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

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*)

Preliminary results regarding the effects of extreme climatic conditions on the yield quality of different Romanian potato varieties

Experiments with varieties Christian, Cumidava, Roclas and Rustic took place in Brasov, in 2012 and 2013, years, very distinct from the point of view of climate during potato growing season. Extreme climate conditions during the growing season of potatoes can strongly disrupt the tubers growth processes, this being reflected on the yield structure. Very high temperatures and drought in 2012 have affected potato crops in the most important production phenological phase, the period of budding-flourishing, when susceptibility face to soil humidity is highest. During this period was the largest consumer of water. Because of these unfavorable circumstances, the new tubers suffered quantitative and qualitative depreciations by deformation, dehydration, second growth and sprouting. In the year 2013, characterized by alternate rainy periods with periods without rain and higher temperatures than normal, have determined foliage lush growth that could not self-holds and went into a very early decline. Thus, starting with first decade of August, the plants were dried on an accelerated basis, starch accumulation and tubers growth being halted. Following the comparison of the years was found differences of varieties yield between 19.7 and 26.8 t/ha. Towards 2012, on 2013, varieties yield was 3-4 times higher and the starch content of plant varieties averaging 1.28%, significant differences being on Roclas and Rustic. In 2012 the average percentage of tubers depreciation by deformation was 84.9%, dehydration -27,9%, second growth - 2.6% and sprouting -24.4%. The research, in addition to the data provided from the reaction conditions of cultivated varieties, put the bases of future research on the yield quality in different agro-climatic contexts

Aqueous Dispersions of Silica Stabilized with Oleic Acid Obtained by Green Chemistry

The present study describes for the first time the synthesis of silica nanoparticles starting from sodium silicate and oleic acid (OLA). The interactions between OLA and sodium silicate require an optimal OLA/OLANa molar ratio able to generate vesicles that can stabilize silica particles obtained by the sol-gel process of sodium silicate. The optimal molar ratio of OLA/OLANa can be ensured by a proper selection of OLA and respectively of sodium silicate concentration. The titration of sodium silicate with OLA revealed a stabilization phenomenon of silica/OLA vesicles and the dependence between their average size and reagent’s molar ratio. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) measurements emphasized the successful synthesis of silica nanoparticles starting from renewable materials, in mild condition of green chemistry. By grafting octadecyltrimethoxysilane on the initial silica particles, an increased interaction between silica particles and the OLA/OLANa complex was achieved. This interaction between the oleyl and octadecyl chains resulted in the formation of stable gel-like aqueous systems. Subsequently, olive oil and an oleophylic red dye were solubilized in these stable aqueous systems. This great dispersing capacity of oleosoluble compounds opens new perspectives for future green chemistry applications. After the removal of water and of the organic chains by thermal treatment, mesoporous silica was obtained