Pre-tuber Application of Fluridone: Effect of Foliar and Root Absorption on Sprouting of Yam (Dioscorea alata L.) Tubers

摘要

The absorption of Fluridone (an abscisic acid biosynthesis inhibitor), prior to yam tuber formation has been shown to induce precocious sprouting on the new tubers that form. However, the use of hydroponics system to achieve root absorption of Fluridone requires high skills and capital, and the effect of pre-tuber application of Fluridone on sprouting of yam tubers produced in a soil medium is not known. Thus, the objectives of this study were to: (1) determine the effect of 30μM Fluridone on sprouting of soil produced yam tubers, and (2) to determine the effect of different methods of applying (root and foliar application) 30μM Fluridone on the timing of sprouting of soil produced yam tubers. The treatments were: (1) nutrient solution medium (Control 1) (2) nutrient solution medium + 30μM Fluridone (root absorbed) (3) soil medium irrigated with distilled water (Control 2) (4) soil medium+ 30μM Fluridone (foliar absorbed) (5) soil medium + 30μM Fluridone (root absorbed). The study was a completely randomized design with five treatments. Results showed that Fluridone treatments induced sprouting on both aerial and new underground tubers while the controls did not. Soil + 30μM Fluridone (foliar absorbed) treatment yielded 36% less sprouting underground tubers but over 50% more sprouting aerial tubers compared to the nutrient solution + 30μM Fluridone treatment. Both treatments however, produced sprouts at 5 weeks after treatment application. Soil + 30μM Fluridone (foliar absorption) treatment induced significantly (P<0.05) more sprouts than soil medium + 30μM Fluridone (root absorption) and sprout was delayed by two weeks in the later. Thus, this study has shown that Soil + 30μM Fluridone (foliar absorption) treatment, which is a cheaper, less skill requiring less cumbersome method, is a potential alternative to the use of nutrient solution + 30μM Fluridone in a hydroponics system for sprout induction.