播期与密度对新疆地区露地洋葱越冬育苗的影响

Effects of Sowing Date and Density on Overw intering Seedling of Open Field Onion in Xinjiang

旨在研究不同播期与不同播种密度对洋葱露地越冬育苗及洋葱生长发育的影响。以‘白雪’F1陈种子为试验材料,设计4个播期:A1(10月22日)、A2(10月28日)、A3(11月3日)、A4(11月9日);3个密度:B1(4粒/穴)、B2(6粒/穴)、B3(9粒/穴),共12个处理,通过测定幼苗的生长指标和光合指标,分析播期及密度对露地越冬洋葱幼苗生长的影响。结果表明,同一播期随密度的增大,幼苗假茎粗与叶片数、叶片的日平均净光合速率、气孔导度、蒸腾速率均呈下降趋势,而幼苗株高和叶片胞间CO_(2)浓度呈增大趋势;同一密度随播期的推迟导致光照时间缩短,幼苗株高、假茎粗、叶片数与胞间CO_(2)浓度呈降低趋势,幼苗叶片日平均净光合速率、气孔导度和蒸腾速率逐渐增大趋势。综上,北疆地区洋葱露地越冬在11月9日采用一穴6粒的方式种植有助于洋葱幼苗叶片进行光合作用,积累更多的光合产物,为植株的生长提供更多的营养物质。

The effects of different sowing dates and different sowing densities on the overwintering of onion seedlings in the open fields of Xinjiang were studied to reveal the effects of different sowing dates and density treatments on the growth and development of onions.‘Baixue’F1 seeds were used as test material,and 4 sowing dates of Al(October 22),A2(October 28),A3(November 3)and A4(November 9);3 densities,of Bl(4 grains/hole),B2(6 grains/hole),B3(9 grains/hole),were de-signed;total of 12 treatments were set up,the effects of sowing dates and densities on overwintering of onion seedlings in the open field were analyzed by measuring the growth index,biomass and photo-synthetic index of the seedlings.The results showed that with the increase of density on the same so-wing dates,the pseudostem thickness and the number of leaves,the daily average of net photosynthetic rate,stoma conductance,and transpiration rate of the seedlings showed a downward trend,while the height of the seedlings and the leaves the intercellular CO_(2) concentration showed an increasing trend;under the same densities,the sowing date was delayed,the light time was shortened,the plant height of seedling,pseudostem thickness,leaf number and intercellular CO_(2) concentration showed a decrea-sing trend.The average of daily net photosynthetic rate and stomata of seedling leaves,the conduct-ance and transpiration rate gradually increased.In summary,the appropriate sowing dates and reason-able dense planting have a certain effect on the growth of seedlings.The onion seedlings in the open field in northern Xinjiang will be planted on November 9 with a method of 6 seeds in one hole.Leaves undergo photosynthesis,accumulate more photosynthetic products to provide more nutrients for plant growth.