Rhizome Pieces Research Articles

Micropropagation of three ginger cultivars and the subsequent growth and rhizome yield assessment and phytochemical composition analysis

Farmers have turned to biotechnology techniques to produce ginger, due to disease issues. Micropropagation is a proven and effective means for mass production of disease-free plants. Our research focused on ginger cultivar specific reactions (from culture initiation to rhizome harvest) to plant growth regulators (PGRs) to determine if plant response to PGRs is cultivar specific. Ginger (Zingiber officinale Rosc.) cultivars studied were: Chinese White (CW), Hawaii Yellow (HY), and Khing Yai (KY) under benzylaminopurine (BA) versus kinetin (KT) treatments using MS basal medium to micropropagate ginger seedlings and subsequent growth and yield performance and phytochemical composition analysis. In vitro culture data were collected every month for number of buds and shoots (and shoot length) produced per initiating bud and shoot growth. Mature seedlings were subsequently transplanted in a greenhouse with a randomized complete block design (RCBD) with 4 replications, 18 plants per replication (Main Plot = Cultivar, Sub Plot = PGR) for a total of 72 pots/plants. Growth data included number of stems per seedling, stem length, and stem diameter. Rhizome yield data included number of pieces of rhizome per seedling, and rhizome weights (biological, edible, and total rhizome weights respectively). Phytochemical composition analysis of ginger rhizome/PGR treatment included average amount of 6-gingerol, 8-gingerol, 10-gingerol, 6-shogoal, 8-shogoal, and 10-shogoal. Data was analyzed using SAS OnDemand for Academics with PROC GLM at α=0.05 level of significance. As ginger tissue culture seedlings progressed in culture, KT was more suitable for multiplication of buds, BA more suitable for proliferation of shoots, and KT matured ginger tissue culture seedlings at a higher rate than BA. CW had the highest rhizome yield and least amount of biological roots in comparison to other cultivars. CW produced the least amount of 8-gingerol, 10-gingerol, 8-shogoal and 10-shogoal of all three cultivars and with no significant change between two PGR treatments. In comparison, HY produced the highest amount of 6-gingerol, 8-gingerol, 10-gingerol, 6-shogoal, and 8-shogoal, followed by KY and CW, when micropropagated with BA. KY produced the highest amount of 10-shogoal when micropropagated with BA and the highest amount of 6-gingerol, 6-shogoal, 8-shogoal, and 10-shogoal when micropropagated with KT.

High-tunnel Organic Ginger: Response to Propagation Material, Fertilizer, and Prepropagation Rhizome Storage

Ginger (Zingiber officinale, Roscoe) is a tropical rhizome crop typically grown from rhizome pieces, but can also be produced from seedlings. No information is available on how the seedling method compares with the rhizome piece method in organic ginger culture. In addition, information on the growing of organic ginger in the mid-Atlantic region is lacking. Some of the challenges include limited knowledge of rhizome storage, types of propagation materials for planting in the field or high tunnel, and acceptable organic fertilizers that will not increase the excess P currently polluting the Chesapeake Bay watershed. The objective of this study was to assess plant development, soil nutrients, and economic feasibility of organic ginger derived from different storage conditions and planting materials when grown in different nutrient sources in a high tunnel. Three types of plant material (single-shoot transplant seedlings derived from 36.5–40.0 g/rhizome, multishoot transplant seedlings derived from 60–120 g/rhizome, and rhizome seeds of 60–120 g) and three fertilizers types [cotton seed meal, 6N–0.9P–0.8K (0.18 kg⋅m–2), plus AZOMITE (1 kg⋅m–2); Nature Safe, 13N–0P–0K (0.07 kg⋅m–2); and Phytamin All Purpose Liquid fertilizer, 4N–1.3P–3.3K (0.26 L⋅m–2)] were used in 2018. In 2019 and 2020, three types of plant material and two fertilizer types at modified rates from the 2018 study, plus two storage containers (pans and flats), were tested. In general, the rhizome storage container did not affect plant height, leaf soil plant analysis development (SPAD) index, and rhizome yield, and its effect on tillers was none or mixed. Fertilizer type had mixed effects on plant height and tiller number, and no effect on the leaf SPAD index. Rhizome yields in 2019 and 2020 were unaffected by fertilizer, but Nature Safe produced a greater benefit-to-cost ratio (BCR) and profitability index (PI) than Phytamin. Soil P was generally less in Nature Safe–fertilized soil than in Phytamin-fertilized soil. Multishoot seedlings produced the greatest rhizome yield, BCR, PI, and tallest plants, and had some of the highest tiller numbers. These findings show that it would be more profitable to use multishoot seedlings as planting material in high tunnels compared with single-shoot seedlings and rhizome seeds. Furthermore, the lower P levels in the Nature Safe–fertilized soils compared with the Phytamin soils, and greater PI suggest that using Nature Safe will be a better choice than Phytamin for growing organic ginger.

