HUMIC SUBSTANCES: A POWERFUL TOOL FOR CONTROLLING FUSARIUM WILT DISEASE AND IMPROVING THE GROWTH OF CUCUMBER PLANTS
M.M.I. Afifi, A.M. Ismail, S.M. Kamel, T.A. Essa
doi: 10.4454/jpp.v99i1.3810
Abstract:
The effects of humic substances (HS) and their basic components, such as humic acid
(HA) and fulvic acid (FA), were evaluated for their ability to control Fusarium
oxysporum f. sp. cucumerinum, as well as to improve vegetative growth of cucumber
plants under pathogen pressure, in greenhouse conditions. Three concentrations ranging
from 50, 100 and 150 ppm for each HS, HA and FA were tested for their efficacy in
reducing pathogen growth. In vitro, FA extracted from green compost of plant residues
and biogas manure significantly reduced (P = 0.05) pathogen growth at a concentration
of 150 ppm compared to the control. FA extracted from plant residues at concentrations
of 150 ppm reduced disease severity significantly (84.7%) in relation to other
treatments. A significant increase in dehydrogenase enzyme activities and total number
of microorganisms in soil were obtained by HA extracted from biogas manure with respect to other treatments. All applications significantly improved growth parameters
of cucumber plants in the presence of natural inoculum, with the effects of HA
treatments being more pronounced.
