Some problems of weed control in row crops in the Ukraine

In the Ukraine, row crops such as corn, sugar beet, sunflower, potato, soy-bean and others are grown over considerable areas - about 10.5 million hectares, almost 32%; of all cultivated land. Over recent years there has been a reduction in the areas cultivated for some row crops, such as potato, and an expansion for others, such as sunflower. All row crops are known to be poor competitors compared with weed species, and this is particularly true for sugar beet, soy-beans and vegetables. As a consequence weed control continues to be the most important technological input in row-crop cultivation. In general, effective weed control in row crops requires larger amounts of herbicides (and in some cases multiple applications), and greater time and financial inputs. Therefore, use of more effective preparates, with lower doses of herbicides, is critical for improved chemical weed-control in row crops. An integrated system of weed control for row crops has to be flexible, and dependent on the competitiveness of the crop, and the technology of mechanical and other non-chemical methods of weed control used. The successful basis of this integrated system of weed control is matching the right combination and sequence of crops in the rotation, to the soil and climate provinces of the Ukraine. In the autumn, good-quality soil treatment, typically down to more than 20 cm, and for sugar beet 28-32 cm deep-tier ploughing, ensures a 50-80% reduction in weed infestation. At the same time, the most weed-infested fields are given a severe soil disking treatment. The peculiarities of sugar beet morphology in their first year of growth weakens their competitiveness against weeds, thus making sugar beet particularly sensitive to weed infestation. This is why pre- and post-emergence herbicide applications have gained such critical importance in the successful establishment of a clean crop. The same is true for soy-beans, except that, with effective pre- and post-emergence control, soy-beans can now be grown and treated in a 'total' sowing method.