Abstract
We have taken notice of volunteer wheat which is one of the factor of mixed foreign plants in barley feild.
Two experimental items were designed. 1) To investigate the grain sizes of falling wheat (lost grains) at combine harvesting, which relate to the germination and growing ability in the field. 2) To make clear the persistence of volunteer wheat under tilling condition.
The results are as follows,
1) Falling grains (lost grains) at combine harvesting with good operating condition were 7.6kg/10a. Seventy five percent of falling grains had grain sizes of>2.4mm, which would be ripend well.
2) Emergence rate of volunteer wheat grains was changing, as high rate at immediately after they fell on the ground and low rate in summer, and high rate again in fall.
3) It showed high emergence rate until the next spring when the grains had been buring at 20cm depth. Shallow depth buring grains showed high rate at immediately after they fell, but low rate in the next spring.
4) Buring wheat grains soon after they fell will help volunteer wheat plants to persist.
5) The number of volunteer wheat plants was the biggest in where the field was plowed soon after wheat grains fell in summer and plowed again in fall.
