Bareroot rose production with underground drip irrigation

Field experiments were carried out in 1996-1997 and in 1998-1999 in Shafter, California, using two rose rootstocks, 'Dr. Huey' and 'Manetti', and the cultivar 'Pink Simplicity' to investigate alternative cultural practices for bare-root rose production. The objectives of the experiments were 1.) to determine effects of different depths of buried drip irrigation on growth of roses on raised beds, and 2.) to determine the effect of three in-row spacings on growth of roses on flat ground. Drip tape buried at 30 cm depth versus 10, 20, or 40 cm depth resulted in greatest biomass production of all cultivars during both years of the experiment. For roses planted on flat ground, an in-row spacing of 20 cm produced greater root dry weight and caliper than the 15 cm spacing during both years. In 1997, shoot and total dry weight were greater when plants were grown at 20 cm or 25 cm in-row spacing versus 15 cm spacing, while smaller differences between treatments were found in 1999.