穴格容積對小白菜穴盤苗生育之影響

Pak-choi cv. 'Dai Tokyo' were sown in 72, 128 and 288-cell plug tray to study the cell sizes effects on seedling growth. Results indicated that, no significant difference on the fresh weigh, dry weight, leaf number, leaf area and root length among different cell sizes at early stages, However, the difference among treatments increased and became significant after 12 days of sowing. Seedlings in 72-cell plugs showed the best growth. The root/shoot ratios was found higher on seedlings in 288-cell plugs than those in 72-cell and 128 cells. The relative growth rates of roots and shoot were also found higher at early growth stage and decreased as seedling ages increased. Both the seedlings in 72 and 128-cell plug had the similar trends in plastchron index values, but that of the seedlings in 288-cell plugs was significantly lower.本試驗探討'大東京'小白菜於72、128及288格三種穴盤育苗對幼苗生育之影響，結果顯示小白菜幼苗之單株鮮重、乾重、本葉數、葉面積、葉長、根鮮重、乾重及根長等皆與穴格容積成正相關，且與播種後天數呈二次回歸正相關。播種後9-12天，在不同穴盤間並無顯著差異，隨著播種後天數增加，差異逐漸加大，以在72格穴盤有最佳生育，Plastochron Index(PI)值在72及128穴格趨勢相似，而288穴格為最低。'大東京'小白菜之地下部/地上部比以288穴格者較72及128穴格者高。地上部及根部鮮重之相對生長速率，在播種後初期成最高值，隨播種後天數增加相對生長速率逐漸降低。288穴格苗株在播種後21天之相對生長速率較72及128穴格者小，其後差異減少不顯著

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

三品種小白菜播種後在72、128及288格穴盤，播種後9-12天，其單株鮮重、乾重、本葉數、葉面積、根鮮重、乾重及根長等，在不同穴盤中並無顯著差異。隨著播種後天數增加，差異逐漸加大，以在72格方型穴盤有最佳生育。大東京小白菜之根/莖比以288穴格者較72及128穴格者高。鮮重及乾重之相對生長速率，在播種後初期呈最高值，隨播種後天數增加相對生長速率逐漸降低。288穴格苗株在播種後21天之相對生長速率較72及128穴格者小，其後差異減少不顯著。根部活力表現，以128穴格者其根部TTC在單位鮮重含量最高，72穴格者最低。PI值計算定植苗齡及穴格容積之表現，以72及128穴格PI值相似且較288穴格高。 定植田間後，品種、苗齡及穴格容積在單株鮮重、乾重、本葉數及株高均呈顯著性差異，以鳳京小白菜之單株鮮重、乾重及株高最佳。苗齡12、15及18天苗株之比較，隨著苗齡愈大，其定植時或定植後採收，均以苗齡18天苗表現最佳。穴格容積以72穴格苗定植後其單株鮮重、乾重、本葉數及株高最佳，以128四孔子母套格最差。但定植後12天初期採收，以18格穴盤者最低，隨著定植後天數的增加，生育速率加大至18天採收其單株產量僅較72穴格低。其相對生長速率以土白菜最高，苗齡之間以18天苗齡最低，隨著定植後天數增加，相對生長速率隨之增加，以128穴格苗直接定植最高，顯示幼苗活性較高，而18格穴盤苗最低。調查最大葉片之鮮重、葉面積及葉片之位置，顯示品種、苗齡及穴格容積均呈顯著性差異，而最大葉片之單葉鮮重及葉面積結果，與單株鮮重相似，呈顯著相關關係，可供作單株鮮重或產量之指標。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.目錄 壹、 前 言………………………………………………………1 貳、 前人研究……………………………………………………3 一、 植物根的功能……………………………………………..3 二、 根域限制對植物生育之影響……………………………..3 三、 穴盤育苗對蔬菜作物生育之影響……………………… 6 四、 穴格容積與苗齡對蔬菜作物生育之影響……………… .8 參、 試驗材料及方法………………………………………… 12 一、 試驗材料………………………………………………….12 二、 試驗方法………………………………………………….12 肆、 試驗結果………………………………………………… 16 一、 穴格容積對小白菜穴盤苗生育之影響………………….16 （一） 小白菜生育性狀……………………………………… 16 （二） 根部/地上部乾重比…………………………………..26 （三） 相對生長速率………………………………………… 26 （四） 根部活性……………………………………………… 32 （五） Plastochron Index（PI）值…………………………32 二、 品種、苗齡及穴格容積對小白菜穴盤苗移植後生育之影響 ………...................................... 37 （一） 單株鮮重……………………………………………….37 （二） 乾重…………………………………………………….37 （三） 株高…………………………………………………….39 （四） 最大單葉鮮重………………………………………….39 （五） 最大單葉之葉面積…………………………………….42 （六） 本葉數………………………………………………….42 （七） 最大葉片之葉數位置………………………………….46 （八） 相對生長速率………………………………………….46 三、 品種、苗齡及穴格容積對小白菜定植後生育性狀之相 關關係…………………………………………………… 46 伍、 討論……………………………………………………… 54 一、 穴格容積對小白菜穴盤苗生育之影響………………….54 （一） 生育性狀之影響……………………………………….54 （二） 穴格容積對小白菜根部活性之影響………………….57 （三） 穴格容積對小白菜Plastochron Index之影響…… 58 二、 品種、定植苗齡及穴格容積對小白菜穴盤苗移植後田 間生育之影響…................................ 58 （一） 生育性狀之影響……………………………………….58 （二） 相對生長速率……………………………………….. 62 （三） 小白菜相關性………………………………………. .63 陸、 中文摘要………………………………………………… 65 柒、 英文摘要………………………………………………… 66 捌、 參考文獻………………………………………………… 6