Breaking Down the Barriers to Organic No-till Soybean and Dry Bean Production through Improved White Mold Management
Project Director
Sarah Pethybridge
Year Funded
2018
Award Number
2018-51106-28775
Funded Institution
Cornell University
Grant Program
ORG (Organic Transitions)
USDA NIFA Report
Project Overview
Organic soybeans planted no-till into a roll-crimped winter cereal rye cover crop can give top yields. However, high soybean planting rates recommended for weed suppression could facilitate the spread of white mold (Sclerotinia sclerotiorum), a devastating disease of soybean and dry bean. Field trials were conducted to compare pathogen development, disease incidence, weed and crop biomass, and crop yield in organic soybean and dry bean planted into roller-crimped rye versus rye tilled in or fallow with shallow tillage. Additional trials were conducted to determine the impact of soybean seeding rate (195,000 to 915,000 seed/ha) and fertilizer nitrogen (N) rates on outcomes and net economic return.
Farmer Takeaways
(1) Organic soybeans planted no-till into roll-crimped rye perform well in the Northeast.
(2) White mold sclerotia (overwintering propagules) can persist for two years near the soil surface, while sclerotia buried deeper than 1.5 inches become nonviable in two years.
(3) Roll-crimped rye disrupts development of sclerotia into infective spores, thereby reducing the risk of white mold even at high soybean seeding rates.
(4) Planting soybeans into roll-crimped rye at 215,000 seeds/ac (140% of standard rate) without supplemental N reduced weeds and gave the highest net economic returns.
(5) Seeding rye at a high rate (3 bu/ac) enhances weed and disease suppression without affecting soybean yield; however, dry bean yielded less after rye at 3 bu/ac than after rye at 1 bu/ac.
(6) Common ragweed may increase in organic no-till because it emerges before roll-crimping and can survive this operation.
Project Outputs
Organic No-Till Planted Soybean Production: A Guidebook for Organic Farmers in New York State | Cornell University
Menalled, U. D., Smith, R. G., Cordeau, S., Di Tommaso, A., Pethybridge, S. J., and Ryan, M. R. 2023. Phylogenetic relatedness can influence cover crop-based weed suppression. Scientific Rep. 13:17323.
Pethybridge, S. J., Murphy, S., Lund, M., and Kikkert. J. R. 2024. Survival of Sclerotinia sclerotiorum sclerotia in central New York. Plant Disease 108(5).
Menalled, U., Pethybridge, S. J., Pelzer, C., Smith, R. G., DiTomasso, A., and Ryan, M. R. 2021. High seeding rates and low soil nitrogen optimize weed suppression and profitability in organic no-till planted soybean. Front. Agron. 3:678567.
Pethybridge, S. J., Brown, B., Kikkert, J. R., and Ryan, M. R. 2020. Rolled–crimped cereal rye residue suppresses white mold in no-till soybean and dry bean. Ren. Agric. Food Sys. 35:599-607.
Vincent-Caboud, L, M Casagrande, C David, MR Ryan, E Silva, and J Peigne. 2019. Can mulch cover no tillage be integrated into organic farming practices for arable crop production? – A review. Agronomy for Sustainable Development 39(5), p.45.