Black pepper plantlets under controlled-release fertilizer: growth and chlorophyll contents

Resumo

The study aimed to investigate the effect of controlled-release fertilizer N14-P14-K14 (CRF) on the morphological traits and chlorophyll indices of black pepper plantlets (cv. Bragantina). One experimentation was carried out in a greenhouse between March and July 2018 in the Rio de Janeiro state/Brazil. Were tested four doses’ equivalents to 0.0, 2.5, 5.0, and 10.0 kilogram of CRF per cubic meter of the substrate, which was obtained by mixing clayey soil and crushed coconut fiber, on 1:3 volume proportion. The experimental design was completely randomized, with 17 replicates to assess the morphological characteristics and nine replicates to assess the chlorophyll contents. At 120 days after transplanting were assessed main stem height (H), the number of leaves (NL), leaf area index (LAI), total dry matter (TDM), shoot dry matter (SDM), and root dry matter (RDM). Chlorophyll a, b, a+b contents and a/b ratio were assessed too. The application of CRF fertilizer increased the NL and SDM values until 9.6 kg m^-3 dose. The values of H, TDM, LAI, and RDM increase until 9.3, 8.4, 8.2, and 6.4 kg m^-3 doses, respectively. The chlorophyll a and b contents increased until 7.7 kg m^-3 dose. It's recommended to apply 8.4 kg of CRF 14N-14P-14K per cubic meter of the substrate to produce black pepper plantlets with adequate commercial pattern and chlorophyll levels.