Spatial Distribution of Brassica napus as a Trap Crop for the Control of Lepidoptera in Broccoli (Brassica oleracea var. italica), Guatemala
Humberto Carranza Bazini (Guatemala); Stephen Weller (US)
This study was conducted to determine if B. napus was effective as a trap crop for lepidopteran pests in broccoli. Two field tests were established in 1997: one in the village of Panimacoc, Tecp?n in the Department of Chimaltenango and the other in Pino Dulce, Mataquescuintla, Department of Jalapa. The treatments were (1) B. napus distributed at random inside the broccoli plots, (2) B. napus distributed around the broccoli plot, (3) B. napus distributed in rows inside the broccoli plot, and (4) the control plot (monocultured broccoli). The lepidopteran species monitored in this study were Plutella xylostella, Trichoplusia ni, Spodoptera spp. and E. acreae, and their effect on yield was recorded.
The objective of this study was to determine if B. napus was effective as a trap crop for lepidopteran pests in broccoli.
Results indicate that none of the Brassica napus spatial arrangement had the desired effect of serving as a trap crop of lepidopteran pests in broccoli, as the populations of both larvae and pupa of Plutella xylostella, Trichoplusia ni, Spodoptera spp. and E. acerae behaved in the same manner in all spatial distribution at both sites. Yield with B. napus around the perimeter of the broccoli field and by rows was similar to the monocultured broccoli, while B. napus distributed at random in the broccoli plot negatively affected yield when compared it to the broccoli in monoculture.