THE INFLUENCE OF POTATO VARIETY AND ORGANO-MINERAL FERTILIZATION ON POTATO STORAGE IN THE APUSENI MTS. AREA PUBLISHEDMarilena Marghitas, C. Toader, Mihaela Mihai, Lavinia Moldovan
Potato, in the Apuseni Mts. area, is the most cultivated plant species. By means of its main products, the tubers, it provides the basic ood support for the locals and their livestock throughout the year. For a long period, mountain agriculture has been regarded as a source of healthy and qualitative food products, but devoid of any significant investments in the past, as well as the present. At present, in the poor economic and financial situation in our country, mountain agriculture does not benenfit from investments, although locals in the area rely on agriculture as their main occupation and the sole source of subzistence. This is the reason why young people have left the area and the population is aging and diminishing. For the development of the area and the achievement of qualitative and quantitative superior productions, it is highly necessary to implement ecologically-protective crop technologies employing the natural organic resources in the area, as well as appropriate measures for the storage of tubers in private households. It is well-known that the potato tuber is a living organisms that continues its physical, biochemical and physiological processes after harvesting. These processes, at various degrees of intensity, may lead to serious weigth losses during storage. One of the factors exerting a great influence on storage is the variety. Potato varieties exhibit different behaviours, as the determining factor is the germinal interval and not the duration of the growing period. The germinal interval is characteristic to the variety, as its duration is genetically determined, with no dependence on the duration of the growth period. Varieties with a long germinal interval, resistant to blight, wet and dry rot, show the least losses during storage (Mureşan S., 1976). In terms of external factors, realtive air temperature and humidity in the storage area exert a major influence in the storage of potato tubers. Optimal temperatures for the storage of potato according to employment are: seed 2-4 o C, consumption 3-6 o C, industrial 8-12 o C (Mureşan S., 1980). Temperature in storage areas determines the direction and speed of essential chemical reactions. As such, when temperature is high in storage areas, there is a favourable climate for tuber germination, the intensification of breathing and the creation of a favourable environment for microorganisms.The slow lowering of temperatures leads to tuber sweetening, which continues up to 0 o C, when the breathing process stops and the potato becomes sweet. Relative air humidity in storage areas is important to maintain potato turgor and thus optimal air humidity must be maintained to 85-90% in storage areas. Under this limit, tubers lose water and wrinkle, while over this 90% limit, there is an excess of humidity in the tuber mass, thus favouring rot diseases. Differentiated fertilization influences the level of loss due to rot diseases, as balanced NPK fertilization in optimal doses according to plant nutrient requirements leads to reduced losses as opposed to the situation when fertilization is umbalanced, favouring rot diseases and implicitly significant weigth losses and a quality decrease for stored tubers. The objective of the research presented therein envision the influence of the variety and differentiated organo-mineral fertilization on quantitative and qualitative achievement of potato tubers in the mountain area and losses through storage in unequipped areas, cellars that are specific to households in the Apuseni Mts. area. The importance, originality and degree of novelty of this agronomic research are due to yet unsolved problems regarding fertilization combinations in potato crops, when undesirable weather events are increasingly present thus increasing the risk for calamity in cultivated agricultural and horticultural crops. In this respect, the experiments and overall research conducted in the present paper are new, useful and aim at the improvement of unfortunate situations (agrochemical risk-insufficiency-defficiency; excess- toxicity for potato tuber production) and provide with alternatives in the field for the differentiation of fertilization systems in order to select practical solutions that are both agrochemically and economically accessible. The implementing of a suitable soil fertilization system that is ecologically-protective for potato in the mountain area must be accompanied by a rigorous agrochemical control that would provide for a diversity of practical solutions in achieving the agrochemical soil-plant optimum and providing the protection of mountain ecosystems. In order to complete this paper, experiments were conducted on differentiated organo-mineral fertilization systems, for the Ostara and Desiree ptato varieties, on a districambosoil, namely a brown acidic soil, located in the high area of the Apuseni Mts. at the basis of the north-north-western slope of the Ariesul Mic river basin.
soil, fertilization, unequipped storage area, potato