蘆筍品質及產量改進方法之初步研究

Preliminary Studies on the Improvements of Quality and Yield of Asparagus

本研究目的在於探究影響蘆筍品質及產量之因子，並加以實驗研究作為改進應用之依據，以建立亞熱帶最合理之蘆筍生產技術基礎，發展臺灣蘆筍產業。本研究方法分為：（一）蘆筍新品種在亞熱帶之生態特性觀察研究，（二）亞熱帶蘆筍栽培技術改進試驗，（三）人為誘導休眠方法試驗，（四）殺草劑藥害測定試驗，（五）蘆筍嫩莖採收後處理試驗五個實驗進行。茲將所得結果摘要如下：1.就供試10個新品種之嫩莖生產力而言，生產力較高之品種有UC309，UC711，UC72，生產力中等之品種有NJ264，NJ265，UC500W，生產力較低之品種有NJ306，NJ305，NJ304，UC66。2.白蘆筍以產量高，嫩莖中大，端正，少扁平莖之品種為佳，本試驗認為UC711品種為白蘆筍有望之品種。3.綠蘆筍品種以嫩莖粗大，色澤濃綠，產量高之品種為佳，本試驗認為UC309品種為最有希望之綠蘆筍品種。4.蘆筍產量之分佈以採收開始時為較高，隨採收期間逐漸遞減，如採收期間不留母莖使其行同化作用則其遞減現象更顯著。5.本試驗結果，白蘆筍開始採收30天後留母莖區比採收後15天，40天，75天留母莖區或不留母莖處理者產量為高，至於所留母莖數以3莖為佳。6.根據本試驗結果，綠蘆筍之留母莖方式以採收後一個月內留母莖較不致影響後期嫩莖之產量。7.綠蘆筍之株距大小，據第一年試驗結果，以20 cm區產量較高，30 cm, 40 cm區次之，但嫩莖平均種以30 cm為較大。8.臺灣冬季低溫不夠，蘆筍植株未能全部進入休眠狀態，如僅用很能制灌水方法，或折莖方法人工控制其休眠效果不大。就本試驗供試8種藥劑而言，以2% Gramoxan, 5% Casoron, 20%硫酸錏，10%尿素，1%MH-30溶液為最有效，前兩者藥效較快，但濃度過高則有抑制新嫩莖生育之現象；後三者藥效較為緩慢，但對新嫩莖之發育有利，為蘆筍有望之人為誘導休眠劑。9.本試驗供試11種殺草劑，對於白綠蘆筍幼莖有發現藥害現象者，有Casoron, TOK E-25, Flight A, Amizol。就殺草效果而言，以每公頃1公斤Diuron或Monuron較有希望。10.蘆筍嫩莖採收後處理對於品質之影響甚大。嫩莖採收後放置於室溫下，在短時間內其維他命C含量亦有顯著之變化。據分析結果，採收3小時之白蘆筍所含維他命C量比採收後即生分析者低12.83%，採收後6小時之綠蘆筍所含之維他命C量比採收後即行分析者低13.30%，因此採收後之蘆筍嫩莖以最迅速方法送至加工廠製罐或快速冷凍加以提高品質。11.嫩莖採收後之貯藏溫度對於維他命C含量變化頗大，在室溫放置二天之白蘆筍僅為2℃低溫處理比5℃低溫處理之貯藏效果更佳。故採收後之嫩莖應立即放置於2℃低溫或行預冷處理除去嫩莖之田間熱後冷藏於低溫，以抑制蘆筍品質之變劣。12.採收後之嫩莖雖在低溫貯藏，但如貯藏期間太外，其維他命C含量亦會減低，據分析結果綠蘆筍在5℃貯藏15天之維他命C含量僅為收直後之24.71%，在2℃貯藏者為42.95%，在-27℃冷凍者為50.72%，故綠蘆筍採收後應立即快速冷凍加工為佳。13.蘆筍嫩莖採收後，其外觀品質如色澤、萎縮、長度、重量、筍尖散開等亦有變化，而此變化速度受水分及溫度之影響為最大。如貯藏於低溫再供90%以上之相對濕度或浸水處理則有利於外觀品質。14.綠蘆筍之營養價值比白蘆筍為高，據分析結果採收直後之白蘆筍每100公克嫩莖之維他命C含量為29.155 mg，而綠蘆筍含有44.636 mg，比白蘆筍高53.10%。再者，綠蘆筍除供冷凍製罐加工用外，又適宜作新鮮蔬菜消費，因此臺灣應多獎勵生產綠蘆筍供國人消費，以提高國民營養。

