SciELO - Scientific Electronic Library Online

 
vol.29 número2Adaptabilidade e estabilidade de cultivares de alfafa avaliadas em minas geraisAvaliação de programas de iluminação sobre o desempenho zootécnico de poedeiras leves índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Ciência e Agrotecnologia

versão impressa ISSN 1413-7054versão On-line ISSN 1981-1829

Resumo

ANDRADE, Alex Carvalho et al. Growth analysis of 'Napier' elephant grass fertilized and irrigated. Ciênc. agrotec. [online]. 2005, vol.29, n.2, pp.415-423. ISSN 1413-7054.  https://doi.org/10.1590/S1413-70542005000200020.

The growth indexes were evaluated: relative to growth rate (RGR), net assimilation rate (NAR), leaf  area ratio (LAR), leaf area index (LAI) and the luminous interception of the 'Napier' elephant grass after graze. The work consisted of two experiments for the study of four manuring treatments of N and K, in kg/ha (T1: 100 kg of N and 80 kg of K, T2: 200 kg of N and 160 kg of K, T3: 300 kg of N and 240 kg of K and T4: 400 kg of N and 320 kg of K), being an irrigated and other without irrigation, according to the randomized block desing, with three replicates. The statistical analysis was  donne in  outline of split plot, tends in the portions the doses of N and K, and in the sub-portions the regrowth ages after graze (2, 8, 15, 45 and 123 days) for LAI and interception of light. The LAI in the irrigated area increased from 0.28 to 8.27, average of the four treatments of N and K, between the smaller and larger regrowth ages. In the not irrigated area also was verified an increase in LAI, although in smaller magnitude that in the irrigated area, of 0.16 for 7.76. The medium values of RGR, NAR and LAR were 0.0083 g/g.day, 3.57 g/cm2.day and 0.0021 m2/g, respectively. The light interception increased with the increase of the LAI, stabilizing in the 51.5th day. therefore, the light penetration inside the dossel reduced asymptotically in function of LAI. The extinction coefficient varied of 0.29 in the largest combination of N and K for 0.53 in the doses of 200 kg/ha of N and 160 kg/ha of K.

Palavras-chave : Extinction coeficient; interception of light; net assimilation rate; leaf area index; leaf area ratio; Pennisetum purpureum; relative growth rate.

        · resumo em Português     · texto em Português     · Português ( pdf )

 

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons