This research was conducted at EI-Baramoon Horticultural Research Farm. Dakahlia governorate. Egypt during the summer seasons of 2001 and 2002. to
evaluate the effect of application of ammonium nitrate (150 kg N/fed). calcium nitrate
(150 kg N/fed) and ammonium nitrate (75 kg Nlfed) + calcium nitrate (75 kg N/fed)
and plant spaces (15. 20 and 25 cm apart) and their combinations on yield and yield
components of tomato plants CII. Peto 86. The obtained results revealed til at Ca-
nitrate 100% application was Ihe most effective treatment (or increasing number of
branches, fruit length. fruit diameter. total yield I plot as number and weight. fruit
weight and lotal soluble solids (TSS). followed by' ammonium nitrate 50% + Ca-nitrate
50% treatment then ammonium nitrate 100% in both seasons. White. the highest
record for plant height gave (rom the application of ammonium nitrate 50% + Ca-
nitrate 50%. followed by ammonium nitrate 100%. then Ca-nitrate 100%. The data
also indicated that the lowest blossom end rot (BER) as number and weight was in
fruits of the treatment Ca-nitrate 100%, followed by ammonium nitrate 50% + Ca-
nitrate 50"10, then ammonium nitrate 100% treatment. With respect to the effect of planting spaces, it was cleared that 15 cm space
between tomato plants increased marketable yield I plot as number and weight and
also gave the highest TSS and plant height compared with wide spaces (20 and 25
cm). While, the 25 ern space gave the highest fruit weight, fruit diameter. fruit length
and No. of branches. 15 ern space gave the highest plant height followed by the
treatment of 20 ern space then 25 em space. The highest marketable yield as weight I plot was obtained from the
combination between Ca-nitrate 100% with different plant spaces (15, 20 and 25 em)
followed by ammonium nitrate 50% + Ca-nitrate 50% x 15 cm space then ammonium
nitrate 100% x 15 cm space between tomato plants in both seasons. Same data
indicated that Ca-nitrate 100% x 25 ern space had the lowest number and weight of
BER fruits. Finally, it could be concluded thatlhe highest marketable yield. best quality and
least BER of tomato fruits (CII Peto 86) was obtained from treatment of Ca-Nitrate
(150 kg N/fed) with 25 cm space between tomato plants.