No-tillage system applied to the sunflower (hybrid pioneer PR64E83) resistant to the tribenuron-methyl in the conditions from Romania.

In the year 2006, the first experience with the NO-TILLAGE system for sunflower crops was organized in Romania, using the Pioneer PR64E83 sunflower hybrid resistant to the tribenuron-methyl herbicide. The experience took place in the Danube river flood plain, on an alluvial soil with a content between 3.1-4.5% and a content of clay of 34-40%. In the conventional system, in the fall of the year 2005, autumn ploughing was carried out, along with harrowing, and in spring the land was tilled two more times, using both the disk and the harrow. Before sowing, the land was prepared by using the combiner-machine. After the sunflower sprouted, three-time mechanical hoeing between the rows, as well as three-time manual hoeing on the sunflower row were performed. In the no-tillage system, no autumn ploughing, nor any other soil work were performed, and the sunflower was sowed directly, by using the Gaspardo seeder. Before sowing, the soil was covered in proportion of 70% by species of weeds of the Cirsum, Sonchus and Polygonum amphibium type. To destroy these species of weeds, 3 days before sowing, the soil was treated with the Roundup herbicide in a dose of 7 litres/ha. After the sunflower sprouted, when the plants had 4-5 leaves, the following sulphonylurea herbicides were applied post-emergently. (1) Express 50SG--which contains tribenuron-methyl (2) Granstar 75DF--which contains 75% tribenuron-methyl (3) Titus 25DF--which contains 25% rimsulfuron (4) Mistral--which contains 40 g/L nicosulfuron (5) Lintur 70WG--which contains 4.1% triasulfuron + 65.9% dicamba (6) Peak 75WG--which contains 75% prosulfuron The Express 50SG and Granstar 75DF herbicides were selective for the sunflower hybrid PR64E83, and the other herbicides although belonging o the same sulphonylurea group, they proved to have a very phytotoxic effect upon the sunflower crop. In the report, selectivity is presented depending on the dose of herbicide, weed control and sunflower production.