Performance of cucumber hybrids cultivated in coconut fiber and soil

The objective of this work was to evaluate the performance of three Japanese group cucumber hybrids, which were cultivated in two cultivation systems. The experiment was designed in a split-plot randomized block design with two cultivation systems (coconut fiber and soil) for commercial Japanese cucumber hybrids ('Tsuyataro', 'Yoshinari' and 'Nankyoku'). After harvesting the cucumbers, we evaluated the number of marketable fruits per plant, the average fruit length, the mean fruit diameter, the bottom fruit diameter, the marketable production of fruits per plant and the marketable yield per hectare. There were significant interactions between the cultivation system and the hybrid, as indicated by the number of marketable fruits. The Nankyoku hybrid had the highest average (14.54 fruits pl(-1)), although it did not differ from the Yoshinari hybrid when grown in coconut fiber. In soil culture, the Yoshinari hybrid had the highest average number of fruits per plant (10.12 fruits pl(-1)) and did not differ from the Tsuyataro hybrid. Cultivation in coconut fiber provided better results for production traits and plant productivity. 'Yoshinari' and 'Nankyoku' were the most productive hybrids. Based on the cucumber cultivation results from a protected environment, the cultivation of hybrid Japanese cucumbers and Yoshinari and Nankyoku hybrids in coconut fiber is recommended.

Soil physical and microbiological attributes cultivated with the common bean under two management systems

Agricultural management systems can alter the physical and biological soil quality, interfering with crop development. The objective of this study was to evaluate the physical and microbiological attributes of a Red Latosol, and its relationship to the biometric parameters of the common bean (Phaseolus vulgaris), irrigated and grown under two management systems (conventional tillage and direct seeding), in Campinas in the state of Sao Paulo, Brazil. The experimental design was of randomised blocks, with a split-plot arrangement for the management system and soil depth, analysed during the 2006/7 and 2007/8 harvest seasons, with 4 replications. The soil physical and microbiological attributes were evaluated at depths of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m. The following were determined for the crop: density, number of pods per plant, number of beans per pod, thousand seed weight, total weight of the shoots and harvest index. Direct seeding resulted in a lower soil physical quality at a depth of 0.00-0.05 m compared to conventional tillage, while the opposite occurred at a depth of 0.05-0.10 m. The direct seeding showed higher soil biological quality, mainly indicated by the microbial biomass nitrogen, basal respiration and metabolic quotient. The biometric parameters in the bean were higher under the direct seeding compared to conventional tillage.

Genetic diversity strategy for the management and use of rubber genetic resources: more than 1,000 wild and cultivated accessions in a 100-genotype core collection

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

Biochemical changes during the induction of mineral stress in plants of bell pepper cultivated in fertigation system

The greenhouse production associated with the fertigation management, have established in Brazil as economical alternative for several horticultural species. With this strategy this study had as aim to evaluate possible impacts in the metabolism of plants of bell pepper (Capsicum annuum L.; cv Elisa) in response to the increase of mineral concentration in the soil. During the experiments, the some nutrient concentrations were altered, to obtain high values of electric conductivity (EC) in the soil solution. The EC values commonly observed in the traditional fertigation system were adopted, as control. It was also verified the possibility of reduction of the mineral stress impact by the application of organic matter in the soil. Parameters of the antioxidative response system, as the superoxide dismutase (SOD) and catalase enzyme activities besides the proline content were evaluated to measure the extension of the saline stress and their effects on the plants. The increase of EC of the soil induced to the increase of the proline concentration and the SOD activity. Unexpectedly, it was verified that the saline stress inhibited the activity of the enzyme catalase. It was also concluded that the monitoring of EC of the soil is an indispensable tool to reach success in the fertigation system and that the study of the activity of the enzymes of the antioxidative response system, and the proline contents can be assumed as indicators in of the levels of stress in bell pepper plants (Capsicum annuum L.; cv Elisa).

Variação sazonal da concentração de nutrientes em folhas de bananeiras, no Vale do Ribeira-SP

The Vale do Ribeira, SP, main agricultural activity is the banana crop, which accounts for most of this fruit production in the State of São Paulo. The nutritional balance of the plant is one of the most important factors for the banana plant can complete the cycle and achieve high productivity. Aiming to evaluate the seasonal variation of leaf nutrient concentration in banana plants in Vale do Ribeira-SP, we used the results of 252 chemical analyses of plant tissue, collected from August 2009 to September 2010, in the 18 representative properties for the region, ten cultivated with subgroup Cavendish banana plant and eight of subgroup Prata banana plant. The largest variation between the macronutrient occurred for K and S, and among the micronutrients, especially for Fe and B. In some dates of evaluation, there was a higher leaf concentration of P, K, Ca and Zn, in subgroup Cavendish banana plants, while the subgroup Prata banana plants showed higher leaf concentration, especially of Mn, B and N. Climatic conditions, especially rain, influenced the leaf nutrient content, especially for K, N, S, B and Fe.

