Perlite Substrate Research Articles

First Report of Crown Rot of Strawberry Caused by Macrophomina phaseolina in Chile.

In recent years, an increase of collapsed and dead strawberry plants has been observed in several fields in central Chile, specifically in San Pedro, Melipilla, an important area for strawberry cultivation in the country. To determine the causal agent of the disease and the extent of the problem, 25 sample sites of 1 ha each, distributed in different San Pedro zones, were surveyed at the end of the 2011 season (from December 2010 to February 2011). Cross sections of the crowns of symptomatic strawberry plants showed necrotic tissue and brown-red to dark brown areas on the vascular ring. Samples of the affected crowns were superficially disinfested and plated on potato dextrose agar with 200 μg/ml of streptomycin sulfate. Dark gray colonies were observed after 7 days of incubation at 24°C. Pure cultures of the pathogen showed aerial mycelium and abundant dark oblong sclerotia. Fifty sclerotia were measured, averaging 120 × 74 μm. Twenty-one isolates were identified molecularly utilizing the species specific primers MpKFI and MpKRI (2) that yielded a 350-bp fragment. The amplified DNA fragments were sequenced and BLAST analysis showed a 99% nucleotide sequence identity with Macrophomina phaseolina (GeneBank Accession No JX535007.1). Both morphological and molecular analyses confirmed that the isolated species corresponded to M. phaseolina, causal agent of crown and root rot in strawberry. Four representative isolates were selected to conduct pathogenicity tests. Inoculum was prepared by incubating the pathogen for 28 days at 20°C in sterilized oat seeds. Pots of 1.5 liters were filled with a mixed substrate of peat and perlite (2:1), amended with inoculated oats at 9 g per liter of substrate. 'Camarosa' strawberry plants were planted and grown in a glasshouse for 1 month. Six replicated plants per isolate and six plants growing on non-inoculated substrate were left as controls. Ninety-five percent of the inoculated plants showed wilt and collapse symptoms 22 days after transplant, whereas no symptoms were observed in the control plants. M. phaseolina was reisolated from the crowns of symptomatic plants, fulfilling Koch's postulates. The pathogen was isolated from symptomatic strawberry plants in 14 of the 25 sampled sites. Although M. phaseolina was described previously on other crops in Chile, to our knowledge, this is the first report of M. phaseolina causing crown rot of strawberry. The disease has been recently reported in Spain, the United States, and Argentina (1,3,4).

Growing carrots hydroponically using perlite substrates

Perlite substrate and nutrient solution were studied for growing carrot [Daucus carota L. cv. Dr. Carotene 5] hydroponically. Three independent studies were conducted to determine the size of perlite particle and concentrations of nutrient solution for growing carrot in hydroponics by evaluating their effects on growth, root yield and qualities of carrot. In the first study, carrots were grown in 1.2 or 5.0mm with 12.5, 25, 50 and 75% ‘Enshi’ nutrient solution. Plants grown in 1.2mm perlites with 50 and 75% nutrient solution produced about 15 and 28% higher root yield, respectively than those plants grown in 5.0mm with same concentration, which was attributed by its longer roots. In the second study, carrots were grown in 0.6, 1.2, 2.5, and 5.0mm perlites and with 25, 50, 100, 200, and 300% of nutrient solution. It was found that, carrot plants grown in 0.6mm perlite supplied with 100% nutrient solution produced significantly higher root yield compared to larger perlite particles and higher concentrations of nutrient solution. In the third study, once used perlites of 0.3, 0.6, and 1.2mm particle and 50, 75, 100, and 150% nutrient solution were investigated and greater root yield was obtained from carrots grown in 0.6mm than in 0.3 or 1.2mm perlite with 75% nutrient solution. Carrots grown in 0.3mm perlites produced shorter roots, wider near the proximal end and whitish in the distal end due to excessive water content causing oxygen deficiency. Carrot root length was greatly hampered leading to decreased root yield in plants grown in 0.3mm perlites compared to other perlite sizes at all concentrations except 100%. This ultra fine perlite hold excessive water causing oxygen deficiency in the substrate air zone and as a result roots become whitish with reduced amount of carotenoids content. Reused perlite culture in the third study lead to maximum root yield at 75% nutrient solution whereas it was with 100% in the second study, which was possibly due to residual nutrient available in the reused perlite which in turn lowers the demand of nutrients in the second culture. Year and growing season along with reused perlite has results in lower root yield and quality in the last two cultures in autumn 2009 and 2010. Therefore, we recommended 0.6mm perlite and 100% (for first culture) or 75% (for second culture) ‘Enshi’ nutrient solution for growing carrots hydroponically with maximum yield and higher quality.

