草苺育苗母株培育期與方法對種苗增殖倍率的影響

Abstract

本試驗目的為在不影響草苺正常開花與生產的前提下，找出培育母株苗作次年用育苗母株的適期與方法。八月初定植之‘桃園三號’草苺，於九月初開始以誘植法與扦插法培育走莖苗，至二月底，誘植法平均每株成活的苗數，以早期(九月至十月中) 0.93株與中期(十月中至十一月底) 0.70株較多，晚期(十二月至一月) 0.25株較少；扦插法則以中期1.25株較多，晚期0.45株次之，早期0.25株較少。培育成活率三個時期皆以誘植法較高(早期90%、中期96%、晚期100%)，而扦插法則早期較低(53%)，中期次之(74%)，晚期較高(91%)。母株苗的株高以扦插法繁殖者較高，葉片數以中期較多，根冠數無顯著差異，根冠高度以誘植法繁殖者較高，根冠直徑以扦插法繁殖者以早期較大，呈現愈後期愈小的趨勢，而誘植法根冠直徑各時期差異不顯著，但呈現愈後期愈大的趨勢，母株疏除的花序以早期及中期較多，晚期較少。迴歸分析顯示根冠高度及葉片數為估算母株重量的良好指標。兩種繁殖方法對栽培植株之開花時間影響不大，但以扦插法處理者定植後產生較多的走莖、花序與母株苗數，花序上的小花數較多。不同繁殖方法與時期之母株苗，定植後的走莖數及總繁殖苗數差異不顯著，但成活的種苗數在誘植法以早期培育者36.1株 (86.0株/m2)較多，中期者27.3株 (65.0株/m2)次之，晚期25.8株 (61.4株/m2)較少；扦插法同樣以早期培育者38.1株 (90.7株/m2)較多，中期者32.3株 (76.9株/m2)次之，晚期者27.4株 (65.2株/m2)較少，而商業等級的種苗數，亦有早期培育者較多，晚期培育者較少之趨勢。扦插法的育苗母株的種苗產生較多葉片數，但各時期差異不顯著；根冠高度及根冠直徑，則繁殖方法與時期的效應皆不顯著。迴歸分析顯示，母株苗定植前的自然株高及第四片展開葉的葉柄長，可能為預估育苗母株育苗表現的指標。試驗結果顯示，於栽培期同時培育母株苗作次年的育苗母株，以早期扦插法繁殖母株苗較佳，不僅有較多的苗供繁殖，且對栽培植株開花的影響較少，且在定植後能產生較多的成活苗數及商業等級苗數。

In order to find the suitable seasons and methods to propagate strawberry runner plant as next year’s nursery stock plants, ‘Tayouan No.3’ strawberry stock plants were planted at early August, and stock plantlets were propagated from Sep. to late Feb. from layering and cutting method. The stock plantlets propagation seasons were divided as early (Sep. to mid-Oct.), mid-term (mid-Oct. to Nov.), and late (Dec. to next Feb.). Mean survival stock plantlets per stock plant from layering method was higher at early with 0.93 plant and mid-term with 0.70 plant, and lower at late with 0.25 plant; as cutting method, it was higher at mid-term with 1.25 plants, next at late with 0.45 plant, and lower at early with 0.25 plant. Stock plantlets survival rate was higher from layering method in all season (early 90%, mid-term 96%, and late 100%) but from cutting method with lower at early (53%), medium at mid-term (74%), and higher at late (91%). Stock plantlets was higher from cutting method had higher plant height and crown height. No matter to method, stock plantlets at mid-term had the most leaves. Stock plantlets propagated from cutting method had larger crown size at early and significantly got smaller at mid-term and late. However, there was no significant difference among all season from layering method, but the crown size was gradually larger since early through late. Numbers of inflorescences removed was more at early and mid-term, less at late. Crown height and number of leaves were the better index to predicted stock plantlets weight by regression analysis. Propagation method had less effect on flowering time of cultivated plants, but those stock plantlets propagated from cutting method had more runners, inflorescences, total survival stock plantlets, and more small flowers on the inflorescence. Runners and total propagated runner plants generated by stock plants were non-significant among all seasons and methods, however, survival runner plants from stock plants by layering were more at early with 36.1 plants (86.0 plants /m2), next at mid-term with 27.3 plants (65.0 plants /m2), and less at late with 25.8 plants (61.4 plants / m2); stock plants by cutting method had the same tendency, more at early with 38.1 plants (90.7 plants /m2), next at mid-term with 32.3 plants (76.9 plants /m2), last at late with 27.4 plants (65.2 plants /m2). Commercial standard runner plants also had the same trend with more at early season and less at late season. Runner plants from stock plants with cutting had more leaves than by layering, but crown height and crown size were non-significant among stock plants from different methods and seasons. Plant height and the petiole of 4th expanded leaf of stock plantlets before planting would be the better index to predict the stock plants appearances in nursery by regression analysis. It was suggested to propagate stock plantlets as next year’s nursery stock plant by using cutting method at early, not only for less effect on flowering of cultivated plants and more runners for propagation, but also for more survival runner plants and commercial standard runner plants after planting at nursery.