Vector analysis in the study of the nutritional status of Philodendron cultivated in compost-based media

Compost (CP) made from 70% ligno-cellulosic compounds and 30% sewage sludge was studied as a component of growing media in a 6-month Philodendron cultivation. CP's agronomic viability was evaluated via four plant-growth media containing 25–50–75–100% CP and white sphagnum peat (WP) in comparison to a commercial substrate with white and black peat. Plant nutrition conditions were investigated by determining macro- (TKN, P, K, Ca, Mg and micronutrients (Mn, Fe, Cu, Zn, Na) and heavy metals (Ni, Cd, Cr, Pb) in roots and shoot tissues. Data were compared by vector analysis against control. Even if no leaf injuries were visible after 6-months’ growth, a CP ratio of up to 50% caused growth depression of canopy tissues, as attested by the 37 and 36% reduction in total leaf dry weight and leaf area, respectively. Root growth decline was also notable at 25% CP, where 38% root dry weight reduction implied a significant increase (46%) in shoot–root dry weight ratio. The investigation on nutrient tissue content showed high accumulation of Ni, Fe, Cr, Zn, Cd, Mn, Mg and P in roots; Mg appeared related to K deficiency. Above-ground nutritional status showed a severe lack of P, Mg and Mn. Vector analysis suggests the sewage sludge CP in Philodendron pot cultivation produces many such effects like direct toxic action and antagonistic action, resulting in a general nutrient imbalance in plants.     

Morpho-physiological plant quality when biochar and vermicompost are used as growing media replacement in urban horticulture

Peat moss is the most used soilless substrate in the production of container plants in floriculture. Nevertheless, the drainage of peat bogs due to the peat extraction has increased the necessity of seeking products that could replace the peat that is used in plant production. Therefore, a comparative study was conducted to evaluate the effect of a biochar (B) - vermicompost (V) mixture, as a partial substitute for peat-based substrates, on the morpho-physiological characteristics of ornamental plants. Different blends containing B and V were compared to a baseline peat-based substrate (S) as control in the cultivation of two ornamental bedding plant species that are widely used in urban areas: geranium (Pelargonium peltatum) and petunia (Petunia hybrida). Plant growth and physiological parameters were assessed. Results showed that it is possible to grow container plants of these two species with commercial quality, using a peat-based substrate mixed with biochar and/or vermicompost (up to 30% V and 12% B). Plants in these substrates showed a similar or enhanced physiological response to those grown in the control using commercial peat-based substrate.     

Root development of Thuja plicata in peat-substitute rooting media

In this study we investigated the potential usefulness of different substrates produced from gorse (Ulex europaeus L.) for propagating cuttings of Thuja plicata ‘Atrovirens’. The gorse was composted by different methods, to produce four types of compost. These composts were then used as such (100% compost) or in mixes with coarse sand and pine bark compost (25% compost, 25% coarse sand and 50% pine bark compost, v/v/v) to prepare eight different substrates. The substrates were compared in cutting propagation trials carried out in a greenhouse, with a standard rooting medium consisting of 25% Sphagnum peat moss, 25% coarse sand and 50% pine bark compost (v/v/v). Cuttings were taken from a garden hedge in March 2003, and comprised shoots of the previous year's growth. The bases of the cuttings were treated with a 0.4% solution of IBA rooting hormone, then inserted into cells filled with the corresponding substrate and placed on a propagation bench. Rooting percentage and visual rooting score were determined in July. The quality of roots was evaluated, as total root length and number of root tips, in July, September and November 2003, by use of a Delta-T Scan system. The rooting success of the cuttings ranged from 75% to 90%, except when the substrate comprised the pure composted gorse, obtained after the shorter period in an enclosed composting system with addition of fertilizer and reuse of leachates. Most of the cuttings in this substrate died and only 4% of the cuttings rooted successfully. Physicochemical characteristics of this rooting medium included very high electrical conductivity, low C/N ratio and high water retention. Addition of coarse sand and pine bark compost to the composted gorse significantly increased the rooting success. The root quality variables differed depending on the substrate considered and date of harvest. The results showed that substrates made from gorse compost are of potential use as a peat substitute for propagating cuttings of T. plicata ‘Atrovirens’. The physicochemical properties of the composted gorse should be determined before its use to establish whether it can be used pure as a substrate for rooting or whether it should be mixed with other substances.     

