WEEDING AND WINTER WHEAT AGROPHYTOCENOSIS PRODUCTIVITY DEPENDING ON SOWING TIME AND SEEDING RATE

The article presents the autumn season growth characteristics of winter wheat under Polissya conditions depending on sowing time and seeding rate .It was determined that the crops planted on the later date (October 10) from the first sowing (September 10) received at 11.7°C less heat per day. It was investigated that after stopping the autumn growing season the mass of aboveground and underground parts of 100 winter wheat plants sown in optimal time (September 10 and September 20) was 3.7-14.2 and 1.4-6.2 times higher in comparison with the plants of later date sowing (October 10) respectively. The winter wheat sowing on later than optimal date (October 10) leads to an increase in the weed-infested crops at the end of growing season in 1.4-2.2 times. The increase of seeding rate by 0.5-1.0 million of germinable seeds per hectare ensures the decrease of weeds by 3-24%. The winter wheat showed the highest grain yield (3.68-3.72 t/ha) when sown on September 10 at seeding rate of 5.0 million germinable seeds per hectare, which was 37% higher than in winter wheat sown on October 10