(Mar 2001)  
 
Rosa damascena ‘Trigintipetala’
....The damask rose enjoys heat, water, and high fertility, and under these conditions it flowers well. Roses can be successfully grown on a wide range of soils but they do best on well-drained soils, with a soil pH of 6.0-6-5. Adequate water is essential throughout the vegetative and flowering periods, and where irrigation is needed, basal watering, such as drippers, are favoured as they avoid wetting the flowers at harvest time. The frequency of watering depends on the porosity of the soil and the seasonal weather conditions. Roses are gross feeders and enjoy high fertility conditions. Fertilisers containing nitrogen, phosphorus, sulphur and potassium are needed for high flower production, and the chosen fertiliser dressing should relate to soil analysis.
...The production block of Trigintipetala at Redbank was established with plants budded on R. multiflora stock.
....As they mature, the plants form hedgerows up to 2 m in height and have good wind
resistance.
....No flowers are produced in the establishment year. The summer damasks only flower well on mature wood and pruning requirements are minimal. The production block at Redbank was left unpruned, and flower production levels continued to increase over three seasons as the plants
grew in size. Under Central Otago conditions there has been minimal incidence of pests and disease, and control strategies for pests such as aphids have not been warranted.
.....Trigintipetala flowers during November and December in Central Otago. The flowers are picked into sacks as early as possible each day on the basis of flower maturity. A flower is picked as it reaches full bloom and unopened buds and flowers are left for subsequent picking.
....Picking is extremely labour intensive. Although there is variation in picker efficiency, plant size and flower density, the best pickers have not exceeded 6 kg of flowers/hour, and typically the average is closer to 3 kg of flowers/hour. At 2.5-5.0 g/flower, this represents 200-400 flowers/kg. At
Redbank Research Station, the crop produced 5.6 kg of flowers/plant in the third flowering season. This equates to a total flower yield of around 9.2 t/ha at a density of 1650 plants/ha. The picked flowers should be chilled immediately to prevent heating, and distilled as soon as practical.