Peat Compost Research Articles

Greenhouse Seed Production of Two Dwarf Green Bean Cultivars in Relation to the Duration of Irrigation

As good quality irrigation water becomes increasingly scarce in the Mediterranean region, especially in coastal areas where greenhouses are located, methods of economizing water consumption are essential. Therefore, the effect of the duration of irrigation on the quality and yield of seed of two cultivars of dwarf green bean (`Larma' and `Montano', Phaseolus vulgaris L.) was studied during fall and spring in Greece. Seeds were sown on 11 Sept. 2000 (fall crop) and 23 Feb. 2001 (spring crop) in peat compost and when the plants had two expanded leaves (11 and 20 days after sowing, respectively), they were transplanted to the soil of an unheated, plastic-covered greenhouse. The following irrigation treatments were applied: 1) irrigation for the entire duration (control), 2) irrigation until the first pods were dry, 3) irrigation until ≈50% of the pods had filled, and 4) irrigation till flowering. Fall cultivation was not suitable for seed production due to low yield and reduced seed quality. By contrast, the spring crop had a higher yield, seed size and good germination. Stopping irrigation of the spring crop at the drying of the first pods achieved an ≈20% saving in water without significantly affecting seed yield or quality. Earlier discontinuation of irrigation to achieve greater savings of water caused a reduction in yield, but did not affect seed quality.

Use of sewage sludge compost and Trichoderma asperellum isolates to suppress Fusarium wilt of tomato

It has been reported that plant growth media amended with composted bark suppress Fusarium wilts whereas media amended with composted municipal sludge aggravate this disease. However, in this study, a compost prepared from vegetable and animal market wastes, sewage sludge and yard wastes showed a high ability to suppress Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici race 1. The ability of this compost to suppress Fusarium wilt of tomato was compared with that of a peat mix (peat:vermiculite, 1:1 v/v) and a naturally suppressive soil from Chateaurenard, France. The compost and the soil from Chateaurenard were highly suppressive, whereas the peat mix was highly conducive. Amendment with this compost significantly ( P<0.05) increased the suppressiveness of the peat mix. Biotic and abiotic properties were compared among these substrates. The peat mix was acidic, and had a low EC, whereas the compost was basic and a high EC. The compost–peat mix had a similar pH to the compost, however EC was approximately half that of the compost. The bacterial populations and microbial activity were highest in the compost and the compost–peat mix. Compost (10%; v/v), Trichoderma asperellum isolates isolated from natural compost–peat mix, and the nonpathogenic biocontrol agent F. oxysporum Fo47 isolated from Chateaurenard soil were inoculated into sterilized compost–peat mix and Chateaurenard soil to assess their ability to restore suppressiveness in the sterilized substrates. Both the natural compost and the T. asperellum isolates significantly ( P<0.05) increased the suppressive ability of sterilized compost–peat mix and Chateaurenard soil. Fo47 was relatively the most effective biocontrol agent. The incidence of Fusarium wilt was lowest in tomato plants grown in either sterilized compost–peat mix or Chateaurenard soil inoculated with this strain. Our results show that the use of some composted sewage sludge in the plant growth medium is effective for suppression of Fusarium wilt at the early stage of plant growth. In addition, the T. asperellum isolates isolated from the suppressive compost–peat mix appear to have the potential to be a new alternative of biocontrol of Fusarium wilt.

Efeitos de fertilizantes orgânicos na nutrição e produção do pimentão

Avaliaram-se os efeitos de três tipos de materiais orgânicos associados com a aplicação de fertilizante mineral NPK sobre a nutrição e produção do pimentão cv. Mayata, cultivado em estufa, na região de Piracicaba (SP). O delineamento experimental foi de blocos casualizados com quatro repetições e seis tratamentos (150 g cova-1 de húmus de turfa + 100% do NPK; 150 g cova-1 de húmus de turfa + 70% do NPK; 100 g cova-1 de húmus de casca de pinus + 100% do NPK; 100 g cova-1 de húmus de casca de pinus + 70% do NPK; 100 g cova-1 de esterco de galinha + 100% do NPK e 100% do NPK). A dose 100% do NPK correspondeu a 100 g cova-1 da fórmula 04-14-08, equivalente a 130-458-262 kg ha-1 de N - P2O5 - K2O. O esterco de galinha + 100% do NPK proporcionou, de modo geral, o maior peso médio de frutos e teor de fósforo nas folhas em relação à adição dos outros materiais orgânicos associados com a adubação mineral. A aplicação dos materiais orgânicos associados com fertilizante mineral NPK não aumentou o peso médio e a produção de frutos em relação à adubação NPK isolada.