Use of organic agricultural wastes as growing media for the production of Anthurium andraeanum ‘Pink Lady’

Summary

The conventional organic growing medium used for anthurium (Anthurium andraeanum) production is peat. Quality peat, however, is costly and is a non-renewable natural resource. The current study compared the suitability of using charred and composted organic agricultural wastes (OAW) vs. sphagnum peat as components of various growth media for the ornamental plant, anthurium (A. andraeanum ‘Pink Lady’). Ten different media were prepared from composted corn cobs (C), charred corn cobs (CC), charred garden waste (CG), and Pindstrup? sphagnum peat moss (P) in various proportions. The media contained [on a % (v/v) basis]: C (100%), CC (100%), CG (100%), C (70%) + CG (30%), CC (70%) + CG (30%), C (35%) + CG (15%) + P (50%), CC (50%) + P (50%), CC (35%) + CG (15%) + P (50%), C (50%) + P (50%), or P (100%) as a control. After 15 months in a greenhouse, the growth and flowering of transplanted anthurium plants were optimal using P, CC+P, or CC+CG+P.These results indicate that mixing charred OAW with peat could provide a suitable medium for anthurium production, thereby reducing the need for peat and converting agricultural waste material into useful products.     

Influence of paclobutrazol and substrate on daily evapotranspiration of potted geranium

The application of plant growth regulators and the use of different culture media are common practices in potted ornamental crops. We report the results of a study to evaluate the effect of two substrates (peat moss or coconut fiber) and spraying 30 ppm paclobutrazol (PAC) on water resource management of zonal geranium (Pelargonium × hortorum L.H. Bailey) seedlings growing in a greenhouse during spring–summer. Growth, water consumption, leaching, evapotranspiration rate (ET), water use efficiency (WUE) and leaf water potential were determined. Plant growth was greater in peat moss (peat) than in coconut fiber (coconut), while the use of PAC decreased plant growth in both substrates, although more markedly in peat. Coconut produced a higher leaching fraction than peat in both PAC-treated plants and non-treated plants, although PAC application increased the leaching fraction in both substrates. Water consumption was lower in coconut than in peat and decreased in response to PAC. Peat was more effective at improving the water-use efficiency and increased the electrical conductivity in the leachate, while PAC decreased the latter in this same substrate. Daily ET showed a maximum of 200 mL/pot in peat and a minimum of 60 mL/pot in the coconut-PAC treatment. During the experimental period, accumulated ET values were higher in peat than in coconut, while the application of PAC reduced the value in peat but increased it in coconut. The evolution of ET per hour during the day showed that the highest rate (23 mL/h) was registered at midday in peat, while about 90% of ET occurred between 10 and 18 h in all treatments. When a cycle of water stress and recovery was applied, the peat induced the highest ET values of all treatments during the first days of drought, but the lowest ET after a week of drought. PAC modified this response, favoring a more balanced behavior of ET, although after the second cycle of drought this effect disappeared. Based on these results, the best strategy in normal irrigation conditions would be to use coconut fiber and not apply PAC, because this provides plants of excellent commercial quality with low water consumption. In plants at moderate water deficit PAC played a more important role than the substrate, improving the water status of plants with both substrates used. However, in the face of severe water stress the effect of PAC disappeared and peat acted as a better substrate than coconut fiber.     

