Soil Texture, Root Lesion Nematodes, and Yield of Peppermint (Mentha × piperita)

ABSTRACT The effect of soil types and initial inoculum level of the root nematode Pratylenchus thornei on growth, oil yield, and physiological and biochemical changes in Mentha × piperita were determined. Reproduction of the nematode was greatest in a sandy clay loam soil and least in a sandy loam soil at the tested inoculum densities. Reduction in plant length, fresh and dry weight, oil yield, leaf chlorophyll content, photosynthetic rate, and total sugar and phenol content in leaves was greatest in sandy clay loam and lowest in sandy loam as compared with uninoculated, control soils. Growth of uninoculated peppermint plants varied significantly among the tested soil types.