| dc.description.abstract | The effects of six spacings (90 by 90, 90 by
60, 90 by 30, 60 by 60, 60 by 30 and 30 by 30 cm)
and four levels of phosphorus (0, 44, 88 and 132
kg P/ha) on growth, fruiting and nutrient accumulation
in sweet peppers were investigated on field
plots at National Horticultural Research Station,
Thika during the Short and Long Rains seasons of
1980 and 1981, respectively.
Dry matter accrimulation and number of
fruits per plant increased significantly with
increasing spacing between and within the rows,
while the total· fruit yield per hectare
decreased. During the Short Rains the total
fruit yield/ha increased from 11.17 to 35.22
"tons/ha when spacing was decreased from 90 by 90
to 30 by 30 cm in plants fertilized with
44 kg P/ha.
Application of 44 kg P/ha significantly
(xviii)
increased dry matter production in plants harvested
8 and 12 weeks after transplanting in all spacings.
There was no effect of P fertilizer on shoot dry
weight in plants harvested during the 4th week
after transplanting. Application of 88 and 132 kg
Plha promoted less dry matter accumulation in
shoots and fruits than 44 kg P/ha. Phosphorus
fertilizer application also promoted earlier
fruiting.
Dry matter accumulation in shoots and
fruits increased continuously throughout the
growth of the plants and the optimum was attained
12 weeks after transplanting. However, during
the Short Rains maximum dry matter was
attained 16 weeks after transplanting In plants
grown at the spacings of 90 by 60, 60 by 60 and
60 by 30 cm at all P levels. Plants at a
spacing of 90 by 90, 90 by 30 and 30 by 30 cm
attained maximum dry matter accumulation 12
weeks after transplanting when supplied with 44,
88 and 132 kg Plha, thereafter followed by a decrease
or stabilizationof dry matter dependingon snacing.
During the Long Rains all the plants supplied
with 44, 88 and 132 kg Plha attained maximum
(xix)
dry matter production 12 weeks after transplanting.
Thereafter, dry matter decreased.
Spacing and P fertilization did not influence
Vitamin C content in fresh fruits.
There were no consistent significant effects
of spacing on the concentration of N, P, K, Ca and
Mg in shoot and fruit tissues.
Application of 44 kg P/ha promoted an
increase in N concentration in shoots during the
4th week after transplanting, but the concentration
decreased during the 8th and 16th weeks and
remained constant during the 12th week after
transplanting, during the Short Rains. During the
Long Rains application of kg P/ha promoted an
increase in N concentration in shoots during the
4th and 12th week and a decrease during the 8th
and 16th week. Phosphorus levels above 44 kg
P/ha had a very slight effect on N concentration
in shoots. There was no effect of P fertilization
on N concentration in fruits.
Phosphorus Qoncentration in shoots
increased with application of 44 kg P/ha, while
(xx)
higher levels of P did not affect the P concentrations-
Phosphorus fertilization had no effect
on P accumulation in fruits although fruits picked
8 weeks after transplanting had higher P
concentration levels than those picked 12 and 16
weeks after transplanting.
Phosphorus fertilization had no effect on
K concentration in shoots and fruits.
Calcium and Mg concentration in shoots
were highest with the P fertilization level of
44 kg/ha during the 4th, 8th and 12th weeks after
transplanting, and decreased with application of
higher P levels. Phosphorus fertilization levels
did not affect the Ca and Mg concentrations in
fruits. | en |
