Stigma Yield Research Articles

Influence of composted manures and co-composted biochar on growth performance of saffron and soil nutrients under varying electrical conductivity soil conditions: A two-year field study

The stigmas of saffron (Crocus sativus L.) are known as “red gold” for being the most expensive spice of the world. This medicinal crop grows well in the regions with cold winter Mediterranean climate. However, salinity can be one of the limiting factors for its cultivation in these regions. Composted manures and their co-compost with wood-derived biochar as fertilizers in saline soil can reduce the salinity stress on saffron. In this study, the composted manures from dairy farms (FYM), sheep and goats (SG) and poultry (PM) and their co-compost with wood-derived biochar (FYM-B, SG-B and PM-B) were amended in non-saline (EC1:2 0.25 dS m−1, SOM; 9.9 g kg−1) and soil with natural slight salinity (EC1:2; 1.95 dS m−1, SOM; 30.9 g kg−1) soil for two consecutive years with the total amendment rate of 65 t ha−1 for each fertilizer. The saline soil was transported from an agricultural farm (30 km away from research field); whereas, the non-saline soil was not transported and was not cultivated before. The amendment of fertilizers and sowing of corms were conducted at the same time in the mid of August. The stigma yield in saline control soil was significantly lower than non-saline control in both cropping years. In non-saline soil, all fertilizers reduced stigma yield of first-year crop by 14–60 % (P < 0.05). No differences between treatments for the stigma yield of second year crop in non-saline and of first year crop in saline soil were observed. In saline soil, FYM and PM fertilizers increased stigma yield of second year crop by 44 % and 41 %, respectively (P < 0.05). The two-year cumulative agronomic efficiencies for nitrogen and phosphorus and the nitrogen use efficiency for leaf biomass were lower under fertilizer treatments than control in non-saline and saline soil. In non-saline soil the PM-B; whereas, in saline soil all fertilizers (except SG) increased the phosphorus use efficiency of leaves (P < 0.05). The two-year amendment of composted manures and FYM-B in non-saline soil resulted in high uptake of sodium in leaves (P < 0.05); whereas, such effect was not observed for saline soil. Almost all fertilizers increased ∼2–5 fold the concentration of bioavailable phosphorus and ∼2–3 fold the concentration of potassium in non-saline and saline soil (P < 0.05). The positive influence of fertilizers on stigma yield and PUE of leaves of second year crop was observed only for saline soil. Furthermore, contrary to the results for non-saline soil, these fertilizers did not cause an increased uptake of Na in leaves in saline soil. We attribute this effect to the high concentration of SOM and gradual decline in EC (0.94–1.71 dS m−1) over time in saline soil. The gradual improvement in yield (from negative to neutral in non-saline and from neutral to positive in saline soil) was observed over time. Amendment of fertilizers and sowing of corms at same time may be the reason for their negative influence on stigma yield in low SOM-containing non-saline soil.

English

The current study was conducted in growth chamber with the aims to examine the effect of different soil types and temperature regimes on quantitative and qualitative traits of saffron and to assess the agro-climatic suitability of selected sites of Poonch Division of Azad Jammu &amp; Kashmir for field scale saffron cultivation. Soil from 07 sites was collected and processed for pot filling. A total of 63 plastic pots (21 for each temperature level i.e., 19, 26 and 32 oC), were filled with soils of each site and incubated separately in growth chambers. The pots were arranged under completely randomized design (CRD) replicated thrice. Results indicated that maximum number of flowers (1.35 per plant), flower fresh weight (29.03 mg per plant), stigma length (1.21 cm), stigma fresh weight (8.97 mg per plant) and stigma yield (8.60 mg per pot) was recorded for Khaigala site (loam textured soil) at 26 oC followed by Trarkhel (sandy loam textured soil) and Abbaspur (loam textured soil) sites. On an average, maximum 58.30 days were taken to initiate flowering in soil of Alisojal site (clay loam textured soil) with flowering period of 17.06 days. The maximum number of daughter corms (2.92 per plant), corm diameter (9.61 mm), corm weight (15.76 g per plant), corm yield (47.28 g per pot), picrocrocin (11.32%) and safranal (0.22%) content was again recorded for Khaigala site (at 26 oC). However, maximum crocin content (14.33%) was noted for Alisojal site (1831 m altitude). The Cluster and PC analyses revealed that Khaigala, Trarkhel and Abbaspur sites produced saffron of better quality and agro-climatically suitable for establishment of saffron. Further, the saffron grown on loam and sandy loam textured soils showed better performance compared to that of clay textured soils.

