Peroxidase activity as an indicator of water stress in sweet pepper plants

The purpose of the study was to evaluate the physiological and biochemical behavior of sweet pepper (Capsicum annuum L.) plants under different soil water availability conditions and the efficiency of the peroxidase (EC. 1.11. 1.7) activity as an indicator of water stress in plants. The experiment was carried out at the Faculdade de Ciências Agronômicas UNESP, Botucatu, SP. Sweet pepper plants were grown for 230 days after transplanting of seedlings and arranged in a completely randomized experimental design with 4 treatments, two irrigation managements (50 and 1500 kPa) and two soil surface managements (presence or absence of black polyethylene covering), and six replications. Physiological activities, such as stomatal transpiration and resistance to water vapor diffusion, were evaluated as well as biochemical activities, such as peroxidase activity and total soluble protein in foliar tissues. It was observed that soil water availability may lead to physiological and biochemical alterations in plants. Successive water stress cycles may promote the development of characteristics responsible for improving plant tolerance to periods of low water availability. The peroxidase enzyme activity showed to be an efficient indicator of water stress in sweet pepper plants.

Produção de frutos de pimentão em diferentes concentrações salinas

An experiment with an Elisa hybrid sweet pepper (Capsicum annuum L) crop using fertirrigation system was carried out in greenhouse. The aim of this study was to evaluate the quantitative effects of an increasing soil saline concentration on the production. The saline concentration was changed by the variation of the KC1 and Ca 2NO 3 concentration in order to obtain high soil electrical conductivity (EC) values. Standard fertigation system (1.5 dS m -1) values were used as control parameters. Besides that, the possibility of saline stress attenuation by applying organic material into the soil was studied. It was observed that the EC levels used in the crop were inversely correlated to the fructification index and the fruit mean weight. Under the most severe treatment (6.0 dS m -1) the fruit mean weight was reduced up to 58% and the mean produced fiuit number per plant was also reduced up to 55%, when compared to the obtained results under controlled conditions. These results demonstrated that the EC variation in the soil solution had strong interference on th production parameters selected for the studies.

Produção de pimentão em substratos e fertirrigação com efluente de biodigestor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atividade de enzimas antioxidativas e absorção de silício em plantas de pimentão submetidas a estresse salino

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fungicidas de efeitos fisiológicos no desenvolvimento de plantas de pimentão enxertadas e não enxertadas sob cultivo protegido

Pós-graduação em Agronomia (Horticultura) - FCA

Identificação e purificação de isolados de Cucumber mosaic virus e triagem de genótipos de pimentão para resistência

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Balanço de radiação de ondas longas em ambiente protegido e avaliação de modelos de estimativa

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

Potyvirus: caracterização parcial de espécies em plantas daninhas associadas a cultura do pimentão, avaliação de genótipos de alface e análise subcelular do eIF4E e de proteínas do Lettuce mosaic virus

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Biofertilizante bovino, cobertura morta e revestimento lateral dos sulcos na produção de pimentão

The adoption of management practices that reduce water losses is essential to conserve moisture and improve soil temperature, especially in arid and semiarid environments of the Brazilian Northeast, characterized by high evapotranspiration and the adoption of irrigation with saline water, which harms growth and yield of commercial crops. Given these factories, an experiment was conducted in Nova Floresta, Paraiba, from August 2010 to February 2011 in Oxisoil, in order to evaluate the production of bell pepper and soil moisture in grooves with side trim, and application of biofertilizer and mulch cattle. The experimental design was randomized blocks with four replications using a factorial 2 x 2 x 2 for the ground beef with and without biofertilizer, with and without residues of sisal fiber (Agave sisalana), with and without the side facing the grooves, to reduce lateral water losses by infiltration of water with polyethylene plastic film. From the results, the lining of the lateral grooves provided higher values of soil moisture, number of fruits, fruit mass, plant production and productivity, bell pepper plants. It was also found that the combination of biofertilizer and mulch the ground beef remained wetter in the first 15 cm depth.

Doenças do pimentão em regiões produtoras do Equador: identificação e manejo da pata seca e ocorrência de viroses

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Effects of mineral stress on the vegetative development of greenhouse-grown bell pepper plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Absorção de micronutrientes em plantas de pimentão submetidas a diferentes lâminas de irrigação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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).

Teores de macronutrientes em plantas de pimentão enxertadas sob fertirrigação

This study aimed at determining the levels of macronutrients (N, P, K, Ca, Mg and S) in grafted plants by contact methods such as bevel, cleft grafting by full rift and approach, as compared to non grafted plants. Analyses were performed in different parts of the plants under fertigation in a greenhouse. The hybrid and rootstock were AF 7125 and AF 8253, respectively. The nutrients were supplied via fertigation during the 150-day cycle. The experiment was carried out at the Teaching, Research and Production Farm in São Manuel city, SP which belongs to FCA-UNESP Campus in Botucatu city/SP. A total of 4 treatments and 5 replications were used. Each plot consisted of 12 plants. Chemical analyses were performed in one plant per plot at 35, 85, 112 and 143 days after transplantation to determine nutrient concentrations. The results showed that the macronutrient concentrations in a decreasing sequence in the vegetative parts (leaf + stem) were as follows: K > N > Ca > Mg > S > P; and in the fruits: K > N > P > S > Mg > Ca. Macronutrient concentrations were similar among grafted plants as compared to ungrafted plants, and the rootstock may have influenced absorption and translocation of minerals in grafted plants.

Avaliação da produção e concentração viral em pimentão infectado por tospovírus com o uso de piraclostrobina + metiram

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)