Response of Single Bud Sprout Technique on Different Ginger (Zingiber officinale Rosc.) Cultivars under Sub-Himalayan Plains of West Bengal

An experiment was carried out at Uttar Banga Krishi Vishwavidyalaya, Cooch Behar, West Bengal, during 2018−2019 and 2019−2020 to study the response of single bud sprout on six different ginger cultivars viz., Suruchi, Surabhi, Suprabha, Bhaisay, Gorubathan and a Local cultivar. Planting materials were raised from the cut pieces of rhizome weighing 5–6 g containing single bud in po-tray. Thirty-five days old planting materials of each cultivar were laid in randomized block design with four replications. Observations on growth, yield and quality parameters were recorded in the field and in laboratory following standard procedure. Results revealed a significant variation among different cultivar with regards to various attributes. The cultivar Suprabha recorded maximum number of tillers plant-1 after 180 days (5.83) after transplanting followed by Surabhi. Bhaisay recorded maximum number of leaves plant-1, plant height (50.27 cm) and produced significantly higher individual clump (145.59 g) with an average yield of 16.32 t ha-1. The cultivar Bhaisay and Suruchi recorded the maximum number of primary fingers (3.04), however maximum secondary fingers was recorded by Suruchi (6.88) followed by Bhaisay (6.12) with higher length and breadth of primary and secondary finger. With respect to quality attributes, Suprabha had higher essential oil content (2.09%), Gorubathan excelled in oleoresin content (12.25%) and lowest crude fibre content (4.42%) was recorded by Suruchi. The yield and quality of ginger raised through single bud sprout particularly with the cultivar Bhaisay and Suruchi was comparable with conventional system and found as profitable tool for large scale commercial cultivation.

Blue mold rot caused by Penicillium expansum on Polygonatum odoratum var. pluriflorum.

Polygonatum odoratum var. pluriflorum, called "Dunggulle", is cultivated in East Asia to obtain rhizomes. In Korea and China, these rhizomes are used in traditional teas, health beverages, and herbal medicines (Zhao and Li, 2015). In 2019, Dunggulle was cultivated in 47 hectares, with an annual output of 120M/T in Korea. In November 2020, Dunggulle rhizomes with symptoms of blue mold rot were observed at a Dunggulle farm storage (36°06'01''N, 127°29'20''E) in Geuman, Korea, where the temperature ranged from 9 to 13°C, with an average humidity of 70%. The disease incidence was 2 to 3% out of 200 rhizomes across all markets surveyed. The disease begins with a greenish blue mold covering the rhizome surface (30 to 60%), followed by rhizome rot with a dark brown color as the disease progresses. Leading edges of the rotten rhizome pieces were sterilized with 1% NaOCl and 70% ethanol and placed on MEA (Malt Extract Agar) with penicillin G and streptomycin (both 50 µg/mL). After 7 days of incubation at 25°C, greenish-blue colonies appeared, from which a monospore was isolated. A representative isolated strain was deposited in the Korean Agricultural Culture Collection (KACC, Wanju, Korea) with Acc. No. KACC 49832. The strain grew slowly on MEA at 25°C (8 to 18 mm diam. after 7 days), producing greenish blue conidia. The conidiophores were hyaline and mostly terverticillate; the branches were appressed against the main axis; the stipes were smooth-walled; and the metulae were cylindrical, 10 to 13 × 2.7 to 3.2 µm, with 6 to 10 flask-shaped phialides, measured 9 to 12 × 2.7 to 3.1 µm. The conidia were globose or subglobose and 2.8 to 4.1 µm diam. These morphological characteristics fit well with the description of Penicillium expansum (Frisvad & Samson, 2004). Genomic DNA was extracted from the mycelia of the KACC 49832 MEA plate. ITS rDNA, beta-tubulin (BenA), and calmodulin (CaM) gene regions were sequenced for identification (Houbraken et al., 2020), and the rsulting sequences were deposited in GenBank (Acc. Nos. MZ189258, MZ226688, and MZ226689, respectively). Comparison with the GenBank sequences revealed that the Korean isolate was highly similar to P. expansum (ITS rDNA 99.8%, BenA 98.6%, and CaM 97.8%). Phylogenetic results based on the maximum-likelihood analysis revealed that KACC 49832 was grouped with P. expansum. To demonstrate pathogenicity, 10 µL of conidial suspension (1.3 × 105 conidia/mL) was dropped on the surface of three Dunggulle rhizomes scratched with a syringe needle. For the control, sterile water was applied on three control rhizomes. All rhizomes were surface-sterilized as referred above before being sprayed and dried. All inoculated and control rhizomes were kept in incubator at 25°C and 90-95% relative humidity. After a week, the inoculated points showed symptoms similar to those of the initial infection, whereas controls remained symptomless. The re-isolated fungus matched KACC 49832 based on morphological and sequence analyses, thereby fulfilling Koch's postulates. The experiment was performed three times. To our knowledge, this is the first report of P. expansum as a Dunggulle rhizome pathogen in Korea. As this pathogen is known to produce patulin, a carcinogenic fungal metabolite, further studies on the mycotoxicity of the infected rhizomes are required. This report might help manage the storage conditions of Dunggulle rhizomes to prevent the blue mold rot.

