TY - JOUR
T1 - Reduction of Pythium Damping-Off in Soybean by Biocontrol Seed Treatment
AU - Pimentel, Mirian F.
AU - Arnao, Erika
AU - Warner, Amanda J.
AU - Rocha, Leonardo F.
AU - Subedi, Arjun
AU - Elsharif, Nariman
AU - Chilvers, Martin I.
AU - Matthiesen, Rashelle
AU - Robertson, Alison E.
AU - Bradley, Carl A.
AU - Neves, Danilo L.
AU - Pedersen, Dianne K.
AU - Reuter-Carlson, Ursula
AU - Lacey, Jonathan V.
AU - Bond, Jason P.
AU - Fakhoury, Ahmad M.
N1 - Publisher Copyright:
© 2022 The American Phytopathological Society.
PY - 2022/9
Y1 - 2022/9
N2 - Pythium spp. is one of the major groups of pathogens that cause seedling diseases on soybean, leading to both preemergence and postemergence damping-off and root rot. More than 100 species have been identified within this genus, with Pythium irregulare, P. sylvaticum, P. ultimum var ultimum, and P. torulosum being particularly important for soybean production given their aggressiveness, prevalence, and abundance in production fields. This study investigated the antagonistic activity of potential biological control agents (BCAs) native to the U.S. Midwest against Pythium spp. First, in vitro screening identified BCAs that inhibit P. ultimum var. ultimum growth. Scanning electron microscopy demonstrated evidence of mycoparasitism of all potential biocontrol isolates against P. ultimum var. ultimum and P. torulosum, with the formation of appressorium-like structures, short hyphal branches around host hyphae, hook-shaped structures, coiling, and parallel growth of the mycoparasite along the host hyphae. Based on these promising results, selected BCAs were tested under field conditions against six different Pythium spp. Trichoderma afroharzianum 26 used alone and a mix of T. hamatum 16 + T. afroharzianum 19 used as seed treatments protected soybean seedlings from Pythium spp. infection, as BCA-treated plots had on average 15 to 20% greater plant stand and vigor than control plots. Our results also indicate that some of these potential BCAs could be added with a fungicide seed treatment with minimum inhibition occurring, depending on the fungicide active ingredient. This research highlights the need to develop tools incorporating biological control as a facet of soybean seedling disease management programs. The harnessing of native BCAs could be integrated with other management strategies to provide efficient control of seedling diseases.
AB - Pythium spp. is one of the major groups of pathogens that cause seedling diseases on soybean, leading to both preemergence and postemergence damping-off and root rot. More than 100 species have been identified within this genus, with Pythium irregulare, P. sylvaticum, P. ultimum var ultimum, and P. torulosum being particularly important for soybean production given their aggressiveness, prevalence, and abundance in production fields. This study investigated the antagonistic activity of potential biological control agents (BCAs) native to the U.S. Midwest against Pythium spp. First, in vitro screening identified BCAs that inhibit P. ultimum var. ultimum growth. Scanning electron microscopy demonstrated evidence of mycoparasitism of all potential biocontrol isolates against P. ultimum var. ultimum and P. torulosum, with the formation of appressorium-like structures, short hyphal branches around host hyphae, hook-shaped structures, coiling, and parallel growth of the mycoparasite along the host hyphae. Based on these promising results, selected BCAs were tested under field conditions against six different Pythium spp. Trichoderma afroharzianum 26 used alone and a mix of T. hamatum 16 + T. afroharzianum 19 used as seed treatments protected soybean seedlings from Pythium spp. infection, as BCA-treated plots had on average 15 to 20% greater plant stand and vigor than control plots. Our results also indicate that some of these potential BCAs could be added with a fungicide seed treatment with minimum inhibition occurring, depending on the fungicide active ingredient. This research highlights the need to develop tools incorporating biological control as a facet of soybean seedling disease management programs. The harnessing of native BCAs could be integrated with other management strategies to provide efficient control of seedling diseases.
KW - Clonostachys rosea
KW - Trichoderma spp
KW - biological control
KW - fungicide tolerance
KW - integrated disease management
KW - mycoparasitism
KW - seedling blight
KW - soybean seedling diseases
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U2 - 10.1094/PDIS-06-21-1313-RE
DO - 10.1094/PDIS-06-21-1313-RE
M3 - Article
C2 - 35171634
AN - SCOPUS:85129601630
SN - 0191-2917
VL - 106
SP - 2403
EP - 2414
JO - Plant Disease
JF - Plant Disease
IS - 9
ER -