Interactive effects of biochar and N-fixing companion plants on growth and physiology of Acer saccharinum

The use of biochar with N-fixing species has been shown to enhance productivity of agricultural systems, both in N-fixing crops, as well as in mixed-species systems. Here we investigate the potential for the use of a granulated mixed conifer biochar and a sugar maple biochar in combination with N-fixing companion plants in an urban forestry context. A factorial greenhouse experiment compared growth responses in silver maple (Acer saccharinum L.) saplings planted with two biochar types as soil amendments, alone and in combination with two N-fixing plant companions (Trifolium repens L. and Dalea purpurea Vent.). Both biochar types enhanced tree growth; however, a maple feedstock biochar resulted in greater increases than a granulated conifer-feedstock biochar. N-fixing companion species also increased tree growth, although the faster-growing Trifolium reduced soil moisture content and reduced sapling growth in the absence of biochar. The highest tree growth performance and total N uptake was obtained with a combination of both biochar and N-fixing plants, with a ~30 % increase in biomass compared to controls for the granulated conifer biochar, and a ~55 % increase for the maple biochar. We conclude that biochar additions in combination with N-fixing companion species have considerable promise in an urban forestry context, but that optimization of the system in terms of biochar type and species combination is an important consideration.     

木本泥炭促进设施番茄生长和改良土壤的效果

针对设施菜田土壤连作障碍、蔬菜品质降低等问题,以北京郊区春大棚番茄为研究对象,通过基施木本泥炭及其他添加物料作土壤调理剂,研究其对番茄产量、品质以及设施土壤改良效果的影响。结果表明:木本泥炭+苛性钾处理较常规施肥处理番茄产量显著增加16.73%,果实VC含量显著增加55.77%,同时明显增加了耕层土壤速效磷、钾养分含量,提高了p H值,而单施木本泥炭、木本泥炭+米糠菌剂处理与常规施肥处理均无显著差异。施用木本泥炭及其他添加物料均有降低土壤表层盐分累积的趋势。综上,施用木本泥炭及其他配合物料对设施番茄生长以及土壤改良有良好的促进作用,其中木本泥炭+苛性钾处理效果最佳。     

不同牛粪配比基质对盆栽五彩观赏椒生长的影响

为筛选出适于盆栽的五彩观赏椒基质配比,以椰糠、园土、牛粪组成6种不同配比基质,分析五彩观赏椒长势的动态变化、植株及结果性状、根冠比差异。试验结果表明,不同牛粪配比基质对五彩观赏椒长势有影响,在定植20d内,各处理的株高、株幅、叶片数差异小,30~50d处理差异拉大,至50d时,T5[(椰糠∶园土)∶牛粪=10∶4]的株幅、叶片数均最大。T5的植株性状、结果性状和根冠比均最优,T6其次。因此,T5基质的牛粪配比最适合五彩观赏椒盆栽。     

Growth of Viburnum tinus in peat-based and peat-substitute growing media

To assess the growth of ornamental shrubs in peat alternative substrates, one ornamental species, Viburnum tinus L., was cultivated in a number of different substrates in two climates: a French oceanic (Oce) and a Spanish Mediterranean (Med). In Oce, three mixtures (1/1, v/v) of Finnish peat/yard compost, yard compost/raw coir and Finnish peat/raw coir were used while the expanded perlite/composted manure (1/1), forest compost/composted bark (1/1) and forest compost/cattle manure compost (2/3) were tested in Med. A mixture (1/1) of Finnish peat/pine bark compost was used in both climates as a control. Plants were cultivated at a density of six plants/m² in 4 l containers with drip irrigation. Plant height, dry mass, and leaf area were measured at intervals during cultivation. In Oce, substrates with yard compost or raw coir produced plants of similar size to those in the control substrate. In Med, forest compost/cattle manure compost mixture produced plants with the same height as those in the control mixture and the two other mixtures produced shorter plants. In both climates, substrates ranked the same whether height, dry mass or leaf area were considered. Using those parameters, significant effects of different substrates were revealed. Those effects are related to the substrate characteristics, mainly physical ones. As peat is used in a large range of situations, the experiment showed that substrate performance varies with its use, so alternative substrates can show better performance than those using peat.     