Growth and yield of ginger (Zingiber officinale Rosc.) as influenced by different seed size and spacing

An experiment was carried out during 2016 and 2017 at Horticultural Research Station, Mondouri, BCKV (West Bengal) to identify the optimum size of seed rhizome and spacing of ginger (Zingiber officinale Roscoe) for production of cv. Gorubathan. Growth parameters viz., plant height, tillers per clump and leaves per clump increased with each successive growth stages i.e. 90 and 150 days after plantingDAP. Among different treatment combinations, maximum plant height (74.16 cm) was observed with rhizome size 25 g and spacing of 20 × 20 cm at 150 DAP. However, maximum number of tillers per clump (14.82) was observed with rhizome size 25 g and 20 × 15 cm spacing at 150 DAP. The highest number of leaves per clump (141.38) were noticed with 25 g, 25 × 20 cm at 150 DAP. Maximum weight of clump and length of clump (200.65 and 16.05 g) were recorded with combination of rhizome size 25 g and spacing 25 × 20 cm, respectively. Breadth of clump (12.54) was maximized with 25 g and 20 × 20 cm and projected yield (t ha-1) were recorded highest in planted with mother rhizome pieces directly sowing of 25 g, with the spacing of 20 × 15 cm (29.95 t ha-1).

Plant growth, tuber yield formation and costs of three different propagation methods of yacon (Smallanthus sonchifolius)

Yacon (Smallanthus sonchifolius) ((Poepp. and Endl.) H. Robinson) is a perennial plant native to the Andean region. Its tubers contain high amounts of fructooligosaccharide and inulin (up to 60% of DM) which are supposed to have positive effects on human health. One major aspect currently limiting yacon cultivation is the high cost of propagation. The aim of the present study was to investigate three different propagation methods i) divided seedling after budding from mother plants with pre-cultivation in the greenhouse (DSAB), ii) seedlings from rhizome pieces pre-cultivated in the greenhouse (RP1), and iii) rhizome pieces directly planted into the field (RP2) in regard to plant growth, tuber yield formation and costs. The propagation methods DSAB (92 cm) and RP2 (85 cm) produced significant bigger plants than RP1 (70 cm). Leaves and ramifications showed a similar trend, additionally number of ramifications of DSAB (24) differed significantly to RP1 (16) but not to RP2 (18). The average rhizome weight at harvest was highest for DSAB with 871 g and lowest for RP1 with 561 g. Contrary to that, on a hectare basis RP1 achieved highest tuber yields (29.8 t FM ha−1). The tuber yields of DSAB and RP2 were considerably lower with 21.3 and 17.8 t FM ha−1 respectively. Mean fresh weight of tubers differed significantly between RP1 (308 g) and RP2 (196 g), whereas DSAB (255 g) did not differ significantly from RP1 or RP2. Furthermore, RP1 reached the highest number of tubers per plant (8.2) compared with DSAB (5.6) and RP2 (6.6).Due to the highest tuber yield and low investment costs, RP1 turned out to be the cheapest propagation method for the cultivation of yacon. The most important cost factors were the procurement of plant material and pre-cultivation. A further mechanization of direct planting of yacon rhizomes (RP2) would offer the chance to decrease the propagation costs within this method significantly.

