THE EFFECT OF BASIC NPK FERTILIZATION AND SOME NITROGEN FORMS APPLIED TO POTATO AND SUGAR BEET CROPS AFTER PLANTING

The identification of complex fertilizer assortments and the development of differentiated methods of application of nitrogen fertilizers to potato and sugar beet crops are major objectives of fertilization technologies, in order to reach the maximum production potential in terms of quantity and quality. Nine variants of fertilization recipes have been experimented with NPK complexes in 2014 and 2015 that included three NPK complexes for basic fertilization, at soil preparation before planting/sowing and fertilizers with various forms of nitrogen for phaseal fertilization applied to potato and sugar beet. The effect of basic NPK fertilization and some forms of nitrogen applied after planting the crops has been studied on the Christian potato variety and Clementina sugar beet variety. The experimental data recorded in 2014-2015 show that all fertilizer recipes tested on potato and sugar beet respond with production increases

AN OVERVIEW REGARDING THE INCIDENCE OF SOME NECROTIC VIRUSES IN SEVERAL ROMANIAN AREAS

PMTV (Potato Mop-Top Virus ) and PAMV (Potato Aucuba Mosaic Virus) are new damaging pathogens of potato crop in Romania. They can cause serious reduced yield and decrease of the tuber’s quality. In case of these viruses, infected plants do not allways show signs of disease and the symptoms depend on potato cultivar, virus strain and the environment. PMTV and PAMV infection of material plants can produce spraing in tubers of sensitive varieties. PMTV causes heavy losses in northen Europe and it is very difficult to control. PAMV is a helping virus for the development of dangerous potyvirus like Potato Virus Y (PVY). Elimination of all these pathogens from the potato supply chain is essential for potato production and choosing resistant varieties to the infection with these viruses could be one of the measures recommended for farmers and producers. The results of this preliminary study shows that PMTV and PAMV were not found in the material collected from the following varieties: Armonia, Azaria, Christian and Millenium (samples collected from the counties Braşov, Covasna, Harghita, Suceava in 2019, 2020 and 2021)

Optimization of sweet potato (Ipomoea batatas L.) in vitro cultivation by using the contaminated cultures for obtaining new shoots in greenhouse conditions

The artificial media used for plant tissue cultures contains numerous nutrients that can create favorable conditions for the development of pathogens. As antibiotic use is not encouraged, a new strategy has been tried to reduce the losses caused by the presence of microbial infections in "in vitro" cultivation of sweet potato. This consisted in the transplantation in greenhouse conditions of sweet potato plantlets from contaminated "in vitro" cultures, in order to obtain new shoots. Five sweet potato varieties were used in this study, and two types of substrate for planting: pearlite and a mixture of peat and pearlite (1:1). The survival rate of the plantlets was 100% on the substrate consisting only of pearlite. The surviving sweet potato plants had a rapid growth rate, the greenhouse conditions being favorable for this culture. Approximately two months after transplantation, the obtained shoots could be used as a source of explants to initiate new "in vitro" cultures. Regarding the number of shoots the highest value was obtained by the Yulmi variety. The length of the shoots varied according to the variety, thus the highest value was recorded by the KSC1 variety (98.30 cm) . The number of buds/shoot is strongly influenced by the variety. In some sweet potato varieties the distance between buds is smaller, and in others larger, this being a characteristic of the variety. Regarding this trait the best results were obtained in Juhwangmi variety. By applying this method, the process of sweet potato "in vitro" multiplication becomes more economically efficient. After only a few weeks under greenhouse conditions, involving minimal costs, many shoots can be obtained

In vitro selection of true potato seed genotypes tolerant to drought stress

The biological material used in this study was produced from true potato seed (TPS). Nine genotypes (MIL19-01-08, MIL19-01-22, MIL19-01-37, ZIL19-02-01 , ZIL19-02-11, ZIL19-02-43, GIL19-03-07, GIL19-03-29 and GIL19-03-38) were tested in vitro for drought tolerance. Four treatments were used to induce in vitro water stress: MS medium with three different concentrations of PEG (1%, 1.5%, 2%) and one variant of MS medium without PEG as control. On culture medium variant with highest concentration of PEG (2%) GIL19-03-29 obtained best results for plantlet height (11.08 cm), leaf number (9.50), root number (5.33), fresh plant weight (0.167 g). In stress conditions GIL19-03-07 recorded best results for plant fresh weight (0.173 g), root length (7.17 cm), plantlet height (12.28 cm) on PEG 1%. Also, ZIL19-02-43 obtained higher values on the culture medium variants with the highest level of water stress for parameters such as root fresh weight (0.146 g), plant fresh weight (0.163 g), root length (7.08 cm) on PEG 1.5%. The potato genotypes GIL19-03-29, GIL19-03-07 and ZIL19-02-43 showed the best tolerance to the water deficit and were selected for further assessments both in protected area (greenhouse) and open-field conditions

