Effect of salt stress on polyamine metabolism in bean cell culture

The adaptive capacity of bean (Phaseolus vulgaris L.) calluses (cultivars IAC-carioca, JALO EEP-558, BAT-93 and IAPAR-14) to salt stress (0-80 mM) was verified to determine the existence of biochemical markers such as organic and inorganic compounds, and metabolism of polyamines. The results obtained demonstrate that salt (NaCl) interfered with all the parameters analyzed and its intensity ranged due to the salt concentration and the cultivars used.

Interferência e estudo fitossociológico da comunidade infestante na cultura da beterraba transplantada

The objective of this research was to Study the phytosociological and critical interference periods of weed communities Oil transplanted beets. The treatments consisted of increasing weekly weedy/weed-free periods, starting it the second week after seedling transplanting. The weed community was evaluated based oil the number of individuals and their corresponding accumulated dry mass, for each weed population and evaluated period. The beets were harvested 91 days after transplanting, followed by evaluation of the cross-sectional diameter and marketable yield. The weed communities were composed mainly of Amaranthus viridis, Coronopus didymus, Galinsoga parviflora, Nicandra physaloides and Solanum americanum, and the populations were very similar. The period before weed interference and the total period of weed interference prevention were 51 and 35 days after transplanting, respectively. The beet yield in the weed-free treatment was 44.92 t ha(-1) and the reduction from weed interference was more than 70%.

Pathogenicity of Curtobacterium flaccumfaciens pv. flaccumfaciens to several plant species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Balanço de radiação em cultivos de feijão-vagem com e sem cobertura de polietileno

The radiation budget in agricultural crops is very important on the microclimate characterization, on the water losses determination and on dry matter accumulation of vegetation. This work describes the radiation budget determination in a green beans crop (Phaseolus vulgaris L.), in Botucatu, SP, Brazil (22° 54′S; 48° 27′W; 850 m), under two different conditions: the normal field culture and in a polyethylene greenhouse. The densities of fluxes of radiation were used to construct diurnal curves of the components of global radiation (Rg), reflected radiation (Rr), net radiation (Rn).The arithmetic's relations allowed to obtain the components net short-waves (Rc) and net long-waves (Rl). The analysis of these components related to the leaf area index (LAI) in many phenological phases of the culture showed Rg distributed in 68%, 85%, 17% and 66%, 76%, 10% to Rn, Rc and Rl in the internal and external ambients in a polyethylene greenhouse, respectively.

Produção de matéria seca de feijoeiros submetidos a diferentes níveis de magnésio em solução nutritiva

The effect of Mg levels in nutrient solution upon root, stem, leaf, fruit and total dry matter production of common bean (Phaseolus vulgaris L. cv. Carioca) was studied. Bean plants were grown in Hoagland & Arnon n. 2 solution modified to obtain 2.4, 24.3, 48.6, 72.9 and 97.2 ppm of Mg. The experimental design was a split-plot factorial replicated three times with five Mg levels and five samplings which were done fortnightly. Results were compared with those observed in plants submitted to a nutrient solution with 48.6 ppm of Mg concentration, considered the ideal Mg content. Only a mild prejudicial effect was observed with Mg excessive levels. Stem, leaves and total dry matter were higher when 2.4 ppm were used, suggesting this level as the concentration chosen for the culture of common bean.

Magnésio, cálcio e potássio em sementes e cotilédones de feijoeiros e sua transferência para plantas jovens

Magnesium, calcium and potassium concentration in the seeds and cotyledons of Phaseolus vulgaris L. cv. Carioca and its translocation from the cotyledons to the plant were evaluated. For such an evaluation plants were cultivated during the cotyledons phase and were irrigated with deionized water. Three samplings of cotyledons completely randomized were done and replicated ten times, before its senescence and fall, at 8, 12 and 15 days after the germination of the seeds. Fresh and dry matter of the cotyledons and its magnesium, calcium and potassium content were determinated in every sample. These parameters were also determined in the seeds from the same lot. Potassium concentration was higher than magnesium in both seeds and cotyledons. Calcium presented the lesser concentration both in seeds and cotyledons. These minerals were translocated from the seeds and cotyledons to the young plants. Eight days after germination 59% of the magnesium, 78% of the calcium and 71% of the potassium were translocated to the plants. Fifteen days after germination these percentages were respectivaley 73%, 82% and 91%. Thus, magnesium was the less and potassium was the most translocated mineral at the end of the study.

