Abstract:

To investigate the effects of different seedling ages and planting densities on the growth period and yield of Chunyou 801，seedling age and planting density tests were conducted. The seedling age test employed a split-plot design with two factors，using three sowing periods，June 25（A1），June 30（A2），and July 5（A3），as the main treatments and three transplanting periods，July 20（B1），July 25（B2），and July 30（B3），as the sub-treatments. The single factor randomized block design was used in planting density test with four cultivation densities：27.8×10⁴ hills per hectare（C1），23.8×10⁴ hills per hectare（C2），20.8×10⁴ hills per hectare（C3）and 18.5×10⁴ hills per hectare（C4）. The results showed that seedling age had a significantly（p0.05）effect on whole growth period and yield under machined-transplanting cultivation. When the sowing period was the same，as the seedling age increased，the days from sowing to heading period prolonged，the days from heading to maturity period shortened，and the whole growth period prolonged. The yield was the highest at 25 d seedling age. The planting density had no significant effect on the growth period. There was no significant difference among treatments in 2021. However，in 2022，the C1 treatment had the highest yield and was significantly higher than the C4 treatment. Overall，Chunyou 801 is suitable for planting as double-cropping late rice in Quzhou. The appropriate seedling age of mechanical transplanting is 25 d，and the planting density is 27.8×10⁴ hills per hectare，which is easy to obtain high yield.

Key words: rice, Chunyou801, seedling age, planting density, growth period, yield