Shoot organogenesis in three Miscanthus species and evaluation for genetic uniformity using AFLP analysis

A simple, efficient protocol for direct in vitro shoot organogenesis and regeneration was established for three species of Miscanthus including two clones of Miscanthus x giganteus, one clone of M. sinensis and one clone of M. sacchariflorus. Shoots were induced from the axillary nodes of both M. x giganteus and M. sacchariflorus and from apical meristems of both M. sinensis and M. sacchariflorus. A tillering method was used to accelerate shoot proliferation. Shoots were rooted in a wet perlite substrate in pots in the greenhouse. Subsequently, rooted plants were transferred to the field. The genetic uniformity of regenerated plants was evaluated using amplified fragment length polymorphism analysis and compared to that of rhizome-propagated plants. A total of 33,443 fragments were generated, representing 869 markers. There were 21 fragments (0.06 % of the fragments) or 19 markers (2.19 % of the markers) that were polymorphic, and almost all of these were singletons. The three species showed similar polymorphisms. Genetic variability was also found in the rhizome-propagated plants, sometimes at a higher rate than in the in vitro culture, indicating that the genetic uniformity was not altered by the protocol. This protocol may help breeders produce new clones of Miscanthus in the future.

Fungi of the genus Fusarium as pathogens of soybean seedlings

Twenty isolates of fungi of the genus <i>Fusarium</i> collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species <i>F. culmorum</i> was most numerously represented among the isolated (4 of 8) pathogens. Isolates of <i>F. sambucinum</i> were also pathogenic (2 of 4) and those of <i>F. soloni</i> (1 of 3), too. The only isolate of <i>F. avenaceum</i> also caused seedling blight. Two isolates of <i>F. oxysporum</i> and two of <i>F. arthrosporioides</i> were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

Micropropagation of Vaccinium arctostaphylos L. via lateral-bud culture

The aim of this study was to determine the most suitable growth medium for rapid and efficient micropropagation of Vaccinium arctostaphylos L. (Ericaceae) via lateral-bud cultures. According to preliminary studies, the best explant collection time was late April and May. Accordingly, cuttings were taken from naturally growing V. arctostaphylos populations, and lateral shoot buds were used as explant sources. Anderson's rhododendron medium (AN), McCown's woody plant medium (WPM), and Murashige and Skoog (MS) basal medium, each supplemented with zeatin/indole-3-butyric acid (IBA) (1.0/0.1 mg L^{-1}), were tested to determine the best basal medium for multiple shoot formation; WPM was the most effective basal medium for this purpose. Subsequent shoot multiplication and development studies were carried out with WPM supplemented with an auxin, IBA (0.1 mg L^{-1}), and 2 different cytokinins, zeatin and thidiazuron (TDZ), in various concentrations (0.5, 1.0, and 2.0 mg L^{-1}, respectively). After a 6-week photoperiod (16/8 h, light/ dark) application, zeatin/IBA combinations were found to be the most suitable for shoot multiplication and growth. The highest shoot length (106.53%) was obtained from the medium supplemented with 1.0/0.1 mg L^{-1} zeatin/IBA, while the highest increases in leaf number (141.89%) and multiple shoot proliferation (10.55-fold) were obtained from medium supplemented with 2.0/0.1 mg L^{-1} zeatin/IBA. WPM was also employed as a rooting medium supplemented with different concentrations of IBA (from 0.5 mg L-1 to 8.0 mg L-1) and a 16/8 photoperiod or a completely dark regime. At this stage, the medium supplemented with 0.5 mg L^{-1} IBA was the best rooting growth regulator with 100% rooting success (16/8 photoperiod). Rooted plantlets transplanted into peat and perlite (2:1) substrate were subsequently acclimatized under climate chamber conditions.

