Saffron Agronomy and Technology
Year:2018 | Volume:5 | Issue:4 |Papers Count:7

Studies that investigated the impact of organic fertilizers (manure, compost and biological fertilizers) and agronomical practices (density, method, date and depth of planting) on saffron yield have a long history in Iran. Due to the distribution and inconsistency in the results obtained from different studies, a meta-analytic approach was used in the current study. To meet this goal, forty seven organic fertilizer studies and forty four agronomical practice studies were selected from the 202 studies that were gathered and analyzed. The criteria for the selection of studies were the adequacy of data for the present meta-analysis. Among the individual fertilizer studies, manure fertilizer had the highest impact on saffron dry weight (g=1.493) at 95% confidence interval. The average amount of 40 to 50 t.ha-1 of cow manure, 20 to 30 t.ha-1 of compost that is used in combination with Biofertilizer (Nitroxin with Nitrogen-fixing bacteria) were more effective than higher amounts of these fertilizers when used alone. Among the agronomical practice studies, plant density had the highest and depth of planting had the lowest effect on economical yield and number of flowers. The optimal density for maximum yield was 50-100 corm per m2, optimal consumed weight average of 9-12 t.ha-1 was observed, and the optimal weight of each corm was 10-20 (g). Among the planting methods, the rowmass method was the most optimal (inter-planting was 20 cm and intra-planting 10 cm). The best planting dates were the end of May and the first decade of Jun. The optimal planting depth was 15-20cm. Homogeneity between organic fertilizer studies was accepted and the homogeneity between agronomical practices except depth of planting studies was accepted. Any observed heterogeneity was caused by factors such as age of farms and different regions that had the most impact on heterogeneity and effect size. The present meta-analysis aims to provide a better understanding of agronomical and fertilizers management and offer the best possible management options for this crop.

This study is aimed at investigating the effect of using humic, bio and nano fertilizers and levels of nitrogen fertilizers in flower yield of saffron (Crocus sativus L.) at the University of Torbat Heydarieh research farm located in Zaveh in 2014-2015. Treatments consisted of three levels of nitrogen application and use of fertilizer sources as the main factor, including Bioumik, Super Humic, combined Super Humic and Bioumik, Humi Ful, Nitrokara and no fertilizer as sub plots as split plot based on randomized complete block design with 18 treatments and three replications. Analysis of data showed that the effect of year and fertilizer sources on all traits measured was significant. The effect of nitrogen treatments was significant (at 1%) except on number of flowers, dry style, mean dry weight stigma, and mean dry weight. Fertilizer sources increased all measured traits significantly. Application of Biomic increased petals and sepals dry weight (736.34 g.m-2) by 46.78% in comparison with the control (464.19 g.m-2). The highest dry weight stigma (524.2 g.m-2) was seen in Super Humic +Bioumik treatment compared to the control group (443.1 g.m-2). Super Humic treatment increased dry weight stigma by 86.49% relative to control. It seems that the use of humic, bio and nano fertilizers has a good effect on saffron performance.

In order to investigate the effects of different types of nano-fertilizers on some of the physiological characteristics of saffron (i.e. antioxidant enzymes, reducing and non-reducing sugars, photosynthetic pigments, total phenol content and relative water content of leaf) the current experiment was conducted at the Malayer University during the 2014-2015 growing season. The study was performed based on randomized complete block design (RCBD) with six treatments and three replications. The experimental treatments were control and five different types of nano-fertilizers (iron: Fe, boron: B, manganese: Mn, potassium: K and zinc: Zn). The effects of experimental treatments on relative water content, protein and total phenol content, reducing and non-reducing sugars were significant. However, there was no significant effect on chlorophyll b, leaf carotenoids, Catalase and Proxidase activity. Although the difference between nano-fertilizers and control treatment for chlorophyll a and also total chlorophyll was not significant the highest amount of chlorophyll a (1.53 mg.g-1 Fw) was measured in the Fe treatment and the lowest amount (0.93 mg.g-1 Fw) was observed in the Mn treatment. Based on the results, all of the experimental treatment increased the relative water content of leaf compared with control. The highest amount of total phenol content (0.27 mg.g-1 FW) with 10.5% increase compared to control was observed in Mn treatment and just the difference of this treatment with the control treatment was significant. By the application of Zn, Mn, K and B nanofertilizer leaf protein content was significantly increased when compared with the control treatment whereas the difference between Fe and control was not significant. The highest concentration of leaf protein (1.56 mg.g-1 Fw) with 12% increase compared to control treatment was observed in the K and B treatments whereas the lowest concentration of leaf protein (1.36 mg.g-1 Fw) with 3% decrease compared to control was related to the Fe treatment. The different response of the studied characteristics to application of various nano-fertilizer showed that different physiological traits did not have a similar sensitivity to all of the mineral nutrients. Therefore, application of entire nanofertilizers with the same concentration is not scientifically recommendable.

