不同类型饲用玉米品种群体生理指标的研究

A study on the population physiological indices of different types of forage Zea mays

通过2种类型饲用玉米品种的密度定额试验，结果表明，2类饲用玉米品种的生理特性和生长发育规律不同。明确了青贮青饲型玉米科多8号的适宜栽培密度为6．73万株／hm^2左右，合理叶面积指数吐丝期为6．80左右·成熟期保持在4．05以上．全生育期总光合势应维持在417．88万（m^2·d）／hm^2以上．平均净同化率应在5．72g／（m^2·d）以上．平均作物生长率在226．12kg／（hm^2·d）以上，其生物学产量可达到20778．4kgthm^2；粮饲兼用型玉米陕单310的适宜栽培密度为6．90～7．95万株／hm^2，合理叶面积指数吐丝期为5．71～6．47．成熟期为3．54～3．94，全生育期总光合势应在358．11万（m^2·d）／hm^2以上．平均净同化率在5．06g／（m^2·d）以上．平均作物生长率在183．66kg／（hm^2·d）以上．其籽粒产量可达7248．5kg／hm^2．生物学产量可达到14798．0kg／hm^2。

The physiological characteristics and growth rates of two different types of forage Zea mays were compared at different plant densities. The optimum plant density for Z. mays silage Keduo 8 was about 67 300 plants/hm^2, An appropriate leaf area index （LAI） was 6.80 and 4.05 in the spinning and mature stages respectively, while the total leaf area duration （LAD） was about 4. 178 8 × 10^6 （m^2 · d）/hm^2. During the whole growth period, average net assimilation rate （NAR） and crop growth rate （CGR） were 5.72 g/（m^2 · d） and 226.12 kg/（hm^2 · d） respectively and biomass was 20 778.4 kg/hm^2. A suitable planting density for dual-purpose Z. mays Shandan 310 was about 69 000-79 500 plants/hm^2, with a LAI ranging from 5.71-6.47 and 3.54-3.94 in the spinning stage and mature stages respectively. Total LAD was about 3. 581 1× 10^ （m^2 · d）/ hm^2 during the whole growth period. Average NAR and CGR were 5.06 g/（m^2 · d）and 183. 66 kg/（hm^2 · d） and biomass and grain yield were 14 798.0 and 7 248.5 kg/hm^2 respectively.