Microbial interactions modify saffron traits selectively and modulate immunity through adaptive antioxidative strategy: Organic cultivation modules should be trait and crop-specific

Saffron (Crocus sativus L.) is a high-value, low-volume niche cash crop that has the unique ability to synthesize apocarotenoids. Since different biofertilizers are advocated for promoting plant health, we aimed to evaluate the interactions of commercially available microbial inoculants with this unique hysteranthous plant species. We studied the interactive effect of microbial inoculants on agronomical, physiological and biochemical aspects of Crocus growth, corm multiplication and apo-carotenoid biosynthesis. Significant differences in nutrient mobilization potential, induced systemic resistance, plant growth, corm, and stigma yield/quality were detected between the different biofertilizer combinations. The arbuscular mycorrhizal fungi (AMF) + phosphate-solubilizing bacteria (PSB) + potassium-solubilizing bacteria (KSB) combination was the most suitable for enhancing shoot biomass, root depth, and root biomass. Additionally, the average number of flowers per corm, stigma yield, and corm yield were greatest for the same combination. The highest multiplication rate of mother corms and a small corm index were recorded for plants inoculated with Azospirillum + PSB + KSB. Although Azospirillum caused maximum multiplication, the percentage of smaller daughter corms was greater, while the replacement of Azospirillum with AMF resulted in maximum percentage of larger corms. Plant health improved through AMF-mediated microbial interactions, which induced systemic resistance via enzymatic and nonenzymatic mechanisms and increased the uptake of P, K, Cu, Fe, Mn, and Zn. The interrelationship between plant and microbial consortium was complex, causing trait-specific qualitative and quantitative impacts on saffron attributes. Microbial inoculants increased nutrient uptake by saffron plants and triggered biochemical defence response by causing mild stress, making the plant more growth-responsive and better equipped for defence. Microbial interaction increased saffron yield and quality by favourably modulating plant metabolism, majorly overlapping with plant protection mechanisms. However, plant-microbial combinations in an organic production module are trait-specific and should be chosen carefully.

Effects of different microbial agent applications on the growth and quality of saffron (Crocus sativus L.) cormels

Saffron (Crocus sativus L.) is a bulbous flower whose dried stigmas are used as a herbal medicine and as a spice. Saffron is cultivated worldwide, but corm degradation is an important factor affecting its yield and quantity. This study investigated the effects of three different microbial agents (Bacillus megaterium, Brevibacillus laterosporus, Paenibacillus mucilaginosus) on the growth and quality of saffron cormels. Both the weight and circumference of the cormels were significantly increased in response to microbial agent treatment. Measurements of the physiological and biochemical characteristics of the cormels as well as the flowering traits showed that the starch and protein contents as well as the flowering rate and stigma yield increased significantly after the application of the three microbial agents. Analyses of soil physicochemical properties and microbial populations revealed increases in the soil potassium content and a significant alteration in the soil microbial community structure in response to treatment. Our results showed that the application of three microbial agents enhances the growth, nutritional status and health of saffron cormels and improves the soil environment during saffron corm cultivation. Paenibacillus mucilaginosus also increased the accumulation of crocins and picrocrocin in stigmas. Our results provide the theoretical and practical knowledge needed to reduce corm degradation and to improve saffron corm cultivation.

Corm size and planting density affect the yield and longevity of saffron (Crocus sativus L.)

