SEEDLING ESTABLISHMENT: THE EFFECT OF CONTAINER SIZE ON PLANT SURVIVAL AND YIELD OF TOMATOES FOR PROCESSING

Crop establishment methods have been changing from naked root plants and direct seeding to seedling transplants in trays during the last five years in Argentina. Nurseries offer plants in different container sizes trying to balance plant cost of production and plant size to achieve high survival rate to avoid replanting. The goal of this study was to evaluate the amount of water a plant needs to survive during transplanting operation and the plant yield depending upon the most common container size in the Argentine market. Trials were conducted from 1998/99 to 2001/02. Trays were 693, 425 and 336 cells per container with a volume of 4.5, 8.5 and 15 mL per cell, respectively. The amount of water needed during transplanting was studied under a permanent wilting point soil conditions and between 24 ºC and 30 ºC soil temperature. Plant survival was counted within 3 hours of planting. Factorial (3 container sizes and 6 water doses) and trend analysis were used to analyze data. Container size on production was evaluated in a complete randomized block design and by Duncans mean separation test. The only acceptable plant survival was found when furrow irrigation was made within 30 minutes after planting. In this case, significant negative linear responses were found between water volume required and cell volume. Water quantities 950, 714 and 238 L ha^-1 were needed for container size of 693, 425 and 336 cells, respectively to achieve a survival of 90% of plants when planting under very dry and warm soil conditions. Crop yield and days to mature to 90% red fruit were not affected by container size.