Antimicrobial activity of lavender oil treated with nicotinamide

Lavendula officinalis plants were grown in perlite substrate culture, treated with three nicotinamide concentrations (0, 75 and 100 mg/L), also foliar spray with two different irrigation scheduling (10, 15 times/day) were used. Essential oil (extracted from two cuts) composition was identified using gas chromatography (GC). Essential oil samples were tested for their antimicrobial activity against five Gram positive bacteria, five Gram negative bacteria, six fungi, and four yeasts. The antimicrobial potency was determined by measuring the inhibition zone (mm) using whole plat diffusion technique. GC data showed the superiority of 1,8 cineol which varied from one cut to another according to the rate of irrigation and application of nicotinamide. Linalool was the second major constituent in all treatments; it showed vacillation due to nicotinamide application and the rate of irrigation from one cut to another. Antimicrobial inhibitory effect of most of the resultant lavender essential oils increased with increasing their volume from 2 to 5 µl. Most strains of fungi and Gram positive and negative bacteria showed high sensitivity and were inhibited to a great extent. Different strains of yeast showed high resistance and survived essential oils test. Data clearly indicated the marked inhibitory effect of lavender crude oil samples against several human and plant pathogens and non pathogenic micro organisms. Key words: Nicotinamide, Lavendula officinalis, essential oil, antimicrobial activity.

USING ACID-WASHED SHREDDED WASTE-TIRE RUBBER IN SOILLESS MEDIA FOR TOMATO PRODUCTION

‘Cerasiforne’ tomato (Lycopersicon esculentum Mill.) was grown in soilless potting media contained different substrate formulas including 25:25:50 volume ratio of acid-washed (AWR) or non-washed shredded rubber (NAWR):vermiculite or zeolite:perlite. Additionally, plants were grown in a peat:perlite substrate. Plants grown in media containing AWR had greater root and shoot dry weight and fruit production than those grown in the NAWR media or the peat:perlite substrate. Fruit zinc (Zn) and iron (Fe) concentration of plants grown in AWR-containing media was significantly lower than those grown in NAWR-containing media. Plants grown in the presence of waste rubber accumulated greater Zn in their shoots compared to those grown in the peat: perlite media. Acid washing of rubber significantly reduced shoot Zn concentration. Shredded waste rubber might be used as a component of container media in production of hydroponically-grown tomato; however, acid-washing of rubber is required to prevent potential Zn toxicity for plant.

Optimization of substrate formulation and mineral nutrition during the production of vegetable seedling grafts

The use of seedling grafts has been increasingly popular in the production of fruit vegetables in Korea. Superior scion cultivars grafted on seedling rootstocks tolerant to soil-borne diseases often results in higher crop yield and quality. For the production of healthy grafted transplants, seedlings have to be grown under the most favorable cultural conditions. Substrate composition and property as well as mineral nutrition play an important role. Various substrates containing peatmoss, perlite, vermiculite, and coir-dust have been tested for their influence on seedling growth. In the chemical properties of substrates investigated just before grafting and after formation of grafted union, the ECs in 4 substrates rose as the pre-plant fertilizer level was elevated. The ECs in peatmoss containing substrates were lower than those in coir dust containing substrates when all substrates contained equal amount of pre-plant fertilizers. The ECs in substrates containing vermiculite were higher than those in perlite. In all substrates, the elevation of pre-plant fertilizer levels resulted in the increase in NO3−-N and K+ concentrations and decrease in Na+ concentration. The recommended EC levels of substrates for the raising of plug seedlings of bedding plants are applicable to fruit vegetables when the seedlings are grown in peatmoss + perlite (PP) substrate. But those in peatmoss + vermiculite (PV), coir-dust + perlite (CP) and coir-dust + vermiculite (CV) substrates should be altered based on the kinds and rates of substrate components. In case of crops, the water melon rootstock ‘Cham Bak’ (Lagenaria siceraria Standl), showed the stronger salt tolerance than cucumber rootstock ‘Heukjong Hobak’ (Cucurbita ficifolia) indicating that pre-or post-plant fertilizer levels should be varied based on the kinds of crops grown. The peppers grew well in PP and PV substrates rather than CP or CV substrates in before or after grafting. This also implies that the components of substrates should be changed based on the specific crops.

