Row cover and plant population density effects were studied at the Agriculture Canada Research Station, Agassiz, BC in 1988 and 1989. Bell pepper plants (Ace Hybrid) were transplanted into twin rows (0.45 m apart) on raised beds (1.8-m centers) at five population densities of 1.39, 1.85, 2.78, 5.56 and 11.1 plant m−2. For 7 wk in 1988 or 8 wk in 1989, subplots were either covered or not covered with slit clear polyethylene tunnels. A nonlinear regression model was used to define yield-population density responses. Row covers enhanced early and overall yields in 1988 and overall yield in 1989. Vegetative and reproductive yields (kg plant−1) declined with increasing plant population density. Yields were directly related to population density when measured on a land-area basis. Maximum fruit yield (7.9 kg m−2) was obtained at the highest population density. Treatment influences on fruit size were small and did not affect horticultural quality. An economic analysis showed that net returns were greatest with plants grown under row covers at the highest population density.Key words: Capsicum annuum L., field bell peppers, population density, row covers
Dispersal of the Invasive Pasture Pest Heteronychus arator into Areas of Low Population Density: Effects of Sex and Season, and Implications for Pest Management