Influence of ethylene on black spot of potato tubers

Abstract

Sound, hand harvested, whole potatoes were exposed to continuous flowing atmosphere containing air, air with 3 or 5% CO2, and air with concentrations of 0.5, 1.0, and 10ppm C2H4 for periods of 1 to 11 days at 20°C. At 1-day intervals, potatoes were bruised and black spot development assessed. Development of black spot in potatoes exposed to C2H4 was equal to or less than in potatoes at harvest. The severity remained low during 3-day exposure to 1 ppm C2H4 and after transfer to 4 days in air, then increased. Severity of black spot increased in potatoes exposed to air, with intermediate response from exposure to air with CO2. With an increase in sprouting, differences in black spot among treatments diminished. Less black spot developed in immature than in mature potatoes.