Replacement Corms Research Articles

Phenological observations on the growth and development of saffron (Crocus sativus L.) in the conditions of the Right-Bank Forest-Steppe of Ukraine

There is a need to summarise information using phenological models to develop a sustainable saffron production technology with further regulation of flowering at a certain phenological stage and determination of the appropriate flowering period to improve yield and quality under different environmental conditions. The purpose of the study is to establish the course of phenological phases of saffron growth and development in the conditions of the Right-Bank Forest-Steppe of Ukraine. Phenological observations and biometric measurements were performed in the study. According to field observations, there are a total of 6 phenological stages of saffron development. The rest period lasts from the third ten days of May to October and is divided into primary and secondary dormancy. During the primary dormant period, corms do not show external morphological changes and growth, but internal physiological and morphogenetic changes occur. In the secondary dormant period, the initial emergence of leaves and flowers and their differentiation take place. During the dormant period, saffron plants were left without aboveground organs. The flowering period falls in October. The passage of this phenological stage may be affected by changes in environmental conditions or agricultural technology. The growth of the root system began with the appearance of flowers and leaves. During the growing season, the growth of the leaf apparatus and the development of the root system continue. During this period, daughter corms are also formed from the buds of the mother corm. During the winter, the replacement corms continue to grow using the nutrient reserves of the mother corm. In early March, the development of the root system slows down and the daughter corms reach almost the final size. At the end of the growing season, the root system of the mother corm stops growing. The leaves begin to age from the top to the base. By the end of May, the daughter corms are fully developed and are preparing for the transition to a dormant state. The number of corms produced per unit area depends on the age of the plot, nutrient supply, and the level of agricultural technology. Older fields produce more corms. Due to the higher density, a larger yield of stamens is formed. Therefore, understanding the phenological reactions and influence of climatic factors on the stages of saffron growth and development in certain soil and climatic conditions is useful for future forecasting of harvest time

Beneficial microorganisms: a sustainable horticultural solution to improve the quality of saffron in hydroponics

Saffron (Crocus sativus L.) is the most expensive spice in the world. Its organoleptic properties are mainly dictated by the apocarotenoids crocins (dyeing capacity), picrocrocin (pleasant taste), and safranal (scent). Cultivation of saffron in controlled conditions with beneficial microorganisms may increase its profitability. In this study saffron was grown in hydroponics under a greenhouse with the PGPR Bacillus megaterium CB97032 and Paenibacillus durus CB1806 (Pgpr treatment), and the AMF Rhizophagus intraradices (Myc treatment), alone or mixed (Mix treatment). The influence exerted during all crop phases on flowering trend, flower and spice yield, secondary metabolites, ecophysiological traits, and corm production was investigated, with the hypothesis that microbial synergy would have more positively affected these parameters. All the bioinoculants did not positively influence flower and spice yield, but enhanced the content of safranal (up to +96% in all the treated plants). When mixed, the PGPR and AMF improved the total phenolic content (+19%) of the saffron spice. Even if no differences emerged from the ecophysiological analysis, the corm yield was improved for the inoculated plants. The single-type bioinoculants allowed to obtain a higher number of replacement corms (up to +13% for the Myc plants) without reducing their weight, but lowering their size. When mixed, the size of the corms was restored. Together, the PGPR and AMF also increased the corm weight (+24%) of the largest corm fraction (> 1.5 cm). Thus, the bioinoculants may have stimulated the secondary metabolism of the plants by improving quality traits, rather than having acted as biofertilizers by increasing yield, at least during flowering. Overall, AMF and PGPR were proved to be a sustainable horticultural solution in hydroponics to improve the quality of saffron, especially when applied in mixed formulations.

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.

Изучение морфобиологических особенностей некоторых сортов Gladiolus × hybridus hort. в условиях Саратовского Поволжья и Пермского края

The paper describes the results of a three-year study of biological characteristics of ‘Malika’, ‘Professor Parolek’, ‘Dolgozhdannyy Debut’ gladiolus cultivars on the territory of the Education and Research Center «Botanical Garden» in Saratov State University (Saratov) and the Genkel Botanical Garden in Perm State University (Perm). Plants in Saratov region experienced a detrimental effect of high summer temperatures and insufficient humidity: the height of the plant and the size of the inflorescence, the number of flowers in the inflorescence decreased. Nevertheless, the gladiolus development rate matched the biological characteristics of the cultivars in the Saratov Botanical Garden, they happened to go through the growing season before the frost and formed a mature replacement corm. In the Perm Botanical Garden, the studied cultivars also went through all the stages of growth and development, but the flowering period of the studied cultivars started later, which may be associated with a decrease in summer temperature below the optimum temperature in some years. This may have impeded the maturation of replacement corms and increased the susceptibility to fungal diseases. At the same time, the studied gladiolus cultivars retained most fully their decorative features in the Perm Botanical Garden.