Comparisons of metal-ion binding to immobilized biogenic materials in a flowing system

The binding of Al(III), Cu(II), and Ag(I) to each of 10 biologically generated materials immobilized within a polysilicate matrix has been investigated within a flowing system. The biogenic materials studied included sphagnum peat, a top soil, peat, compost peat, organic peat, peat replacer, dead Chlorella vulgaris (a green algae), and a cultured cell material from the plant Datura innoxia. Breakthrough curves were generated for flow rates of one-sixth bed volume per minute (5.0 ml bed volume). Metal binding was observed to vary with the Lewis acidity of the targeted metal (increasing from hard to soft).

Toxicity level for phytoavailable zinc in compost–peat substrates

Petunias were grown in compost–peat substrates with different Zn contents (basic load, 400, 800, and 1600 mg kg –1) in order to identify toxic levels of Zn in plant dry matter and of phytoavailable (CaCl 2-extractable) Zn in compost–peat substrates. Yield reduction of petunias was only observed at an extremely high Zn content (635 mg Zn kg –1 plant d.m.), although chlorosis was evident at lower Zn levels (160 mg Zn kg –1 plant d.m.). Thus, the occurrence of Zn-induced chlorosis during the growth period was chosen as the toxicity parameter. Chlorosis and plant Zn content were reduced by additional Fe supply, although the Fe content of the plants was not affected. During a six week growth period, petunia Zn content and chlorosis increased in the first two and three weeks, respectively, and then decreased, whereas plant Fe content decreased sharply between the second and third week after the start of Zn treatment. Chlorosis first occurred with a plant Zn content of 160 mg kg –1, corresponding to a CaCl 2-extractable Zn content in the substrate of 6 mg l –1, which was identified as the toxicity level for phytoavailable Zn in compost–peat substrates. Taking a safety factor into account, a critical level of 4.5 mg l –1 was computed, which should not be exceeded in order to avoid Zn-induced chlorosis.

Sorption of ammonia and release of humic substances as related to selected peat properties

Peat is a hetorogenous material containing humic substances (HS) that increase its fertilizer value, and acid functional groups that react with ammonia. However, polyvalent cations may block some ammonia-sorbing sites. Sixty-seven peat samples were collected in Quebec (i) to relate the colorimetric Kaila pyrophosphate test for extracting HS to the von Post field test and (ii) to correlate ammonia sorption capacity (ASC) to selected peat properties as follows: von Post test, Kaila pyrophosphate test, pH(H2O), pH(CaCl2), pH(KCl), exchangeable acidity as well as ash, Ca, Al and Fe contents. Exchangeable acidity was the most highly correlated with ASC (P &lt; 0.01). Using field-moist material and a 1:4 peat:solution volumetric ratio, the most reliable criteria were pH(CaCl2) &lt; 4.4 and pH(KCl) &lt; 4.5. Using air-dry peat and a 3:50 peat:solution ratio, the corresponding criteria were pH(CaCl2) &lt; 4.3 and pH(KCl) &lt; 4.1. The pH(CaCl2) method provided the most consistent determination of peat acidity, whether taken on a volume or weight basis. A minimum pyrophosphatate test value between 0.1 and 0.2 absorbance unit is apparently required for making peat composts and peat-ammonia-mineral fertilizers enriched in soluble humic substances. The pH(CaCl2) method and the Kaila pyrophosphate test should be combined to routinely control the quality of peat materials for making peat composts and peat-ammonia-mineral fertilizers. Key words: pH, exchangeable acidity, pyrophosphate test, ammonia sorption capacity

A low-energy process for the conversion of fisheries waste biomass

Studies have been conducted in the composting of fisheries processing wastes with peat as a means of recovering the valuable biomass present in the fish waste. Subsequently, extracts from this compost were utilized as a substrate source in the growth of microorganisms in submerged fermentation. The production of fish wastes - peat compost was found to be an easy and inexpensive process which required a low energy input. The concentrations of nutrients such as N were higher in the compost than in the original peat. Thus, a process of bioconversion from a waste material to a product with commercial potential can be conducted with minimal energy requirements.