The effect of the corm size of saffron (Crocus sativus L.) and the planting density was determined on a field study for six years. The objective of the present study was to determine the impact of the corm size and planting density on flower and stigma yields. Two corm sizes were used: corms with a diameter up to 2.5 cm and corms with a diameter greater than 2.5 cm, and five planting density: 22, 27, 33, 44 and 67 corms/m2 with planting distances 30, 25, 20, 15 and 10 cm on the plant row, respectively. The results showed that the year (growing season) and the interaction of year (growing season) with corm size affected all the characteristics that were studied. Over the six-year study period, there was a gradual increase in flowering from the first to the third year, followed by a decline in the fifth and sixth years. The yield of larger corms (greater than 2.5 cm) was higher during the first three years, while smaller corms (less than 2.5 cm) produced higher yields in the fourth through sixth years. On the contrary, the planting density, did not significantly affect the characteristics studied over the six years of cultivation and therefore did not affect the stigma yield of saffron. Therefore, corm size together with the environment are important factors that can affect the productivity and the longevity of the crop and should be considered when planting a new saffron cultivation.

Simulation of saffron growth using AquaCrop model with high-resolution measured data

Saffron is one of the most expensive and worth-to-cultivate crops in countries struggling with water scarcity due to its low water requirement and compatibility with arid climates. This study was conducted to calibrate and validate the AquaCrop model for saffron at the research farm of the Ferdowsi University of Mashhad (FUM), Iran, in two growing seasons of 2021–2022 (two-year-old saffron) and 2022–2023 (three-year-old saffron). The soil water content, canopy cover, and biomass values were measured continuously during both growing seasons. The field measurements of the first and second growing seasons were used to calibrate and validate the AquaCrop model, respectively. Furthermore, using the Particle Swarm Optimization (PSO) algorithm, a new module for the inverse solution of the AquaCrop model has been presented. The module was successfully employed to fine-tune sensitive soil parameters of the field. The results showed that the AquaCrop model could accurately simulate soil water content, biomass, and canopy cover in both growing seasons. The root mean square error (RMSE) of simulations for soil water content, biomass, and canopy cover comparing to in-situ measured data was 8.3 mm, 0.3 ton ha−1 and 3.4% for the first year and 5.5 mm, 0.4 ton ha−1 and 2.7% for the second year, respectively. In these simulations, the saffron daughter corm production was considered as the crop yield, because the stigma yield is affected by the climatic conditions of the past year while corms are produced at the end of the prevailing season. To investigate the effect of cold and heat on saffron yield, the hottest and coldest growing seasons in the past 30 years were determined in 6 regions besides Mashhad, and the biomass in these seasons was simulated using the model. It was concluded that the cold growing season had a more significant effect than the hot season in reducing the saffron corm yield.

Evaluating the Effects of Bacillus subtilis Treatment and Planting Depth on Saffron (Crocus sativus L.) Production in a Green Roof System

Given the current urbanization context and rising interest in green roof systems, growing a high-value crop such as saffron crocus in green roof medium could be an opportunity to use the benefits of both the crop and the green roof system; the drainage, aeration, and sand-like texture of green roof media make it suited for saffron production, and the saffron market price could make green roof production commercially viable. Various factors, including plant diseases and planting depth, could affect saffron production. Therefore, this research was conducted to evaluate the effects of planting depth and biofungicide treatments using Bacillus subtilis on saffron production in a green roof system. A completely randomized factorial block design was used with planting depth (10 cm and 15 cm) and B. subtilis strain QST 713 biofungicide treatments (an untreated control, 15.6 × 109 cfu/L, and 31.2 × 109 cfu/L) as independent variables. In 2019, fresh flower yield, fresh stigma yield, and dry stigma yield were calculated during harvesting, and additional data on flower number, tepal length and width, stigma length, and harvest time were collected in 2020. All variables were analyzed using analysis of variance (ANOVA) with planting depth and biofungicide treatments as fixed effects using R. Fresh stigma yield and dry stigma yield were higher in the 10-cm planting depth in 2019. Results were opposite in 2020: flower number, fresh flower yield, fresh stigma yield, dry stigma yield, and harvest time were higher in the 15-cm planting depth than the 10-cm planting depth. B. subtilis treatments did not affect any studied variable in 2020, but in 2019, the higher level of fungicide treatment resulted in lower fresh flower yield and dry stigma yield. There was no effect of biofungicide treatment and planting depth on tepal length, tepal width, and stigma length in both years. This study showed that growing saffron crocus on green roofs is feasible and even resulted in higher yield than field production in many saffron-producing regions and countries. In addition, results indicated that shallow planting might be suitable for annual production, whereas deeper planting could be ideal for perennial production based on the objective. Our findings demonstrated the feasibility of saffron production in the green roof system and suggest further research to develop best management practices.

