Field investigation was conducted during the fall seasons of 2000 and 2001 to
study effects of spacing and P-K fertilization on tomato (Lycopersicon esculentun,
Mill.) production and quality, and fertilizers use efficiency, in a newly reclaimed
calcareous soil. The obtained results indicated that planting tomato transplants at
20cm, significantly gave greater early and total yield than 40cm. However, a reverse
trend was true for average fruit weight. Fertilizing tomato plants with 60 kg P20S + 72
kg K20 fed" resulted in the highest mean value of acidity in fruits juice. The plants
fertilized with the highest levels of P and K produced fruits having the lowest titratable
acidity percentage. The interaction of plant distance by P-K fertilization treatments had
significant influences on N, P and K concentration in leaves and fruits. The most
effective treatment combination was that of the narrow spacing with 60 and 24 kg of
P20s and. K20 fed", respectively, for leaf N concentration and the wide spacing with
90 and 72 kg of P20S and K20 fed", respectively, for leaf P and K%. Values of Nand
P % in tomato fruits were the highest under wide spacing with 60 and 24 kg of P20S
and K20 fed-' and 90 kg P20S + 72 kg K20 fed- , respectively. K concentration in
tomato fruits recorded the maximum magnitude as a result of planting at the narrow
spacing and fertilizing with 60 and 72 kg P20S and K20 fed'. A higher N uptake in
fruits was obtained from the intensive planting, at any level of P; whereas increasing K
level depressed fruits N uptake. However values of N uptake were in a decreasing
order with 30, 60 and 90 kg P20S, irrespective of K level. P uptake in tomato fruits was
significantly higher with intensive than low plant density. At any level of P, increasing
K level decreased P uptake. growing tomato plants at 20cm, significantly stimulated
the use efficiency of NPK than at 40cm. Use efficiency of N, P and K reached the
maximum with the applications of 30 kg P20S fed" and 24 kg K20 ted" together, and
decreased with increasing fertilization level. When tomato plants spaced 20cm and
provided with 30 kg P20s and 72kg K20 fed", use efficiency of N, P and K reached
the maximum.