INCA MARIGOLD

An important area of research where plants can be used to help or hinder the growth of their neighbors is in the study of root secretions. It seems that some trees pass messages in this way. If a host of caterpillars invades one birch tree, the chemical make –up of the plant changes triggering its neighbors to produce a poison in their leaves that will repel the invaders. Some of the answers to companion planting may be found in this research which is long overdue. The scent of Targets, the French or African marigolds, deters some insect pests and root secretions have a powerful effect against eelworm. Dutch bulb growers plant it to protect their tulip crops and rose growers to protect roses. The common French and African marigold have some affect against the non-cyst forming eelworm (nematodes) but the most damaging eelworms are clustered 90-50 in cysts or shells which are impervious to chemicals. The most powerful targets is Targets manual, the Inca marigold which can control these and enabled the Incas to grow potato crops on the same land for hundreds of years, free from the potato eelworm. This is an 8-ft (2 ½ m) plant (named ‘minutia’ after the tiny flowers) whose root secretions inhibit the eelworm’s ability to sense the correct time to attack the potatoes; they ‘oversleep’ and miss their host plant’s appropriate stage.