Running bamboo species pose a greater invasion risk than clumping bamboo species in the continental United States

Bamboo species have been promoted for utility in both biomass and pulp production because of their high productivity. However, some bamboo species are known to be problematic invaders. Our goal was to use a weed risk assessment (WRA) tool to evaluate and compare invasion risk of non-native running and clumping bamboo species, many of which are under consideration as paper pulp and bioenergy crops in the continental United States. WRAs were conducted for 18 running and 29 clumping bamboo species using a version of the Australian WRA modified for the U.S. We tested for differences in scores and the number of questions answered for clumping and running species, the relationship between the WRA score and the number of questions answered, and the questions that differentiated low and high-risk species. Overall, we found that running bamboo species present a significantly higher invasion risk than clumping species. Only one running bamboo species (Chimonobambusa tumidissinoda) was identified as low risk and one clumping species (Bambusa bambos) was high risk for invasion. History of invasiveness elsewhere, the ability to form dense thickets, and unintentional dispersal of viable rhizome pieces were associated with significantly greater predicted risk. Commercial applications of bamboo should focus on the use of low invasion risk clumping bamboo species to reduce the risk of escape and colonization of nearby natural areas. Further, bamboo-specific best management practices (BMPs) should be implemented to reduce the probability of invasion for species used in commercial production.

Quantifying the economic and greenhouse gas balance advantages of establishing miscanthus from stem cuttings

The establishment of miscanthus conventionally propagated from rhizome pieces is an expensive and carbon intensive process. A method to establish miscanthus crops through harvesting stem segments in autumn and sowing directly into a field can provide a low cost alternative to rhizome propagation. This study aims to assign both economic and GHG intensity values to the system in comparison to rhizome propagation. This study employed sensitivity analyses to investigate the effect of nitrogen rate and three different stem segment sowing densities. The cost of harvesting plant material and sowing 1 ha was found to be 1703 € for conventional rhizome propagation and 810 € for the autumn harvest and direct sowing stem nodal propagation system. This study also found considerable reductions in the GHG emissions of the stem based system which were 535 kg CO2 equivalent compared to 2118 kg CO2 equivalent for conventional rhizome propagation. Sensitivity analysis of the stem based system found that at the highest stem sowing rate of 39 999 ha-1 and applying 150 kg nitrogen ha-1 would increase cost to 976 € ha-1 with emissions of 1151 kg CO2 equivalent. At the lowest stem sowing rate of 13 333 ha-1 and the application of 0 kg N ha-1 to the mother crop an expense of 809 € ha-1 was incurred with emissions of 513 kg CO2 equivalent. There are significant economic and GHG advantages of moving from a rhizome based propagation system to a stem based propagation system.

Morphological studies and development of Ex-situ protocol for rehabilitation of threatened Rheum species under nursery conditions

<p><em>Rheum</em> is a strong vigorous plant and can live long even in tough conditions. The <em>Rheum</em> species have been domesticated as medicinal plants for human consumption. <em>Rheum</em> species are perennial stout herbs. Rhubarb is a common English name of the genus <em>Rheum</em>. Rhubarb is a plant name for the many different species of <em>Rheum</em>, distributed in the temperate and sub tropical regions of Himalaya from Kashmir to Sikkim and growing wild in the mountains of the Western and North-western provinces of China and adjoining Tibetan territory. It is cultivated much in Europe and the United States. In Kashmir Himalaya, it ranges from an altitude of 1700 - 5500m. It is famous for its medicinal uses. Roots are long and stout. Stem is erect, hollow, sulcate, glabrous or strigose. It is native to Asia-Temperate to Asia – Tropical, from China to India, Nepal and Pakistan. In India, its found in Himachal Pradesh Jammu & Kashmir and Uttar Pradesh. In Jammu and Kashmir, it grows on open slopes and shrubberies in Kashmir, Leh and Zanaskar valley between 3000-5000 m, where <em>R.webbianum</em> is found. The <em>Rheum spiciforme</em> is also one of most known medicinal plant and is found on high altitudes of Gurez valley(3000m 5000m). <em>Rheum</em> also prefers a full sunny location and thrives in a moist, fertile soil. Most <em>Rheum</em> species can handle heavier clay soils better than many other herbs and makes a striking addition to the spring landscape. Rhubarb is propagated from seeds, seedlings, or pieces of rhizome. </p>

Tulbaghia--A Southern African Phytomedicine.