Production systems and methods affect the quality and the quantity of saffron (Crocus sativus L.)

Aim of study: Comparison of saffron flowering between open field and controlled environment. Possibility of saffron transplanting.Area of study: University of Birjand (Iran)Material and methods: In a first experiment, saffron yield and quality produced by traditional production system (TPS) and by soilless one (SPS) were compared. In a second experiment, the effects of the production method, by direct planting (DP) or by transplanting plant (TP) in open field were studied.Main results: Percentage of flowering corms grown by SPS was 39% and 65%, while by TPS was 6% and 56% in 2018 and 2019, respectively. Flower and stigma yields were significantly higher by SPS than by TPS. Stigma obtained from SPS had higher L (lightness) and crocin. Safranal content was higher in stigma produced by TPS. Leaf and root numbers and corm weight were higher for SPS, but after transplanting there was better status for DP than for TP. At the end of the first growing season (2018-19), mean replacement corms weight (4.4 vs 3.0 g), replacement corms yield (21.3 vs 12.8 g per plant), weight of main replacement corm (11.7 vs 6.0 g) and number of large replacement corms (0.6 vs 0.1 corms per plant) for DP were significantly higher than for TP. However, during the second growing season (2019-20), the plants in TP plots improved their performances.Research highlights: Saffron production was more favorable under controlled environment. Transplanting is possible, but there is a need to improve methods to gain more favorable results.

The possibility of improving saffron (Crocus sativus L.) flower and corm yield through the irrigation and soil texture managements

In order to study the effect of soil texture and irrigation management on flower and corm yield of saffron (Crocus sativus L.), an experiment was conducted at research field of Agricultural Faculty of Sarayan, University of Birjand during two growing seasons (2013–2015). The study was performed as factorial based on Randomized Complete Block Design. Experimental factors were irrigation intervals (every one and two weeks equal to 3000 and 1600 m3. ha−1 as normal and deficit irrigation, respectively) and soil texture (100 % soil, 75 % soil+25 % sand, 50 % soil+50 % sand, 25 % soil+75 % sand and 100 % sand). Results of the first flowering season showed that maximum number of flowers (74.33 No. m-2) and yield of dry stigma (3.216 kg.ha-1) obtained in one week irrigation interval with 50 % sand+50 % soil. The maximum values of these traits (308.2 flower per m2 and 9.37 kg.ha-1 dry stigma) during the second year were gained in one week irrigation interval with 75 % sand+25 % soil. The highest amounts of large (≥9 g) replacement corms number (111 and 200 No.m-2) and yield (11,289 and 21,582 kg.ha-1) were obtained by one week irrigation interval and 25 % sand+75 % soil and 75 % sand+25 % soil at the end of first and second growing seasons, respectively. Furthermore, one week irrigation interval increased replacement corms yield by 20 % compared with two weeks irrigation intervals in both growing seasons. Therefore, it was concluded that selection of moderate and light soil texture and shorter irrigation intervals (equal to 3000 m3. ha-1) are important factors for improving flower and corm yield of saffron.

Arbuscular Mycorrhizal Fungi Modulate the Crop Performance and Metabolic Profile of Saffron in Soilless Cultivation

