TITLE:
Production of Lettuce Seedlings with Association of Diazotrophic Bacteria and Humic Acids
AUTHORS:
Carlos Augusto Rocha de Moraes Rego, Bruna Penha Costa, Marinez Carpiski Sampaio, Marcos Massuo Kashiwaqui, João Henrique Silva Caetano, Vandeir Francisco Guimarães, Juan López de Herrera, Pablo Wenderson Ribeiro Coutinho, Cláudio Yuji Tsutsumi, Maria Soraia Fortado Vera Cruz, Thatiane Nepomuceno Alves, Shirlene Souza Oliveira, Ana Carolina Pinguelli Ristau, Hannah Braz
KEYWORDS:
Azospirillum brasilense, Humic Substances, Lactuca sativa L., Productive Characteristics
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.5,
April
18,
2018
ABSTRACT: The objective of this work was to verify the
responses in agronomic and physiological characters of lettuce seedlings when
submitted to different doses of humic acids and the presence or absence of
inoculation of the bacterium Azospirillum
brasilense. The experiment was carried out at the Protected Cultivation
Station and Biological Control Teacher Mário César Lopes, belonging to the
Experimental Stations Nucleus of the State University of the West of Paraná.
The experimental design was a randomized block design, in a 5 × 2 factorial scheme, with four repetitions, totaling 40 plots. The first
factor consisted of five solutions containing humic acid (100%, 75%, 50%, 25%
and 0%) and the second factor was the presence or absence of the diazotrophic
bacterium Azospirillum brasilense obtained by commercial product. Germination tests were carried out in addition
to the determination of agronomic characters such as the number of fully
expanded leaves, plant height, stem diameter, main root length, shoot dry mass,
root dry mass, total dry mass, and Dickson quality index. The association of diazotrophic
bacteria and humic acids did not influence the emergency rate, mean emergence
time, mean speed of emergency, emergence speed index, plant height, and root
length of lettuce seedlings. The dilutions of humic acids, regardless of
inoculation with bacteria diazotrophic favored the development of the number of
leaves, stem diameter and Dickson quality index. Inoculation of lettuce seeds
with diazotrophic bacteria associated with the addition of humic acids, favored
the development of the dry mass of root and total dry matter.