Strawberry cultivar response to plant density using tray plant in macrotunnel

The profitability of the strawberry in Mexico depends on the exports of fresh strawberry to the United States during autumn and winter. Macrotunnel is essential in the production system, but it is necessary to integrate and harmonize other technological components, such as plant density, that contribute to raise the productivity for the export marked. The use of tray plant has that potential, but it is important to optimize its management, among others, the plant density. With this purpose the response of the cultivars 'Nikte', 'Pakal' and 'Camino Real', in beds 1.5 m wide, with four rows of plants at distances of 17, 22, 27 and 32 cm between them, corresponding to 155,294, 120,000, 98,000 and 82,500 plants ha(-1), respectively, were evaluated. Fruit yield was recorded and analyzed based on three categories and their respective average weights, considering the fruit yield per plant and per area, based on the accumulated periods from October to February (early yield = EY), and from October to June (total yield = TY), as well as two morphological characters of the plant. For both harvest periods, there was a linear response in yield, and the maximum production of fruits plant(-1), in most categories, was with the lowest plant density (PD). In contrast, when estimating yields in kg ha-1, although the response was also linear, the maximum productivity in both periods, and for all categories, was with the highest PD. With both productivity estimating methods there was no cultivar x PD interaction for any of the variables, except for TY plant(-1) for the three categories. PD had little effect on fruit weight per category, but high PD significantly decreased the appearance of fruit, the plant diameter and the number of leaves plant(-1). The distance of 27 cm between plants was the most profitable, with the highest cost-benefit rate.