Virulência de isolados Dexanthomonas campestris pv. Phaseoli (Smith) dye em feijoeiro

The objective of this research was to evaluate de reaction of leaves and pods of five cultivars of bean (Phaseolus vulgaris L.) plants to twenty strains of Xanthomonas campestris pv. phaseoli. The strains were inoculated onto leaves in a greenhouse, and onto pods in a growth chamber. The results obtained were analyzed and the strains classified into three groups: low, medium, and high virulence. Most of the strains showed high virulence on leaves of Carioca and Rio Negro cultivars, as opposed to only low to medium virulence on leaves of IAPAR 14, IAPAR 16, and G. N. Nebraska # 1 sel. 27 cultivars. There were, however, individual strains powerful enough to overcome the leaf resistance of IAPAR 14, IAPAR 16, and G. N. Nebraska # 1 sel. 27. With regard to pods, most strains showed high virulence on all bean cultivars, with exception of IAPAR 14 where virulence was at medium level. A correlation between leaf and pod symptoms was found to exist in Carioca, Rio Negro, and IAPAR 14 cultivars. No such correlation was observed in IAPAR 16 and G. N. Nebraska # 1 sel. 27. Comparing strains producing melanine in vitro with those not producing this pigment, no difference was observed with regard to virulence.

Reação de genótipos de feijoeiro comum a Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli

The behavior of dry bean (Phaseolus vulgaris L.) genotypes PI 150414, PI 163117, PI 175829 white, PI 175829 purple, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40, and IAC Carioca inoculated with Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli was evaluated under greenhouse condition. The bean genotypes Xan 160, PI 150414, A 417, PI 175829 purple, Xan 161, A 420, PI 163117, and PI 175829 white were resistant to F. oxysporum f. sp. phaseoli, and only PI 155829 white had a good level of resistance to M. phaseolina. All bean genotypes were susceptible to Feij-4 strain, and only Xan 161 had some level of leaf resistance to Feij-41 strain of X. campestris pv. phaseoli.

Analysis of the Priestley-Taylor α parameter for a bean crop

This work deals with the Priestley-Taylor model for evapotranspiration in different grown stages of a bean crop. Priestley and Taylor derived a practical formulation for energy partitioning between the sensible and latent heat fluxes through the α parameter. Bowen ratio energy balance (BREB) was carried out for daily sensible and latent heat flux estimations in three different crop stages. Mean daily values of Priestley-Taylor α parameter were determined for eleven days during the crop cycle. Diurnal variation patterns of α are presented for the growing, flowering and graining periods. The mean values of 1.13 ± 0.33, 1.26 ± 0.74, 1.22 ± 0.55 were obtained for a day in the growing, in the flowering and for graining periods, respectively. Eleven days values of α are shown and gave a mean value of 1.23 ± 0.10 which agree on the reported literature.

Preferência alimentar de adultos de Diabrotica speciosa (Ger.) (Coleoptera: Chrysomelidae) por genótipos de feijoeiro

Tests were carried out to evaluate resistance of common bean (Phaseolus vulgaris L.) to Diabrotica speciosa (Ger.) with the genotypes Goiano Precoce, Jalo Precoce, PR 95105146, PR 95105142 (Andean domestication center, AN), Emgopa 201 Ouro and IAPAR 57 (Middle American domestication center, MA). The experiments were conducted in 1998 and 1999, at the farm of UNESP-FCAV, Jaboticabal, SP, Brazil. The genotypes were planted in pots and 20 day-old leaflets were collected and foliar disks were cut of for the test. Two trials, a no-choice test and a free-choice test, were set up in BOD. In free-choice test, two disks of each genotype were kept in a 140-mm-diameter petri dish (total of 12 disks), where 12 adults were confined. In no-choice test, two disks of one genotype and two insects were placed in a 60-mm-diameter petri dish. A field experiment was conducted when 400 adults of D. speciosa were released. Fifteen leaflets per plot were collected 30 days after planting and the leaf area consumption was evaluated. A no-choice experiment was carried out with 20 day-old genotypes protected in individual cages and infested by 10 adults, for 72h. The MA genotypes were the most preferred on feeding tests conducted at BOD, field and individual cages, while the AN genotypes were less eaten.

Efeitos de sistemas de preparo do solo no potencial matricial de um Latossolo Vermelho (Oxisol)

The present work aimed to investigate which was the soil tillage system that better fits for conditions of intensive agriculture, on the region of Selviria-MS. The main objective of this paper was to study the conservation and availability of water in the soil profile. In order to evaluate the soil matric potential in field conditions, readings were accomplished, using tensiometers with a mercury gauger. Matric potential was measured at 0.10 m depth, during the vegetative period of Triticum aestivum L. and at four depths 0.10; 0.20; 0.30 e 0.40 m during the vegetative period of Phaseolus vulgaris L. The study areas were located in the municipal district of Selviria, MS, Brazil. The used experimental set-up was entirely random designed, with treatments disposed in strips; three treatments and four repetitions were used. In the different treatments, soil matric potential was determined. Result allow to conclude that the water matric potential was highest for no-tillage and minimum tillage; however, it was also shown that these two tillage systems, allowed to conserve more water in the soil, when compared to the conventional tillage. In the last cycle of the Phaseolus vulgaris L. crop, no-tillage presented smaller storage of water in the soil, compared to the minimum tillage.