Effects of several organic fertilizers on growth of greenhouse tomato transplants

An experiment was conducted to evaluate the potential of different organic wastes from the agri-food industry for growing greenhouse tomato (Lycopersicon esculentum Mill. 'Vision') transplants. The organic materials were thoroughly mixed with a peat–compost growing medium prior to transplanting. Meal from blood, feathers, meat, crab shells, fish, cottonseed and whey by-products produced the best growth, significantly increasing the shoot dry weight by 57–83 % compared with non-fertilized plants. Key words:Lycopersicon esculentum, organic fertilizer, peat, tomato, mineralization, nitrogen

Direct and Residual Effect of Different Organic Fertilizers on Potato and Cereals

AbstractField experiment with 8 different organic fertilizers (cattle dung with and without litter, pig slurry, peat compost formed from hen and pig slurry, sawdust‐duck manure, noncomposted peat and straw litter with pig slurry) was carried out on loamy brown podzoluvisol since 1985.The organic fertilizers were applied in the spring of 1985 on two backgrounds: with and without mineral fertilizers. The material is based on the data of four years (1985–1988). The arrangement of crops was the following: potato, spring wheat, barley and early barley.On both backgrounds cattle dung with litter turned out to be the best organic fertilizer, while noncomposted peat manure had a low direct and residual effect. However, before the application it must be composted with pig or hen slurry. The effect of peat composts was dependent on the background of mineral fertilizers. Pig slurry had a low residual effect and acted only as a liquid nitrogen fertilizer. The joint application of straw and pig slurry can be a suitable opportunity for diminishing their undesirable effects.

Selection of Virulent and Persistent Metarhizium anisopliae Isolates to Control Black Vine Weevil ( Otiorhynchus sulcatus) Larvae on Glasshouse Begonia

The virulence of 10 Metarhizium anisopliae isolates against black vine weevil, Otiorhynchus sulcatus, larvae was examined in the glasshouse using potted Begonia. The most virulent isolate, 275-86, reduced larval numbers by 86% compared to the control population (pots treated with 0.05% Triton X-100 only) and two other M. anisopliae isolates reduced the larval population by over 80%. Only one isolate, 313-87, failed significantly to reduce the larval population. There were no significant differences between the six most virulent strains, however, four of these were significantly more virulent than 313-87. There was no significant correlation between larval number and plant biomass. Three M. anisopliae isolates were further examined for persistence in peat compost. All three strains significantly reduced larval numbers on Begonia compared with the control population. The highest levels of control were recorded with strain 100-82 (67-80%) which was significantly more virulent than strain 35-79. The fungal drenches were most effective when they were applied 8 weeks before the application of O. sulcatus eggs, however, significant levels of control were also recorded with spores which were applied 16 weeks before the eggs. Control with conidia applied 4 weeks after the eggs was significantly lower than that with the application 8 weeks before the eggs, suggesting that there might be differences in the levels of control achieved using curative and prophylactic spore applications. The results of these experiments demonstrate that M. anisopliae has considerable potential as a prophylactic microbial control agent for O. sulcatus in the glasshouse.

COMPARISON OF HYDROPHILIC POLYMER AMENDMENT ON MEDIA LEACHATE AND CHRYSANTHEMUM GROWTH

Soil Moist, acrylic polymer, was incorporated into a soil, peat compost, pinebark, and perlite medium at 0, 5, 10, and 20 g per 10 cm (500 ml) pot. One rooted cutting of Dendranthema grandiflora (Ramat) Kitamura was planted into the pot. Prior to planting, each pot received 0.25 mg of ancymidol in a 80 ml drench. Leachate was collected at drenching for foxtail millet bioassay. Chrysanthemum height, dry weight, area, flower number, and date of flowering were recorded at flowering. In a second experiment, Soil Moist, Supersorb C, Agrosoake and Broadleaf brand polymers were evaluated at the manufacturer's recommended rate. Height of millet seedlings grown in ancymidol leachate from polymer-treated media was greater than seedlings grown in ancymidol drench solution. Height of millet seedlings grown with ancymidol leachate from the various polymer media did not differ in height from seedlings which received tap water lechate. Growth parameters were unaffected by polymer rate or brand.

