Rj. Dufault, DYNAMIC RELATIONSHIPS BETWEEN FIELD TEMPERATURES AND BROCCOLI HEAD QUALITY, Journal of the American Society for Horticultural Science, 121(4), 1996, pp. 705-710
Fifty-six field plantings of 'Baccus', 'Citation', 'Packman', and 'Sou
thern Comet' broccoli were made in Charleston, S.C., at 2-week interva
ls from February to November from 1990 to 1999. The objective was to d
etermine broccoli's response to growing season mean (GSM) temperatures
for several important market quality characteristics, such as head sh
ape, color, density, leafiness, and bead size. Regression analysis det
ermined whether quality was more affected by GSM minimum (min) or maxi
mum (max) temperature for each head quality characteristic. Head leafi
ness and density of 'Baccus' were insensitive to GSM min (7.0 to 23.5
degrees C) and GSM max (17.5 to 32.5 degrees C) temperatures experienc
ed during these years, 'Baccus' head color was unacceptable at <20.3 d
egrees C GSM max and head shape was unacceptable at <19.8 and >26.8 de
grees C GSM max. 'Citation' head color and leafiness were unacceptable
at >20.5 and >20.2 degrees C GSM max, respectively. Head density of '
Citation' was unacceptable at <19.2 and >28.9 degrees C GSM max and he
ad shape was unacceptable at <18.4 and >25.7 degrees C GSM max. Qualit
y of 'Packman' was unacceptable for head color at <21.0 and <27.3 degr
ees C GSM max, head leafiness at >32.0 degrees C GSM max, head density
at <8.4 and >18.0 degrees C GSM min, and head shape at >22.0 degrees
C GSM max. 'Southern Comet'' head quality was unacceptable for head co
lor at <9.2 and >16.5 degrees C GSM min, head leafiness at >32.0 degre
es C GSM max, head density at <8.9 and >16.2 degrees C GSM min, and he
ad shape at <21.0 and >25.3 degrees C GSM max. GSM min or max temperat
ures did not affect bead size of any cultivar during any planting time
studied.