生物炭对干旱胁迫下蓝盆花生长及根际土壤真菌丰度的影响

以蓝盆花为试材,在土壤中分别施入浓度为0、10、20、30、40 g·kg^-1的玉米秸秆生物炭,研究了玉米秸秆生物炭施用对干旱胁迫下蓝盆花生长及根际土壤真菌丰度的影响,以期为利用生物炭缓解干旱胁迫对园林植物的生长提供科学依据。结果表明:干旱胁迫下,T2处理下蓝盆花的株高、茎粗、根数和根鲜质量均显著高于CK,其中在处理20 d后,分别比对照高26.23%、17.79%、26.67%和13.93%,T1和T3处理下蓝盆花的株高、茎粗、根数与对照差异不显著,T4处理下蓝盆花的各形态指标均显著低于对照。生物炭处理后还提高了干旱胁迫下土壤真菌丰度,随着生物炭含量的升高,土壤中子囊菌门、担子菌门、接合菌门、壶菌门和球囊菌门,以及子囊菌门未分类或未识别科、毛壳菌科、小子囊菌科、毛球壳科、丛赤壳科、小疱毛科、假球壳科以及担子菌门蘑菇科、接合菌门被孢霉科和半知菌亚门掷孢酵母科,所占群落比例均呈抛物线状变化,T2处理下,上述真菌在门和科分类水平所占群落的比例最大。在干旱胁迫下子囊菌门小子囊菌科、毛壳菌科、毛球壳科、接合菌门被孢霉科在促进蓝盆花生长方面的作用较为显著。土壤中施入浓度为20 g·kg^-1生物炭最能缓解干旱胁迫对蓝盆花生长产生的影响。     

不同基质配比对欧洲报春观赏品质的影响

以欧洲报春"丹诺娃"为试材,以蛭石、珍珠岩、炭化稻壳和草炭及回笼土为基质成分,研究了不同基质理化性质对报春花观赏品质的影响。结果表明:7个指标中,基质2和基质3与基质1差异极显著;就叶片数而言,基质3与基质2有显著差异,但与基质1差异极显著;叶长、叶宽等5个指标在3种基质间的平均值呈基质2基质3基质1变化,而叶片数和花朵数在3种基质中呈基质3基质2基质1的变化。     

Suitability of wood fiber substrate for production of vegetable transplants: I. Physical properties of wood fiber substrates

Several experiments were conducted with the objective to find suitable alternatives for peat substrates. Physical properties of wood fiber substrates in comparison to other organic substrates were examined. Volume weight, total pore space, pore size distribution, available water, container and air capacity, saturated hydraulic conductivity and volume loss of these substrates were determined. Wood fiber substrates showed a similar volume weight and total pore space as peat substrates, but lower water retention. Particularly the drainage performance of wood substrates results in a quick drainage of surplus water. An increase of volume weight caused a decrease of total pore space, air content and saturated hydraulic conductivity and an increase in water retention. Evaluation of these parameters under container conditions is critical since they are directly related to irrigation and therefore to plant growth. A compression of wood fiber substrates in the pots is recommended to minimize substrate loss. An increase of compression levels reduced the volume loss to almost 0 vol.%. The effect of wood fiber substrates and their volume weight on plant growth will be reported in a second paper.     

Influence of substrate on strawberry plug plant production

Summary

The plug plant technique for the commercial propagation of strawberries is increasing in importance. Several factors, including the properties of the substrate, can affect plug plant quality. Tests on nine substrates containing different proportions of perlite [from 0 – 75%, (v/v)], and dark and light peat [both from 0 – 80% (v/v)], were performed using a simplex-lattice design in order to establish a model for strawberry plug plant production based not only on the single component composition of the substrate, but also on the influences of the chemical and physical properties of the substrate on plug plant quality. Notable differences in physical and chemical properties were found among the nine different substrates tested, as a consequence of the broad range of their component compositions. Substrate mixes containing medium-to-high proportions [from 60 – 70% (v/v)] of light peat and low proportions of dark peat and perlite are recommended, as these resulted in a low nutrient content, a high organic matter content, a low pH, and a low “coarseness” index, which led to high-grade plug plants with greater root and crown dry weights.     

