Spacing, Root Cell Volume, and Age Affect Production and Economics of Compact-growth-habit Tomatoes

Abstract

Compact-growth-habit (CGH) tomatoes (Lycopersicon esculentum Mill.) do not require the pruning, staking, and tying required for many fresh-market tomato cultivars. In 1990, 5-week-old transplants of the CGH tomato breeding line NC 13G-1 were grown in single rows with in-row spacings of 31, 46, 61, and 76 cm and in double rows with in-row spacings of 31 and 46 cm. NC 13G-1 produced high early and total season marketable yields when grown in either double-row treatment compared to any single-row treatment. In 1991 and 1992, 4- and 5-week-old NC 13G-1 transplants were produced in five root cell volumes (8.6, 13.6, 27.0, 37.1, and 80.0 cm3), transplanted into double rows with an in-row spacing of 46 cm, and evaluated for yield. Five-week-old transplants produced in 37.1- and 80-cm3 cells flowered sooner after transplanting and produced higher early season yields than 4-week-old transplants produced in the three smaller cells. Midseason yields increased quadratically and late-season yields decreased quadratically as root cell volume increased. Total season marketable yields did not differ among treatments. In 1991, production costs were influenced by root cell volume, but not in 1992. In 1992, net returns for the four smallest cell volumes were similar, and lower than for transplants grown in the largest cell volume. In both years, highest net returns were achieved with transplants produced in 37.1-cm3 cells. Considering the estimated 1992 net returns of $17,000/ha, production of CGH tomatoes may provide an alternative for staked-tomato growers concerned with labor availability and production costs, even though marketable yield from NC 13G-1 was lower than with a conventional cultivar under the standard system.