Marigold Seeds Research Articles

Suitability of Fly Ash Vermicompost as a Component of Pine Bark Growing Media: Effects on Media Physicochemical Properties and Ornamental Marigold (Tagetes spp.) Growth and Flowering

ABSTRACTThis study evaluated the possibility of mixing fly ash vermicompost (FA) with pine bark (PB) compost to produce a horticultural growing medium for ornamental plants using ornamental marigolds (Tagetes spp.) as the test crop. Fly ash vermicompost was mixed with pine bark compost at 0, 25, 50, 75, and 100% and marigold seeds were sown with or without fertilizer in the resultant media to test their suitability as seedling growing media. FA substitution up to 50% significantly improved water-holding capacity, total porosity, and air-filled porosity. It also raised pH from 4.52 to a maximum of 8.33 when incorporated up to 75%. Incorporation of FA up to 75% resulted in significantly high germination percentages above 90% compared to only 22.5% for the 100% PB medium. However, after 4 weeks of growth, seedlings in the 25 and 50% FA substituted media had higher plant height and leaf area. The 25% FA treatment resulted in significantly higher number of flowers and buds compared to the 50 and 75%. For effective marigold seedling germination and growth, a 50% FA:50% PB growing medium is recommended while for maturity and flower production, the 25% FA:75% PB combination is preferred.

Additive and synergistic effects of Bacillus spp. isolates and essential oils on the control of phytopathogenic and saprophytic fungi from medicinal plants and marigold seeds

Contamination of plants and seeds with microorganisms is one of the main problems in the production and distribution of various agricultural products, as well as raw herbal material for the preparation of herbal remedies. In targeting microbial contamination, among other bacteria, Bacillus species showed a significant capacity for biocontrol. The antifungal activity of 14 isolates of Bacillus spp. against 15 fungal isolates from medicinal plants was examined utilizing a dual plate assay. The strongest and broadest antagonistic activity against all fungi tested was exhibited by isolates SS-12.6 and SS-13.1 (from a 43% to 74% reduction in fungal growth), while isolates SS-39.1 and SS-39.3 were effective against the fewest fungus species and also had the weakest antifungal activity. The effect of a crude lipopeptide extract (CLE) of Bacillus sp. SS-12.6 was similar to that achieved by a dual culture with isolate SS-12.6, confirming that the antagonism was the result of the antifungal activities of lipopeptides. In addition, essential oils of thyme (0.55mg/mL) and savory (0.32mg/mL) in various combinations with the CLE of SS-12.6 were tested for antifungal activity, and additive and synergistic effects for some of the fungi were obtained. When testing the effect of CLE, oils (0.40mg/mL for thyme oil and 0.21mg/mL for savory oil) and combinations in situ on marigold seeds, a reduction of total fungal infection without an adverse effect on germination was accomplished by 6-h treatments with CLE of SS-12.6 (85% reduction of fungal infection and 63% germination), supernatant from liquid culture of SS-12.6 (more than 90% reduction of fungal infection with 69% seed germination) and combinations of CLE and savory oil (77% reduction of fungal infection and 62% seed germination) and CLE with thyme and savory oils (about 75% reduction of fungal infection with 69% seed germination).

Effect of marigold (Calendula officinalis L.) cogermination, extracts and residues on weed species hoary cress (Cardaria draba (L.) Desv.

The aim of the study was to examine allelopathic effect of marigold (Calendula officinalis L.) on germination and growth parameters of weed species hoary cress (Cardaria draba (L.) Desv.). In total, four experiments were conducted. In Petri dishes, cogermination of hoary cress and marigold seeds, and extracts from fresh and dry marigold biomass in concentrations of 5 and 10% (50 and 100 g per litre of distilled water) were evaluated. In pots with soil, effect of extracts from fresh marigold biomass in aforementioned concentrations and effects of fresh and dry marigold residues in two rates (10 and 20 g/kg of soil) were examined. Cogermination of hoary cress and marigold seeds promoted germination and growth of weed. Extracts from fresh and dry marigold biomass, in Petri dish assay, reduced germination of hoary cress on average for 11.9 and 96.9%. Extracts from fresh biomass promoted shoot length of weed seedlings. On the other hand, extracts from dry biomass strongly inhibited all measured parameters. Higher concentration had greater inhibitory effect. Extracts from fresh marigold biomass applied in pots with soil, had stimulatory effect on weed growth, except for root growth which was inhibited with higher concentration (for 6.6%). Fresh marigold residues incorporated in soil had stimulatory effect on germination and seedling growth of hoary cress. Dry residues also had positive effect, but root length was inhibited for 15.4% with lower and 10.2% with higher rate.

