穗位高系数对玉米产量及产量构成的影响

为探究穗位高系数对玉米产量及产量构成的影响，采用125份玉米材料开展大田试验，测定株高、穗位高、穗位高系数、单穗粒数、千粒重及产量等性状指标。同时对1985—2019年可查文献中已发表的相关数据进行Meta分析。结果表明：1)株高和穗位高对单穗粒数、千粒重、产量均有极显著影响(P<0.01);穗位高系数对单穗粒数和千粒重影响显著(P<0.05)。2)玉米株高分布在175.10～295.00 cm,穗位高在53.50—127.67 cm,穗位高系数在0.29～0.49,随着株高、穗位高、穗位高系数的增加，单穗粒数呈先上升后下降的趋势，当株高为267.76 cm,穗位高为99.46 cm,穗位高系数为0.40时，单穗粒数达到最大值；千粒重随着株高、穗位高、穗位高系数的增加先呈直线上升趋势，之后不再增加，千粒重达到最大值时，株高为292.25 cm,穗位高为80.95 cm,穗位高系数为0.50;产量随株高、穗位高的增加而增加，随着穗位高系数的增加呈现先上升后下降的趋势，当穗位高系数为0.42时，产量达到最大值。3)对文献和本试验的数据分别进行决策树分析，结果均表明，株高较穗位高...

Effects of ear-to-plant height ratio on yield and yield composition of maize

In order to explore the effect of ear-to-plant height ratio on maize yield and yield composition, taking 125 maize materials as study object, field experiments were conducted to investigate effects of plant height, ear height, ear-to-plant height ratio on the kernel number, thousand kernel weight, and yield of maize. At the same time, the meta-analysis was adopted to analyze the data in related literature published from 1985 to 2019. The results showed that: 1)Plant height and ear height had significant effects on kernel number, thousand kernel weight and yield(P<0. 01). The ear-to-plant height ratio had significant effect on kernel number and thousand kernel weight(P<0. 05). 2)In this study, plant height ranged from 175. 10 to 295. 00 cm, ear height ranged from 53. 50 to 127. 67 cm, and ear-to-plant height ratio ranged from 0. 29 to 0. 49. With the increase of plant height, ear height and ear-to-plant height ratio, the kernel number first increased and then decreased. When plant height was 267. 76 cm, ear height was 99. 46 cm and ear-to-plant height ratio was 0. 40 cm, the kernel number reached the maximum. The thousand kernel weight first increased linearly with the increase of plant height, ear height and ear-to-plant height ratio, and then remained at a stable level. When the thousand kernel weight reached the maximum, the plant height was 292. 25 cm, the ear height was 80. 95 cm, and the ear-to-plant height ratio was 0. 50. The yield increased with the increase of plant height and ear height. With the increase of ear-to-plant height ratio, the yield first increased and then decreased. When the ear-to-plant height ratio was 0. 42, the yield reached the maximum. 3)The regression tree analysis of literature and field experiment data showed that plant height had a greater influence on kernel number than ear-to-plant height ratio. In view of the important influence of ear-to-plant height ratio on lodging resistance and kernel number of maize, the ear-to-plant height ratio is the key index of maize yield improvement. In conclusion, the stronger lodging resistance and higher kernel number are conducive to the further improvement of maize yield at ear-to-plant height ratio within 0. 40 to 0. 42.