A Study of Allelochemical Insect Control by Three Herbs Grown in a Companion Planting System with Mustard (Brassica juncea cv. Florida Broadleaf)
Abstract
Numerous gardening publications report that the companion planting of various herbs among vegetable crops repels insects from the garden, thereby reducing insect damage considerably. An experiment was conducted to test the validity of these claims.
A complete randomized block design with four replications of four treatments was utilized in a field study. Each of three herbs – sweet marjoram, dill, and shallots -- was planted on both sides of a row of mustard (Brassica juncea cv. Florida Broadleaf ) on a raised bed; a control with mustard only was used, totalling four treatments. When the plants were ready for harvest, data was collected on the types and degree of damage found on the youngest fully expanded leaf of ten plants chosen at random from each plot. Two raters collected data independently. Ratings were based on a 1 - 3 scale, ranging from none-to-slight damage to severe damage. Three categories of damage were considered -- holes, presence of aphids, and spots.
Totals from each plot were calculated and an analysis of variance run on each rater's data for each of the three categories of damage. In the analysis, no significant differences were found between treatments. Average treatment ratings were compared and showed only slight differences. Records of insects found on the sample plants revealed no patterns in frequency of appearance within the various treatments.
Description
Program year: 1981/1982Digitized from print original stored in HDR
Citation
Smith, Kristina J. (1982). A Study of Allelochemical Insect Control by Three Herbs Grown in a Companion Planting System with Mustard (Brassica juncea cv. Florida Broadleaf). University Undergraduate Fellow. Available electronically from https : / /hdl .handle .net /1969 .1 /CAPSTONE -MurphyA _1998.