Planting densities and growing times of tomato cultivars for industrial processing in the climatic conditions of the Cerrado of Goiás (Brazilian Savanna)

The tomato planting density for industrial processing is usually 30 thousand plants ha-1 in Goiás region, to any hybrids and planting times. However, this is a topic that farmers still have many doubts about it. Thus, the objective of this work was to evaluate the response of different hybrids, grown in different planting densities and growing seasons. For this, six experiments were conducted in 2017, in Abadia de Goiás, Brazil, three experiments in season 1 (April-August), and three experiments in season 2 (May-October), for three hybrids: N-901, U-2006 and CVR- 2909, and five planting densities: 20, 25, 30, 35 and 40 thousand plants ha-1, and five replications (experimental design randomized complete blocks) and the total fresh mass of the fruits was collected to determine the production per plant (kg.plant-1) and total productivity (t ha-1). There was a significant interaction between planting densities and hybrids for all production factors evaluated. The total and commercial productivity of the hybrids CVR-2909 and N-901 responded quadratically to the evaluated planting densities, and the yields presented by the U-2006 hybrid did not respond to variations in planting densities. The plants of the hybrid U-2006 are small in size with more compact growth compared to the plants of the other hybrids evaluated, which probably confers a lower leaf area index and, consequently, a lower rate of photosynthesis due to the lower interception of solar radiation. The total productivity of hybrid N-901 when cultivated in season 1 (autumn-winter) was 28.6% lower than the total productivity of cultivation in season 2 (winter-spring). The hybrid U-2006 presents the lowest productive performance among the other hybrids evaluated and its productivity does not respond to the variation in planting density between 20 thousand plants ha-1 and 40 thousand plants ha-1. The yields of the hybrids CVR-2909 and N-901 respond positively to the increase in planting density up to 40 thousand plants ha-1.