綠蘆筍嫩莖開芒控制之研究

Abstract

綠蘆筍嫩莖在溫度較高之6～9月份（平均溫度30℃以上），容易發生頂部鬆開，除了受品種及氣溫因子所影響外，適當之施肥及灌溉可減少頂部鬆開，且可促進嫩莖肥大。採收期間每隔五天灌水一次（土壤保持含水量16～20％），或每隔八天灌水一次（土壤保持含水量14～20％），且畦面覆蓋稻草，嫩莖之頂開數最少，產量較高，嫩莖亦較粗大，每隔十五天灌水一次（土壤含水量保持10～20％），則嫩莖頂開數增加，嫩莖較細小，產量亦較低。氮肥施用較多時，嫩莖頂開數有增加之現象。每十公畝施用氮素180kg，較施用60kg，及120kg者所得之頂開數為多，產量亦不因多施氮素有顯著之增加。 The tops of green asparagus spears tend to loose more bracts during the high temperature period (above 30℃) from June to September in Taiwan. Previous reports have stated that many factors such as variety, climate, fertilization, soil moisture content, etc. all affect the size and tightness of bracts of spears. This experiment attempts to measure the suitable methods in fertilizer application and irrigation for decreasing the number of open-head spears and increasing the spear size for processing use. The results are summarized as follows: 1.Among four irrigation intervals: 5,8,10 and 15 days, it is found that 5 or 8 days interval plus straw mulching on the surface of designed plots maintained soil moisture content within 14~20%, and produced bigger and less open-head spears. Applying nitrogenous fertilizer 60, 120, 180 kg per 0.1 ha per year found that the 180 kg one produced more open-head spears than the low fertilizer applications. Also it is found that nitrogenous fertilizer 60 kg per 0.1 ha would be enough to produce the maximum yield of green asparagus spears.