Enrichment of marigold (Calendula officinalis) seeds influences seedling vigor and essential oil yield in flowers

Most of soils in Iran are deficient in micro-elements. Enrichment of seeds is found to be as suitable method for overcoming micronutrient deficiencies. Marigold is a herbal medicinal plant. In order to study evaluate of seed enrichment by some of micro-nutrients on seedling establishment and yield of marigold two laboratory and field experiments were carried out on marigold (Calendula officinalis L.) at the Islamic Azad University, Tabriz, Iran, during 2012. Treatments were 0.5%, 1%, 1.5% and 2% Zinc or Manganese, such as 14.5, 29, 43.5 and 58 g Zinc or 19, 38.5, 58 and 77 g Manganese per liter water, respectively. Each treatment involved weighing nearly 10 g of the seed in a glass cup, adding 20 m L of the priming and allowing the seed + solution mixture to sit covered with plastic. Enrichment at the concentrations of 1%; 1.5%, 2% of zinc or manganese increased final germination percentage of marigold seeds in comparison to the control. The data show that mean seedling vigor index can be increased by seed enrichment with zinc sulfate and manganese sulfate, compared to the control. Seeds enriched in 1% Zinc had higher seedling vigor index, but a greater improvement in the Zinc concentration of the solution did not further increase in seedling vigor index. When seeds primed in the highest concentration of manganese, marigold statistically produced flower yield similar to unprimed treatment. Significant increase in essential oil yield of marigold due to seed enrichment treatments relative to not-enrichment was expected. Enrichment of marigold seeds positively influenced seedling vigor and essential oil yield in flowers.

Extractions of High Quality RNA from the Seeds of Jerusalem Artichoke and Other Plant Species with High Levels of Starch and Lipid.

Jerusalem artichoke (Helianthus tuberosus L.) is an important tuber crop. However, Jerusalem artichoke seeds contain high levels of starch and lipid, making the extraction of high-quality RNA extremely difficult and the gene expression analysis challenging. This study was aimed to improve existing methods for extracting total RNA from Jerusalem artichoke dry seeds and to assess the applicability of the improved method in other plant species. Five RNA extraction methods were evaluated on Jerusalem artichoke seeds and two were modified. One modified method with the significant improvement was applied to assay seeds of diverse Jerusalem artichoke accessions, sunflower, rice, maize, peanut and marigold. The effectiveness of the improved method to extract total RNA from seeds was assessed using qPCR analysis of four selected genes. The improved method of Ma and Yang (2011) yielded a maximum RNA solubility and removed most interfering substances. The improved protocol generated 29 to 41 µg RNA/30 mg fresh weight. An A260/A280 ratio of 1.79 to 2.22 showed their RNA purity. Extracted RNA was effective for downstream applications such as first-stranded cDNA synthesis, cDNA cloning and qPCR. The improved method was also effective to extract total RNA from seeds of sunflower, rice, maize and peanut that are rich in polyphenols, lipids and polysaccharides.

Fatty acid composition of lipids in pot marigold (Calendula officinalisL.) seed genotypes

BackgroundCalendula officinalis L. (pot marigold) is an annual aromatic herb with yellow or golden-orange flowers, native to the Mediterranean climate areas. Their seeds contain significant amounts of oil (around 20%), of which about 60% is calendic acid. For these reasons, in Europe concentrated research efforts have been directed towards the development of pot marigold as an oilseed crop for industrial purposes.ResultsThe oil content and fatty acid composition of major lipid fractions in seeds from eleven genotypes of pot marigold (Calendula officinalis L.) were determined. The lipid content of seeds varied between 13.6 and 21.7 g oil/100 g seeds. The calendic and linoleic acids were the two dominant fatty acids in total lipid (51.4 to 57.6% and 28.5 to 31.9%) and triacylglycerol (45.7 to 54.7% and 22.6 to 29.2%) fractions. Polar lipids were also characterised by higher unsaturation ratios (with the PUFAs content between 60.4 and 66.4%), while saturates (consisted mainly of palmitic and very long-chain saturated fatty acids) were found in higher amounts in sterol esters (ranging between 49.3 and 55.7% of total fatty acids).ConclusionsAll the pot marigold seed oils investigated contain high levels of calendic acid (more than 50% of total fatty acids), making them favorable for industrial use. The compositional differences between the genotypes should be considered when breeding and exploiting the pot marigold seeds for nutraceutical and pharmacological purposes.

