EFFECTIVENESS OF HERBICIDES AGAINST FIELD BINDWEED (CONVOLVULUS ARVENSIS L.) IN SPRING WHEAT PLANTINGS DEPENDING ON SPRAYING DATES
Field bindweed is a common species in the Altai Region. Spraying prior to flowering and after seed ripening is the most effective control technique, but difficult to perform in spring wheat plantings. The research purpose was to identify effective herbicides and the optimal spraying time against field bindweed in spring wheat plantings. The following herbicides of different chemical compound classes were chosen: 2.4-D (Esteron, EC), Dicamba (Dianat, water solution), fluroxypyr (Starane, EC), and tribenuron-methyl (Granstar PRO, water dispersible granules). The herbicides were sprayed in four dates from the beginning of tillering. The following is concluded: at early spraying (tillering beginning) particularly in the seasons with no high average temperature in the first and second ten-days of June, field bindweed suppression is insignificant. The time when field bindweed runners in wheat crops reach 35 cm is the optimum time to control the weed, still the crop growth stage should be considered and the recommended spraying dates should be followed. The most effective herbicides to control field bindweed are Esteron (EC), Dianat (water solution) and Starane (EC). To avoid crop damage, Dianat (water solution) and Esteron (EC) are sprayed before the end of tillering, while Starane (EC) may be sprayed after stem elongation beginning. Due to their different action, Granstar PRO (water dispersible granules) is not effective to control field bindweed. This herbicide is most effective to control field bindweed in the beginning of stem elongation when the average length of shoots reaches 35 cm.