The study of Potato growth indices in response to redroot pigweed and lambsquarter competition

To study the competitive effects of redroot pigweed (Amaranthus retroflexus) andlambsquarter (Chenopodium album) on potato growth indices, an additive experiment wasconducted in the spring of 2004 and 2005 in split-split plot based on randomized completeblock design with 4 replications at the Seed Potato Production Station of RAN inFirouzkooh. Treatments were included 2 weed species in main plots (Amaranthusretroflexus and Chenopodium album), weed density in sub plots (2, 4 and 8 plants per meter of row) and relative time of weed emergence in sub-sub plots (8 and 4 days prior to potato and the same time with potato emergence in 2004 and the same time with potato, 2 and 4 weeks after potato in 2005). Results showed that both weed species reduced height, LAI, CGR and RGR. Redroot pigweed caused more reduction in potato growth indices thanlambsquarter.