Effect of potting media on the control of Otiorhynchus sulcatus larvae on outdoor strawberry plants using the entomogenous fungus Metarhizium anisopliae

The potential of entomogenous fungi to control black vine weevil (Otiorhynchus sulcatus (Fabricius)) larvae has been demonstrated on a range of protected crops species, but very little attention has been paid to weevil control on outdoor crops, such as strawberry. Curative applications of Metarhizium anisopliae (Metschnikoff) Sorokin conidia to strawberry plants potted in field soil (5 × 108 conidia/pot) reduced the population of O. sulcatus larvae by up to 94%, whereas similar treatments reduced larval numbers in peat compost by a maximum of 53%. Significant differences in relative performance were observed among the four M. anisopliae strains (37-80, 101-82, 189-83, and 275-86) in the two media. Strain 189-83 was the most virulent isolate in both media, whereas strain 101-82 reduced the O. sulcatus population in field soil by only 15% and had no effect in peat compost. Larval establishment in the pots treated with 0.05% Triton X-100 (control treatment) was greater in peat compost than in field soil with nearly twice as many larvae in the former medium. The larval population was evenly distributed in most of the pots with the exception of the pots containing peat compost treated with strain 189-83 which showed significant heterogeneity. Spore density declined with increasing depth in pots containing peat compost. The situation was reversed in the pots of field soil and the highest spore concentrations were found at the base of the pots. More conidia were recovered from the pots containing peat compost than from the pots of field soil. There were also significant differences between strains in the number of colony forming units per sample. In both media, mean counts for strains 37-80 and 275-86 were significantly greater than those for strain 101-82; strain 189-83, however, had a low count in peat relative to 37-80 and 275-86, but had a higher count in field soil.

Expanded clays as growing media for Croton in pot culture

A trial was carried out on the use of mixes with expanded clays as substrates in the cultivation of Croton ( Codiaeum variegatum L. v. aucubaefolium). Four types of expanded clay were used: «Leca» 2-3 mm, «Leca» 3-8 mm, «Agrileca» (new type) 0-3 mm and «Agrileca» 3-8 mm; the expanded clays are mixed with a commercial peat compost (50%, 33,3% and 20% by volume; ratios 1:1, 1:2 and 1:4). Analysis made on the chemical and physical properties of the mixes shoved good values; the expanded clays increased the free porosity in the mixes; «Agrileca» showed lower pH and salinity if compared to the «Leca» expanded clay. Growth was good with all mixes, but the best growing results in Croton were obtained with the mixes containing «Agrileca» (both 0-3 mm and 3-8 mm) and the peat compost at the ratio of 1:2 v/v.

The influence of mineral nutrition on fruit yield, seed yield and quality in tomato

SummaryA nutritional experiment under glass used the tomato cv Moneymaker grown in pots of peat compost. The nutrient levels applied were: N (N150, N2100 g N m−2), P (P121.8, P243.6 g P m−2) and K (K183, K2166 g K m−2). The high N level increased flower number, fruit and seed yields and gave early flowering and ripening. The high P level increased seed yield. P2K2 and P1K1 led to earlier flowering than P1K2, and the percentage of fruit setting was higher in P1K2 than P1K1. The 100-seed weight was highest for trusses (T) 1 and 5 than for the other trusses. N2P2K2T1 gave the highest and N1P1K2T4 and N1P1K2T3 the lowest 100-seed weights. When the seeds from plants of the various treatments were sown, N2 seeds emerged earlier than N1 seeds. The results show that the most favourable combination for high fruit and seed yield, percentage of fruit setting and a higher seed weight was N2P2K2.

