Influence of plug size and seedling age on growth of Pak-choi(Brassica campestris L.)

• Main Authors: Chia-Ling Hsu, 許佳玲
• Other Authors: Woo-Nang Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/21789147953564839531

碩士 === 國立中興大學 === 園藝學系 === 90 === Three cultivars of Pak-choi were sown in 72,128 and 288-cell plug trays, their plant fresh weight, dry weight, leaf number, leaf area, root fresh weight, root dry weight and root length showed no significant difference among different cell size after 9 to 12 days of sowing. However, the difference would increase gradually as days after sowing increased. Seedlings in 72-cell plug showed best growth. The root shoot ratio of cultivar ‘Dai Tokyo’ in 288-cell was higher than seedlings sowed in 72 and 128 cell plug. Relative growth rate of fresh weight and dry weight had the highest value in early seedling growth, but gradually increased as sowing days increased. Plants sowed in 288-cell showed less in relative growth rate at 21 days after sowing in comparison to seedlings in 72 and 128-cell but difference become less in later growth. Testing of root vigor indicated that seedling in 128-cell had higher TTC in fresh weight unit and seedlings in 72-cell were the lowest. Using PI value for measuring vigor affected by seedling age and cell size in plant growth after transplanting showed that both plants in 128 and 72-cell had higher PI value than the 288-cell. There were significant difference among cultivars, seedling age and cell size on fresh weight, dry weight, leaf number and plant height after transplanting into field. Cultivar ‘Feng Jing’ had the highest shoot fresh weight, dry weight and plant height. Among seedling age of 12, 15 and 18 days, the higher seedling age of the 18 day seedling had the best growth after transplanting. Plants in difference cell size showed that 72-cell plug seedling had the best shoot fresh weight, dry weight, leaf number and plant height, but the 4-unit of 128 cell was the lowest. Plants in 18-cell plug showed lower growth rate at 12 days after transplanting but growth rate increased with number of planting days. It was only less than plant in 72-cell when harvested at the 18th day. Relative growth rate after transplanting was highest in cultivar ‘To Pak-choi’ or those directly transplanting from 128-cell plug and 18 day seedling were lower in early growth than increased later which indicated that young seedlings had higher vigor. There were significant differences on fresh weight of the largest leaf, leaf area, position of leaf among cultivars, seedling age and plug size. The single leaf fresh weight and leaf area were positive correlated with single plant fresh weight which can be used as index for predicting yield.