Received: January 25th, 2022 ; Accepted: April 5th, 2022 ; Published: April 19th, 2022 ; Correspondence: [email protected], no herbicide is registered for grain amaranth in Europe, the United States
and South America. Hence, weed control must be addressed with alternative methods. Field trials
were conducted in 2018 and 2019 in Central Italy by comparing some mechanical weed control
treatments in grain amaranth (Amaranthus cruentus L.). In 2018, the five treatments were:
untreated control (T118), cutter hoeing (T218), flat share cuts and one central duck foot tine (T318),
flat share cuts and two central duck foot tines (T418), and three duck foot tines (T518). In 2019,
the five treatments were: untreated control (T119), three duck foot tines (T219), flex tine harrowing
(T319), flex tine harrowing plus finger weeding with red fingers (T419), and finger weeding with
red fingers (T520). In 2018, amaranth was a successful competitor against weeds from 40 days
after emergence (10 true leaf stage, corresponding to BBCH code 15). The competitive ability
was showed by excellent seed yields averaging 1.2 t ha-1
, for all treatments. This feature was also
confirmed to some degree in 2019. However, seed yield in 2019 was more strongly influenced
by treatment as well as by the lower emergence of plants. All the mechanical methods employed
can be effectively used for weed control in grain amaranth. Treatments with the flex tine harrower
and finger weeder negatively affected the plant density at harvest, necessitating further
optimization. However, combined mechanical strategies proved the most effective, especially in
controlling dicot weeds. There is a need to optimize strategies, with mechanical equipment, to
anticipate and improve the ground cover of amaranth. These strategies include selecting optimal
plant density and the correct distancing between the rows for easier mechanical control