Comparison of date-palm wastes and perlite as culture substrates on growing indices in greenhouse cucumber

Different substrates have several materials which could have direct and/or indirect effects on plant growth and development. Therefore selecting the best substrate between the various materials is imperative to plant productivity. This research was carried out with using a completely randomized design with three treatments and seven replications. The treatments were including perlite, date-palm waste and soil. During plant growth irrigation rate, temperature, humidity, pest control for all treatments were similar. Cucumis Stativus cultivar was used for seeds. During plant growth Papadopolus formula with fertigation method used for nutrient solution. Some physiochemical characteristics of cultivation substrates were measured. The growth indices of cucumber plant were measured at the end of growth period. Results showed that higher amount of yield, biomass weight, SD, plant height, root weight, LAI and fruit TSS related to date-palm waste that had a significant difference with soil at 5% level but generally had not any significant difference at 5% level as compared with perlite substrate.

BORON DISTRIBUTION AND THE EFFECT OF LIME ON BORON UPTAKE BY PANSY, PETUNIA AND GERBERA PLANTS

Reports of boron (B) deficiency have become more prevalent in pansy (Viola ×wittrockiana), petunia (Petunia ×hybrida), and gerbera (Gerbera jamesonii) plug production. When symptoms are observed in production the presence and severity of symptoms have no obvious pattern; symptomatic plants can be located adjacent to asymptomatic plants in the same plug flat. The availability of B in the soil decreases as soil pH increases. ‘Yellow Dynamite’ pansy, ‘White Storm’ petunia, and ‘Festival Apricot’ gerbera seedlings were grown in a peat:perlite substrate that was amended with pulverized dolomitic limestone at a rate of 3,560, 4,746, 5,933, or 11,866 g/m3. As the rate of lime incorporated into the substrate increased so did soil pH and shoot tissue concentrations of Ca while shoot tissue concentrations of B decreased. Many commercially available germination substrates are amended with macro- and micro-nutrient fertilizers as fertilizer granules. Relatively small amounts of each element are incorporated into the substrate and uneven mixing could result in varying amounts of nutrients in individual cells of a plug flat. This variability could lead to nutrient deficiencies early in the crop cycle. Six commercially available germination substrates were used to fill plug flats and individual cells were sampled and analyzed for B concentrations. Of the substrates tested, there was no variation in B concentration from cell to cell.

EFFECT OF VESICULAR ARBUSCULAR MYCORRHIZAS ON PLANT GROWTH OF SOILLESS GROWN MUSKMELON

The effectiveness of vesicular arbuscular mycorrhizas (AM) (Glomus mosseae, Glomus etinicatum, Glomus fasciculatum and Glomus Caledonium) on plant development of soilless grown muskmelon was investigated. Plants were cultivated in a plastic house, in perlite substrate. Investigated plant growth parameters were plant height, stem diameter, number of leaf, fresh weights of root, stem and leaves. Results showed that all mycorrhiza species increased the plant growth of melon plant in comparison to non inoculated control plants. However, among AM fungi species the better plant growth was obtained with Glomus coledonium and Glomus fasciculatum.

Micropropagation of Pinus massoniana and mycorrhiza formation in vitro

A protocol was developed for the micropropagation of Pinus massoniana and mycorrhiza formation on rooted microshoots. Seedling explants were first cultured on Gresshoff and Doy (GD) medium supplemented with 6-benzyladenine (BA) alone or in combination with α-napthaleneacetic acid (NAA) to stimulate the formation of intercotyledonary axillary buds. The frequency of axillary bud induction was up to 97% on medium supplemented with 4.0 mg l−1 BA and 0. 2 mg l−1 NAA, and the average number of buds per explant reached up to 5.5 on medium with 4.0 mg l−1 BA and 0.1 mg l−1 NAA. Axillary buds elongated rapidly after being transferred to half-strength GD medium containing activated charcoal (0.1% w/v). Shoot proliferation was achieved by cutting elongated shoots into stem segments and subculturing on GD medium containing 2 mg l−1 BA and 0.2 mg l−1 NAA. Root primordia were induced in 82% of shoots when transferred to half-strength GD medium containing 0.2 mg l−1 NAA. Root elongation was achieved in a hormone-free GD agar medium or a perlite substrate. Rooted plantlets were inoculated with the mycelium of ectomycorrhizal fungus Pisolithus tinctorius and the formation of ectomycorrhiza-like structures was achieved in vitro.

