جستجوی مقالات مرتبط با کلیدواژه « شکر » در نشریات گروه « زراعت »

Sugar is one of the basic and strategic products that has always been considered and supported by governments. Sugar is an international and strategic commodity that has a special place in the trade, social and economic policies of many countries. Given that part of the country's needs is met through imports, therefore, one of the important issues in the sugar market in the country is the effect of domestic sugar prices on exchange rate fluctuations, which in turn affects the production of sugar beet and sugar. The aim of this study was to evaluate the effect of variation in foreign exchange policies on sugar price using the monthly time series data of 2018-20 and also due to the relationship between imports and sugar beet and sugar production, the indirect effect of this policy on production be analyzed. Monthly data were analyzed to using VAR model. Results showed that change in foreign exchange policy (exchange rate change from 42,000 Rials to the Nima currency) with a two-month break had a direct effect on sugar price. Due to the causal relationship between the variables, it was also observed that variation in foreign exchange policy has also affected the sugar beet production. Considering the results of this study, in order to sustain the effect of this policy in the coming years, it is necessary to pay special attention to the effect of these variables in designing related policies so that from the beginning with the implementation of the policy to other effective factors in this regard, including increase in the productivity of production factors and supporting technology, especially the production of suitable and economical seeds for producers, more attention should be given to the growing trend of production in the country against the import of sugar.

The purpose of this study was to estimate the demand for Iranian sugar imports considering the two countries of Brazil and the United Arab Emirates as the major importers of sugar to Iran. It should be noted that the UAE acts as a re-exporter and is not a sugar producer. Therefore, time series data from 1992-2016 and Auto-Regressive Distributed lag (ARDL) was used. The results of long-term estimates show that 1% increase in GDP increases the demand for sugar imports by 4.73%, and 1% increase in relative prices and exchange rate reduces the demand for sugar imports by 28%. Also, if the Brazilian export rate increases by one unit, the demand for Iranian sugar imports from Brazil would increase by 0.8% unit compared with the UAE. The Error Correction Model (ECM) in the sugar import demand function also shows that the rate of 0.68% deviation of sugar import from its long-term path is corrected by pattern variables in the next period. Finally, policymakers should consider the exchange rate variable as one of the most important factors influencing foreign trade, especially sugar.

In semi-arid regions e.g. Iran, water is the major limiting factor for the growth and yield of sugar beet. Development of cultivars with flexible growth period, dependent on the environmental condition, is one of the methods to reduce water usage for sugar beet cultivation. The present study was performed in Sugar Beet Research Station of Motahhari, Karaj, Iran as a split factorial based on a randomized complete blocks design with four replications in two years (2015-16). Main plots were devoted to sowing date (mid-April and late-June), and sub-plots to the factorial combinations of three harvest dates (12 October, 1 November, and 21 November) and six genotypes including promising hybrids (7112*261)*5RR-87-HF.33 and 261*276.P.77.SP.19 and commercial cultivars Pars, Jolgeh, Paya and IR7. Potential root yield (RY) and sugar yield (SY) was reduced by 3.5-3.8% per week owing to delay in sowing. The significance of sowing date × genotype interaction (P<0.05) highlights diverse response of various genotypes to the shortening of the growth period. Superior genotypes for delayed planting were identified based on the combination of two components of the least response to delayed sowing as well as achieving the highest yield under delayed sowing condition in terms of SY as Paya, IR7, and Pars. Although the direct effect of harvest date on RY, SY, and sugar content (SC) was not significant due to the significant interaction of year × harvest date, however in general, it increased RY, SY, and SC by 21, 38, and 1.72 %, respectively via delaying the harvest date from 12 October to 1 November 1 in 2015. Therefore, the harvest date of 1 November was the most suitable time for sugar beets harvest in Karaj region. Non-significant interaction between sowing and harvest date for various studied traits indicated that the impacts of delay in sowing cannot be offset by delay in harvest. Overall, results showed that by each single day advancement in sowing (between mid-April and late-June) RY and SY increased by 400 and 50 kg ha-1, respectively and for each day delay in harvest (between 12 October and 1 November) RY and SY were increased by 370 and 100 kg ha-1, respectively.

Mismanagement of nitrogenous fertilizers has caused serious nitrate (NO3) contamination in many flood-irrigated. Low-volume irrigation practices can offer an alternative approach for controlling NO3 leaching and agricultural water use. The simultaneous application of fertilizers and irrigation water is an appropriate alternative to increase the efficiency of applied water and fertilizers. The nitrogen use efficiency of sugar beet (Beta Vulgaris L.) has been studied through the Iran but there is limited information about the response to irrigation and amount nitrogen fertilizer. The objective of this study was to investigate the effect of various irrigation and nitrogen amounts on efficiency of applied fertilizers. A field experiment with sugar beet as randomized block, split-plot design with irrigation treatments as main plots and N fertilizer rates as subplots, with three replications, was used. Four levels of the water (40, 80, 120 and 160% evaporation from surface of A class pan, treatments I1 to I4) and nitrogen fertilizer (urea) rates (N0, N1, N2, and N3, respectively 0, 90, 180 and 270 kg N ha-1 were applied. The results indicated there were significant differences (P0.01) in root yield, sugar content, total dry matter and nitrogen use efficiency (NUE) basis of root yield, sugar and total dry matter yield between treatments Treatment I4 with 47969 kg ha-1, root yield and treatment I2 with 6855 kg ha-1, sugar content had maximum production. The result showed, root yield, sugar content and total dry matter increased with increasing applied nitrogen. Treatment I4N3 with 53621 kg ha-1 root yield, 7887 kg ha-1 sugar content and treatment I3N3 with 53075 kg ha-1 root yield, 7689 kg ha-1 sugar content had maximum yield. Nitrogen use efficiency maintained an order I4>I3>I2>I1 and F1>F2>F3. There was a decreasing pattern in NUE values with increasing fertilizer rates. The results showed that by increasing applied water, nitrogen use efficiency increased and affected by fertilizers treatments. Fertilizer use efficiency also decreased by increasing fertilizer rate. The results also demonstrated there were significant differences in all the treatment.