Saffron (Crocus sativus L.) is cultivated worldwide. Its stigmas represent the highest-priced spice and contain bioactive compounds beneficial for human health. Saffron cultivation commonly occurs in open field, and spice yield can vary greatly, from 0.15 to 1.5 g m−2, based on several agronomic and climatic factors. In this study, we evaluated saffron cultivation in soilless systems, where plants can benefit from a wealth of nutrients without competition with pathogens or stresses related to nutrient-soil interaction. In addition, as plant nutrient and water uptake can be enhanced by the symbiosis with arbuscular mycorrhizal fungi (AMF), we also tested two inocula: a single species (Rhizophagus intraradices) or a mixture of R. intraradices and Funneliformis mosseae. After one cultivation cycle, we evaluated the spice yield, quality (ISO category), antioxidant activity, and bioactive compound contents of saffron produced in soilless systems and the effect of the applied AMF inocula. Spice yield in soilless systems (0.55 g m−2) was on average with that produced in open field, while presented a superior content of several health-promoting compounds, such as polyphenols, anthocyanins, vitamin C, and elevated antioxidant activity. The AMF symbiosis with saffron roots was verified by light and transmission electron microscopy. Inoculated corms showed larger replacement corms (+50% ca.). Corms inoculated with R. intraradices performed better than those inoculated with the mix in terms of spice quality (+90% ca.) and antioxidant activity (+88% ca.). Conversely, the mixture of R. intraradices and F. mosseae increased the polyphenol content (+343% ca.). Thus, soilless systems appeared as an effective alternative cultivation strategy for the production of high quality saffron. Further benefits can be obtained by the application of targeted AMF-based biostimulants.

Corm weight or number per unit of land: Which one is more effective when planting corm, based on the age of the field from which corms were selected?

In this study the best corm weight (4–6 g as small-sized and 6–8 g as medium-sized corms) and density (50, 75 and 100 corm m−2) was determined for saffron fields in different ages (1, 2 and 3 years-old). For this purpose, a factorial experiment based on a randomized complete block design with 3 replications was performed during 3 growing seasons from autumn 2015 up to spring 2018, in Ferdowsi University of Mashhad research site. The highest flower number, flower and stigma yields in one- (21.7 flower per m2, 67 and 0.97 kg ha-1, respectively) and two-years old (70.4 flower per m2, 214 and 2.92 kg ha-1, respectively) fields were obtained from medium-sized and density of 100 corms per m2, while in three-years old field, their maximum values (101 flower per m2, 302 and 4.09 kg ha-1, respectively) were gained when medium-sized corms were planted at density of 75 corms per m2. The priority of corm weight in lower corm densities was higher, so that, flower yield in medium sized corms was 2.43, 1.87 and 1.62 times more than small-sized corm in 50, 75 and 100 corms per m2 densities, respectively. Corm weight was prior to corm density, so that, planting of 3.5-ton ha-1 medium-sized corm with density of 50 corms per m2, was produced more flower than planting of 5-ton ha-1 small-sized corm with density of 100 corms per m2 (47.5 vs. 36.7 flower per m2 and 1.99 vs. 1.50 kg ha-1 dry stigma). Corm weight preference in one- and two-years old fields were more than three-years old filed, where larger corms increased flower yield by 1.94, 2.15 and 1.75 times compared with small-sized ones in mentioned fields, respectively. Mean replacement corm weight and number of large replacement corms (>9 g) decreased when small-sized mother corms were planted and when the farm became elderly. The highest replacement corm yield (52.8-ton ha-1) and number (2034 NO. m−2) were obtained when medium-sized mother corms were planted at density of 100 corms per m2 and remained in field for three years. Overall, the corm harvesting from one-year-old field was preferable in terms of mean corm weight and production of larger replacement corms.

Increasing saffron (Crocus sativus L.) corm size through the mycorrhizal inoculation, humic acid application and irrigation managements

ABSTRACTCorm size is the most important factor in production of replacement corms and flower yield of saffron. The aim of this study was to investigate the effect of nutrition and irrigation managements on saffron corms characteristics in the experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013–2015. The experiment was carried out as split-split plot based on a Randomized Complete Block Design with 18 treatments and three replications. Experimental factors were: 1- superabsorbent (SA) [application and no-application of superabsorbent (non-SA)], 2- irrigation intervals [irrigation every 2, 3 and 4 weeks] and 3- nutrition management [humic acid, mycorrhiza (Glomus intraradices) and control]. The results showed that the highest total weight of replacement corms per clone in sum of two years was obtained in non-SA application, two weeks irrigation intervals and humic acid treatment. The corm/tunic weight ratio decreased by increasing the irrigation intervals and this index in two weeks irrigation intervals was 31% more than four weeks irrigation intervals. Application of nutritional treatments increased the number of saffron replacement corms per clone in all of the weight categories (0-3, 3–6, 6–9 and more than 9 g) on averaged 5, 40, 36 and 25%, respectively compared with control treatment in both years. Results showed that the replacement corms yield in large weight groups was on average 34% higher in the second year than the first year. Finally, application of SA, organic and bio fertilizers and four weeks irrigation intervals improved most of criteria and yield of saffron replacement corms.