STRATEGIES FOR AUTUMN STRAWBERRY PLANTINGS USING DIFFERENT PLUG PLANT FORMATS IN MILD WINTER CLIMATES

Plugs of the strawberry cultivar 'Camarosa' were rooted in peat:perlite (5:1) substrate and placed at high (HE, 802 m) or low (LE, 10 m) elevations at the end of July. Then they were planted as rooted plants in a Venlo-type greenhouse in perlite bags on 22 September and on 17 October 2006. Before the first planting date, half of the plants from LE were kept at 4°C for two weeks to compare with the other treatments. Early fruit yield was higher with HE plugs planted in October and significantly lower with LE plugs planted in September. No significant differences were found for total yields. Fruit weight was significantly higher with HE plugs planted in October both for early and total production. The extra chilling of September LE plants increased early yields, which were not significantly different from those of HE plants planted in September.

RESPONSE OF POTTED AUSTRALIAN ORNAMENTAL PLANTS TO DIFFERENT SOIL WATER CONDITIONS

RESPONSE OF POTTED AUSTRALIAN ORNAMENTAL PLANTS TO DIFFERENT SOIL WATER CONDITIONS

Responses of soilless grown tomato plants to arbuscular mycorrhizal fungal (Glomus fasciculatum) colonization in re-cycling and open systems

Mycorrhizal fungi species Glomus fasciculatum was used to determine its effects on tomato growth, yield, fruit properties, nutrient uptake and substrate ion accumulation of plants grown hydroponically under open and re-cycling (closed) perlite substrate. AM inoculation in both open and closed soilless systems did not increasingly influence the vegetative plant growing and nutrient uptake of tomato cultivar M19. However, fruit yield absolutely increased with inoculation. AM inoculated tomato plants could effectively use photo assimilates for fruit production instead of vegetative growing. In the closed system with AM, ion accumulation and EC increases (salinity effects) were well controlled. Results indicated that mycorrhizal inoculation improved yield and fruit size, which can help alleviate deleterious effects of re-cycling soilless systems for tomato crop.

Impacts of the substrate medium on tomato yield and fruit quality in soilless cultivation

The performance and suitability of different substrates for the soilless culture of tomato plants (<I>Lycopersicum esculentum</I> Mill., cv. Belladona) were studied over a 5-month period in a closed soilless culture system employing five different substrates (perlite, pumice or maize and their mixtures with 50% shredded maize stems in an unheated glasshouse). Plants grown in a maize stem-containing medium produced earlier fruits, followed by pumice. Plants grown in pumice and perlite substrates obtained lower total yield; a higher yield was associated with the addition of maize shredded stems. Pumice + 50% maize and 100% maize produced higher total number of fruits per plant. Fruit quality parameters such as mean fruit weight, fruit firmness, total soluble solids, titratable acidity, ascorbic acid and carotenoids were influenced by the treatment, while EC, pH and dry matter content were not. The results suggest that the addition of maize in perlite and pumice could improve inorganic substrates properties for tomato soilless culture, leading to higher yields and better fruit quality.

CONSERVATION, PROPAGATION, DEVELOPMENT AND UTILIZATION OF XEROPHYTIC SPECIES OF THE NATIVE GREEK FLORA TOWARDS COMMERCIAL FLORICULTURE

CONSERVATION, PROPAGATION, DEVELOPMENT AND UTILIZATION OF XEROPHYTIC SPECIES OF THE NATIVE GREEK FLORA TOWARDS COMMERCIAL FLORICULTURE

The influence of the rooting substrate at 5 Gymnosperm species.

