In Rumania eggplants are grown in hotbeds and greenhouse over a considerable area.
In previous publications (I. Meier, M. Boulboaka, M. Mihalake - 1961 and 1964; I. Meier, K. Popescu - 1967; I. Meier and Chaushescu - 1966 and 1967) it was tried to work out the agricultural management of this vegetable crop, in hotbeds, greenhouses and plant-growing structures covered with polyethylene.
This was deemed necessary due to the fact that plants grown on protected areas have a very vigorous growth, a weak fruit setting and respectively low yields, in case when the necessary measures to control their growth are not taken.
It is proved that with the removal of certain offshoots the plants give high and early yields.
Leaving 3 offshoots to every plants proved to be the best method.
This gave an increase in the yield of 178 per cent, as compared to the control plants.
Besides the yield was the earliest possible and the income was greater.
In case of transplanting the seedlings, according to the scheme 80 x 40 x 50 cm the yield was almost similar even when 4 offshoots were left to every plant (the main stem and 3 offshoots).
The aim of the experiments was to determine the optimum period of defoliation and its intensity, with a view to obtain a normal growth and fruit bearing.
The experiments were performed with a '166 x Lungi' hybrid, in a block greenhouse, with sheds of 3.20 metres.
The seedlings were grown under artificial lighting.
The distance between the plants, after their transplanting, was 80 x 40 cm.
The plants were left with 4 stems (the main stem and 3 offshoots).
Defoliation was carried out in 5 phases:
- at the formation of the first flower buds;
- at the appearance of the first flowers;
- during the period of formation of the first offshoots;
- during the period of the second offshoot formation;
- during the formation of the third offshoot.
The scheme of the experiment was scheduled with 14 variants as follows:
Variant 1 - plants, not defoliated (control).
Variant 2 - removing 1 leaf at the base of the plant prior to flowering.
Variant 3 - removing 2 leaves at the base of the plant prior to flowering.
Variant 4 - removal of 3 leaves.
Variant 5 - removing 2 leaves during the period of flowering.
Variant 6 - removing 3 leaves during the period of flowering.
Variant 7 - removing 4 leaves during the period of flowering.
Variant 8 - removing 3 leaves at the time when the first offshoot is formed (up to 4 leaves under the first fruit).