TY  - JOUR 
T1  - Portable chlorophyll meter can estimate the nitrogen sufficiency index and levels of topdressing nitrogen in common bean
JO  - Pesquisa Agropecuária Tropical
A1  - Silveira, Pedro Marques da
A1  - Gonzaga, Augusto Cesar de Oliveira
SN  - 1983-4063
UL  - 10.1590/1983-40632016v4742128
VL  - 47 
Y1  - 2017
PB  - Brasil 
ER  -