Growth and Yield of Cucumber in a High-Wire Growing System with Different Training Methods

Abstract

In this study, we analyzed European medium-sized cucumber (Cucumis sativus cv. Zeco) growth and yield in a high-wire growing system using different training methods in a smart greenhouse. The experimental treatments were applied as follows: 4P1S, four plants were trained on a single main stem; 4P2S, four plants were trained to one main stem plus a lateral stem from the seventh node in a slab; 3P2S, three plants were trained on two stems from the seventh node of a slab. The average daily drainage volume was lower in the 4P2S than other treatments with approximately 10% lower drainage ratio than that in 4P1S. The retained volume, the difference between the total irrigation and drainage volumes, was 154 L·m-2 for 4P1S, 199 L·m-2 for 4P2S, and 151 L·m-2 for 3P2S. Water use (L·kg-1fruit) was in the order 4P2S (14.88) > 3P2S (12.34) ≥ 4P1S (12.00). The plant height, number of nodes, and length from the apex to the last flower were significantly lower in the 3P2S group than that of other treatments. Higher leaf dry weight was observed with the 4P1S treatment than with the 4P2S treatment. The number of stem nodes was highest in 4P1S, indicating a good relationship between this and the leaf dry weight. The number of fruits and fruits per plant was in the order of 3P2S > 4P2S > 4P1S, indicating that it was higher in the 6 stems per slab group than in the 4-or 8-stem groups. There was no significant difference in the fruit yield per unit area (m2). It was 13.0 kg·m-2 for all treatments, which was about 1.6-fold higher than that from the greenhouse cultivation in Korea (7.96 kg·m2). It may be due to the cucumber variety with a high-wire growing system. The yield for each week was constant in the 4P1S group in accordance with the CSR (Cumulative Solar Radiation) level, whereas there was a large variation in the weekly yield harvested from plants grown with the 4P2S and 3P2S treatments. All the integrated results in the present study suggested that training one main stem per slab might be better for the European cucumber variety in terms of the water consumption, yield, and workload.