A field trial was conducted during the two successive seasons
2003 and 2004 in the Experimental Farm, Faculty of Agriculture,
Fayoum, Cairo University to investigate the influence of
paclobutrazol (PP333) foliar spray at the rates 5, 10, 15 and 20 mg l-1
on growth, flowering, seed yield, seed germinability as well as some
chemical constituents of sweet pepper (Capsicum annuum L.) plants.
Convincing influences of PP333 treatments, especially at the rate 15
mg l-1 were observed on all studied parameters during the two
growing seasons. Vegetative growth characters, floral traits, seed
yield and its components, seed germinability, leaf pigments
concentrations, and some nutrients concentrations in leaves were
positively affected in PP333-treated plants. Spraying plants foliage
with PP333 at all studied rates significantly reduced plant height, leaf
area leaf-1, and leaf area plant-1 at the same time in which No. of
main shoots plant-1, No. of lateral shoots on main stem plant-1, No. of
leaves plant-1, fresh and dry weights of leaves and canopy plant-1,
stem thickness upon the soil surface, flowering time, No. of flowers
plant-1, pollen viability, fruit set% (only in the second season), No. of
fruits plant-1, No. of seeds fruit-1, seed yield fruit-1, plant-1 and
feddan-1, seed germination%, germination rate, chlorophylls (a, b and
total) and carotenoids concentrations in fresh leaves, and nutrients
(N, P, K, Fe, Mn, and Zn) concentrations in dry matter of leaves were
significantly increased. On the other hand, fruit set% (only in the first
season) and seed weight index nonsignificantly affected under the
same treatments
In view of these results, growth, flowering, seed production,
and germinability of the developing seeds of sweet pepper could be
improved by the foliar application of PP333 at the rate 15 mg l-1.