Changes in the intensity of bud dormancy and internal compositions of current shoot in fig

Abstract

To estimate the intensity of bud dormancy in fig (Ficus carica L.) 'Masui Dauphine', current shoots in the field were collected monthly from July 1999 to March 2000 and cut at the 5th, 8th, 11th, 14th, 17th and 20th nodes. The cutting were kept in water at 25°C under fluorescent light (5 kix) continuously. The percentage of budbreak within 20 days and the days to 80% budbreak were recorded. The water, carbohydrate, and abscisic acid (ABA) contents of each shoot were also measured. The percentage of budbreak within 20 days at 25°C on all nodal position was 40%, in late November; the basal nodes tended to have lower % budbreak than the upper ones. Water content increased with the growth of the current shoots, reaching over 60% during the introductory phase of endodormancy. The starch accumulated during this period; it was hydrolyzed to sugar at the onset of budbreak or the awaking phase. The ABA content increased only during the introductory phase of endodormancy. The endodormancy of the fig bud was classified into three phases, i.e., 1) introductory (early October to early November), 2) deepest (late November) and 3) awaking phases (middle December to late January). The fig shoot can be heated or headed back at any season to get fruit-bearing shoots for double cropping or year-round production. These treatments force most buds to sprout within a short period, even when they are in the deepest phase of endodormancy.