Magnetic stimulation of marigold seed

Abstract The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

'On-farm' seed priming with Zn+Mn is an effective way to improve germination and yield of marigold

One of the major crop productivity constraints in the world is the unavailability of crop nutrients in appropriate amount and form to crops. In order to study the effect of seed priming with zinc and manganese on germination and essence of marigold in laboratory and field seed priming experiments were done at the Research Station of Islamic Azad University, Tabriz, Iran, with marigold (Calendula officinalis L.), using solutions at four concentrations of zinc and manganese. The priming solution concentrations were 0.5, 1, 1.5 and 2% Zn or Mn, that is, 14.5, 29, 43.5 and 58 g Zn L-1 or 19, 38.5, 58 and 77 g Mn L-1, respectively. Each treatment involved weighing approximately 10 g of the seed in a plastic cup, adding 20 mL of the priming solution, and allowing the seed/solution mixture to sit covered with plastic for 12 h. The essential oil from marigold flowers was isolated by hydro distillation using Clevenger's apparatus. All data was statistically analyzed using MSTAT-C software. Results showed that priming at the concentrations of 1%, 1.5% Zn,1% Mn, or 1% Zn+1.5% Mn increased germination rate of marigold seeds compared to an unprimed control. It is revealed that seed priming with ZnSO4 and MnSO4 may give better results on seedling vigor index of marigold. The highest yield was obtained from seed soaking treatments in 1% Zn+1.5% Mn, 1.5% Zn, 1% and 1.5% Mn solutions. When seeds primed in the highest concentration of Mn, marigold statistically produced flower yield similar to unprimed treatment. Flower essential oil yield among treatments ranged from 0.12 to 0.27mL per 100 g dry weight in 0.5% Mn and 1% Zn+1.5% Mn solutions, respectively. All the seed treatments gave a significant increase in essential oil yield over control. The data from this study confirm that simple 'on-farm' seed priming with Zn+Mn is an effective way to improve germination and yield of marigold. Key words: Essential oil, flower yield, hydro distillation, unprimed treatment.

Desinfestação superficial, germinação e regeneração in vitro a partir de sementes de calêndula

Os objetivos deste trabalho foram: desenvolver um protocolo de desinfestação superficial de sementes, selecionar uma metodologia de germinação in vitro, avaliar o potencial de regeneração no cultivo in vitro e a influência do tempo de cultivo no tipo de calo formado e na regeneração a partir de calos de calêndula. Para a desinfestação superficial, foram testados diferentes tempos de imersão em solução de hipoclorito de sódio a 2,5%. Na germinação in vitro, foram testados: imersão em ácido sulfúrico absoluto; imersão em ácido clorídrico absoluto; retirada do tegumento e embebição das sementes; e embebição das sementes sem a retirada do tegumento. Para avaliar o potencial de regeneração in vitro, foram testadas diferentes concentrações de 6-benzilaminopurina (BAP) e ácido alfa-naftaleno acético (ANA) e tempos de cultivo. A imersão em solução de hipoclorito de sódio a 2,5% por 30 minutos aliada à remoção do tegumento promove a germinação in vitro de sementes de calêndula, efetuando uma desinfestação superficial satisfatória. Para a regeneração de partes aéreas e raízes a partir de sementes de calêndula não é necessária a suplementação com fitorreguladores. Na presença de BAP, independentemente da presença ou não de ANA, calos primários induzem à formação de calos esponjosos e friáveis e de calos verdes e rígidos, estes em menor número; na ausência de BAP é induzida a formação de calos pequenos. Calos jovens são mais eficientes em regenerar partes aéreas em calêndula.

Effect of seed priming on germination and seedling growth of two medicinal plants under salinity

Priming is one of the seed enhancement methods that might be resulted in increasing seedperformance (germination and emergence) under stress conditions such as salinity, temperature anddrought stress. The objective of this research was to evaluate the effect of different priming types onseed germination of two medicinal plants including pot marigold (Calendula officinalis) and sweetfennel (Foeniculum vulgare) under salinity stress. Treatments were combinations of 5 levels ofsalinity stress (0, 2.5, 5, 7.5 and 10 ds m-1) and 5 levels of priming (control, GA3, Manitol, NaCl anddistilled water) with 3 replications. Seeds of pot marigold and sweet fennel were primed for 24 h at25°C. Results indicated that with increasing salinity, germination traits such as germination percent,rate and plumule length decreased, but seed priming with GA3 and NaCl showed lower decrease. Inall of the salinity levels, primed seeds (except manitol) possessed more germination rate and plumulelength than control. The highest radicle fresh and dry weight in pot marigold was seen at 7.5 ds m-1salinity stress level. It seems that higher germination rate in pot marigold shows higher tolerance tosalinity than sweet fennel. Priming with NaCl and GA3 caused an increase in germination percent ofpot marigold and sweet fennel in various range of salinity, but in lower salinity levels percent ofgermination was higher than upper ones. The result of this experiment is consistent with thehypothesis that under undesirable conditions such as salinity stress, priming with GA3 and NaCl canprepare a suitable metabolic reaction in seeds and can improve seed germination performance andseedling establishment

Ácido salicílico em sementes de calêndula (Calendula officinalis L.) sob diferentes estresses

As plantas sofrem agressões por agentes bióticos e abióticos e apesar de não apresentarem defesas através de movimentos ágeis, podem ocorrer adaptações e profundas alterações no metabolismo celular, entre elas a síntese de proteínas de defesas, ativada através de mecanismos complexos. A aplicação exógena ou o estímulo à síntese endógena de ácidos orgânicos como o ácido salicílico, pode agir como indutor de proteínas de tolerância aos diferentes estresses, bem como para elevar a atividade de enzimas de desintoxicação celular, especialmente às envolvidas na degradação de radicais ativos oxigenados. O objetivo deste trabalho foi estudar o efeito do ácido salicílico sobre a germinação e o vigor de sementes de calêndula (Calendula officinalis L.) em condições ideais e sob estresse térmico e hídrico. As sementes foram colocadas para germinar em papel embebido em soluções crescentes de ácido salicílico (zero, 0,0125, 0,025, 0,05, 0,1 e 0,2mM); medindo-se as variáveis: percentagem de germinação; índice de velocidade de germinação e primeira contagem da germinação. Ficou constatado através do teste de Tukey que apenas a germinação foi significativa, sendo que as melhores dosagens de sementes germinadas ficou entre 0,025 e 0,05mM de ácido salicílico. Três outros experimentos foram feitos, um com água acidulada aos pH respectivos às concentrações de ácido salicílico (6,0; 4,8; 4,2; 3,6 e 3,2), um com diferentes potenciais hídricos induzidos por manitol (0; -0,3; -0,6; -0,9 e -1,2MPa), e outro com temperaturas (20, 25, 30 e 35ºC). O ácido salicílico na dose de 0,025mM interferiu positivamente na percentagem de germinação e no índice de velocidade de germinação de sementes da calêndula em condições ideais e sob efeito de estresse hídrico e térmico a 35º.

Controlling Height and Seedling Emergence of French Marigold and Celosia Plugs with Plant Growth Regulators

Abstract Soaking French marigold seeds in growth regulator solutions produced larger reductions in seedling height than foliar sprays. Seeds soaked in 1 to 5 ppm uniconazole solutions for 0.15, 5, or 45 min resulted in plants that were up to 23% shorter than controls at 30 DAS, whereas foliar applications of 10 to 20 ppm uniconazole solutions resulted in plants 18% shorter than controls at 14 DAS. French marigold seedlings from seeds soaked in 60 pm ancymidol for 5 or 45 min were 5 or 6%, respectively, shorter than controls. Foliar spray applications of 25 or 100 ppm ancymidol to French marigold seedlings resulted in plants 8% shorter than controls. Chlormequat solutions applied either as a seed soak (1000–5000 ppm) or foliar spray (500–3000 ppm) did not reduce French marigold seedling height. Emergence of French marigold seedlings from seeds soaked in uniconazole, ancymidol, or chlormequat solutions was not different from that of control seeds. No effect on seedling height or emergence was found when soaking celosia seeds in uniconazole, ancymidol, or chlormequat solutions. Spraying celosia seedlings with uniconazole, ancymidol, or chlormequat solutions did not reduce seedling height.

