Ethylene in a compacted field soil and its effect on growth,tuber quality,and yield of potatoes

Ethylene (C₂H₄) produced by soil microorganisms at concentrations sufficient to affect root development has previously been identified in the gas phase of anaerobic or partially anaerobic soils. This research was initiated to establish the existence of and to determine concentrations of C₂H₄ in soil in relation to matric potential, oxygen (O₂) and compaction, and effects on growth and tuber yield of potatoes (Solanum tuberosum L.). Ethylene initially appeared at the 10-cm depth after 2.5-cm/day increments of water were applied by furrow irrigation for 3 days. Levels of C₂H₄ increased to 18.4 ppm and O₂ decreased to 8% after 12.5 cm of water had been applied in 2.5-cm increments for 5 days. Ethylene was found in two partially compacted plots. High C₂H₄ concentrations and low O₂ levels in the soil atmosphere were associated with reduced top growth, leaf injury, lower tuber quality, and a 20% decrease in potato yields. Since C₂H₄ and low O₂ levels occur simultaneously in soil, further research is needed to identify their individual effects on root and tuber development.