Regeneration of tomato

Seed dormancy

Fresh seeds may germinate irregularly. After storing the seeds for about half a year, the germination becomes normal.

Vernalization

None.

Sowing

Before sowing seeds are disinfected (see pepper), to avoid infection with Tobacco Mosaic Virus (TMV), other Tobamoviruses and Pepino Mosaic Virus. Seeds are sown in seed trays at 23°C, generally between January and March, but it is possible to sow until July. After 10-14 days the seedlings are transplanted to rockwool blocks (12x12 cm) at a temperature of 20/15°C day/night.

Planting

About 7 weeks after sowing the plants in the Rockwool blocks are placed on Rockwool bags at a distance of 50 cm in the row and alternating 60 and 100 cm between the rows, at a temperature of 20/15°C day/night. The plants are grown along wires (1 stem per plant for the indeterminate types). Plants are pruned regularly, taking precautions to prevent virus transmission. During regeneration, plants are tested twice for occurrence of Pepino Mosaic Virus. About 2.5 months after sowing, the plants start to flower. To improve seed set the racemes are touched with a vibrator, improving the pollination.

Per accession seven plants are used for regeneration. For cross-pollinating wild species or heterogeneous accessions up to 14 plants are used. For these species a pollen-mixture of all plants in the accession is used for hand pollination.

Harvesting

About 5 months after sowing, the fruits start to ripen. Per plant, 10 or more ripe fruits are harvested.

Pest and disease control


Biological control

  • Spider mites with Phytoseiulus persimilis
  • Thrips with Phytoseiulus persimilis and Orius laevigatus
  • Whitefly with Aphidius colemani
  • Aphids with Encarsia formosa

Pesticide treatments
 Non-preventive:

  • Spider mites, in case biological control is not effective.