Mechanical weed control in sunflower and soyabean crops using spring-tine harrow: results of two-year trials

摘要

The present study aimed to investigate the possibility of using spring tine harrowing for weed control on sunflower cv. Ketil and soyabean cv. Gemma, and to define the most efficient adjustments of the working tools for the different operative conditions. The experimental treatments included one or two passes with a spring-tine harrow combined with four tine adjustments (-30deg, -15deg, 0deg and 15deg), a "conventional" herbicide treatment (metolachlor+metobromuron at 3.5 litre/ha for sunflowers, and linuron at 1 litre/ha+metolachlor at 3 litre/ha for soyabean) and an unweeded control. The trials were conducted in Italy, in 1998 and 1999. The results of the trials indicated that it is possible to achieve efficient weed control on sunflower and soyabean crops with spring tine harrowing while also preserving the grain yield. The machine adjustments affected grain yield and weed control. Both the crops were sensitive to weed competition and direct weed control was needed. Spring tine harrowing was gentle towards the crops. Moreover the results obtained confirmed that the use of spring tine harrows allows substantial operative advantages and emphasized that soil mechanical characteristics strongly affect treatments performed with the spring tine harrow.