PROBLEMS AND SOLUTIONS IN GROWING WINTER AND SPRING TOMATOES UNDER PLASTICS
Most tomatoes are grown under low plastic tunnels. Polyvinyl sheets have shown better results than polyethylene(PE) in respect of temperatures (higher), effect on ripening(earlier) and duration of harvesting period (shorter). Perforated P.E. sheets permit better growth conditions than unperforated sheets.
Three methods of covering have been found preferable to others.
- upper rubber strips
- upper hoops
- side cranking
The combination of trickle irrigation, herbicides and clear P.E. mulch, gave better effects and results than black mulch. Determinate varieties like 1589 F1, 1407 F1, 1683 F1 and others are now the main varieties which have characteristics suitable for short days and low temperature periods.
The product "Oraset" based on metha tolylphtalamie acid causes a considerable improvement in fruit setting, increase of yields, concentration of yield and increase of average fruit weight.