The influence of different production systems, planting densities and levels of shading on the yield, quality and growth potential of 'Chandler' strawberry plants (Fragaria ananassa) grown in coir

[摘要] The use of hydroponic strawberry production systems is increasing worldwide.Although higher planting densities are possible in vertical production systems, thesehigher planting densities may have a negative effect on individual plant yield and fruitquality due to lower light levels when compared to conventional (horizontal)production systems. Optimum planting densities will for this reason be affected bylight intensities inside the greenhouse and configuration of the vertical productionsystems.Two experiments were conducted in a plastic cladded greenhouse, fitted with a wetwalland fan cooling system, at the Department of Agronomy, University ofStellenbosch, South Africa during the period of April 2007 to November 2007 (lateautumn to early summer). Mean daily maximum temperatures exceeded 26 oC duringmost of the 14 week harvest period (22 August to 30 November 2007), whilephotosynthetic active radiation (PAR), measured at 12h00 on cloudless days, insidethe greenhouse increased from about 200 μMol m-2 s-1 to about 460 μMol m-2 s-1during this period. The first experiment compared the effect of two vertical productionsystems (vertical system and 'A-shape' system), subjected to different plantingdensity (16.7, 23.3 and 33.3 plants m-2) and shading (0%, 20%, 50%) treatments, asmeasured on selected yield, quality and growth factors. The second experimentstudied the effect of different planting density (3.3, 5.6 and 10 plants m-2) and shading(0%, 20%, 50%) treatments on the same yield, quality and growth factors in aconventional production system. A comparison with regard to these factors was alsomade between the highest planting densities of the conventional-, vertical- and'A-shape' system.

[发布机构] Stellenbosch University