Factors Affecting the Development of Cavity Spot of Carrot

Abstract

Pythium violae and P. ultimum, isolated from cavity spot lesions on carrots produced in California, caused typical cavity spots on carrots grown in artificially infested soil in the greenhouse. In a 2-yr survey of 54 fields in the San Joaquin Valley of California, cavity spot incidence was not correlated with soil pH, electrical conductivity, moisture-holding capacity, organic matter, total and exchangeable calcium, particle size distribution, or planting densities (57, 115, or 230 carrots per meter of row). In a growth chamber maintained at 20 C, six commonly grown carrot cultivars were susceptible to both Pythium spp (.)