Early Growth Control of Plants by Seed Soaking in Growth Regulator Solutions

Regulation of excessive vegetative growth is of importance in both field and bedding plant production. The goal of the study was to evaluate the effect of preplant seed soaking in growth regulators on the growth control of floricultural (verbena, salvia, pansy, marigold, celosia) and agronomic (cucumber, dill) crops. Seeds were soaked in water solutions of growth regulators of different concentrations ranging according to the crop from 50 to 1000 mg·L-1 for paclobutrazol, 1 to 10 mg·L-1 for uniconazole, 10 to 200 mg·L-1 for ancymidol, 100 to 5000 mg·L-1 for chlormequate chloride and dried at 20 °C for 24 h prior to sowing into plugs. In the first experiment, seeds of verbena, salvia, pansy, and dill soaked for 5 minutes in 50 mg·L-1 paclobutrazol solutions produced seedlings that were up to 43, 18, 30, and 22% shorter than the controls, respectively. Increased paclobutrazol concentrations and soaking time generally corresponded to a greater reduction of plant height, as well as delays and reduction in seedling emergence of all crops, except cucumber. In the second experiment, growth of marigold plugs from seeds soaked in 5 mg·L-1 uniconazole or 60 mg·L-1 ancymidol solutions during 45 min was associated with 23% or 6% plant height reduction, respectively. Soaking of marigold seeds in the solutions of chlormequate chloride did not significantly affect seedling growth. Increasing time of seed soaking in growth regulator solutions did not influence emergence of marigold seedlings. The height of celosia seedlings was only slightly reduced by soaking seeds in the solutions of all studied growth regulators. Results indicate that seed treatments with growth regulators might be useful in growth control of selected bedding plants.

Maintenance and enhancement of germination and vigour in Marigold (Tagetes spp.) seed

Marigold is one of the important annual flowers grown for commercial purposes in India. Non availability of high quality seeds of marigold is one of the major constraints to its cultivation. The present investigations reveal that there is a rapid decline in vigour and viability of marigold seed under ambient conditions of storage from April to October in North Indian plains. Drying seeds to about 8% moisture content and storing in sealed moisture resistant packages resulted in maintenance of satisfactory levels of germination (above 50%) for 6 to 10 months at ambient temperatures, while placing silica gel with seeds in paper packets was effective up to 4 months. When stored at 15 ± 2°C germination could be maintained for 8-10 Months in moisture resistant containers and for 6-8 months in paper packets with silica gel, respectively. Germination (%) after 4 days of accelerated ageing (100%, 40°C) was a good indicator of seed vigour and its field emergence potential. A simple pre-sowing seed hydration treatment (soaking for 24 hours at room temperature) was effective in increasing the speed and the final germination percentage. Slow drying of the hydrated seed over silica gel was preferred over sun drying, which was detrimental to seed quality.

TEMPERATURE EFFECTS ON PHOTOSYNTHESIS, GROWTH RESPIRATION, AND MAINTENANCE RESPIRATION OF MARIGOLD

TEMPERATURE EFFECTS ON PHOTOSYNTHESIS, GROWTH RESPIRATION, AND MAINTENANCE RESPIRATION OF MARIGOLD

An environmentally sound method for disposal of both ash and sludge wastes by mixing with soil: a case study of Bangkok plain.

This study reported the test done on ash-sludge mixture for amendment of soil in pot experiments. Ash-sludge mixture ratio studies revealed that 1:5 fly ash-sludge mixture and 1:10 bottom ash-sludge mixture were the optimum mixture ratio that minimized toxic element and provided sufficient nutrients. Experiments indicated that ash-sludge mixtures is more suitable for amendment of acid soil than neutral soil which can increase soil pH and reduce available heavy metal toxicity. The maximum heavy metal adsorption occurred in a pH range of 4 to 6 for all soil studied. The finding also revealed that fly ash application seemed more effective than bottom ash, due to its higher loading rate and metal contents. Heavy metal toxicity was monitored using seed germination test. Marigold and tomato seeds were the two crops selected for this test. Seed germination test result shows that percentage of seed germination increased in pot experiments with sludge only and ash-sludge mixtures. In addition, higher percentages of seed germination were observed to vary with longer incubation time (1-8 weeks). After week 12 of the incubation period, percentage of seed germination began to decline, as a result of reduced soil pH and release of toxic heavy metals.

Emergence and Shoot Growth of Cosmos and Marigold from Paclobutrazol-treated Seed

Abstract This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.

