Wood chip-polyacrylamide medium for biocontrol bacteria decreases Verticillium dahliae infection on potato

Medio de Poliacrilamido de Trozos de Madera para la Bacteria de Biocontrol Aminora la Infección de Verticillium dahliae en Papa

Entry, J.A. and Strausbaugh, C.A. and Sojka, R.E. (2000) Wood chip-polyacrylamide medium for biocontrol bacteria decreases Verticillium dahliae infection on potato. Biocontrol Science and Technology. 10:677-686.

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Abstract

The lack of consistent success of biological control of soilborne plant pathogen's may be due
to the introduction of the organism into a foreign environment. We hypothesized that wood
chip-polyacrylamide ( PAM) cores surrounding host plant roots could alter the soil environment
to favour growth of introduced biocontrol microorganisms, thereby reducing Verticillium
dahliae infection of potato (Solanum tuberosum L.) in a greenhouse. A 7 cm diameter x 15 cm
deep hole (core) was drilled in the center of a 20 x 30 cm deep pot ( 1.9 kg) containing soil
infested with V. dahliae inoculum. Cores were then filled with wood chip-PAM-biocontrol
organism mixtures. Soils that had Streptomyces lydicus inoculated into wood chip-PAM cores
had lower levels of V. dahliae symptoms (Vvis) and V. dahliae isolations (Viso) than all other
treatments in three soils. Vvis and Viso on plants growing in soils amended with S. lydicus or
Pseudomona corrugata inoculated into the soil itself (without wood chip-PAM cores) did not
differ from soils that were unamended with these biocontrol organisms. V. dahliae biomass was
lower in wood chip-PAM cores inoculated with S. lydicus than control or wood chip-PAM
cores without biocontrol bacteria. Soils with wood chip-PAM cores inoculated with S. lydicus
or P. corrugata generally had higher microbial biomass/V. dahliae biomass (MB/VB) ratios
than control soils, or soils with S. lydicus or P. corrugata inoculated into the soil. Wood chip-PAM
cores alone and wood chip-PAM cores inoculated with S. lydicus had higher MB/VB
ratios than wood chip-PAM cores inoculated with P. corrugata. Vvis and Viso were curvilinearly
correlated with the MB/VB ratios in negative relationships, respectively (r2 = 0.68, r2 = 0.68).
As the MB/VB ratio increased, Vvis and Viso decreased. Although field studies and economic
evaluations are necessary, amending soil with wood chips-PAM and a biocontrol bacterium
may be a valuable method to increase the effectiveness of biocontrol organisms.

Item Type:	Article
NWISRL Publication Number:	1021
Subjects:	Irrigated crops > Potato Polyacrylamide (PAM) > Water-soluble PAM (WSPAM)
Depositing User:	Users 3 not found.
Date Deposited:	24 Mar 2008 20:59
Last Modified:	15 Nov 2016 15:27
Item ID:	110
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/110