The purposes of those studios were to ascertain the factors of affecting the quality and yield of asparagus (Asparagus officinalis L.) and to establish a reasonable cultural methods in the Tropics and to develop the asparagus industry in Taiwan. There were many ways to improve the asparagus quality and yield such as through genetic factors cultual physiological factors and post-harvest physiological factors. Five experiments including (1) Ecological observation of new varieties in the Tropics, (2) Improvement of cultural practices, (3) Effect of artificial dormancy, (4) Plant injury of herbicides. (5) Post-harvest handling practices were carried out at Fengshan Trop. Hort. Expt. Sta. The experimental results were summarized as follows: 1. With regard to the productivity of variety used, UC309, UC711, UC72 were high yield varieties, NJ254, NJ265 UC500W were medium, and NJ107, NJ305 NJ304, UC500W were low yield varieties. 2. UC711 was considered as the most promising variety in this trial for white asparagus due to its high yielding and uniform, medium-sized spears. 8. UC309 was considered as the most promising variety in this trial for green asparagus due to its larger spears with dark green color and high yielding 4. The distribution of yield would be declined from the beginning of harvesting and this inclination would be significant and rapid if no stems reserved during the harvesting period. 5. The yield of white asparagus in the plot with reserving stems after 30 days harvesting was higher than those in plots with reserving stems after 15 days, 40 days, 15 days harvesting or without reserving stems. As to the number of reserving stems, 3 stems seemed to be better than 2 ones. 6. As to the green asparagus the stem-reserving within one month after harvesting would not affect greatly on the yield of late stage. 7. Spacing study of green asparagus in the first year showed that the highest yield was spaced at 20 cm., and 30 cm., 40 cm. spacings were next in order. However, the average weight of spears was the highest from 30 cm spacings in rows. 8. Since the dormancy in the tropics was a chief problem due to insufficient cold in winter, some possible measures of inducing artificial dormancy were devised in the experiment. The effect of limiting irrigation alone or breaking stems were not effective, whereas 2% Gramoxan 5% Casoron, 20% Ammonium sulfate, 10% Urea, and 1% MH-30 solution were effective. The first two chemicals had rapid effect, but the development of new shoots would be inhibited at higher concentration, whereas the last three ones had slow effect but helpful to the development of new shoots. 9. Casoron, TOK E-25, Flight A and Amizol of 11 herbicides used were found to have injuries on both green and white shoots 1 kg of Diuron or Monuron per hectare would be promising for weed control. 10. The post-harvest handling practices had great effects on the quality of harvested asparagus. The ascorbic acid content, the internal quality of asparagus showed a significant change in the spears stored in room temperature conditions even in short time. Based on the results of analysis 12.83% of ascorbic acid content of white asparagus were reduced after 3 hours storing in room, and 13.30% of ascorbic acid content of green asparagus were reduced after e hours storing in room. Hence, it is very important to deliver harvested asparagus immediately to canneries for processing to raise quality of asparagus. 11. The temperature of holding had much influenced on the deterioration of asparagus quality. The ascorbic acid content of white spears stored at room temperature for 2 days was only 46.82% of that stored at 2℃. Moreover, the effect of 2℃ cold storage was better than that of 5℃ cold storage. Therefore, it is very important to cool harvested asparagus at 2℃ as rapidly as possible or make precooling to remove the field heat of harvested spears and maintain at the conditions of low temperature to inhibit the deterioration of quality asparagus. 12. Much deterior after of internal quality was also caused under the different conditions after long time of holding. Green asparagus stored at 5℃ for 15 days lost 75.29% of its ascorbic acid, at 2℃ it lost 57.05% and at -27℃ it lost 49.28%. Hence, green asparagus is recommended to process as quick frozen products. 13. In addition to the changes of internal quality as mentioned above, the external quality such as freshness, crispness, length and weight of spears, discoloration, shrivel and feathering would be changed too. These changes could be greatly affected by water and temperature of holding. If stored spears with the butts in water or provided high relative humidity above 90% in addition to the cold air alone was considered helpful to external quality. 14. The ascorbic acid content of green asparagus was 53.10% higher than that of white one. Moreover, green asparagus can be used for fresh market in addition to freezing and canning. Therefore it is recommended to produce more green asparagus for local consumption to raise national nutrition.