV-UNESP was observed. This paper gives information useful for nursery growers: average fruit weight, seed germination, procedures for sowing, time of fruit harvest and possibility of seed storage. At the nursery, the time until the first seedling emerged has varied, according to the species, from one to more than ten months. For better germination, fruits must be collected when completely mature; the fleshy mesocarp must be removed before sowing. Seed storage for a few months has been possible for some species, by removing the fleshy mesocarp, drying the seeds in shade, treating them with a fungicide, packing them in plastic bags and maintaining the seed lots at 20°C. These results agree with reports about some other species and general recommendations of the related literature.

Effect of different plot coverings on emergence and early development of seven palm species (arecaceae)

The Arecaceae family comprises plants with economical importance in many Brazilian regions, for agricultural exploration or for landscaping. In great portion, species of this family present low germination velocity and percentage. This work meant to evaluate the germination and early development of seven palm species (Archontophoenix alexandrae H. Wendl. et Drude, Copernicia prunifera (Miller) H.E. Moore, Latania commersonii Gmel., Livistona chinensis R. Br., Syagrus campos-portoana Bondar, Syagrus coronata (Mart.) Beccari, Syagrus picrophylla Barb. Rod.), submitted to three kinds of seed bed plot coverings. Three 10 x 2 m seedbeds were built and filled with a mixture of sand, soil and chicken manure (1:3:0.5 proportion), where two lines were sown with each specie. On top of each seedbed, plastic covering and fifty percent screen were set allowing one third of the seedbed to full sunlight exposure. Seedbeds were irrigated by dripping system. All species had the same germination rate, regardless of the covering, by the end of the experiment (146 days after sowing), eventhough, A. alexandrae under plastic covering conditions, L. commersonii at full sunlight exposure and Syagrus campos-portoana under fifty percent shade, had reached that percentage around 51 days after sowing. The remaining species reached the greatest germination percentage earlier with some of the coverings, rather than at full sunlight exposure. For the studied conditions, covering type had no effect in leaf length and width. For leaf number, there was interaction between species x covering type for Livistona chinensis and Copernicia prunifera.