Effects of total daily light integral from blue and broad-band red LEDs on flowering of saffron (Crocus sativus L.)

Present indoor cultivation of saffron (Crocus sativus L.) only depends on artificial planting experience, so that flower number and stigma yield are seriously affected in case of cloudy or rainy days and temperature changes. In this study, a luminaire was used at 10-h photoperiod combined 450 nm blue LEDs with 660 nm broad-band red LEDs, which respectively had full width at half maximum (FWHM) of 15 nm and 85 nm, in a ratio of blue: red: far-red light = 20%: 62%: 18%. The influence of total daily light integral (TDLI) was evaluated on flowering characteristics, stigma quality, as well as leaf morphological characteristics. The results showed that flower number, daily flowering proportion, stigma dry weight and crocetin esters content were significantly correlated with TDLI (P < 0.01). The increasing TDLI could slightly promote leaf width and leaf area beyond buds, but had no significant effect on bud length and leaf length. Both the average flower number per corm and dried stigma yield was the highest under the 150 mol m−2 TDLI treatment, up to 3.63 and 24.19 mg respectively. The former was 0.7 more than that under original natural light treatment, while the later was 50% higher. Totaling, combining blue LEDs with a broad-band red LEDs of the 150 mol m−2 TDLI was the most favorable condition for flower number and stigma quality of saffron in this study.

Growth and production response in saffron-chickpea intercropping under different irrigation regimes

The present study aimed to evaluate saffron production in intercropping with chickpea under different irrigation regimes. The experiment was a split plot based on a randomized complete block design with three replications during two years (2018–19 and 2019–20). The main plot consisted of two irrigation regimes [i.e. one-time and conventional irrigations], and the sub-plot included eight planting ratios [i.e. saffron mono-crop (C1), chickpea mono-crop (C2), 100% saffron + 50% chickpea (C3) and 100% saffron + 100% chickpea (C4) as additive ratios, and 1:1 (C5), 2:2 (C6), 2:1(C7), and 3:1(C8) saffron:chickpea as replacement ratios]. Based on the results, the effect of the irrigation regime was not significant on flower number, fresh weight of flower, and dried stigma yield of saffron. In intercropping ratios, the highest flower number (141.5 ± 4.26 m−2), fresh weight of flower (108.22 ± 3.4 g m−2), and dried stigma yield (4.1 ± 0.01 kg h−1) were observed in saffron mono-crop and approximately equaled by C3 treatment. The conventional irrigation regime increased the pod and seed numbers, the grain and biological yields, and the harvest index of chickpea. In the intercropping ratios, the maximum aforementioned traits were obtained by chickpea mono-crop. The maximum total land equivalent ratio (1.86) was obtained by the C3 treatment, which showed an intercropping advantage as compared to mono-crop. In summary, the C3 treatment showed the same effects as the mono-crop treatment on the saffron parameters, therefore, this treatment could be considered a proper alternative combination as compared to mono-crop for improving environmental resources absorption and soil fertility.

The saffron plant´s generative corm generation and stigma yield are influenced by planting methods and corm depths

The saffron plant´s generative corm generation and stigma yield are influenced by planting methods and corm depths

Microbiome contributes to phenotypic plasticity in saffron crocus.

Saffron crocus is a sterile plant species that propagates vegetatively, and consequently, narrow genetic variation is detected in this species. Besides the narrow genetic variation, there is significant phenotypic variation in different traits in this plant. Here we tested this hypothesis that plant microbiome is a major contributor to the phenotypic variation. We focused our analysis on culturable bacteria that were dominant in saffron fields with high stigma yield compared to the fields with low stigma yield. Following this strategy, four rhizospheric (Cupriavidus metallidurans, Bacillus sp., Solibacillus sp., and Planococcus sp.) and two endophytic bacteria (Serratia oryzae and S. odorifera) were identified. The effects of the bacteria on the growth and development of the model plant Arabidopsis were assessed both in agar plate and pot assays. Results showed that these bacteria influence the vegetative growth and flowering time of Arabidopsis. In the next step, corms of saffron were inoculated with these bacteria and the growth and development of the saffron plants were monitored for five months. Remarkably, inoculation of the bacteria had significant influence on vegetative growth, flowering time, and stigma yield of saffron crocus. Furthermore, one of the bacteria, C. metallidurans, is reported here for the first time as a naturally occurring plant-associated bacteria. Altogether our results suggest that plant microbiome is an important factor in phenotypic variation in saffron crocus.

