Dry matter productivity and overwintering ability of the dwarf and normal napiergrasses as affected by the planting density and cutting frequency
Dry matter productivity and overwintering ability of the dwarf and normal napiergrasses as affected by the planting density and cutting frequency
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DOI：
10.1626/pps.6.65
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发表时间：
2003-03-01
影响因子：
2.5
通讯作者：
Sonoda, T
中科院分区：
文献类型：
--
作者：
Mukhtar, M;Ishii, Y;Sonoda, T
在日本九州南部地区，比较了矮秆品种（早抽穗、晚抽穗、DL）和正常品种（Wruk wona, Wr）和Merkeron （Me）建立后数年种植密度和刈割频率对干物质生产力和越冬能力的影响。Wr、DE和DL的种植密度为高（16株m(-2)，间距为25 cm × 25 cm）、中（8株m(-2)，间距为50 cm × 25 cm）和低（4株m(-2)，间距为50 cm × 50 cm）， Me仅为中密度。1999年每隔60天切割3次，2000年每隔90天切割2次。在不同种植密度下，矮秆品种分蘖数（TN）、叶面积指数（LAI）和叶片干重率（PLB）均高于普通品种，株高（PLH）、平均分蘖干物质重（MTW）和总干物质重均低于普通品种。随着种植密度的增加，全氮和牧草年干物质产量（HDMY）均增加。2000年的年HDMY（两次刈割）高于1999年的年HDMY（三次刈割），矮品种与正常品种的年HDMY差异通过高密度种植和两次刈割而减小。这是由于在高全氮条件下矮秆品种的MTW高于普通品种。越冬植株（POP）比例在DL品种中呈高于其他品种的趋势，2000年各品种均高于2001年，但随种植密度的增加呈下降趋势。尽管在任何种植密度和刈割频率下，正常品种的干物质生产力都高于矮秆品种，但无论种植密度和刈割频率如何，高PLB条件下，低密度品种的干物质生产力都趋于稳定。此外，与其他品种相比，它具有较高的越冬能力。
The effects of planting density and cutting frequency on dry matter productivity and overwintering ability were compared in the years following establishment among dwarf varieties (early-heading, DE and late-heading, DL) and normal varieties, Wruk wona (Wr) and Merkeron (Me), in the southern part of Kyushu, Japan. The planting densities examined were high (16 plants m(-2), 25 cm x 25 cm of spacing), medium (8 plants m(-2), 50 cm x 25 cm), and low (4 plants m(-2), 50 cm x 50 cm) for Wr, DE and DL, and was only medium for Me. The cutting frequency was three times at about 60-day intervals in 1999 and two times at about 90-day intervals in 2000. Irrespective of the planting density, dwarf varieties were higher in tiller number (TN), leaf area index (LAI) and dry weight percentage of leaf blade (PLB) than normal varieties, but lower in plant height (PLH), mean tiller dry matter weight (MTW) and total dry matter weight at all planting densities in both years. With the increase in planting density, TN and annual herbage dry matter yield (HDMY) increased. The annual HDMY was higher in 2000 (cut twice) than in 1999 (cut three times), and the difference in annual HDMY between the dwarf and normal varieties was reduced by planting at a high density and cut twice. This was due to higher MTW in dwarf varieties than in normal varieties at the higher TN conditions. The percentage of overwintered plant (POP) tended to be higher in DL than in other varieties and was higher in 2000 than in 2001 for all varieties, while it tended to decrease with the increase in planting density. Even though the dry matter productivity was higher in the normal varieties than in the dwarf varieties at any planting density and cutting frequency, DL tended to show a stable productivity with high PLB irrespective of planting density and cutting frequency. In addition, it had a high overwintering ability compared with the other varieties.