Mentha spicata - A Potential Cover Crop for Tropical Conservation Agriculture

Abstract

Mint (Mentha sp.) is an important crop used raw or processed into oil for a variety of consumption purposes. This thesis evaluated mint for its potential to be a valuable living mulch in conservation agriculture-vegetable production. Furthermore, mint, as a living mulch, creates multiple benefits including reduction of soil erosion, reduction of water and nutrient runoff, retention of water, and reduction of weeds and pests. Mint susceptibility to plant-parasitic nematodes and the profitability of mint in a vegetable agro ecosystem have not been well studied. A greenhouse experiment was conducted to examine susceptibility of spearmint (Mentha spicata) and peppermint (Mentha pepreti) to root-knot (Meloidogyne incognita, M. javanica) and reniform (Rotylenchulus. reniformis) nemtodoes. Both mint species were not a host to M. incognita, M. javanica, nor R. reniformis. The nematode reproductive factors (Rf = final nematode population/initial nematodes population) after 2 months were all < 1.0 for these nematodes on mint. A micro-plot field experiment was conducted to examine the effect of spearmint living mulch eggplant vegetable system compared to a bare ground eggplant vegetable system. The spearmint living mulch did not affect eggplant yield throughout the 14 months of the experiment as compared to the bare ground system. After the initial year of establishment, additional profit from harvesting spearmint for sale was estimated to be $20,949.06 per hectare annually based on a partial budget economic analysis. Planting spearmint as a living mulch in an eggplant agro ecosystem provides an economically viable conservation agricultural production system in a water resourceful environment.