The occurrence of weed control methods in stands of grasses spring cereals

This work focused on the problems of weed plants in spring cereals on plots of agricultural cooperative Čížová. The company is located in South Bohemia, 5 km from Písek. The evaluation of weed infestation was made by numerical method in period from spring 2011 to summer 2011. The issue of weed plants is one of the main negative factors affecting yield and grain quality. Number of weed plants, which at a given location occurred, was regularly observed and evaluated. The most commonly occurring weeds were Viola arvensis, which made up approximately 50 % of all the range of weeds which occurred in the explored land. Other significant weeds were Thlaspi arvense L. and Capsella bursa-pastoris L. We can suppose that Viola arvensis will be a problematic weed. The conclusions can be stated that long-term regulation against the occurrence of perennial weeds must be done carefully and must be based on complete protection which consists of direct and indirect methods of weed control products. Underestimating the occurrence of weeds in crops can cause serious problems