Kinetics of organic compound removal from waste gases with a biological filter

In order to eliminate organic pollutants in waste gases, a biological filter bed technique has been developed, with a high self-regenerating capacity and a low pressure drop. The bed consists of an appropriate filling material (mainly peat compost), in order to let the microorganisms grow on the solid surface and to supply them with inorganic nutrients. Most organic compounds are oxidized to carbon dioxide and water. The compositions of the solid phase and the viable organisms present are such that aging is prevented, as a result of which a relatively high activity can be maintained during a long period of time (years). Experiments have been carried out in laboratory-scale columns with composite gas mixtures at varied concentrations and superficial gas velocities. The (macro) kinetics of the elimination processes have been studied, which enables the prediction of the elimination capacity of the filter bed.

Determination of residues of furalaxyl and metalaxyl in nutrient solution, peat compost and soil samples by gas chromatography

Rapid and sensitive techniques for the determination of residues of the fungicides furalaxyl and metalaxyl in agricultural samples are described. Air-dried soils and peat composts are extracted with acetone in a Soxhlet apparatus; the extract is applied directly to the gas chromatograph and detected using a nitrogen-selective detector. Plants are macerated with acetone and, after filtration and dilution with water, partitioned with chloroform; nutrient solutions are similarly extracted with chloroform. The extracts are subjected to gas chromatography after removal of chloroform and dissolution in acetone. Recoveries are generally better than 80% with detection limits of 0.5 mg kg–1 for peat, 0.1 mg kg–1 for soils and plants and 0.02 mg kg–1 for nutrient solutions.

Modified Leaf Anatomy of Cauliflower Plantlets Regenerated from Meristem Culture

Investigations concerned with the regeneration of Brassica oleracea var botrytis (cauliflower) from meristem culture have shown that, whilst in culture, plantlets differ from conventionally-produced seedlings in a number of morphological and physiological features (Grout and Aston, 1 911a , b ; Grout and Crisp, 1 977). Plantlets removed from shaken liquid cultures have little epicuticular wax and poor vascular connection between root and shoot, making them particularly vulnerable to severe wilting. Plantlets regenerated on solid medium have increased levels of epicuticular wax, although still significantly less than seedlings of comparable age or size, and are better able to restrict water loss. The rate of photosynthesis in both types of regenerated plantlets is so low as to make no positive contribution to the net carbon balance at the time of transplanting. Plantlets make the transition to normal whole plant morphology and physiology during growth after transplanting, surviving the transfer to the glasshouse if the appropriate hardening procedures are used (Grout and Crisp, 1977). Plantlet leaves are produced in culture under conditions of relatively high humidity, especially with liquid medium, and with nutrient conditions that are designed to sustain heterotrophic, not autotrophic, growth. This investigation was begun to see if leaves were modified internally as a consequence of development in such a culture environment. Comparisons were made between leaves produced in culture, leaves produced by the regenerated plantlets after transplanting, and those of glasshouse-grown seedlings. Meristem cultures were established as previously described (Crisp and Walkey, 1974; Grout and Crisp, 1977), using Brassica oleracea var botrytis cv. Armado Tardo. These cultures were examined 7 weeks after isolation. Regenerated plantlets were taken from culture and hardened (Grout and Crisp, 1977) before becoming established under standard horticultural glasshouse conditions. These plants were examined 3 weeks after transplanting from culture. Seedlings were grown under normal horticultural conditions in the glasshouse and also in culture vessels in the culture room. Seeds in these latter conditions were germinated and grown in conical flasks, in small aluminium thimbles containing peat compost, with 30 ml of water to simulate the physical effects of the culture medium (Grout and Aston, 1977a). Seeds were also grown in these small thimbles embedded in

A Method for the Isolation of Stable Mesophyll Protoplasts from Tomato Leaves throughout the Year under Standard Conditions

AbstractA method is described, based on growing tomato plants under low light intensities and feeding with calcium nitrate, whereby stable protoplasts can be isolated throughout the year under standard conditions. Plants are grown in the equivalent of spring and winter light intensities (i. e. incoming solar radiation 2.52 to 10.8 MJ m−2 day−1 15 h day) in the glasshouse on peat compost supplied with a balanced fertilizer containing nitrate and urea as nitrogen sources and given a supplementary feed of calcium nitrate. Under these conditions, high yields of protoplasts can be isolated on incubation in the dark using low enzyme concentrations at 25°C for 2 h. Protoplasts isolated in this way can support tobacco mosaic virus replication and are capable of cell division.