期作與秈稉二型水稻品種之生育相研究

Abstract

本試驗在探討瞭解稻生產過程中影響高產的生理過程，形態特徵，以明瞭不同期作對秈稉二型水稻品種產量的高低是否由於品種的本質或其也因素或產量組成成份，以供今後改良二期作品種選拔之參考，玆將試驗結果摘要如下： 不同類型品種間期作對株高伸長的過程有極大的差異，半矮性秈稻品種或植株較矮的稉稻品種（如Todorokiwase）一期作株高的伸長速度，以生育前期大於生育後期，高稈的稉稻品種則生育後期大於生育前期，但以抽穗期達最高峰。二期作，二型品種株高的伸長速度，均以生育前期大於生育後期，但所受環境的影譽稉稻大於秈稻。 在第一期作之環境下，品種間初期分蘗數的增加影響甚微，移植後5~6週間為分蘗最旺盛時期，分蘗期約可延續一個月之久。二期作分蘗的增加趨勢與第一期作不相同，分蘗期短促為其一大特色但穗數仍以秈稻品種較梗稻品種多。 就供試6個品種言，一期作之稈高均高於第二期作，穗數亦以第一期作較第二期作多，但稉稻較秈稻差異大，（如高雄64號，一二期作差異27%為最大，次為Todorokiwase 12.5%，新竹矮腳尖4.1%，而嘉農秈11號無差異）。一穗粒數一二期作之差異以Todorokiwase為最大(24.8%)，次為臺農38號，高雄34號，新竹矮腳尖，分別為12.4, 10.5, 8.4%，以嘉農仙11號之3.2%最低。千粒重以新竹矮腳尖之差異最大(15.2%)，嘉農仙11號較少(4.7%)。 一二期作單位面積稻殼產量的差異，以Todorokiwase最大（減產30%）臺農38號及高雄64號次之（分別減產21.3及21.5%）新竹矮腳尖及嘉農秈11號居三（分別減產17.4及15.7％）以花草18號減產8.3為最少。 Plant type and growth pattern are known to be closely related with the physiological status which will effects directly to the yield of rice. The present studies are aimed to investigate the growth pattern and yield components of Japonica-and indica-type rices as influence by crop seasons. The results of the research findings are summarized in the followings: 1. The growth rate of semi-dwarf varieties was larger in the early stage than the later stage of growth, however, the opposite was true for the long-culmed japonica type varieties, but in the second crop season, it was larger in the early stage than in the later stage in the both types of varieties. The japonica type varieties were found to be more sensitive to the enviromental conditions of second crop within the materials used. 2. Under the first crop season, no remarkable difference in the tillering numbers at the early stage between indica and Japonica varieties was observed. The No. of tillers increased rapidly thereafter and reached its maximum 5-6 weeks after tansplanting. The period developing tillers remain as long as one month. In the second crop season it took only 7-10 days to reach the maximum tillering stage. It was observed also that the indica type varieties have more effective tillers than the japonica type varieties. 3. Yield components differ remarkably between japonica and indica rices and also between different crop seasons. In general, the larger values were observed with the first crop season. For example, the japonica type varieties Kaohsiung 64 and Todorodiwase showed 27% and 21.5% increase in panicle per hill in the first crop than that in the secon crop. The indica type variety Hsinchu Ai-chiao-chien showed a smaller value (4.1%)of increment and no difference was observed for Chianung-sen 11 between the two crops. 4. Todorokiwase showed 24.8% more number of grains per panicle in the first crop than the second crop ofllowed by Tainung 33(12.4%), Kaosiung 64(10.5%) and Hsinchu Aichiao-chien (8.4%). Hsinchu Ai-chiao-chien shoved 15.2% higher in 1,000 grain weight in the first crop than that in the second crop, while Chianung-sen 11 was 4.7% more in the first crop. 5. Varietal difference in the degree of yield decrease in the second crop than of first crop was observed which were in the .order of Todorokiwase (30%), Tainung 38 (21.3%) Kaohsiung 64 (21.5%), Hsinchu Ai-chaio-chien (17.4%) , Chianung-sen 11 (15.7%) and Hualien 18 (8.3%) respectively.