Authors names: Dragomir Claudia-Loredana, Hoza Gheorghita University of Agronomic Sciences and Veterinary Medicine of Bucharest Faculty of Horticulture International Student Symposium “Hortus Academicus” March 29, 2019, Bucharest, Romania Research regarding the cultivation of purple potatoes in the Bucharest area Authors names: Dragomir Claudia-Loredana, Hoza Gheorghita Coordinator Professor: Hoza Gheorghita International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Introduction The potato, (Solanum tuberosum L.) originally from South America, is cultivated in many regions around the world, having an important role in global diet as well as providing raw materials for various industrial branches. Due to the lack of produce in the XVII-XVIII century, the cultivation of potatoes played an important role in assuring the dietary needs of both people and livestock, especially in France, the British Isles and Germanic countries (Rousselle, 1996). In Romania, it appeared for the first time in Transylvania in the year 1760 (Morar, 1999) and is considered the second bread of the country. The potato along with wheat, corn and rice are some of the most popular species known by the entire world, the potato also having the advantage of being 10-15 times more productive than these. The potato is a staple food for almost the entire world, being considered just as important as cereal, fruit and meat. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

A large number of varieties were created, approximately 4,000 varieties, thus allowing the potato to be cultivated from Ecuador to the polar regions in over 140 countries in the entire world. Until 1990, the surfaces cultivated with potatoes registered a continuous increase, the most known basins in Romania that produce early potato being Lungulețu, Brezoaiele, Beleuți, Verești. Currently the larges surfaces on which potato is cultivated are in the following counties: Covasna, Brașov, Maramureș, Harghita, Dâmbovița and Suceava, whilst the smallest surfaces are found in: Calarași, Braila, Olt and Teleorman, the latter ones being known for their tomato production. Romania is 3rd in the European Union in terms of the surface cultivated with potato. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Materials and Methods The experiment was conducted in the didactic fields of the Faculty of Horticulture of Bucharest in 2018. The primary goal of the research was to track the behaviour of violet potatoes cultures in comparison to that of white and red potatoes in Romania. The varieties used were Carrera (white potato) and Bellarosa (red potato), Purple Peruvian and Salad Blue (violet potato). International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

The planting of the tubers took place on 11. 04 The planting of the tubers took place on 11.04.2018, with a distance between rows of 70cm and 25cm between plants, resulting in a density of 58000 plants/ha. During the vegetation period, the culture was attended to in accordance with the known technology, closely following its behaviour, in particular that of the purple potato, which is a novelty for this area. Observations and determinations conducted throughout the vegetation period were: the percentage of sprouting, number of stems and diameter of the bush. During harvest, the number of potatoes and their weight per plant, tuber production per hectar and biochemical analysis were determined. The vegetation period of the tubers was 104 days, after which they were harvested. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

The tests were carried out by the Research Centre for the Quality Study of agricultural and foodproducts - USAMV Bucharest Determining the total content of anthocyanins. Determining the total content of anthocyanins - method adapted after Giusti MM et al (Giusti M.M.,Wrolstad R.E., 2001). Anthocyanins absorbance light at wavelength rage of 520-530 mm (Curr. Protoc. In Food. Anal. Chem. 2001:F1.2.1-F1.2.13). The total content of anthocyanins was determined after the extraction in acidulated methanol with 1% hydrochloric acid and a spectrophotometric dosage at a wavelength of 530 nm. 1g of plant material was placed in a jar and in the presence of quartz sand was washed quantitatively a few times with acidulated methanol with 1% hydrochloric acid up to a volume of 50 ml. The alcoholic extract was stirred, centrifuged and the plant material was subsequently extracted until the residue broke down. A spectrometric dose was compared with an acidulated methanol blank with 1% hydrochloric acid a wavelength of 530 nm. The results were calculated based on the following formula: Total anthocyanins = DO530 x 11.16 and the results were expressed in mg 100g-1 of plant material. Also the firmness, humidity and brix were measured.