The phytomedicine Tulbaghia consists of the fresh or dried subterranean organs of various Tulbaghia species. The genus is endemic to Southern Africa and includes about 20 species, of which only T. alliacea and T. capensis are naturally found in the winter rainfall climate area (the Western Cape). The genus forms part of the Alliaceae family and is a geophyte (plants with an underground perennation organ and leaves that die back annually). Their habitat can range from semi-desert to wet and boggy terrain. Wild garlic is most commonly prepared as an infusion or boiled in water and taken orally. Externally, as a medicated bath, wild garlic is used to treat paralysis and rheumatism and to reduce the temperature in a feverish patient. Internally, rhizome or bulb preparations are taken orally to treat fever; as a remedy for colds and influenza, asthma, tuberculosis, and stomach problems; as an antihypertensive; or to expel intestinal worms. It is also used as a prophylactic against winter infections. Rhizome pieces are often placed in castor oil to make eardrops. For fever and high blood pressure, a tea is made from the bulbs or rhizomes and a small cup taken three times daily. The leaves of the plant are used to treat esophageal cancer and may also be eaten as a vegetable. The demand for Tulbaghia in both formal and informal markets has grown exponentially. Sustainable harvesting focuses on only harvesting enough of the plant so that it still has the capacity for self-renewal. However, because both the above-ground and underground parts of Tulbaghia are commonly used in African traditional medicine, destructive harvesting of the whole plant is inevitable, thus necessitating the large-scale organized propagation of these plants. It is therefore important to establish a new strategy for the sustainable harvesting of these plants as commercial crops.

Effect of Planting Material on Growth and Yield of Turmeric

Curcuma longa L. (Zingiberaceae) rhizomes, commonly known as turmeric, is a rhizomatous, herbaceous, monocotyledonous spice as well as medicinal plant and has been traditionally used as a source of coloring matter for foods, cosmetics and textiles and as a medicinal ingredient of formulations of the Indian system of medicine for several common ailments. Turmeric is propagated through rhizomes and large quantity of rhizome is required because of the low efficiency of vegetative propagation. In addition, during storage and cultivation, rhizomes are susceptible to diseases that cause tissue senescence and degeneration. Survival percentage of plants through rhizome is low (80 per cent) in field condition. The availability of quality planting material is also scarce during the cropping season (June – September). To overcome these problems, a trial to standardize the size of the planting material and to study the effect of the transplants on growth and yield parameters was laid out with nine different treatments. Among the various treatments, single node rhizome (5g) raised in protray (1 month) and planted in the main field recorded the highest plant height (82.79 cm), more number of leaves (7.29) and number of tillers per plant (4.00). Among the nine different treatments, single node rhizome (5 g) raised in protray (1 month) and planted in the main field recorded the maximum yield of 46.20 t/ha with the highest C:B ratio of 1: 2.47 followed by mother rhizome pieces (10-15 g) raised in protray (1 month) and planted in the main field recorded the yield of 41.87 t/ha and C:B ratio of 1:2.14 as compared to control of primary full length rhizome (25-30 g) planted directly in the field (34.47 t/ha).

Sprouting Ability and Seasonal Changes of Sugar Concentrations in Rhizomes of Calystegia sepium and Roots of Convolvulus arvensis

Factors influencing the sprouting ability of rhizome pieces of Calystegia sepium and root pieces of Convolvulus arvensis were analyzed in four experiments. In the first experiment, sprouting was investigated as a function of bud number. About half of the rhizome and root pieces with one bud could sprout. Almost all pieces with 6 or more buds sprouted. Mostly several buds sprouted in longer rhizome and root pieces. In the second experiment, sprouting of rhizomes and roots was measured in dependence of burial depth in the soil. With increasing depth, the sprouting ability of about 10 cm long rhizome and root pieces decreased. From deeper than 35 cm for C. sepium and 30 cm for C. arvensis no new shoots emerged. This shows that common shallow tillage practices are mostly not sufficient to suppress vegetative regeneration of these two weed species. In the third experiment, rhizome and root pieces were collected in the field and their sprouting ability was examined in the greenhouse over the season. Rhizomes of C. sepium and the roots of C. arvensis were dormant in the winter and sprouting was highest in April and May. In the fourth trial, seasonal changes of sugar concentrations were studied in the rhizomes and roots. It was found that concentrations of fructose, glucose and saccharose were highest and starch rates were lowest in mid-June for both species. We assume that this time corresponds to the optimum time for herbicide translocation in the roots/rhizomes.