Biologia comparada de Trialeurodes vaporariorum (West.) (Hemiptera - Homoptera: Aleyrodidae) em soja e cinco cultivares de feijão

With the development of greenhouse grown crops, the whitefly Trialeurodes vaporariorum (West.) has become an important pest. Aiming at verifying the effect of host on the development of this species, the biology of the whitefly was studied on bean (Phaseolus vulgaris L.) cultivars IAC-Carioca Pyatã, IAPAR-57, Jalo Precoce, IAC-Bico de Ouro, IAC-Maravilha and on soybean (Glycine max L.) cultivar Cristalina. The study was conducted at the Laboratório de Entomologia Agrícola - FCA-UNESP, at 25 ± 3°C temperature, 80 ± 10% RH and 14h photophase. The biological parameters assessed were duration, viability and number of nymphal instars; male and female longevity, oviposition period, number of eggs per female and sex ratio; egg viability and incubation period and the life cycle duration. Based on data obtained, fertility life tables were constructed to allow a comparative analysis of the effect of cultivars on the biological development and consequent population growth of this species. The bean cultivars IAC-Maravilha and Jalo Precoce negatively influenced T. vaporariorum development, whereas, the other bean cultivars studied, as well as the soybean cultivar Cristalina, provided good conditions for development of this pest.

Growth and yield analysis in different methods of beet (Cv. 'tall top early wonder') plantation

This objective of this study was to evaluate the effects of different methods of red beet seedling production and direct sowing on the development of the plant in field conditions. 'Tall Top Early Wonder' was used as the cultivar. The experimental design was a randomized blocks with 4 replications of each treatment: T1 - seedling produced in trays of 288 cells; T2 - 200 cells; T3 - 128 cells; T4 - 128 cells; T5 - direct sowing and T6 - bare-root seedling. The seedlings produced in trays and bare root seedlings were transplanted in the field 28 DAS with spacing of 0.20 x 0.10m. The mean height of plants, leaf area, leaf dry matter, petiole dry matter, shoot dry matter, root dry matter, relationship between shoot dry matter and root dry matter, absolute growth rate, relative growth rate, net assimilation rate, leaf area ratio and specific leaf area were determined. Storage root fresh matter and mean storage root diameter were determined starting from 77 DAS. Initial growth of the plants were superior for the direct sowing, resulting in smaller RGR and NAR than the other treatments. Independent of the production method, an increase of the cycle of the crop was verified. T6 had larger delay in the initial development. There was no difference for productivity. Method T1, had less expenses with respect to substrate and space in the vegetation home, without reduction in production.

Efeitos de níveis de cobertura do solo sobre a produtividade e crescimento do feijoeiro irrigado, em sistema de plantio direto

The objective of this research was to study the effects of five different treatments of grass (Brachiaria decumbens) straw mulch on common beans (Phaseolus vulgaris L.): 0% (0 t.ha-1), 25% (2,25 t.ha-1), 50% (4,5 t.ha-1), 75% (6,75 t. ha-1) and 100% (9,0 t/ha) designed by randomized blocks, with four replicates. The irrigation was applied when minimum soil water potential were reached about - 30kPa. The water management based on tensiometers and soil water characteristic curve. A microsprinkler irrigation system was used. The experiment was set up at the Experimental Station of Embrapa Rice and Bean (Empresa Brasileira de Pesquisa Agropecuária Arroz e Feijão) at Santo Antonio de Goiás, Brazil, in a Dark - Red Latosol soil. The results showed: the bean yield and his components were not affected by treatments, except grain number/pod,. The mulch increased the water use efficiency and, consequently, decreased the number of irrigations when the mulch reached more than 50% straw mulch. The treatment with 100% of mulching presented the largest leaf area index and dry matter accumulation was not affected by mulching.

Efeito de métodos de determinação de parâmetros para o controle da irrigação na eficência do uso da água do feijoeiro, sob três diferentes lâminas de água no solo

The objective of this research was to study three methods of parameter determination for irrigation control under different tensions in common bean (Phaseolus vulgaris L.). The treatments were a combination of three methods of parameter determination for irrigation control (tensiometer, water retention curve, USWB Class A pan) with three soil water tensions (1:-30 kPa; 2:-60, kPa both for the whole plant cycle; 3:-60 kPa for the vegetative phase and -30 kPa for the reproductive phase). The experimental design was randomized blocks, factorial 32 with three replicates. Although no significant effect on water use efficiency was found, a tendency for increasing water use efficiency in treatments with tensions of -60 kPa at the vegetative phase and -30 kPa at the reproductive phase was observed in all methods of parameter determination for irrigation control. Water was saved as less irrigation was applied during the vegetative phase and more irrigation at the reproductive phase. No precipitation was observed from June to September 1995, leading to a high yield and therefore to a higher water use efficiency.