New potato varieties obtained at National Institute of Research and Development for potato and sugar beet Braşov

Potato is a plant with great ecological plasticity, nutritious, tasty and inexpensive, which is the staple food of many peoples. Potato use efficiently use the modern technologies and provides the greatest amount of food per unit of area. In terms of energy is of great importance for human consumption in a variety of ways of preparation and industrialization. National Institute of Research and Development for Potato and Sugar Beet Brasov is working constantly to create new potato varieties adapted to changing climatic conditions, with high yield, suitable for the processing industry, to satisfy the both quantitative and qualitative needs of consumers. Regarding the genetic complex structure of potato (2n = 4 x = 48 chromosomes) and the segregation of the desired character in the offspring produced by sexual hybridisation, creating new varieties of potato requires a long period (10-12 years) and a large volume of activity (chance for registration of a new variety is 1 to over 100.000 seedlings). The key objective was to select varieties immune to wart disease, with high resistance to other diseases (mainly potato late blight), with good agronomic and cooking qualities. As the result of breeding work three new varieties were produced: Azaria, Darilena and Asinaria. The varieties are conceived for autumn-winter consumption, being suitable for most culinary preparations, from salad, pommes frites to mash potatoes. The potato varieties were breed using the hybrid cross method followed by individual clonal selection, according to the classical scheme of potato breeding. The best potato clone was selected from many others. The resistance to wart disease was tested at Pojorâta Station (Suceava) and the resistance to late blight and viruses were determinated in the fields and laboratories of NIRDPSB Brasov. Also to NIRDPSB Brasov it has been determined the culinary quality of potato tubers by assesing their behavior to boiling. The yield capacity in different environmental conditions and also the ecological plasticity of the varieties were tested in State Institute for Variety Testing and Registration network

The NPK fertilization effects on culinary and technological potato quality

In this research we propose different levels of fertilization and NPK ratios, for Roclas and Christian potato varieties. The experiment was done in Braşov in a non-irrigated crop, studied during 2013-2014. Research methods in laboratory included analysis, qualitative and quantitative determinations designed for tubers using purpose. This permits multicriterial qualitative characterization of production from the studied fertilization variants. We analyzed the culinary quality traits and the correlations with tubers starch content before storage. Also we studied the average suitability for processing into chips and correlations between dry matter, starch, reducing sugar, efficiency to processing into chips and chips color before storage. Comparing variants of fertilization, on Roclas variety, tubers from variant with N100 P100 K100 louder crashed on boiling, pulp consistency is more reduced, are more farinaceous and moisture toward the rest of variants for both years, tubers starch contents positively significantly correlate with appreciation notes for milling, moisture and starch structure. With the increase of the NPK ratio from 1:1:1 to 1:0.9:2 and with increasing nitrogen dose combinations from 100 to 200 kg N/ha the decline in yield is found in chips. Notes for the chips’ color have a tendency to decrease, which indicates a darker color of chips with increasing doses of nitrogen on variants with ratio 1:0.9:2, on both varieties and both experimental years. No significant correlation was obtained between reducing sugar and color of chips tubers for data achieved in the years 2013-2014, before storage for the studied varieties. The correlation between the efficiency to processing into chips and the color of chips was significant only for Christian variety (0.444*)

Researches regarding the minitubers production from potato lines

In this study was done researches about minitubers production from 14 potato lines studied: TS 12-1488-1574, TS 12- 1489-1574, TS 12-1497-1573, TS 11-1475-1633, TS 12-1502-1675, TS 11-1472-1633, TS 11-1468-1633, TS 09-1441- 1525, TS 11-1486-1642, TS 12-1501-1582, TS 11-1480-1633, TS 96 -1207-169, TS 11-1467-1633, TS 09-1442-1525. The experience was monofactorial, in which the analyzed factor was the genotype, consisted of 14 variants, divided into 3 repetitions. As a control, the average of the determined values was determined for each parameter taken in the study. The parameters analyzed were: minitubers number / plant and minitubers weight minitubers / pl. TS 12-1489-1574 potato line was the most representative, being a productive line, which was distinguished by a number of 11.83 minitubers / plant and a significantly positive difference of + 4.21 comparative with control taken in the study. Weight of minitubers / plant was influenced by genotype, proving superiority TS11-1468-1633 potato line which had a good capacity to produce minitubers with high weight (295.17 g) (and a distinct significant difference, positive, to control +114,83). Thus, this potato line has a high potential for producing high yields