不同排种量对甘薯采苗量和薯苗质量的影响

为了明确排种量对甘薯采苗量和薯苗质量的影响，以商薯19(S19)和烟薯25(Y25)为试验材料，采用平排的方式，设置10、15、20、25 kg/m² 4个排种量，其中25 kg/m²为常规排种量，从采苗量、薯苗质量、薯苗生长特性和薯苗群内环境条件(温湿度和光照强度)等方面进行分析。结果表明：S19和Y25的采苗量均随排种量的增加表现先升高后降低的趋势，以20 kg/m²排种量处理最高，分别为2 124株/m²和986株/m²，较10、15、25 kg/m²处理分别显著增加107.4%、19.1%、10.1%和100.4%、45.4%、8.6%;Y25叶片净光合速率、茎部剪切力和拉伸力也均以20 kg/m²排种量处理最高，分别较25 kg/m²排种量处理显著增加16.54%、25.4%、44.5%;S19和Y25薯苗壮弱比、茎部机械力、茎部木质素含量及叶片、叶柄和茎干率也都是20 kg/m²...

The Effect of Different Seeding Amounts on Quantity and Quality of Sweet Potato Seedlings

Abstract: In order to determine the effect of seeding amounts on the quantity and quality of sweet potato seedlings, ''Shangshu19'' (S19) and ''Yanshu25'' (Y25) were used as experimental materials, and four seeding amounts of 10, 15, 20, 25 kg/m2 were set in a way of horizontal arrangement, in which 25 kg/m2was the conventional seeding amount. The quantity, quality, growth characteristics of seedlings and internal environment conditions (temperature, humidity and light intensity) of sweet potato seedling groups were studied. The results showed that the seedling quantity of ''S19'' and ''Y25'' increased at and then decreased with the increase of seeding amounts, the highest seeding amount treatments of 20 kg/m2 were 2 124 plants/m2 and 986 plants/m2, which were 107.4%, 19.1%, 10.1% and 100.4%, 45.4%, 8.6% higher than those of seeding amount treatments of 10, 15, 25 kg/m2, respectively. The net photosynthetic rate of leaf, shear force and tensile force of stem of ''Y25'' were also the highest in seeding amount treatment of 20 kg/m2, which increased by 16.54%, 25.4% and 44.5% compared with seeding amount treatment of 25 kg/m2, respectively. ''S19'' and ''Y25'' treated with 20 kg/m2 seeding amount were also significantly higher than those of 25 kg/m2 seeding amount treatment, such as the strength-weakness ratio of seedlings, mechanical force of stems, lignin content of stems, dry-matter rate of leaves, petioles and stems. The light intensity of ''S19'' and ''Y25'' seedlings decreased with the increase of seeding amounts, and the seeding amount treatment of 20 kg/m2 increased by 20.1% and 18.2% compared with 25 kg/m2seeding amount, respectively. The relative humidity of seeding amount treatment of 20 kg/m2 decreased by 12.2% and 4.7% compared with 25 kg/m2 seeding amount, respectively. The temperature of seedling population decreased first and then increased with the increase of seeding amounts, and the temperature of of 20 kg/m2seeding amount of ''S19'' decreased significantly by 5.1% compared with that of 25 kg/m2 seeding amount. In summary, the appropriate seeding amounts could form a reasonable population structure of sweet potato seedlings, improve the microclimate within the population, advance the photosynthetic performance and stem mechanical force of sweet potato seedlings, promote dry-matter accumulation of seedlings, and significantly raise the quantity and quality of sweet potato seedlings. Under the condition of horizontal row, the optimum seeding amounts for the purpose of seedling quantity was 20 kg/m2.