Crocus sativus (L.) Grown in Pots with High Volume Capacity: From a Case of Study to a Patent

Saffron (Crocus sativus L.) cultivation is widespread in different parts of the world, including various Mediterranean areas. The crop management techniques, requiring intensive manual labor from planting, weeding, flower picking to the collecting of stigmas, contribute greatly to the high price of the spice. Traditionally, the corms are cultivated in field soil and only stigmas are collected to obtain the spice while the flower’s remaining parts, corresponding to about 90% of the total biomass, are discarded and thrown away. In this study, in order to overcome some difficulties occurring during the whole crop cycle (pathogens, fungi, pests, weeds, etc.), as well as to ease and increase floral bioresidue recovery, an alternative planting way for Crocus sativus L. was proposed relying on the use of large pots. For this aim, corms with 3.0–3.5 cm diameter size, from two different geographical origins (Spain, Holland), were planted in plastic pots with a volume of 250 L or 350 L, placed in two different areas of the Basilicata region (Italy). The effect of this new growing condition on dry stigma yield as well as daughter corm yield and size was evaluated. Although this cultivation system is more expensive than the traditional one, it offers numerous and huge advantages. Among them, it allows us to maintain a more correct posture and to preserve flower integrity during harvesting. The structural integrity of the tepals is a very important factor to obtain innovative dried flowers in their original tridimensional shape (3D). Consequently, the proposed cultivation system facilitates the achievement of a real “niche product” with high added value (absence of pollen grains). Moreover, the qualitative analysis of the spice, performed according to the International Standardization Organization Normative 3632 (ISO 3632-2/1:2010/2011), classified all investigated saffron samples in the first qualitative category. The results of the first three trial years are very exciting and promising as they are similar to those from the literature carried out in ground soil. However, corms from Spain gave the best results. Further investigations are in progress in order to optimize this alternative cultivation system.

Growth and Flowering of Saffron (Crocus sativus L.) with Three Corm Weights under Different LED Light Qualities

• Saffron (Crocus sativus L.) is referred ‘red gold’ worldwide as it is the most expensive spice. • The cultivation of saffron has been limited due to low flower yields. • Light emitting diode (LED) emits monochromatic light, which can improve crop quality and yield. • The effects of LED supplementation on growth and flowering of saffron ( Crocus sativus ) with three corm weights were studied. • Monochromatic red light significantly promoted saffron growth and increase stigmas yields with three corm weights. Saffron ( Crocus sativus L.) is a flowering plant whose dried stigma is an expensive and well-known spice. The major goal in saffron cultivation is to improve flower quality and yield. The present research aimed to understand the influence of LED light quality on the growth and flowering of saffron and provide valuable guidance to explore modern techniques to promote flower and stigma yield. The growth characteristics, flowering characteristics, hormone and nutrient content, and stigma quality and value were determined at three different corm weights (20–25 g, 25–30 g, 30–35 g per corm) under six LED light qualities [white (control, CK); monochromatic blue light (B); monochromatic red light (R); red and blue light at 1:2 ratio (R1B2); red and blue light at 1:1 ratio (R1B1); red and blue light at 2:1 ratio (R2B1)]. Monochromatic red light reduced corm biomass loss, accelerated apical bud growth, enhanced flower size and number, and advanced flowering. Monochromatic red light significantly increased the indole-3-acetic acid (IAA), soluble protein (SP), and zeatin riboside (ZR) levels in the mature corms compared with CK. Besides, red light demonstrated the highest hormone and nutrient content for the 30–35 g corm weight. Furthermore, monochromatic red light improved stigma yield (total dry weight), total crocin production, and the practical value ratio of saffron. The present study's observations indicate that monochromatic red light promoted saffron growth, advanced flowering, and increased stigma yield by regulating the corm phytohormones and enzyme activity. The study provides valuable guidance to explore modern techniques to promote saffron flower and stigma yield.

