effect of plant density on yield and fruit quality of strawberry (fragaria ananassa) in soilless vertical system

abstract strawberry is one of the most important fruit crops in the world. in this study, effect of different plant densities were studied on yield and fruit quality of strawberry 'selva' in greenhouse and laboratories of university college of agriculture and natural resources during 2002-2003. uniform stolens of strawberry were planted in holes of plastic column according to factorial in completely randomized block design with three replications. in each column, 16 or 24 stolens were planted and space among columns was 75 or 100 cm. according to statistical design. results showed that number of plants in each column had significant effect on each plant yield. however, different space among columns had significant effect on each plant and each column yield in a way that yield was higher when 16 stolens were planted in each column and distance among columns was 100cm. in each column, stolens in top of plastic column had higher yield compared with those in bottom of plastic column (each plant at the top 50 cm. of plastic top had 50gr more yield which ended up to 300gr more yield for that part of column). in spite of higher yield for above-mentioned treatment, plant density of 24 plants per column and distance of 75cm. among columns produced more fruits per unit (m2) of greenhouse. the above-mentioned treatments had some effects on most qualitative characteristics of fruits such as length and diameter of fruits, vitamin c content, ph, tss, ta, tss/ta, which generally were higher for treatment of 16 plant/column and distance of 100cm. among columns. however, these differences did not reach significant level.