Field response of papaya (Carica papaya L. cv. Coorg Honey Dew) to inoculation with arbuscular mycorrhizal fungi at different levels of phosphorus

Summary

Papaya (Carica papaya L.) cv. Coorg Honey Dew is one of the most popular cultivars grown in Southern India, but it requires high doses of inorganic phosphorus (P) fertilisation for growth. Arbuscular mycorrhizal fungi (AMF) are known to improve plant growth and nutrient uptake, especially the uptake of P and micronutrients. As papaya plants respond well to high levels of P, inoculation with AMF was studied to see if AMF could fulfill the requirement for P in plants grown under field conditions. Papaya seedlings (n = 36 per AMF) were colonised separately, in polybags, for 45 d by two species of AMF, Glomus mosseae and G. fasciculatum. Seedlings were then transplanted to the field, with uninoculated seedlings as controls, in a replicated randomised block design. Three levels of P were applied [50, 75, or 100% of the recommended dose (240 g plant^–1 year^–1) of P fertiliser, as super-phosphate]. Plants were studied for root colonisation by AMF, for growth parameters, and for leaf nutrient contents (especially, P, Zn, and Cu). Acidic and alkaline phosphatase activities in the roots of AMF-colonised plants were recorded as these enzymes are involved in the mobilisation of P. The yields of plants up to 18 months-old, and fruit quality, measured by total soluble solids contents (TSSC) and β-carotene contents, were recorded. AMF-inoculated plants performed better than uninoculated control plants at all levels of P applied. G. mosseae was more effective at improving plant growth, fruit yield, and P and Zn contents than G. fasciculatum at the 75% and 50% P-levels. Cu contents increased at all P-levels in G. fasciculatum-colonised plants. Total soluble solids contents showed marginal improvements at the 75% P level with both fungi. β-carotene contents increased significantly in G. mosseae-colonised plants at the 50% and 75% P-levels, and in G. fasciculatum-colonised plants at the 75% P-level. The feasibility of applying on-farm produced AMF inoculum to improve papaya cultivation and to save 25% of the P applied during papaya cultivation is discussed.     

Vermicompost as a substitute for peat in potting media: Effects on germination,biomass allocation,yields and fruit quality of three tomato varieties

Commercial potting media often contain substantial amounts of peat that was mined from endangered bog and fen ecosystems. The main objectives of this study were to assess (1) whether the amendment of 0, 20, 40, 60, 80 and 100% (v/v) of vermicompost (VC) to a fertilized commercial peat potting substrate has effects on the emergence, growth and biomass allocation of tomato seedlings (Lycopersicon esculentum Mill.) under greenhouse conditions, (2) whether possible impacts on seedlings can affect tomato yields and fruit quality even when transplanted into equally fertilized field soil, and (3) whether effects are consistent among different tomato varieties. Amended VC was produced in a windrow system of food and cotton waste mainly by earthworms Eisenia fetida Sav. Vermicompost amendments significantly influenced, specifically for each tomato variety, emergence and elongation of seedlings. Biomass allocation (root:shoot ratio) was affected by VC amendments for two varieties in seedling stage and one field-grown tomato variety. Marketable and total yields of field tomatoes were not affected by VC amendments used for seedling husbandry. However, morphological (circumference, dry matter content, peel firmness) and chemical fruit parameters (contents of C, N, P, K, Ca, Mg, l-ascorbic acid, glucose, fructose) were significantly affected by VC amendments in seedling substrates; these effects again were specific for each tomato variety. Overall, vermicompost could be an environmentally friendly substitute for peat in potting media with similar or beneficial effects on seedling performance and fruit quality. However, at least for tomatoes, variety-specific responses should be considered when giving recommendations on the optimum proportion of vermicompost amendment to horticultural potting substrate.     

