Maria APAHIDEAN, Al. S. APAHIDEAN, D. MĂNIUŢIU, Rodica GANEA, Diana FICIOR, Mihai JURIAN

Vegetable Growing Department, University of Agricultural Sciences and Veterinary Medicine Cluj Napoca, Romania (E-mail: fdiana29@yahoo.com)

Introduction
In Romania, the greenhouses are cultivated in classical culture system (in soil) and as a result, the yields are relatively small and late and economically efficiency is reduced. With a view to finding a new technological solution for greenhouse tomatoes yield, at the USAMV Cluj-Napoca we have studied the possibility of growing soilless tomatoes, on organic substratum, using cheap and local, easy available materials. The systems on organic substratum in mat polyethylene bags are simple, cheap, no polluting and can represent for Romania an alternative for the soil culture systems. The aim of our research was to establish the influence of plants density and fertilization manner upon the greenhouse tomatoes grown on organic substratum.

Materials and Methods
The research concerning the type of fertilization and tomatoes plant density cultivated on organic substratum was organized as a bifactorial experience.
   A factor - plant density: a1= 20 000 pl/ha, a2= 32 000 pl/ha, a3= 42 000 pl/ha.
   B factor - type of fertilization: b1= root fertilization, b2= root and foliar fertilization.
The experiments were developed between 2001-2002 in USAMV Cluj-Napoca greenhouse. As biological material has used CRONOS F1, obtained by Nunhems Concern.
Root fertilization has made once at two weeks using N, P, K solutions. Foliar fertilization has made three times during the period of vegetation. It was used a foliar fertilizer with micro and macronutrients made by Chemistry Faculty of Cluj-Napoca.
The planting of the transplants in experimental culture was done in the second part of January 2002. Usual technology for Ist cycle tomatoes culture was applied. An irrigation pipe was laid along the middle of the double rows and small-bore tubing was moved into position to water each plant.
Observations concerning growth and plant fructification, quantity and quality of yield were done.

Results and discussion
The plants vigorous manifested by plant height and average number of leaves, records better results at variants with 42 000 pl/ha and root + foliar fertilization.
Data concerning combined influence of both experimental factors on early yield of tomatoes reveal important findings (table 1).
Thus lower early yield recording in 2002 was owed to an unfavorable climate in the beginning of plants growth (low temperature, high cloudiness). On the other hand, early yield recording in 2002, about 5,0-6,7 kg/m² were higher as early yield recording in classical system (in soil), about 2-3 kg/m².
The best total yields were recorded for all variants with great plant density. On an average, the evolution of total yield was similar with the evolution of early yield. It increases with the increase of plants density. The best results statistical provided were recorded at the variants with great plants density and root and foliar fertilization 11,8-12,3 kg/m².
The yield quality was influenced positive by both plants density and type of fertilization.

Conclusions
1. Early yield for variants with great plants density was significantly better than early yield for variants with 20 000 pl/ha, indifferently of fertilization type. The best early yield, 6,7 kg/m² was obtained at variant with 32 000 pl/ha root and foliar fertilization.
2. The increase of plants density combined with a root and foliar fertilization lead to increase of total yield from 9,1 kg/m² to 12,3 kg/m².

References
Baudoin, W. O., Winsor G. V., Schwarz M., 1990, Soilless culture for Horticultural Crop Production, F.A.O.
Plant-Prod.
Carpentier, T. D., 1995, Analyzing an Managing Nutrition of Vegetables Grown in Upright Polyethylene bags, Journal of Plant Nutrition, vol. 5/8.
Table 1. The influence of plants density and type of fertilization on tomatoes yield

Variants		Early yield				Total yield
Plants density	Type of fertilization	Mean Yield	%	+D Kg/m2	Significance of difference	Mean Yield	%	+D Kg/m2	Significance of difference
20000	Root fertilization	5,0	100,0	-	-	9,1	100,0	-	-
32000	Root fertilization	5,8	118,0	+0,8	*	10,9	118,8	+1,8	**
42000	Root fertilization	6,0	121,0	+1,0	*	10,6	116,0	+1,5	*
20000	Root + foliar fertilization	5,2	104,2	+0,2	-	9,9	108,1	+0,8	-
32000	Root + foliar fertilization	6,7	135,3	+1,7	***	11,8	129,2	+2,7	***
42000	Root + foliar fertilization	6,5	131,1	+1,5	**	12,3	134,1	+3,2	***
DL 5%				0,8
DL 1%				1,2
DL 0,1%				1,7