Crop rotation as an effective strategy for saffron (Crocus sativus L.) cultivation

Saffron is an annual plant usually grown as a perennial crop, with well-known problems, which are related to the reduction of soil fertility (mainly caused by weeds, biotic pathologies and micronutrients scarcity) that in the long run determine a dramatic yield reduction and overexploitation of the soil. In this view, crop rotations are considered the traditional antidote to the soil sickness. However, the evidence of the effects of previous crop on saffron stigma yield and corm production is slender and fragmentary. A two-year study was carried out to evaluate the effect of three different previous crops (faba bean, saffron and fallow) on saffron stigmas yield and replacement corms production. Two different corm densities (30 and 45 corms m−2) were also studied. Faba bean as previous crop determined the highest performance in terms of flower number (up to 400 flowers m−2), stigma yield (up to 2gm−2) and replacement corms (up to 4.7kgm−2). This paper, to our knowledge, is the first experimental based research on the effects of previous crop on stigma and corm yield of saffron.

Influence of superabsorbent polymer rates on growth of saffron replacement corms

Mother corm size is the most important factor for production of replacement corms, flower, and stigma yield in saffron. In semi-arid regions, water shortage is a deterrent agent for appropriate corm growth of saffron. Therefore, in this experiment the effects of six levels of superabsorbent polymer (SAP) including 0, 10, 20, 30, 40, and 50 kg ha-1 was investigated on growth indices of replacement corms of saffron. For this purpose, an experiment was evaluated at the research farm of the Saffron Research Group, Sarayan Faculty of Agriculture, University of Birjand, Iran, during 2013-2015. Results showed that SAP application did not considerable effect on corm growth indices in the first life cycle of saffron. Nevertheless, consumption of 30-40 kg ha-1 SAP somewhat improved the number and total weight of replacement corms per clone. In the second life cycle of saffron, the positive impact of SAP was clearly observed on the growth of replacement corms. The application of 40 kg ha-1 SAP increased the amount of number of replacement corms per clone by 13%, total weight of replacement corms per clone by 36%, and scale weight of corms per clone by 50% compared with control. In addition, the amount of mean weight of replacement corms and mean number of buds per corm in treatment of application of 40 kg ha-1 SAP were 29 and 27% higher than the control treatment, respectively. SAP application decreased the amount of non-standard (< 8 g) corm production while significantly increased the percentage of corms with standard weight. Overall, the increasing effect of SAP application on corm weight, bud number, and standard corm yield was higher than the number of produced corms per clone. In addition, water-use efficiency in SAP application treatments (6.1 kg standard corm m-3) was more than the control (4.34 kg m-3) treatment. In total, SAP application is an appropriate strategy for production of standard saffron corms in semi-arid regions.

Biomass partitioning during the life cycle of saffron (Crocus sativus L.) using regression models

In this study saffron biomass partitioning was investigated in the research station of the Saffron Research Group, University of Birjand, Iran during 2009 - 2010. Plant sampling was done 25 times during the crop growth cycle. In each sampling date, the amounts of corm dry weight, root dry weight, root length, leaf dry weight, leaf area, bud number, bud dry weight (nodes on the surface of the corm), and flower weight were measured. Finally, different regression models were tested for predicting biomass partitioning in saffron. The cubic polynomial model was found to be the best for predicting biomass changes in most saffron organs (R2 = ~74%). Total corm dry weight showed a decreasing trend up to the 120th day of plant growth and then increased until the end of the life cycle (mid-May). However, different trends were observed for root and leaf dry weights. Root and leaf dry weight increased up to the 120th and 150th day of the plant growth cycle, respectively, followed then by decreasing trends. Therefore, in the early growing season, leaves and root systems were developed using mother corms reservoirs, but at the end of the growth cycle replacement corms were grown by translocation of reservoirs from other saffron organs. In addition, the number and dry weight of buds had increasing trends during 160 days of measurement from the beginning of the growing season. The total length of roots and leaf area increased up to the middle of the growth cycle (Feb. 10) and then decreased. Moreover, saffron flower yield showed a rapid increasing trend in the first phase of the flowering period and then declined with a slower trend during the second flowering phase.

