155 resultados para déficit hídrico do solo


Relevância:

90.00% 90.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

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

Relevância:

90.00% 90.00%

Publicador:

Resumo:

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

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The success of conservation systems such as no-till depends on adequate soil cover throughout the year, which is possible through the use of cover crops. For this purpose the species belonging to the genus Urochloa has stood out by virtue of its hardiness and tolerance to drought. Aiming ground cover for the no-till system, the objective was to evaluate the establishment of two species of the genus Urochloa, in three sowing methods, in the weed suppression and the sensitivity of these forages to glyphosate. The study design was a randomized block with a 2 x 3 x 3 factorial arrangement, in which factor A was composed of Urochloa ruziziensis and Urochloa hybrid CIAT 36087 cv. Mulato II, factor B was formed by sowing methods: sown without embedding, sown with light embedding and sown in rows, and factor C was composed of three doses of glyphosate (0.975, 1.625 and 2.275 kg ha(-1) of acid equivalent). For determination of weed suppression, assessment of biomass yield and soil cover was performed, by brachiaria and weeds, at 30, 60, 90, 120 and 258 days after sowing. Visual assessment of the desiccation efficiency at 7 and 14 days after herbicide application was performed. It is concluded that embedding Urochloa seeds stands out in relation to sowing in the soil surface. Urochloa ruziziensis is more efficient in the dry weight yield, weed suppression, in addition to being more sensitive to glyphosate herbicide.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A crescente conscientização da água como bem de alto valor econômico, social, cultural e ecológico exige cada vez mais o uso racional desse recurso baseados em parâmetros técnicos que levem a um aumento da eficiência do manejo de irrigação. Utilizou-se o programa STELLA 10.0.3 para simular o balanço hídrico de um solo cultivado com meloeiro (Cucumis melo L.) no município de Iguatu/Ceará. Os parâmetros meteorológicos corresponderam aos valores diários de temperatura máxima, temperatura mínima, temperatura média e radiação solar no topo da atmosfera. Utilizou-se o método de Hargreaves-Samani para determinar a Evapotranspiração de Referência. A capacidade de campo, ponto de murcha permanente, densidade aparente, profundidade efetiva do sistema radicular e o déficit hídrico tolerável foram os parâmetros físicos do solo para determinar sua capacidade de água disponível e o nível mínimo de água disponível. As irrigações são realizadas sempre que o nível de umidade do solo fica muito próximo ou abaixo do nível mínimo de água disponível. Os resultados mostraram que o modelo desenvolvido utilizando dinâmica de sistemas, analisa todos os parâmetros envolvidos de forma sistêmica e dinâmica fornecendo como resultado valores de lâminas de irrigação a serem aplicadas e os momentos em que sua aplicação é necessária.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Water deficit is one of the factors which most limit agriculture yield and growth. Although sugar cane has moderate tolerance to drought, it presents high yield losses under the influence of this abiotic factor. Based on this fact, selection of genotypes tolerant to water stress may represent an alternative for decreasing the amount of water used for irrigation, while keeping or increasing yield. This study was performed in order to evaluate the performance of four sugarcane cultivars during initial development under water stress conditions, by means of morphological variables to select more tolerant genotypes to drought. The experiment was carried out in a greenhouse at the Department of Rural Engineering, College of Agricultural Sciences - UNESP/Botucatu – SP, from November 26th 2010 to April 5th 2011. A total of four sugar cane cultivars were evaluated (RB855453, RB92579, RB965902 and RB965917) under two treatments as follows: control (100% field capacity) and water stress (50% field capacity). Evaluations were performed at 0, 28 and 63 days after treatment application. The following morphological variables were analyzed: plant height, leaf area, leaf length, leaf width, number of green leaves, shoot and root dry matter. The RB855453 and RB92579 cultivars produced more shoot and root dry matter under water stress treatment, while the RB965902 and RB965917 cultivars had lower shoot and root dry matter production under the same conditions. Therefore, the RB855453 and RB 92579 cultivars can be considered tolerant while the RB965902 and RB965917 cultivars can be considered susceptible.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

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