Effect of triticale (×Triticosecale Wittmack) and daikon radish (Raphanus sativus L.) cover crops on weed suppression, grain yield and yield components of maize (Zea mays L. cv. Kousha)

One of the environmentally friendly methods of weed control in cropping syastems is using of cover crops. Cover crops can reduce or control weeds through different mevhanisms such as physical suppression (suffocation of weeds), ecological suppression (competition for limited resources of nutrients, water, and light), and chemical suppression (emission of allelochemicals).

To investigate the effect of monoculture and intercropping of cover crops on weed control and grain yield and yield components of corn (Zea mays L. cv. Kousha), a randomized complete block design with four replications was used in the research farm of faculty of agriculture and natural resources of Mohaghegh Ardabili University in ardabil, Iran, in 2018-9 and 2019-20. The experimental treatments included: triticale (×Triticosecale Wittmack) and daikon radish (Raphanus sativus var. Longipinnatus) as monocultures, intercropping of triticale + daikon radish with a control treatment (without cover crops).

The results showed positive effect of triticale monoculture on reducing the density of lamb’s quarters (Chenopodium album), pigweed (Amaranthus retroflexus), and wild mustard (Sinapis arvensis) weeds by 36.7%, 50% and 53.8%, respectively. The highest grain yield (3782.5 kg.ha-1) and number of grain.ear-1 (444.8) of maize were obtained in triticale monoculture. The results showed that triticale monoculture had the most desirable weed control efficiency index (44.1), Simpson index (0.61), Shannon-Wiener index (1.33) and Margalef’s species richness index (1.21).

Based on the results of this experiment, the success of the intercropping of triticale and daikon radish on controlling weeds density and improving maize grain yield was related to suitable density of the plant species used in this experiment. Triticale monoculture, grown in winter, can be considered as an effective cover crop for weed control and improving maize grain yield in Ardabil and similar environmental conditions.