Planting density and arrangement for the mechanized spraying of vertically staked tomatoes

ABSTRACT We aimed to determine an adequate planting density and arrangement for the mechanized spraying of vertically staked tomatoes. Two experiments were carried out in the 2013/14 and 2014/15 harvests in the city of Calmon, state of Santa Catarina, Brazil, both in randomized block design. In 2013/14, treatments were arranged in a 4x2 factorial, corresponding to four planting densities (10,753, 12,903, 16,129 and 21,505 plants/ha) and two planting arrangements (single and double rows). In 2014/15, treatments were arranged in a 5x2 factorial, corresponding to five plant densities (the same planting densities of the previous harvest beyond 32,258 plants/ha) and the same planting arrangements. Total, marketable (considering extra AA and extra A fruits as marketable) and unmarketable yield, the average mass of marketable fruits and severity of leaf diseases were evaluated. Economic analysis was also performed. For tomatoes grown under mechanized spraying, double row plantings resulted in higher yield of marketable fruits and a higher percentage of top grade fruits compared to single row plantings. Maximum fruit yield was reached at approximately 34,000 plants/ha, although maximum revenue was estimated for 23,000 plants/ha. Bacterial spot and Septoria leaf spot severity were higher in double rows than in single rows. Increases in planting density resulted also in increases in bacterial spot and early blight severity.