|Title:||水稻之穗肥效應及診斷研究||Other Titles:||Response of Rice Yield to Nitrogen Top-Dressing during Panicle Initiation Stage and the Diagnosis||Authors:||連深
|Issue Date:||2-Mar-1972||Publisher:||農業試驗所||Journal Volume:||21||Journal Issue:||1||Start page/Pages:||11-17||Source:||農業研究||Abstract:||
2. 穗肥之效果和葉鞘之澱粉堆積程度大致成正相關關係。即殿粉堆積愈明顯者，穗肥效果亦愈大。但其判定之基準仍因環境而稍異，如據臺北第一期作試驗結果，第四葉葉鞘之 部位，若有澱粉堆積則穗肥有效，若完全無碘反應則穗肥無效。但據屏東第一期作試驗結果，所觀察之判定基準則以四葉葉鞘之 部位（由底部量）為適合，即第四葉葉鞘之 部位如有澱粉堆積，則穗肥有效。
To develop a simple scheme for diagnosing the demand of nitrogen topdressing during panicle initiation stage (the stage when panicle primordium of about 1-2 mm long appears in the sheath), a study on relationship between the nutritional status of rice plant and its response to the fertilizer application has been conducted. The results are as follows:
1. The response of rice plant to panicle fertilizer was observed well correlated with the nitrogen content in the plant during panicle initiation stage, i.e., the lower the nitrogen content in the plant, the higher the response of the plant to the topdressing. In the first crop, the critical nitrogen content for obtaining positive yield response as observed in the Pingtung experiment (1968) was about 1.8-1.9%. However, as environmental condition varies, some fluctuation seems inevitable, e.g., the critical level observed in the Taipei expeirments (both 1968 and 1969 first crop) was about 2.0%.
2. The iodine reaction of sheath during panicle initiation stage was also correlated with the response of the rice plant to panicle fertilizer, although the criteria for determining the necessity of top dressing differ considerably among localities. For instance, in the Pingtung experiment (1968 first crop) the iodine reaction on the 3/4 position (as measured form the bottom of the sheath) of the fourth leaf sheath (the sheath attached to the fourth leaf as counted from the top, including the needle leaf) was observed critical for the diagnosis, i.e., if the reactions are mostly negative (90/100), the application of panicle fertilizer is not recommended and vice versa. Howver, in the Taipei experiment (1968 and 1969 first crop) the examination of the 1/2 position was observed more adequate for the diagnostic purpose.
3. Since the criteria for the diagnosis vary somewhat according to environmental conditions and to rice varieties, it is recommended that the exact figure should be determined locally where environmental conditions and varieties are similar.
|Appears in Collections:||1.台灣農業研究(1950～迄今)|
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