Effects of Nutrient Solution Electrical Conductivity on the Leaf Gas Exchange, Biochemical Stress Markers, Growth, Stigma Yield, and Daughter Corm Yield of Saffron in a Plant Factory

Indoor saffron farming systems under controlled conditions are required to meet the high demand for this valuable crop. The aim of the present study was to determine the flowering, growth, and yield responses of saffron grown using nutrient solutions with different electrical conductivity (EC) levels (0.7, 1.4, and 2.1 dS m−1). Sprouted saffron corms were cultured for 24 weeks under a volcanic rock-based aerated continuous immersion system. Vegetative growth and leaf gas exchange, but not flowering, were affected significantly by EC levels. The optimal EC in a balanced nutrient solution was 0.7 dS m−1, at which level the highest plant height, leaf area, biomass, photosynthetic rate, number of daughter corms, and percentage of corms ≥ 25 mm were recorded. An EC level of 2.1 dS m−1 decreased the photosynthetic rate, stomatal conductance, and transpiration rate of saffron but increased biochemical stress marker levels and elevated various antioxidant defense enzyme levels significantly in saffron leaves, possibly reflecting a defense response to the cellular damage provoked by the higher EC level. In terms of nutrient solution EC, 0.7 dS m−1 was optimal in saffron, whereas 2.1 dS m−1 caused oxidative stress that led to reduced growth and daughter corm production.

Replacing chemical fertilizers with organic and biological ones in transition to organic farming systems in saffron (Crocus sativus) cultivation

To evaluate the response of saffron to animal manure, and biological and chemical fertilizer in an arid climate, an experiment was performed as split plots based on a randomized complete blocks design with three replications during three consecutive crop growth seasons (2015–2018) at the Research Farm of University of Gonabad, Iran. The experimental treatments included application (60 t ha−1) and non-application (control) of manure as the main plot and the use of biosulfur (5 kg ha−1), biophosphate (3 L ha−1), nitroxin (3 L ha−1), chemical fertilizer (150, 100, and 100 kg ha−1 of urea, triple superphosphate, and potassium sulfate, respectively), and no fertilizer application (control) as the sub-plot. The results showed a highly significant response of the quantitative traits of saffron to the application of manure, which increased the leaf, flower, and corm indices of saffron by a mean of 15.1–35.7% than control. The interaction effect of manure with biological and chemical fertilizers for leaf, flower, and weeds indices of saffron was significant. There was no significant difference between the interaction treatments of manure and chemical fertilizer with nitroxin and biophosphorus fertilizers in most of the mentioned traits in the three experiment years. The simultaneous application of these fertilizers increased the average by about 60, 105, 135, 110, 165, and 55% of the leaf dry weight, the number of flowers, fresh flower yield, dry flower yield, dry stigma yield, and weed dry weight of saffron, respectively as compared to control. There was no significant difference between the chemical fertilizer with nitroxin or biophosphate in terms of the effect on the traits related to saffron corm so the use of these fertilizers, as compared to control, increased replacement corm weight, replacement corm size, and bud number per corm by, respectively, about 35, 60, and 40% on average. The chemical and biological fertilizers improved the content of crocin, picrocrocin, and safranal of saffron stigma. The best results were obtained from the use of chemical fertilizers, although no significant difference was observed between this treatment and the nitroxin and biophosphate treatments. Overall, the results of this three-year experiment show a very high response of the saffron plant to the simultaneous use of manure and biological fertilizers and, therefore, it is possible to replace chemical fertilizers with organic and biological fertilizers in saffron cultivation to implement organic agriculture and achieve acceptable quantitative and qualitative yields in areas similar to the experiment location.

