경종조건에 따른 벼 이형주의 발생양상과 특성은 다음과 같다. 1.벼 이형주의 발생량은 종자의 자가 채종년수가 증가할수 록 많았고, 직파재배 포장에서 이앙재배 포장보다 2배 가량 많았다. 2. 재배벼의 재배포장에 장립적미와 단립적미를 인위적으로 산파 하였을 때 담수표면산파 재배에서 기계이앙 재배보다 발생량이 많고 간장이 길고 주당 유효경수가 많았으며, 장립적미가 단립적미보다 이런 특성들을 많이 지녔다. 3. 이앙재배 포장에서 이형주가 재배벼의 포기 밖에서 발생하는 비율은 농가관행재배의 경우 0∼6%인 반면, 장립적미와 단립적미를 인위적으로 산파하였을 때는 70.6∼91.1% 이기 때문에 농가포장에서 발생하는 이형주군의 대부분은 종자흔입에 의해 발생하는 것으로 보아진다
This study was carried out to investigate the occurrence and characteristics of off-type rice plant according to agronomic conditions. The occurrence density of the off-type rice plant in farmer's paddy field was greater as the years of self-produced seed use increased, and in the direct sowing paddy field it was twice as much as in the transplanting paddy field. When the long-grain red rice and the short-grain red rice in the cultivated field of cultivar were artificially sown, in the direct sowing on a flooded paddy surface culture rather than in the machine transplanting culture the off-type rice plant occurred much more, the culm length was longer, and the number of productive culm per plant increased. These characteristics were more conspicuous in the long-grain red rice than in the short-grain red rice. In the transplanting farmer's paddy fields, the off-type rice plant that occurred outside of the hills of the cultivar rice ranged 0 to 6%. Whereas in was 70.6 to 91.9% when the long-grain red rice and short-grain red rice were artificially sown. Therefore, it was assumed that most of the off-type rice plants occurred in the farmer's paddy fields was caused by seed contamination.