The Effect of Seed‐Borne Pathogens on Emergence of Globe Amaranth, Calendula and Tagetes and the Methods of Control

Nimbya gomphrenae, Stemphylium vesicarium and Alternaria tagetica were isolated for the first time from seeds of diseased globe amaranth (Gomphrena globosa), pot marigold (Calendula officinalis) and marigold (Tagetes erecta), respectively, in Taiwan. The amount of seed‐borne N. gomphrenae or Colletotrichum dematium was positively correlated (P=0.05) with the amount of the abnormal seedling and unemergent seed of globe amaranth. Similarly, the amount of seed‐borne Alternaria alternata or S. vesicarium was negatively correlated (P=0.05) with the emergent rate of pot marigold. Treating the fungi‐contaminated globe amaranth seeds with Bacillus megaterium [1.3 × 109colony‐forming units (CFU)/ml] or 1% NaOCl significantly (P=0.05) increased seed emergence over control whereas 10 p.p.m. pyrifenox could control N. gomphrenae on globe amaranth. Stemphylium‐contaminated pot marigold seeds responded to 200 p.p.m. iprodione treatment by increasing significantly (P=0.05) in seed emergence over untreated control. For seed‐borne A. tagetica, treating marigold seeds with Bacillus azotoformanis (1 × 109CFU/ml) was found effective and mancozeb highly effective.

Earthworm-Processed Organic Wastes as Components Of Horticultural Potting Media for Growing Marigold and Vegetable Seedlings

We germinated and grew tomato, pepper, lettuce, and marigold seedlings in a standard commercial soilless plant growth medium (Metro-Mix 360), and in coir/perlite and peat/perlite-based container media substituted with 10% or 20%, by volume, of vermicompost derived from pig manure or food wastes. Half of the treatments were watered with liquid inorganic fertilizer while the other half received only water. Germination rates of tomato, pepper, lettuce, and marigold seeds in the coir/perlite mixture did not differ significantly from that in Metro-Mix 360. However, the germination rate of tomato, pepper and lettuce seedlings was very low in the peat/perlite mixture. Substituting some of the peat/perlite mixtures with equal amounts of vermicomposts, particularly pig manure vermicompost, enhanced germination rates greatly, making it comparable to that in the commercial medium (Metro-Mix 360). Pepper, lettuce, and marigold seedlings grown in Metro-Mix 360, which already contains a starter nutrient fertilizer in its formulation, had greater root and shoot dry weights than those grown in the control media (coir/perlite mix and peat/perlite mix). Substituting coir/perlite and peat/perlite mixtures with 10% or 20% of either vermicompost enhanced the growth of seedlings significantly, resulting in an overall plant growth as good as and sometimes better than that in Metro-Mix 360. When the plants were provided daily with a complete fertilizer solution, marigold seedlings in peat-based substrate with 20% pig waste vermicompost, and lettuce seedlings in both coir and peat-based substrates, mixed with 20% food wastes vermicompost, produced greater shoot dry weights than those grown in the commercial potting medium. The growth enhancements tended to be greater in peat/perlite-based mixes than in coir/perlite-based mixes, more so with the addition of pig manure vermicompost than with food waste vermicompost. Earthworm-processed pig manure and food wastes would be suitable materials for inclusion into the formulation of soilless potting media, since substitution of these media with relatively low concentrations of vermicomposts can promote plant growth.

192 Controlling Early Growth of Marigold and Tomato Plugs

Some transplanted crops, like tomato and marigolds, tend to stretch very early after germination, especially if grown in low light environments. By the time growers apply growth regulators (PGRs), the stretching of the hypocotyl has already occurred and sprays are ineffective. Seeds of marigold `Bonanza Gold' and tomato `Sun 6108' were soaked for 6, 16, and 24 h in paclobutrazol solutions of 0, 500, and 1000 ppm. After imbibition, seeds were dried for 24 h before sowing in plugs. Sixteen, 26, and 36 days after sowing, seedling height and percent emergence were measured. Increasing concentrations of PGR and time of imbibition produced shorter seedlings. Tomato seedling heights measured 36 days after sowing were 1.9, 1.5, and 1.7 cm when imbibed in water for 6, 16, and 24 h, respectively. When PGR was used at 500 ppm, seedling heights were: 1.4, 1.2, and 1.2 cm, respectively. Similar reductions were observed for marigolds. It was hypothesized that some seeds have coats that are impermeable to PGRs. These impermeable coats might serve as PGR carriers, delivering the chemical into the growing medium of the plug cell. When the root emerges from the seed, it absorbs the growth regulator. These preliminary results indicate that this method of PGR application may be feasible and could benefit plug growers of marigold and other ornamental plant species prone to early stretching (e.g., cosmos).