Biology of the Geophyte,Triteleia ixioidessubsp.anilina(Themidaceae), In Coniferous Forests of Butte County, California

The life cycle of the widespread, cormous geophyte, Triteleia ixioides (W. T. Aiton) Greene subsp. anilina (Greene) L. W. Lenz (Themidaceae) was studied in the field over several years in coniferous forest sites in Butte County, CA. All sites, ranging from 1383 to 1774 meters in elevation, have a Mediterranean climate and loamy soils above Tuscan mudflow substrate. Flowering scape height, corm weight, and corm depth varied significantly. Old corms decreased in dry weight throughout the winter, as shoots, roots, and new corms grew. By spring, each old corm had produced a leaf and a flowering scape, was depleted of stored food, and had a new “replacement corm” (without roots) already developed on top of it. Fruit set varied from 38.5% to 89.1%, with significant differences among populations sampled in different years and sites. Seed set was low (overall mean 38.4%), but varied significantly among years and sites, ranging from 26.4% to 56.3%. Plants are partially self-compatible. Soil moisture was not limiting to seed set, nor was pollen vectors, except on cold days. The most important pollinator was a bee fly (Bombylius facialis, Bombyliidae), although native bees provided some pollination at higher sites. Ten-minute observation periods, during bee fly activity, showed up to 15 visits to plants in a square meter. Percent seed germination was high (88–100%), with germination after the first rains and seedling growth continuing during the cold months. Seedlings produced single leaves up to 60.4 mm long, and corms averaged 1.6 ± 0.1 mm wide at one site. Contractile roots, produced lateral to the primary roots, averaged 16.13 ± 1.00 cm long. Shrinking and wrinkling at the upper part of the contractile root pulled the newly formed corm deeper in the soil. Study of contractile roots in Triteleia and other geophytes may help illustrate adaptation to summer drought in Mediterranean California.

EFFECTS OF TEMPERATURE ON THE FLOWERING OF THE SAFFRON CROCUS (CROCUS SATIVUS L.): INDUCTION OF HYSTERANTHY

ABSTRACT The saffron crocus (Crocus sativus L.), a sterile geophyte propagated by annual replacement corms, is cultivated for its red stigmatic lobes that constitute, after drying, the spice saffron. C. sativus is a subhysteranthous species, i.e., it blooms in autumn shortly after planting, before, concomitantly with, or after leaf appearance. The remainder of its growing season consists of initiation, filling up, and maturation of the daughter corms at the beginning of summer. In the countries where saffron crocus is grown, cultivation is still performed by traditional methods: corm planting, flower harvesting, stigma separation, and corm lifting are carried out manually. These labour-consuming practices greatly contribute to the high price of the spice. The study of the physiological background of the developmental processes in C. sativus was aimed at improving the cultivation methods. It is demonstrated that a controlled temperature regime during corm storage affects flowering and production of daughte...

Effect of corm size, water stress and cultivation conditions on photosynthesis and biomass partitioning during the vegetative growth of saffron (Crocus sativus L.)

A major constraint limiting saffron cultivation is the difficulty of obtaining high quality corms for propagation. There is limited knowledge about the physiology of vegetative development of saffron. The aim of this work was to analyse the relative contribution of different carbon sources (leaf photosynthetic activity and mother corm reserves) to the growth of vegetative organs and to analyse the influence of internal and external factors on the photosynthetic processes sustaining corm growth. The photosynthetic rate and changes in biomass were measured over the course of the vegetative growing season. The influence of the size of the mother corm, the cultivation method used (greenhouse versus field) and water availability on saffron production was assessed.Most of the remaining mother corm reserves after flowering were depleted during root and leaf development. After these organs reached their maximum size, the growth of replacement corms was initiated, and this development primarily relied on photosynthesis. Saffron mother corm reserves only contributed 10% to the biomass during vegetative development. The photosynthetic rate was consistently very high (26μmolm−2s−1) throughout the year but was reduced in plants from the largest corms. A sink capacity limitation arose during growth of replacement corms since the increase of biomass was limited before total leaf senescence. Saffron grown under greenhouse conditions exhibited traits characteristic of plants grown under low-irradiance, even after the saffron plants were transferred to the field. This fact limits the production of replacement corms in this environment. A decrease in the photosynthetic rate was observed under water stress, but the supply of water to the leaves from the corms and roots was found to maintain a still high photosynthetic rate (12μmolm−2s−1) even at highly negative soil water potentials.

Ex vitro shoot regeneration and lateral buds of freshly harvested saffron corms

After formation of the replacement corms, the saffron leaves wither and the apical buds enter dormancy, which is released after-ripening at 23 to 30°C. This study aimed to break this dormancy and reports successful ex vitro shoot regeneration from saffron corms, just after harvesting by pulse treating for 30, 60, 90, 120 and 150 min with 50 mg/L Indole acetic acid (IAA) or 50 mg/L IAA + 10 mg/L Thidiazuron (TDZ). All corms were cultured in organic matter rich soil contained in plastic sieve trays in greenhouse with day time temperature in range of 9 to 15°C and night temperature in range of 5 to 8°C during experimentation with relative humidity of 50 to 60%. After 2 to 3 weeks, the pulse treated corms regenerated multiple number of shoots, which increased to 5-6 shoots per corm after 10 weeks of culture; showing statistically different and superior regeneration on 50 mg/L IAA + 10 mg/L TDZ pulse treated corms compared to IAA pulse treated corms. This protocol will help to increase and improve flowering for an extended period of time. Key words: Ex vitro, shoot regeneration, lateral buds, saffron, multiplication.

اثرات الگوی کاشت و زمان اولین آبیاری بر رشد و عملکرد زعفران (Crocus sativus L.)

انجام مطالعات در زمینه به زراعی زعفران (Crocus sativus L.) می تواند نقش مهمی در افزایش عملکرد در واحد سطح این محصول مهم و بومی ایران داشته باشد. در این راستا آزمایشی طی سال های زراعی 89-1384 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد، به صورت آزمایش فاکتوریل بر مبنای طرح پایه بلوک های کامل تصادفی با سه تکرار اجرا شد. فاکتورهای مورد مطالعه عبارت بودند از : الگوی کاشت زعفران (فواصل کاشت 5×20، 10×20، 15×20 و 20×20 سانتیمتر) (در تمام الگوهای کاشت، فاصله بین ردیف ها 20 سانتیمتر بود) و مدیریت آبیاری (انجام اولین آبیاری در ابتدای شهریور ماه، ابتدای مهر ماه و ابتدای آبان ماه). در این آزمایش صفات عملکرد گل تر، عملکرد کلاله خشک، عملکرد تر و خشک علوفه، تعداد بنه مادری، تعداد بنه خواهری، تعداد بنه خواهری به ازای هر بنه مادری، وزن کل بنه ها بدون فلس، وزن کل فلس ها، نسبت وزن بنه های بدون فلس به وزن فلس، وزن کل بنه ها، متوسط وزن هر بنه، متوسط قطر هر بنه، متوسط تعداد جوانه در هر بنه، تعداد کل جوانه ها، درصد بنه های دارای ریشه نابجا، وزن خشک برگ و سطح برگ مورد بررسی قرار گرفتند. نتایج نشان داد که تنها فاکتور الگوی کاشت بر صفات مورد مطالعه اثر گذار بود و اثر زمان آبیاری و نیز اثرات متقابل روش کاشت در زمان آبیاری معنی دار نبود. نتایج مقایسه میانگین ها نشان داد که الگوی کاشت10×20 سانتیمتر از نظر صفات مورد مطالعه دارای برتری نسبی بود، طوری که در این تیمار بیشترین عملکرد گل تر (170 کیلوگرم در هکتار)، عملکرد کلاله خشک (12 کیلوگرم درهکتار)، وزن متوسط بنه (9/2 گرم) و قطر متوسط بنه (5/1 سانتیمتر) مشاهده شد. بیشترین عملکرد علوفه تر و خشک (3916 و 1276 کیلوگرم در هکتار) در الگوی کاشت 5×20 سانتیمتر به دست آمد و پس از آن روش کاشت10×20 سانتیمتر قرار داشت. همچنین بیشترین توزیع فراوانی بنه ها در وزن کمتر از سه گرم و قطر کمتر از دو سانتیمتر قرار داشت. به طور کلی نتایج این آزمایش نشان دهنده بهبود فاکتورهای رشد و عملکرد زعفران در الگوی کاشت 10×20 سانتیمتر بود.

Effect of mother corm dimension and sowing time on stigma yield, daughter corms and qualitative aspects of saffron (Crocus sativus L.) in a Mediterranean environment

AbstractBACKGROUND: Saffron is one of the most appreciated and expensive spices known and has been used from the oldest times as a dye for fabrics, a condiment to enrich food and for medicinal purposes. The aim of this study was to evaluate the effect of crop management methods on the quantitative and qualitative characteristics of the spice in southern Italy. Two sowing times (end of July and end of August) and two corm dimensions (4 and 3 cm horizontal diameter) were evaluated.RESULTS: Flowering period and duration were not influenced by the studied factors, while early sowing time and greater corm dimension resulted in a greater number of flowers per m2, increased stigma yield and a greater total yield of replacement corms. Early sowing time also showed a significant positive influence on stigma quality measured as apocarotenoid content according to ISO guidelines.CONCLUSION: The results show that, in a Mediterranean environment, appropriate crop techniques and selection of corms can result in economic levels of production and improve the quantitative and qualitative characteristics of saffron. In fact, according to their apocarotenoid contents, samples from the early (July) and late (August) sowing times belonged to the first and second ISO categories respectively. Copyright © 2008 Society of Chemical Industry

CONANTHERA SPP. LIFE CYCLE AND ORNAMENTAL POTENTIAL

The endemic Chilean genus Conanthera belongs to the Tecophilaeaceae family and is distributed in the northern and central parts of Chile. This genus is formed of various species, all of which have a fibrous corm and beautiful blue, violet or white flowers of variable size and shape. These species could be used for ornamental purposes as pot or garden plants, and for this reason various studies were performed in the Maule Region of central Chile to obtain information about the genus Conanthera useful to its ornamental potential. Conanthera populations from diverse locations were prospected to determine species or types present and their floral characteristics. An attractive variety of colors and shapes was found, but in the studied region C. bifolia and C. campanulata were the most frequent species. All studied species grew in poor soils and with a limited water supply in the flowering season, in spring. All aerial parts of plants died during the summer and new sprouting occurred in autumn or early in winter. These plants have shown that they are easily grown, which could make them good garden plants. Also, the life cycle of C. bifolia, grown from autumn to spring under greenhouse conditions without heating, was studied. Under these conditions this species had an annual replacement corm and flower differentiation was completed after leaves emerged.

The effect of time of corm lifting and duration of incubation at inductive temperature on flowering in the saffron plant ( Crocus sativus L.)

After the formation of the replacement corms of saffron ( Crocus sativus L.) the leaves withered and the apical buds entered dormancy. This dormancy was released by high summer temperature. Optimal flower formation was obtained under controlled conditions when corms were held at 25 °C longer than 55 days followed by forcing at 17 °C. Since the shoot apical meristem of the replacement corms was formed long before leaf withering, it was feasible to accelerate flowering by an early harvest. Corms lifted 1 month before leaf withering, incubated for 55 days at 25 °C, and then forced at 17 °C, flowered by early September, 6 weeks earlier than in the open. Flowering could be further accelerated (up to 7 days) by curing the corms for 20 days at 30 °C prior to 25 °C storage. This high temperature incubation shortened the rest period of the buds. However, a longer exposure to 30 °C was deleterious for bud growth and flower formation. A 24 h incubation with ethylene (1–10 ppm) had no effect on dormancy or flower formation. The flowering of corms lifted after leaf withering could be delayed until early December by extending the incubation at 25 °C for 150 days. A longer incubation at 25 °C resulted in flower abortion. Combining the date of corm lifting and the duration of 25 °C incubation, corms could be flowered from early September to mid-December. Since a batch of corms needed an average of 13 days in a lighted greenhouse at 17 °C to complete flowering, 7–8 batches of corms may be forced each growing season. At the corm density used in our experiments (457 corms m −2), 67.2 g of the spice saffron per square meter was obtained. This yield was 30 times higher than the maximum yield reported under field conditions, and about 300-fold higher than the average yield in many saffron-producing regions. Furthermore, the harvest of the container-grown saffron may be easily mechanised.