群体密度对夏玉米穗下茎秆性状及抗倒力学特性的影响

设置4.50、5.25、6.00、6.75、7.50万株?hm-2 5个密度处理,于2015和2016年研究种植密度对川中丘区夏玉米穗下茎节性状和抗倒力学特性的影响,为玉米密植抗逆高产栽培提供理论依据。结果表明:随群体密度增加,穗下由基部向上第2-5节节长增长,第3和5节T5较T1分别增加了19.04%、13.93%(2015)和22.84%、26.76%(2016),第6-8节变化不显著,穗下各节节粗变细。节干重、单位茎长干物质重、穿刺强度和压碎强度均随密度的增加而降低。相关分析结果表明,茎秆倒伏率与茎秆节间直径、茎秆的干重、单位茎长干物质重呈极显著的负相关,而与种植密度、节间长度呈显著正相关;与第3-5节和第8节(穗下第1节)的穿刺强度和压碎强度均呈极显著负相关,茎秆压碎强度和外皮穿刺强度也具有非常密切的相关关系,相关系数为r = 0.96**。 英文摘要: The effects of planting density on the stalk traits and the lodging-resistance of summer maize were studied in 2015 and 2016 by setting 5 density treatment, respectively 45000, 52500, 60000, 67500 and 75000 plants/ha, providing the theoretical basis for the anti-adversity and high-yielding cultivation of maize close planting. The results showed that the length of section 2-5 increased and the 6-8 section changes were not significant from the base up with the increase of population density .Compared with T1, T5 was increased by 19.04%, 13.93% (2015) and 22.84% and 26.76% (2016) respectively in the 3rd and 5th. With the increase of population density, internode diameter of stem under the ear was decreased . With the increase of density, the dry weight, dry matter weight per unit length, puncture strength and crushing strength per internode were decreased. The correlation analysis showed that there was a significant negative correlation between stalk lodging rate and internode diameter of stem, stem dry weight and dry matter weight per unit length, but significant positive correlation with planting density and internode length. There was a significant negative correlation between puncture strength and crushing strength in section 3-5 and section 8 (the first section under the ear), and the crushing strength of stem and the puncture strength were also closely related with the correlation coefficient r= 0.96 **. 查看全文
;