| Autor: |
Pedro Marques da Silveira, Augusto Cesar de Oliveira Gonzaga |
| Jazyk: |
English<br />Portuguese |
| Rok vydání: |
2017 |
| Předmět: |
|
| Zdroj: |
Pesquisa Agropecuária Tropical, Vol 47, Iss 1, Pp 1-6 (2017) |
| Druh dokumentu: |
article |
| ISSN: |
1983-4063 |
| DOI: |
10.1590/1983-40632016v4742128 |
| Popis: |
The nitrogen sufficiency index (NSI) obtained by using a portable chlorophyll meter is a practical alternative to evaluate the N levels in plants. This study aimed at determining the appropriate NSI value for leaves of common bean plants, in order to define the need and amount of N to be applied as topdressing, using the Minolta SPAD-502 portable chlorophyll meter. Three field experiments were conducted using a randomized blocks design, with four replications. Nitrogen doses were applied as topdressing and compared with a treatment in which a high dose of N was used as a reference to calculate the NSI, whose value was 95 %. According to the results observed using the chlorophyll meter and the NSI, for each 0.1 percentage point increase in the NSI to reach the adequate level (95 %), it is necessary to apply 1.1-1.5 kg ha-1 of topdressing N. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