Eutrofização e qualidade da água na piscicultura: consequências e recomendações

The eutrophication (cultural or anthropogenic) is induced by man and can have different origins, such as domestic sewage, industrial and agricultural activities, including the effluent still breeding systems of aquatic organisms. The expansion of aquaculture, with production of biomass and increase of nutrients in water may cause acceleration of productivity of algae, changing the ecology of aquatic systems. In addition, these waste water may present a risk to health through the transfer of pathogens from manure, plant residues, composted material, among others that are major sources of organic waste in some farming systems. Depending on the trophic level of fish ponds, which are dynamic environments, different planktonic species with short reproductive cycle and adapted to the changes contained in these systems can appear in high abundance. Water quality in the systems for raising fish is related to several factors, such as water source, management (liming, fertilizing, cleaning), cultivated species and quantity and composition of exogenous food. In order to minimize environmental impacts, there are techniques to improve the quality of water in fish farming systems and thus satisfactory answers can be obtained through the application of management practices. This paper aims to review the subject that deals with changes in water quality resulting from the activity of freshwater fish culture in Brazil. Search also recommend techniques of good management practices to minimize the impact generated by the activity.

Trichodina colisae (Ciliophora: Trichodinidae): new parasite records for two freshwater fish species farmed in Brazil

Tricodinídeos são protozoários ciliados móveis com ampla distribuição mundial; são considerados um dos agentes parasitários que mais acometem peixes cultivados. No Brasil, a maioria dos tricodinídeos que parasitam importantes espécies de peixes cultivados são desconhecidos, o que requer mais estudos taxonômicos com esse grupo de parasitos. Este estudo caracteriza morfologicamente Trichodina colisae Asmat & Sultana, 2005 de pacu (Piaractus mesopotamicus) e do híbrido patinga (P. mesopotamicus × P. brachypomus) cultivados, respectivamente, no Centro-Oeste e Sudeste do Brasil. Foram feitas montagens a fresco do raspado de muco da pele, nadadeiras e brânquias, fixados com metanol e, posteriormente, impregnados com nitrato de prata e coradas com Giemsa para avaliação em microscopia óptica. O presente estudo relata não só a segunda ocorrência de T. colisae no mundo, mas também a primeira ocorrência na América do Sul.

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

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

Nesting biology of the fungus growing ants Mycetarotes Emery (Attini, Formicidae)

Fungus-growing ants of the genus Mycetarotes are among the least studied in the tribe Attini. This report documents nest architecture and worker population numbers for 19 nests of M. parallelus and 5 nests of M. acutus, including the first such report for M. acutus. This new information is integrated with the scant biological information reported on Mycetarotes to date. The resulting picture of Mycetarotes life history, as well as the relative ease with which large numbers of nests can be collected and observed in the field, suggest that Mycetarotes (particularly M. parallelus) is an ideal model system for the study of coevolution of lower-attine ants and their cultivated fungi.

Triterpene benzoates from the bark of Picramnia teapensis (Simaroubaceae)

Two new benzoic acid esters of triterpene alcohols [lup-20 (29)-en-28-oic acid 3 alpha, 7 beta -dibenzoate and 3 alpha -hydroxy-lup-20(29)-en-28-ic acid 7 beta -benzoate] were isolated from the stem bark of Picramnia teapensis Tul. The structures of these compounds were established on the basis of spectral analyses. Other known compounds, beta -sitosterol, estigmasterol, lupeol and epilupeol, were identified in mixture by GC-MS. The triterpene esters have not shown in-vitro inhibitory effect on the growth of Leucoagaricus gongylophorus (Fisher), referred also as Leucocoprinus gongylophorus (Heim), syn Rozites gongylophora (Moller), the symbiotic fungus cultivated by the leaf-cutting ant Atta sexdens L.

Activity of sesame leaf extracts against the symbiotic fungus of Atta sexdens L.

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

Allelopathic plants. 7. Sunflower (Helianthus annuus L.)

Sunflower is an annual dicotyledonous plant, herbaceous, erect and native of North America. It is thermo- and photo-insensitive, hence, can be grown round the year in sub-tropical and tropical countries. Only two spp. H. annuus and H. tuberosum are cultivated for food, remaining spp. are ornamentals, weeds and wild plants. However, H. annuus is allelopathic and inhibit the growth and development of other plants thus reducing their productivity. Much information is available about the allelopathic effects of sunflower crop on following crops in crop rotations. Although it is harmful to all crops, but, is less harmful to crops of Graminae family than other families. It seems that the harmful effects of sunflower in crop rotations are due to release and accumulation of root exudates during crop growth in soil. Soil incorporation of its fresh (green manure) or dry biomass in soil is inhibitory to both crops and weed spp. Several allelochemicals have been characterized from the H. annuus, which inhibit the seed germination and seedling growth of A. albus, A. viridis, Agropyron repens (Elymus repens), Ambrosia artemsiifolia, Avena fatua, Celosia crustata, Chenopodium album, Chloris barbara, Cynodon dactylon, D. sanguinalis, Dactyloctenium ageyptium, Digitaria ciliaris, Echinochloa crus-galli, Flaveria australasica, Parthenium hysterophorus, Portulaca oleracea, Sida spinosa, Trianthema portulacastrum, Veronica perisca the inhibitory effects of this crop may be used for weed management with less herbicides for sustainable agriculture.

Photoacoustics as a tool for the diagnosis of radicular stress: Measurements in eucalyptus seedlings

In reforesting companies (cellulose industry), eucalyptus is usually cultivated in small plastic containers (50 mL). As seedlings remain for about 120 days in these containers-until transplantation-their roots become space restricted, with consequent limitations in water and nutrient absorption. These restrictions may lead to plant stress, decreasing productivity. In this work, we used the photoacoustic technique to evaluate the photosynthetic activity of Eucalyptus grandis, E. urophylla and E. urograndis seedlings subjected to this limited space availability, seeking a correlation with morphological parameters and fluorescence measurements in these seedlings. Photoacoustic, fluorescence, and morphological analysis were conducted every 15 days, from 45 to 120 days after sowing. Fluorescence and photosynthetic rate were evaluated in vivo and in situ, the latter one using the open photoacoustic technique. Data show that root dry matter diminished markedly at 90 and 120 days after sowing; this behavior showed a high correlation with the gas exchange component of the photoacoustic signal, as well as with the fluorescence ratio Fv/Fm. These results indicate that the soil volume of the container becomes insufficient for the roots after 90 days, probably leading to a nutritional deficiency in plants, which explains the decrease observed in the photosynthetic rate of seedlings. (C) 2003 American Institute of Physics.

Efeito da densidade e proporção de plantas de tomate industrial e de maria-pretinha em competição

O presente trabalho foi realizado com o objetivo de quantificar as interações competitivas e os índices de competitividade entre plantas de tomate industrial (Lycopersicon esculentum cv. Heinz 9553) e maria-pretinha (Solanum americanum). Usou-se como método um experimento substitutivo, com densidade total de 40 plantas m-2 e 11 proporções, além das monoculturas em densidades, que variaram de 20 a 100 plantas m-2, em intervalos de 20 plantas, conduzidos no delineamento de blocos casualizados com três repetições. Os resultados obtidos foram analisados pelo método convencional de análise de experimentos substitutivos e pela produção recíproca total. A maria-pretinha mostrou ser um competidor mais agressivo que o tomate, sendo mais importante a competição interespecífica para a planta cultivada. Para a biomassa seca total, as duas espécies não competiram pelos mesmos fatores de crescimento. Já para a área foliar, as duas espécies se mostraram competidoras pelos mesmos fatores de crescimento, mostrando ser essa a característica mais sensível à interferência.

Interferência de caruru-de-mancha sobre características de crescimento e produção da beterraba

A beterraba (Beta vulgaris), importante hortaliça cultivada no Brasil, é muito suscetível à interferência de plantas daninhas, sendo Amaranthus viridis uma das principais espécies encontradas em áreas de horticultura. O objetivo deste trabalho foi estudar a resposta da beterraba à competição com diferentes densidades de A. viridis, por meio da avaliação de características de crescimento e produção da cultura. Um experimento em caixas, com área útil de 0,25 m², foi conduzido em Jaboticabal-SP, Brasil, mantendo-se constante oito plantas por caixa de beterraba em convivência com 0, 1, 2, 3, 4 e 6 plantas por caixa de A. viridis. A cultura da beterraba foi muito suscetível à interferência imposta por plantas de A. viridis, tendo sua área foliar, número de folhas, massa seca de folhas, diâmetro médio da raiz e massa fresca de raízes significativamente reduzidos mesmo em baixas densidades populacionais da planta daninha; a massa fresca de raízes foi a mais sensível à interferência.