First Report in Chile of Mycocentrospora acerina, Causal Agent of Peony (Paeonialactiflora) Red Spot.

A survey to identify pathogens causing peony diseases in southern Chile (37°95' to 40°58'S) was conducted from 2008 to 2011. A noticeable symptom consisted of small red spots on leaves, stems, sepals, and first petals of the bud. The central part of the lesions (1 cm) enlarged, darkened, and became necrotic, coincident with rainy and cold weather, including frosts. Lesions grew but never coalesced completely. At the edges of leaves, the infected tissues cracked and produced a twisted and corrugated appearance. Rhizome symptoms were also observed and consisted of black spots, which enlarged to elongated lesions. Small pieces (~1 × 1 mm) of symptomatic leaves, previously washed with 2% NaOCl for 2 min were cultured on potato dextrose agar (PDA) and V8 juice agar (20%) media. The cultures were incubated in growth chambers at 20°C (dark) and 5°C (dark)/20°C (light) for 12/12 h (dark/light). Sporulation was obtained only with V8 under the dark and light regime. Mycelia growth was superficial and immersed in the media; hyphae were septate with thick black walls. Conidiophores were flexuous, not branched, and produced a single spore. Spores were elongate, multiseptate, with a long, strongly curved beak. After one week, sporulation decreased and thick-walled, round black clamydospores formed in the media. Spores ranged from 125 to 235 μm long and most frequently were 170 to 220 μm. The number of septa ranged from 5 to 12. Morphological and cultural characteristics fit the description of Mycocentrospora acerina (Harting) Deighton (1,2). DNA was obtained from fungal culture. The internal transcribed spacer (ITS) region was amplified using ITS1/ITS4 primers (3), and part of the amplicon (502 of 550 pb) was sequenced. The sequence was deposited in GeneBank (Accession No. KF015599) and showed 100% identity values with sequences of similar regions from M. acerina (strain ATCC 16259, Accession No. KF278454). Healthy leaves and rhizome pieces were washed with sterile distilled water and placed on sterile moist paper towel. A small agar disc with mycelium was placed on the leaves and rhizomes with and without wounding before inoculation. The inoculated materials were kept in closed boxes with high humidity at 5 to 20°C. Tests were positive in leaves and rhizomes with and without wounds. Seven days after leaf inoculations, necrotic symptoms developed. A second inoculation test in peony leaves of plants bagged with plastic under field conditions corroborated the in vitro test. Inoculated rhizomes developed dark orange lesions initially, then turned black with a watery consistency, similarly to affected rhizomes in the field. In both tests, controls showed no symptoms. To our knowledge, this is the first report of M. acerina on P. lactiflora globally (4). In an evaluation at Carillanca (38°41'S, 72°25'W), using a scale from 0 (no symptoms) to 7 (necrotic lesions covering >60% of foliage, with death of stems), 11 out of 31 peony varieties scored 0-1. As a reference, a score of 3 is the maximum damage allowed on peonies for export. These varieties might help to keep Chilean peonies in the market without an economic impact.

Pharmacognostical studies on the Rhizome of Sansevieria roxburghiana Schult. and Schult. f. - a botanical source for Murva - an Ayurveda drug

Aim: The aim of the present study was to carry out a detailed pharmacognostical investigation on the rhizome of S. roxburghiana which includes exomorphological, macro-, microscopical characters, macerate, powder, phytochemical analysis and HPTLC studies. Methods: Rhizomes of S. roxburghiana were collected from Kadavur village, Karur district, Tamil Nadu, India, shade dried and powdered. A few fresh pieces of rhizome were preserved in 70% alcohol to carry out pharmacognostical studies. Dried rhizomes were powdered; successive solvent extraction was carried out to perform preliminary phytochemical analysis. HPTLC studies were carried out on ethanol, aqueous extracts and volatile oil. Results: The plant is identified by deep concave-channelled linear leaves with a number of dark transverse bands, flowers in long racemes and pedicels jointed in the middle. Rhizomes are identified by the presence of distinct nodes and internodes, cylindrical shape, ground tissue with three distinct zones; presence of oil globules in the cells of outer zone; presence of raphide bundles and mucilage content in the inner zone. Vascular bundles are found scattered in the inner zone of ground tissue. Rhizome contains carbohydrates, saponins, proteins, alkaloids, fats and phytosterols. The percentage yield of volatile oil was 0.2 % v/w by hydro-distillation. Rf values obtained in HPTLC studies will be helpful in identifying and isolating the phytoconstituents. Conclusion: The pharmacognostical investigation on the rhizome of S. roxburghiana helps in identifying the botanical source of the ayurveda drug Murva, establishing the pharmacopoeial parameters and for undertaking further studies to determine the biomarker compounds.

The Pharmacognosy of Rauwolfia

Summary Rauwolfia of Indian commerce consists of the dried rhizomes and roots, with occasional small pieces of attached aerial stem, of Rauwolfia serpentina Benth. The important histological features are the cork, composed of alternating layers of broad and narrow cells, giving a somewhat spongy and friable exterior to the drug; the narrow bark and the wide central mass of wood in the root or broad ring in the rhizome, showing about 3 to 8 growth rings; a tetrarch, or occasionally triarch, primary xylem in roots or a very small pith at the centre of rhizomes; in the periphery of the pith a ring of about 20 small groups of perimedullary phloem. All the cells of the wood, including those of the medullary rays are lignified. The xylem vessels, fibres and parenchyma form narrow undulating radially arranged bands, separated by large medullary rays in the root and by smaller ones in the rhizome. The vessel segments are small and narrow and the xylem fibres are often irregularly shaped with long, usually much contorted, tapering ends; many of the vessels, especially in the rhizome, show tylosis and occasionally contain resinous masses. The phloem also occurs in undulating bands similar to those of the xylem; phloem fibres are absent. In the rhizome, unlignified pericyclic fibres occur, either singly or in groups of 2 to 4; they show the local and sub-terminal elongated-oval enlargements characteristic of the Apocynaceæ. All the parenchymatous tissues, except the cork, contain numerous starch grains, about 4 to 20 to 50μ in diameter. Cells containing a brownish yellow secretion occur in small numbers, either singly or in short longitudinal rows, in the bark, wood and pith, being most frequent in the cortex of pieces of rhizome. Typical laticiferous tubes are absent. Calcium oxalate occurs in numerous cells of the phloem and of the medullary rays of the bark; the crystals are either well-formed prisms or aggregates of irregular angular components.

Effects of tractor weight, wheel placement and depth of ploughing on the infestation of perennial weeds in organically farmed cereals

To ensure optimum conditions for organic cereal growing, it is important to minimize both compaction and soil inversion depth. The relative effects of using light versus heavier tractors, shallow versus deeper ploughing and on-land versus in-furrow wheel placement during ploughing were investigated in three-year organic rotations dominated by cereals with naturally infested stands of perennial weeds. The second part of the experiments was carried out in continuous barley with transplanted root fragments of Cirsium arvense (L.) Scop. and rhizome pieces of Elymus repens (L.) Gould. Ploughing was performed in spring under favourable weather conditions. Neither tractor weight nor wheel placement influenced decisively the numbers and above-ground biomass of perennial weeds. Depth of ploughing, on the other hand, affected both perennial weed infestation and yield levels consistently. Weed numbers and the total above-ground weed biomass were mostly 50% lower with deep ploughing (25 cm) than with shallow ploughing (15 cm). The greatest advantage of deep ploughing appeared in the control of C. arvense, which in some cases was reduced by more than 90% compared to shallow ploughing. In organic rotations dominated by cereals, therefore, combating of perennial weeds by deep ploughing may be more important than factors such as tractor weight and wheel placement.

Review:Physiological Approaches to the Improvement of Chemical Control of Japanese Knotweed (Fallopia japonica)

Japanese knotweed is an aggressive alien species in Europe, North America, and Australia, causing a range of environmental problems. Eradication of Japanese knotweed is proving to be a difficult task, because the plant is able to propagate generatively by intra- and interspecific hybridization, and vegetatively from shoot and tiny rhizome pieces. Despite the economic consequences of Japanese knotweed on natural and built environments, its physiology is not yet fully understood; especially important are sink-source relations between old and young parts of the rhizome and growth of lateral and latent rhizome buds. Current methods of chemical control include three types of phloem-mobile herbicides, such as glyphosate, imazapyr, and synthetic auxins. These herbicides have limitations on their use, and all fail to eradicate the plant completely, for the reasons discussed in this review. Our aim is to suggest prospective approaches to enable chemical eradication: use of signals to induce controlled growth and development of quiescent rhizome buds; use of phytohormones, sugars, and light to increase allocation of phloem-mobile herbicides to the rhizome; use of xylem-mobile herbicides to exterminate the old rhizome parts; and use of different phloem-mobile herbicides at different growth stages.