Substrate temperature fluctuation and dry-weight partitioning of Lantana grown in four green roof growing media

Summary

Four potential green roof substrates were evaluated in a field study for their thermal characteristics and their impact on Lantana camara dry-weight accumulation. The substrates were a) a sandy loam soil (S), b) the sandy loam soil amended with urea formaldehyde resin foam (S:F) at a proportion of 60:40 v/v, c) the sandy loam soil mixed with peat and perlite (S:P:Per) at a proportion of 50:30:20 v/v, respectively and, d) peat amended with urea-formaldehyde resin foam (P:F) at a proportion of 60:40 v/v. Measurements included the monitoring of the substrate temperature and the determination of the dry-weight accumulation rhythm of shoots, leaves and roots. In addition, the lateral spreading of the roots was recorded and the shoot/root ratio determined. Temperature fluctuation within the substrates was found to depend on the type of the substrate, plant growth, and season. Temperature fluctuation was high in S, moderate in S:F and S:P:Per and low in P:F. Shoot and root dry-weight accumulation was reduced in P:F, while root growth was promoted in S substrate. Differences in dry-weight accumulation and the lateral spreading of the roots were affected more by the water holding capacity of the substrate than by the substrate temperature.     

Effects of high salinity and the exogenous application of an osmolyte on growth,photosynthesis, and mineral composition in two ornamental shrubs

A greenhouse experiment was carried out to determine the growth, photosynthetic activity, and mineral composition in two ornamental shrubs [Viburnum lucidum L. (arrow-wood) and Callistemon citrinus (Curtis) Stapf. (red bottlebrush)] that had been treated or not treated with 2.5 mM glycine betaine (GB) or 5.0 mM proline (Pro). Plants were supplied with a non-salinised or salinised nutrient solution containing 200 mM NaCl. Salinity caused reductions in plant growth parameters, shoot biomass production, and net CO₂ assimilation in both species. Neither Pro nor GB were able to mitigate the adverse effects of salinity in bottlebrush, whereas GB reduced the deleterious effects of salt stress on arrow-wood, indicating a differential species-specific response to these osmolytes. The application of GB to salt-stressed arrow-wood increased apical and lateral shoot lengths, the number of leaves per plant, and shoot dry biomass by 222%, 113%, 238%, and 49%, respectively, compared to untreated or Pro-treated plants. The improved performance of salt-stressed arrow-wood plants whose roots were treated with 2.5 mM GB was attributed to partial suppression of Na uptake, higher chlorophyll concentrations, and the better nutritional status (higher K) of shoots.     

The response of chilli (Capsicum annuum L.) plants to early inoculation with mycorrhizal fungi at different levels of phosphorus

Summary

Chilli plants cv. Pusa Jwala were inoculated in the nursery beds with three mycorrhizal fungi, Gigaspora calospora, G. margarita and Glomus fasciculatum and transplanted to plots supplied with 0, 25 and 50% of a recommended P level (65 kg ha^?1). Uninoculated plants were also transplanted at 0 (Control) and 100% of.the recommended P level. Plant growth, height, shoot dry weight, uptake of P, root colonization and yield of green chillies were measured. Chilli responded well to inoculation and P. G. margarita best improved growth and yield. Inoculation plus 25 and 50% P were equally better than the control and equal to uninoculated plants at 100% P. As much as 50–75% P can be dispensed with by inoculation with mycorrhizal fungi and this represents a considerable economic saving in cost.     

百合镰刀菌枯萎病防治药剂的研究

采用含毒介质法测定18种杀菌剂对百合枯萎病病原菌(Fusarium oxysporumf.sp.lilii)的生物活性,50mg·L-140%菌核净可湿性粉剂(WP)的抑菌率为74.12%,125mg·L-112.5%腈菌唑乳油(EC)的抑菌率为73.05%。通过盆栽试验(拌土法和浸球法)进一步测定8种杀菌剂对百合枯萎病的防治效果,40%菌核净WP、30%恶霉灵水剂(AS)、50%福美双WP2g·kg-1拌土,12.5%腈菌唑EC1g·kg-1拌土防治百合枯萎病效果良好,防效分别为100.00%、95.80%、83.33%和85.50%。其中,二甲酰亚胺类杀菌剂菌核净和三唑类杀菌剂腈菌唑防治百合镰刀菌枯萎病为首次报道。