(40(2):209-224)Regional Trial on the Yield Performance and Adaptability of Hybrid Rice Strains

試驗的目的在調整雜種水稻品系之種植適期，利用疑似感光性，探討每年種植單期作條件下，是否可發揮雜種優勢而提高增產潛力，以應稻田轉作政策及改進輪作制度之需。本試驗於民國77年利用氣溫較高之夏秋季於全省七個地點進行，測驗八個秈稻雜種品系之稻穀產量及適應性。試驗結果顯示；參試品系在各地之稻穀產量差異極大，在桃園新屋、花蓮、宜蘭三星三處因種植期較早，臺秈雜育1、7及11號等三品系因抽穗障礙而致產量偏低或全無收穫，僅有臺秈雜育2與6號兩品系的平均稻穀產量比對照品種臺中秈10號稍高；在彰化大村等四處採用一般正常二期作之早植，疑似感光性之臺秈雜育1、7及11號三品系平均稻穀產量較對照品種增產10.1─24.9％。臺秈雜育2號在各試驗地區產量最穩定，不論於五月的中間作或七月的一般二期作早植栽培，其平均產量都超過對照品種臺中秈10號。試驗結果顯示如能適當的調整種植時期及利用雜種品系之疑似感光性，可使雜種水稻品系發揮其高產潛力。Experiments were conducted at 7 locations to study the yield performance, adaptability and response to photoperiod of 8 indica hybrid rice strains, Rice was cultured as a mid-season crop with transplanting dates ranged from May to July in 1988. Experimental results indicated significant yield variation for hybrid strains among locations. At Hsinwu (Taoyuan), Sanhsing (Ilan) and Hualien, early transplanting in May rendered the three photosensitive strains, i. e. Tainung Sen Hybrid (TNSH) Nos. 1,7 and 11, to show difficulties in panicle extrusion. Grain yield was therefore very low, or even no harvest, for these strains. For overall average grain yield of the other 5 photo-insensitive strains, only TNSH Nos. 2 and 6 was higher than the check variety Taichung Sen No. 10. At Tatsun (Changhua), Lutsao (Chiayi), Pingtung and Taitung, late transplanting in June and July was carried out and different results were recorded. The three photo-sensitive strains out yielded the check variety by 10.1-24.9%, and all the photo-insensitive strains. TNSH No.2 showed the best adaptability as its grain yield averaged from 7 locations was 6.3% higher than the check variety. Based on the results of this experiment, it is suggested that by adjusting planting date and utilizing photosensitivity, yield performance of hybrid rice can be improved greatly when cultured under local conditions