The aim of this work was to determine the effect of plant density on dry matter accumulation and distribution to fruits of pickling cucumber plants. Experiments were carried out inside a polyethylene greenhouse, where plants were grown in densities of 2.00, 2.50, 3.33 and 5.00 plants m-2 in spring 1999, and of 4.00, 5.00, 6.66 and 10.00 plants m-2 in summer-autumn 2000, in order to determine the effect of plant density on dry matter accumulation and partitioning between vegetative parts and fruits. Plants grew in rows and were trained according to the high-wire system. Dry matter accumulation of stem, leaves and fruits was measured weekly. Fruits were harvested daily, the dry matter measured and values were summed together to determine the cumulative week weight. In the first experiment, a positive effect of the higher plant density was observed on dry matter accumulation of shoot and fruits, with a mean fraction of 49.5% allocated to fruits. In the second experiment, this effect was recorded only on the stem and the fraction of dry matter allocated to fruits decreased when plant density changed from four to 10 plants.m-2. Cumulative fruit yield in the first experiment showed a linear response to plant density while in the second experiment no effect of this variable was observed on fruit yield. It was concluded that it is not possible to use a pre-fixed plant density all over the year for the commercial production of pickling cucumber crops.
Cucumis sativus; growth; yield; growth efficiency; radiation; dry matter allocation