In this paper there are presented the results regarding the influence of the rooting substrate on 5 species from the Coniferales order, subdividion Gymnospermae. The species take it into study are: Cryptomeria japonica D.Don (Fam. Taxodiaceae), Chamaecyparis pisifera S. et Z. (Fam. Cupressaceae), Thuja occidentalis L. (Fam. Cupressaceae), Juniperus horizontalis Mnch. (Fam. Cupressaceae) and Taxus baccata L. (Fam. Taxaceae). All the research has been carried out within the Botanical Garden Al. Buia from Craiova, in the multiplication greenhouse, using warm substrate. There has been used 2 rooting substrate perlite and sand (Table 1, Table 2). For the rooting percentage an important role have the rooting substrate and thats why we have to take it into account their capacity for water retaining and the aeration coefficient.

Secondary Macro- and Microelements in Sphagnum Peat-based Substrates Amended with Parboiled Fresh Rice Hulls or Perlite

Substrates were formulated by blending parboiled fresh rice (Oryza sativa) hulls (PBH) or perlite with sphagnum peat (peat) to produce root substrates (substrates) that contained 20%, 30%, 40%, 50%, or 60% (by volume) PBH or perlite with the remainder being peat. After 0, 4, or 8 weeks in a greenhouse environment, samples were taken and calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), and boron (B) were determined. At all sampling times, substrates containing PBH had higher Ca concentrations than perlite-containing substrates. At all sampling times, Ca concentration decreased as the amount of perlite or PBH was increased, but the Ca concentration decreased at a higher rate in perlite-containing substrates than in PBH-containing substrates. After 0 weeks, perlite-containing substrates had higher Mg concentrations than equivalent PBH-containing substrates, but the opposite was true after 4 weeks. After 8 weeks, perlite- and PBH-containing substrates had similar concentrations of Mg. At all times, Mg concentration decreased as the amount of perlite or PBH was increased. Perlite substrates had higher concentrations of Fe than equivalent PBH substrates, and as the amount of perlite or PBH was increased, the amount of Fe decreased. PBH-containing substrates had higher concentrations of Mn than equivalent perlite-containing substrates, and as the amount of PBH was increased, the amount of Mn increased. Cu concentrations were significantly affected by sampling time, but at all sampling times, PBH-containing substrates had similar or higher Cu concentrations than equivalent perlite-containing substrates. Perlite substrates had higher concentrations of Zn than equivalent PBH substrates, and as the amount of perlite was increased, the amount of Zn increased. S and B were not significantly affected by substrate component or time. Secondary macro- and microelement concentrations of all substrates were within recommended levels for greenhouse crops except for Mn. Mn concentrations were within recommended ranges at up to 50% PBH. In most cases, PBH would be used at levels lower than 50%, but in cases where more than 50% PBH were used in the substrate, proper pH management may be important to prevent excessive Mn availability.

Influence of Nitrate Fertilizer on Macronutrient Contents of Celery Plants on Soil-Less Culture

ABSTRACT Two rates of nitrate (NO3) supply were used in production of celery plants (Apium graveolens L., cv. ‘Istar’) grown on perlite or coir substrates. A standard nitrogen dose (CN) was compared to a concentration that was 25% less (RN). Other nutrients were supplied at the same level for both treatments. Plants were harvested after 85 d of growth, divided into leaves, petioles, internal stalks, basal disc, and roots, and the macronutrient contents [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] were analyzed. The ratios between elements (Na/K, Mg/Ca, and N/P) were also determined at the whole plant level. Commercial yield was statistically the same for CN and RN treatments. Nutrient content for plants cultivated on coir were slightly higher than those on perlite. Petioles and leaves showed the highest accumulation of K, Ca, and Mg; the roots also had similar high levels. The basal disc and internal stalks tended to accumulate S. Nitrogen and P were uniformly distributed throughout the plant. Roots showed the highest accumulation of Na. On a whole plant basis, the nutrient contents for CN and RN were almost the same, with only a slightly higher N concentration for CN. Within the edible fraction (petioles + internal stalks), the RN treatment resulted in a higher concentrations for all the nutrients except N, compared to CN. Thus, celery plants cultivated with a nitrogen dose 25% lower than that commonly used by producers had a balanced nutrient content and were safer for consumers.