Separation of stigma from petals is one of the required tasks in saffron production. The mechanical separation of saffron flowers may be performed through the following steps: I) singulation of the flowers ii) aligning the flowers iii) cutting the style (Konje) and iv) separating the stigma from the petals. Because of the importance of saffron flower separation, a prototype device was constructed in this project for singulating and aligning of saffron flowers, prior to the cutting operation. This device can also be installed to work with other cutting and separating equipment and produce on an industrial scale. A pickup vacuum cylinder was used for singulating the flowers and an inclined V-shaped surface was employed for aligning of saffron flowers. The constructed apparatus was evaluated from the standpoint of singling efficiency and losses. For this purpose, three types of saffron flowers (buds, open short tail and long tail), three rotational speeds of pickup cylinder (6, 12 and 21.5 rpm), three levels of suction (30, 70 and 100 mm Hg), and four different inner diameters of finger’s nozzle (2, 3, 4 and 5 mm) were used with three replications. The results of analysis on the constructed device showed that the highest efficiency (75%) is observed for short tailopen saffron flowers with 5 mm inner diameter of sucking nozzles, suction of 100 mm Hg and the rotational speed of 6 rpm. To evaluate the performance of flower aligning, 100 saffron flowers with an average length of 5 cm were selected and tested with 5 replications. The average aligning with the correct direction obtained was equal to 84%.

Yield prediction for agricultural crops plays an important role in export-import planning, purchase guarantees, pricing, secure profits and increasing agricultural productivity. Crop yield is affected by several parameters especially climate. In this study, saffron yield in the Khorasan-Razavi province was evaluated by different classification algorithms including artificial neural networks, regression models, local linear trees, decision trees, discriminant analysis, random forest, support vector machine and nearest neighbor analysis. These algorithms analyzed data for 20 years (1989-2009) including 11 climatological parameters. The results showed that a few number of climatological parameters affect saffron yield. The minimum, mean and maximum of temperature have the highest positive correlations and the relative humidity of 6.5h, sunny hours, relative humidity of 18.5h, evaporation, relative humidity of 12.5h and absolute humidity have the highest negative correlations with saffron cultivation areas, respectively. In addition, in classification of saffron cultivation areas, the discriminant analysis and support vector machine had higher accuracies. The correlation between saffron cultivation area and saffron yield values was relatively high (r=0.38). The nearest neighbor analysis had the best prediction accuracy for classification of cultivation areas. For this algorithm, the coefficients of determination were 1 and 0.944 for the training and testing stages, respectively. However, the algorithms accuracy for prediction of crop yield from climatological parameters was low (the average coefficients of determination equal to 0.48 and 0.05 for training and testing stages). The best algorithm i.e. nearest neighbor analysis had coefficients of determination equal to 1 and 0.177 for saffron yield prediction. The results showed that using climatological parameters and data mining algorithms can classify cultivation areas. Using this approach, it is possible to identify areas that have similar climate to prone areas and recognize suitable areas for cultivation.

In terms of quality and quantity, Iranian saffron has a considerable position at the international level. We can significantly increase our export earnings from saffron by taking advantage of the existing capacity. It should be noted that sales forecasting based on time series analysis is a very important element for the design and implementation of marketing strategies in the international arena. However, the conventional approaches to forecasting which rely on ignoring the linear (or nonlinear) structure of data do not provide accurate results. Therefore, the main objective of this study is to design a hybrid model consisting of two methods, artificial neural networks (ANN) and autoregressive integrated moving average (ARIMA), in order to use the unique features of the each of these methods and overcome the existing deficiencies. Using the data related to the export of Iranian saffron during the period of 1904-2013, the results of the study showed that the ARIMA-ANN hybrid model is stronger and has better performance than the ARIMA and ANN individual models in order to forecast Iranian saffron export. Therefore, given the considerable performance of the ARIMA-ANN hybrid model, the use of this model is recommended in developing strategies related to the export of saffron and also in the forecasting of variables for time series.

Saffron is one of the most important economic plants in the world that also has many pharmaceutical applications. Genus Crocus SPP. L. (Saffron) with about 90 species of the Iridaceae family in the northern hemisphere, are scattered especially in West Asia and Iran. The aim of the present study is to investigate the antimicrobial activity of extracts of various parts such as cover of corm, corm, perianth and stigma of a variety of saffron (C. sativus var. haussknechtii) on some pathogenic microorganisms (Bacillus cereus, Enterococcus faecalis, Escherichia coli, Pseudomonas fluorescens, Salmonella typhimurium, Staphylococcus aureus) extrusion. Plant specimens were collected from four different habitats of the Kermanshah province and then they were identified in the herbarium of the Razi University. After preparing raw plant, extracts from four different parts of the plants (cover of corm, corm, perianth, and stigma) were extracted by soaking (maceration). Microbial tests using minimum inhibitory concentration (MIC) of the broth micro-dilution method were determined. The results of analysis by statistical tests showed a significant correlation (p>0.001) between the increase in the concentration of alcoholic extracts of the perianth saffron and diameter of the inhibition zone. Thus, Perianth methanol extract in Enterococcus (0.128) g ml, Salmonella and Staphylococcus (0.512) g ml has inhibitory effects against bacteria. Based on the findings of this study, the non-alcoholic extracts of different parts of a flower in this plant do not show any antimicrobial properties. Thus, perianth of these wild saffron flowers may be a good candidate for laboratory tests and the isolation of active ingredients to achieve antimicrobial drugs is highly recommended.