Results and discussions In what concerns the sprouting percentage (Figure 1), all the varieties registered high sprouting (97-98%), except for the Carrera variety which registered 89% on the sprouting scale. This demonstrates the fact that sprouting is not influenced by the type of potato, but by the quality of the planted material and environmental conditions, the purple potato behaving very well from this point of view. Figure 1. Sprouting scale, % International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

The biometric traits of the potato The purple potato grown in the conditions of the Bucharest area formed a large number of stalks during the vegetation period, while the Purple Peruvian variety had a number double in size compared to the Bellarosa variety (table 1). Also, the Salad Blue variety formed more stalks than the Carrera and Bellarosa variety. By analysing the diameter of the bush of the studied varieties, it was identified that the Salad blue variety had bushes with an average diameter of 50.9 cm, followed by the Bellarosa variety with bushes of 48.8 cm in diameter. The other varieties registered similar values of vegetative plant growth. Table 1 The biometric traits of the potato Specification   Number of stalks, stalks/plant Bush diameter, cm Salad Blue 4.2 50.9 Purple Peruvian 6.4 45.3 Bellarosa 3 48.8 Carrera 3.9 44.4 International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Number of tubers for consumption Number of tubers below STANDARD The number of tubers per plant was different (table 2). Thus, the largest number of tubers per plant was obtained by the Purple Peruvian variety, respectively 12.8, of which 4.9 tubers for consumption , followed by the Salad Blue variety with 9, of which 4.8 tubers for consumption, the Bellarosa varieties having 7.2, and 4.3 tubers for consumption and Carrera has 8.8 tubers and 3.6 tubers for consumtion . The average weight of the tubers (table 2) varied between 51g for Purple Peruvian, respectively 72 g for Salad Blue and 96 g for Bellarosa and Carrera.The tubers of the purple potato are smaller, in particular with regard to early cultivation, the tubers that weigh less than the average weight can be used for consumption, as well as material to be planted for other cultures. Table 2 The number of tubers and their average weight based on variety Specification   Number of tubers for consumption Number of tubers below STANDARD Average weight Of tubers for consumption, g of tubers below STANDARD, g Salad Blue 4.8 4.2 72 25 Purple Peruvian 4.9 7.9 51 17 Bellarosa 4.3 2.9 96 30 Carrera 3.6 5.2 International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Figure 2. The tuber production , t/ha The tuber production has been influenced by the variety. The Purple Peruvian variety had the smallest production of 18,6 t/ha, of which 14 t/ha tubers for consumption (Table 2), followed by the Salad Blue variety with 23.3 t/ha of which 20 t/ha of tubers for consumption. The Carrera variety obtained 25 t/ha tubers, of which 20 t/ha tubers for consumption and the Bellarosa variety obtained 26,7 t/ha, of which 24 t/ha tubers for consumption. Figure 2. The tuber production , t/ha International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

The biochemical composition of the potato tubers The biochemical analyses (Table 3) have shown that the Purple Peruvian variety stood out due to a better firmness, a higher content of phenolic compounds and antioxidant activity that is 2-3 times higher than that of white and red varieties. Concerning the number of anthocyanins, the Purple Peruvian variety exceeds the Salad Blue variety by 5 times. Table 3 The biochemical composition of the potato tubers Specification   Firmness, kg Humidity,% Starch, % Reducing Glucides, % Brix, Phenolic compounds, mg GAE/100g Vitamin C, mg/100g Antioxidant activity DPPH μMTE/100g Anthocyanins, mg/100g Salad Blue 8.27 74,012 14.37 0.23 5.6 45,175 5.81 222 2.2275 Purple Peruvian 12.51 74,007 18.43 0,528 5.8 64.40 5.27 290.91 12.6677 Bellarosa 9.85 79,431 17.68 0,368 6.4 22,076 5.43 144.48 Carrera 8.91 79,005 15.92 0,367 5.7 39,973 5.2 76.14 International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Conclusions and recommendations Concerning growth power, the purple potato varieties stood out due to their better sprouting percentage, with 4.75 % better than the white and red varieties. The diameter of the purple variety bush was larger, and the number of tubers per plant of the Purple Peruvian and Salad Blue varieties was 1.45 higher than that of the Carrera and Bellarosa variety. The tuber production of the purple potato varieties were approximately equal to those of the white and red varieties, thus the Salad Blue variety had the same yield as the Carrera variety of 20 t/ha. The Puple Peruvian variety has done the smallest production of 14 t/ha because it is an early variety and forms small tubers, and the variety with the highest production is Bellarosa with 24 t/ha. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

Based on the carried out tests, the Salad Blue variety had the best response to the pedoclimatic conditions, as well as to the cultivation technology applied in the Bucharest area, obtaining the same production as the Carrera variety, respectively 20 t/ha. The results obtained by the biochemical analyses make the Salad Blue variety even more appreciated from this point of view: the smaller content of starch and reducing glucides, a large number of phenolic compounds, vitamin C, and its antioxidant activity is 2-3 times higher than that of the white and red varieties. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania