THE EFFECTS OF LIFTING DATE, CHILLING DURATION AND FORCING TEMPERATURE ON VEGETATIVE GROWTH AND FRUIT PRODUCTION IN THE JUNE BEARING STRAWBERRY CULTIVAR ELSANTA
A. Tehranifar et al., THE EFFECTS OF LIFTING DATE, CHILLING DURATION AND FORCING TEMPERATURE ON VEGETATIVE GROWTH AND FRUIT PRODUCTION IN THE JUNE BEARING STRAWBERRY CULTIVAR ELSANTA, Journal of horticultural science & biotechnology, 73(4), 1998, pp. 453-460
The effects of different durations of cold storage (0, 2, 4, 6, 8, 10
and 12 weeks at -2 degrees C and +3 degrees C) on strawberry plants cv
. Elsanta from two different lifting dates (6 November and 6 December)
were investigated, to determine the chilling required for optimum gro
wth and development. With greater durations of chilling, the petiole l
ength, leaf weight and runner production of plants were increased. The
chilling requirement for optimum vegetative growth was saturated afte
r 6-8 weeks. For chilling durations up to six weeks there was no diffe
rence between the two cold storage temperatures, but with larger durat
ions subsequent vegetative growth of the plants stored at -2 degrees C
was reduced compared with plants stored at +3 degrees C. The vegetati
ve growth after cold storage of plants lifted on 6 December was greate
r than that of plants lifted on 6 November. Cold storage temperature d
id not affect the number of flowers produced per plant, fruit number o
r fruit weight. However fruit number and fruit weight were both greate
r in plants lifted on 6 November than in those lifted on 6 December. I
n a second experiment, the effects of chilling duration on growth and
fruiting at three forcing temperatures were studied. There was no sign
ificant interaction between chilling duration and temperature during f
orcing, and while eight weeks chilling was optimum for vegetative grow
th, in terms of fruit production four weeks chilling was optimum. Over
all, these results indicate that there may be an important interaction
between fruit set and vegetative vigour and that field chilling is mo
re effective than cold store chilling in promoting vegetative growth.
The results also show that the optimum chilling requirements for veget
ative vigour and fruit production are different, and that chilling bec
omes more important when the temperature during forcing is low.