Effects of Growing Substrate, Mode of Nutrient Supply, and Saffron Corm Size on Flowering, Growth, Photosynthetic Competence, and Cormlet Formation in Hydroponics

Hydroponics is a promising method for cultivation of saffron (Crocus sativus). In this study, saffron corms were sprouted using a gradual decrease in air temperature, and they were cultivated hydroponically in either perlite or volcanic rock for 24 weeks. A nutrient solution was supplied using either an ebb-and-flow system or continuous immersion. First blooming was observed 29 days after transplantation. Among flowering traits, only the stigma length was significantly influenced by the type of hydroponic system. Saffron plants displayed better growth parameters, a higher photosynthetic rate and stomatal conductance (gS), as well as daughter corm (cormlet) production under the continuous immersion system, in comparison with the ebb-and-flow system. Small corms (22–25 mm diameter) did not bloom, and the emergence of flowers increased with corm size. Plant growth and photosynthetic parameters, as well as cormlet production, significantly increased with corm size. We obtained the highest stigma yield [number of flowers (1.9), stigma length (39.4 mm), stigma fresh (42.8 mg), and dry weight (5.3 mg)] and cormlet yield [number of cormlets (5.7), average corm diameter (25 mm), and fresh weight (6.4 g)] using mother corms sized ≥32 mm diameter grown hydroponically in the volcanic rock–based continuous immersion system.

The Effect of Using Solarized and Methanized Manure on Weeds Control in Eastern Moroccan Saffron Cultivation

Cultivated for its red stigmas, saffron is arguably the most expensive and precious spice in the world. However, saffron production is limited by a number of factors, including weed infestation which causes damage to this crop both quantitatively and qualitatively. Solarization and anaerobic digestion are techniques used to control weeds and plant diseases. It is for this purpose an experiment was conducted in 2018 with an objective to compare solarized manure and that resulting from anaerobic digestion on the development of weeds associated with saffron crop. During the trial, the parameters measured correspond, on the one hand, to morpho-metric measurements and the determination of saffron stigmas yield and, on the other hand, to the determination of density, dry biomass and weed control capacity. In this study, 16 weed species were recorded. The two treatments applied reduced weed density and biomass by about 55% of the weed species, including problematic species such as Cynodon dactylon, Cyperus rotundus and Convolvulus arvensis. However, there was no effect of manure treatment (T2, T3) on the populations of Chenopodium album, Aster squamatus and Medicago truncatula. The average stigmata yield from the addition of digested manure was 4% higher than the control. Similarly, the number, weight and percentage of daughter corms with a large diameter were higher for plants grown on treated manure. It was concluded that the incorporation of treated manure as a soil amendment slightly increased saffron yield and effectively controlled more than half of the weed species present. Keywords: Solarization, saffron, weeds, management strategies, manure, anaerobic digestion

Yield and qualitative and biochemical characteristics of saffron (Crocus sativus L.) cultivated in different soil, water, and climate conditions

Saffron is highly valued for its unique aroma, taste, color, and medicinal properties. Iran is one of the most important saffron-producing countries. The present study aimed to investigate the effect of climatic and environmental characteristics of six sites (Shirvan, Faruj, Zavareh, Torbat-e Heydarieh, Ghayen, and Birjand) on the yield and qualitative, and biochemical characteristics of saffron. The studied sites were considered as treatments. The obtained data were analyzed based on a nested design, where the village within the site was considered an experimental error, and the farm within the village within each site was considered a sampling error. The Torbat-e Heydarieh treatment with altitudes of ~1323.3 m produced the maximum saffron flower yield (0.83 g m2), stigma yield (0.098 g m2), safranal content (15.8%), picrocrocin content (30.6%), and crocins content (69.3%). Evidently that the low maximum summer temperature in the area is one of the reasons for its superiority. The correlation analysis between traits shows that the maximum summer temperature had a significant negative correlation with saffron flower yield, stigma yield, and picrocrocin and crocin content. Results showed the highest total flavonoid and phenol content and DPPH activity related to Shirvan and Faruj. Although the results showed that selenium could increase the quantitative and qualitative yield of saffron, this requires further studies to confirm it. Based on the findings, it is concluded that I) qualitative and quantitative characteristics of saffron are strongly controlled by the environmental and climatic conditions and II) Razavi Khorasan province had a significant advantage in terms of flower and stigma yield and safranal, picrocrocin and crocin content of saffron and North Khorasan province in terms of biochemical characteristics.

Study of the Effect of Mulching Materials on Weed Control in Saffron Cultivation in Eastern Morocco.

Saffron (Crocus sativus L.) is cultivated in many countries for its culinary and medicinal values. The production of saffron is limited by several factors, including weed infestation, which causes damage to the crop in terms of quantity and quality. However, little information is available on the different weed management strategies for saffron cultivation, as most of the strategies implemented are developed for large-scale and conventional agriculture. As a result, they are not applicable or affordable for organic or smallholder farmers, as is the case for saffron cultivation. The objective of this study is to compare the effectiveness of plastic mulching versus mulching in controlling weeds in saffron cultivation in the eastern region of Morocco. During the trial, which was conducted in 2018, the parameters measured correspond, on the one hand, to morphometric measurements and determination of saffron stigma yield and, on the other hand, to the determination of density, dry biomass, and weed control capacity. Compared to the control, mulching reduced the population and dry biomass of the most formidable weeds such as Cynodon dactylon, Aster squamatus, Cyperus rotundus, and Convolvulus arvensis. The average stigmata yield from plastic mulch treatment was 9% higher than of the control, and the number of leaves, leaf area, number, weight, and percentage of daughter corms with large diameter were higher for plants grown under mulch. Overall, the results of this study showed that the use of PE (polyethylene) mulch effectively reduced weed populations and improved saffron yield and vegetative growth.

Optimal light intensity and quality increased the saffron daughter corm yield by inhibiting the degradation of reserves in mother corms during the reproductive stage

Saffron (Crocus sativus L.) two-segment (TS) cropping system, with mother corms flowering in a controlled environment first and then growing daughter corms in the field, can greatly increase stigma yield and quality, but may decrease daughter corm yield (mainly due to depletion of nutrient reserves in mother corms). Light plays crucial roles in regulation of nutrient reserve metabolism in tubers, corms, and other storage organs. However, how the metabolism of mother corm reserves, which determines the daughter corm yield, responds to light intensity and quality during the reproductive stage remains unclear. Plants grew under five light intensities (56, 200, 400, 600, and 800 μmol m−2 s−1) and three combinations of red (R) to blue (B) light (4R1B, 3R1B, and 3R2B) at 200 μmol m−2 s−1 during the reproductive stage. After flowering, the plants were transplanted to the field. Leaf growth, net photosynthesis, carbohydrate and nutrient content, stigma yield and quality, and daughter corm yield were assessed. The stigma yield and quality decreased with increasing light intensity, whereas the carbohydrate and total N, P, and K content in the mother corm showed the opposite trend. The light treatment of 200(3R2B) not only maintained the stigma yield (up to 482.4 mg (10 corms)−1) at a highest level, but also improved the apocarotenoid content (up to 33.6%) in stigma, and carbohydrate and nutrient content in mother corm. Compared with 56 μmol m−2 s−1, light 200 (3R2B) decreased the length and weight of leaves, ratio of leaf to corm weight, and starch and nutrient decomposition in corms, but increased the rate of photomorphogenesis, stomatal opening, chlorophyll concentration (up to 72.9%), net photosynthesis (up to 448.6%), and leaf sucrose concentration (up to 156.7%). A decreased demand for leaf development and increased carbon capture inhibited the decomposition of carbohydrates and nutrients in the mother corm. The high sucrose concentration in leaves served not only as a carbon substrate for leaf growth, but also as a signal for inhibiting the translocation of carbon from corm to leaves and then the decomposition of starch in corm. The increased reserves in mother corms and improved stomatal opening combined to result in large leaf area, well-developed vascular tissue, and then high rate of leaf photosynthesis in the field, which provided assimilates for achieving yield potential and a high proportion of large-size corms. This is the first report on optimizing light intensity and quality during the reproductive stage to partially eliminate daughter corm yield decreases in the TS cropping system. Furthermore, this work also contributed to understanding the metabolism of nutrient reserves and leaf growth in saffron as regulated by light intensity and quality.