Estimation of ramet production from Miscanthus × giganteus rhizome of different ages

In Miscanthus × giganteus the perenating organ is the rhizome. This can be divided mechanically in the field from “mother crops” to provide rhizome pieces for replanting. A preliminary experiment was conducted to investigate the effect on establishment rate of using mother crops that were of 1-year-old, 5-year-old and 9-year-old material. Most successful establishment was achieved with the material from 5-year-old plants where 88% of rhizome pieces produced ramets compared to 52% for 9-year-old and 25% for 1-year-old material. Although the actual rhizome age from 5-year-old to 9-year-old material that successfully produced shoots could not be determined, the results indicated that, with further study, the planting rate for pieces of rhizome from different ages of mother crops could be calculated to achieve a planting density of normally 1–4 m −2.

Weed control in maize (Zea mays L.) with effective minimum rates of foramsulfuron

Dose-response experiments were conducted under controlled conditions to determine the effective minimum rates (ED_{90}) of foramsulfuron for 11 weed species that occur in maize growing areas in Turkey. Annual weeds were collected from maize fields in the cotyledon stage and transferred to pots containing a mixture of soil-turf (1:1 ratio). Perennial weeds were grown from rhizome pieces collected from infested fields. Weeds were then treated with different rates of foramsulfuron to determine the effective minimum rate (ED_{90}) for each weed species via dose-response experiments. Results showed that ED_{90} rates were lower than the recommended herbicide rate for most weed species. Weeds were grouped with respect to their sensitivities into 5 different groups: ED_{90} < 25%, ED_{90} between 25% and 50%, ED_{90} between 50% and 75%, ED_{90} between 75% and 100%, and ED_{90} > 100% of the recommended herbicide rate. In additional field experiments the performance of these rates applied alone or in combination with ammonium-sulphate on weed and maize grain yield was evaluated, and ED_{90} rates were determined for some weed species. The results show that 25% of the herbicide rate alone insufficiently controlled weeds; however, the addition of AS improved the effect of this rate. In general, the 50% rate was as efficient as the recommended rate and provided similar maize yield as obtained from plots treated with higher rates or from weed-free control plots. As compared to the ED_{90} rates determined under controlled conditions, effective minimum rates observed under field conditions were similar for some weed species, but higher for some others. In the case of total weeds the ED_{90} rate of the herbicide corresponded to 54% of the recommended herbicide rate. Results of these experiments suggest that weed control in maize can be effectively achieved with about half the recommended rate of foramsulfuron, without a loss in yield.

High-frequency, direct bulblet induction from rhizome explants of Curculigo orchioides Gaertn., an endangered medicinal herb

An efficient and reproducible method for inducing a large number of bulblets from rhizome explants of Curculigo orchioides Gaertn., an endangered medicinal herb, has been developed. The rhizome pieces, measuring about 1 × 1 cm (length × width), were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of the cytokinins 6-benzylaminopurine, kinetin, and thidiazuron (TDZ) alone or in combination with 1-naphthalene acetic acid or indole-3-butyric acid (IBA). Of the three cytokinins used, TDZ at 7 μM gave the maximum response, with 82% of the cultures responding with an average number of 15.4 bulblets per explant. The addition of auxins with cytokinin considerably increased the response. The optimum induction occurred on MS medium supplemented with 7 μM TDZ and 0.5 μM IBA. On this medium, 88% of the cultures responded with an average number of 21.4 bulblets per explant. Experiments were also carried out to investigate the role of the sugars sucrose, mannose, and glucose along with 7 μM TDZ and 0.5 μM IBA. The results indicate that sucrose and mannose at particular concentrations have critical roles in promoting in vitro bulblet induction. The maximum result was observed on MS medium supplemented with 7 μM TDZ, 0.5 μM IBA, and 200 mM mannose. On this medium, 97% of the cultures responded with an average number of 26.8 bulblets per culture. Several secondary bulblets developing from the leaf blades of primary bulblets were produced when the latter were transferred to MS basal medium for further development. Out of the 45 bulblets transferred to soil, 40 survived. This protocol can be used for the rapid micropropagation of this endangered medicinal herb.