Text 4. A screening test for the determination of cut flower longevity and ethylene sensitivity of carnation

Ten carnation (Dianthus caryophyllus L.) flowers of six different cultivars: ‘Dover’, ‘Famosa’, ‘Fuente’, ‘Hugo’, ‘Master’ and ‘Mundo’ were harvested from the Barberet & Blanc Company (Murcia, Spain) and transported to the laboratory on the day of harvest. The flowers were harvested at the early stage of flower opening and immediately transferred to the laboratory at the University of Almeria, Spain. In the laboratory, the flowers were trimmed to a stem length of 30 cm, randomized and divided into two groups. The first group of flowers was exposed to 10 ppm of ethyl­ene for 8 h with the flowers held in distilled water. The other groups of flowers (control) were held in distilled water in an air atmosphere for 8 hours. At the end of the treatments (start of the measure­ments), the flowers were held in distilled water. The distilled water was replaced every two days. The environmental conditions maintained throughout the experiment were: 12 h light, 12 h darkness at 21 ± 1°C and 60–70% relative humidity.

In addition, 75 cuttings of the same previously mentioned cultivars were harvested. Twenty five were used to measure ethylene production and the rest were divided into two groups. Half of the cut­tings of each cultivar were treated with 10 ppm of ethylene for 24 h, and the rest were held in an air atmosphere for 24 hours. At the end of the treat­ments (start of the measurements), the cuttings were transplanted into a hydroponics system for 30 days. Experiments were carried out in a propa­gation tunnel. The growing system consisted of polystyrene panels floating in polystyrene trays filled with 10 l of nutrient solution. The polystyrene panels had holes in them and a cutting was placed in each hole. The nutrient solution was pumped to provide enough oxygen to the systems. The nu­trient solutions were replaced with fresh solution every week. Heating was set to maintain a minimum of 22°C and a relative humidity of at least 65% was maintained by a fog-system.

3. Using the text above, finish the following sentences:

1) The flowers were harvested at the early stage of….

2) …was exposed to 10 ppm of ethyl­ene for 8 h with the flowers held in distilled water.

3) … of flowers (control) were held in distilled water in an air atmosphere for 8 hours.

4) The environmental conditions maintained throughout the experiment were…

5) Twenty-five were used to measure ethylene production and the rest …

6) … were carried out in a propa­gation tunnel.

7) … was pumped to provide enough oxygen to the systems.

4. Answer the following questions:

1) How many carnation (Dianthus caryophyllus L.) flowers of six different cultivars were harvested from the Barberet & Blanc Company (Murcia, Spain) and transported to the laboratory on the day of harvest?

2) At what stage were the flowers harvested and immediately transferred to the laboratory at the University of Almeria, Spain?

3) Where was exposed the first group of flowers and were other groups of flowers (control) held?

4) When were the cuttings transplanted into a hydroponics system for 30 days?

5) Why was the nutrient solution pumped to the systems?