2.2. Field layout and induction of flowering
Planting was timed to occur in spring and approximately 12
to 15 months later plants in the field were sufficiently mature
to be sprayed with Ethrel® growth regulator (Ethephon 480 g/L,
Bayer Crop Science) to initiate uniform flowering. When flowering
commenced after approximately three months, individual flowerheads
were bagged to prevent cross-pollination of surrounding
non-transformed pineapple plantings on the station, which was a
biosecurity requirement (licence number DIR:028/2003) imposed
by the Gene Technology Regulator (Fig. 1B). Ideally, early fruit
development occurred during the colder months.
Four pineapple field trials were established at two sites over a
five year period (2002–2007) (Table 1). All were completely randomised
blocks with 5 plants per plot and surrounded with guard
rows. The plots were arranged in rows with the plants positioned
with a distance of 25cm between them within the raised beds
which contained two rows of plants (Fig. 1A). Harvest of fruit
occurred weekly over a two month period. The total number of
fruit assessed per line in trial 1 varied between 5 and 21, in trial 2
between 5 and 40, in trial 3 between 5 and 33, and in trial 4 between
7 and 51.