Rice Husk Substrate Research Articles

Effect of Cold Exposure on the Biofoam Produced from Different Types of Oyster Mushroom

Mycelium-based biofoam is a sustainable material derived from the growth of fungal mycelium on lignocellulosic agricultural waste substrate, as it has potential use in a variety of applications. The main objective of this research is to advance the sustainable alternatives for various application by investigating the mycelium growth of the biofoam produced from Pleurotus florida and Pleurotus sajor-caju on rice husk substrate, in improving the properties of the biofoam through innovative cold exposure. This study showed P. florida can produce mycelium biofoam at a faster rate, 7.022mm/day compared to P. sajor-caju 6.08mm/day). By cold exposure at 0°C and 10°C for 3 hours, every 2 days and 5 days, respectively until the mycelium are fully grown in the substrate, sample exposed to the latter condition for P. florida exhibits a faster growth rate at 7.3037 mm/day. However, cold exposure on biofoam produced from P sajor-caju had not improved the mycelium growth rate. Cold exposure samples at 0°C every 5 days and 10°C every 2 days have demonstrated capability in water (103.51%) and oil absorption (143.23%), proving their effectiveness in absorbing pollutants for the purpose of environmental remediation. The FTIR analysis confirmed the presence of hydrophilic and oleophilic characteristics in the biofoam, indicating its capability to absorb water and oil. By subjecting biofoam to cold exposure, its properties can be altered, broadening its potential applications.

Preparation and Performance Analysis of New Multi stage Porous Carbon Materials for Air Pollution Treatmentials on Atmospheric Pollution Sources under the Background of Carbon Peak and Carbon Neutrality

The adsorption of toxic and harmful gases through porous materials is an effective means of air pollution control. A multi-level porous carbon material with ultra-high-specific surface area was made based on rice husk biomass to improve the air pollution controlling efficiency and reduce its cost. The rice husk substrate was pretreated using T.viride spore suspension during the preparation of this material. This changes the proportion of various components in the matrix, thereby achieving an increase in the multi-level porous carbon material’s specific surface area. Its performance was analyzed through various means in the study. The results confirmed that when the activation treatment time was 60 minutes, the porous carbon material’s specific surface area was the highest, reaching 3714 m2/g. After 30 days of treatment with T.viride spore suspension, the cellulose content in rice husks decreased by about 40 g/kg. Compared to untreated porous carbon materials, after 20 days of treatment, the micropores and mesopores of these materials significantly increased. The research has successfully increased the multi-level porous carbon material’s specific surface area and achieved rapid absorption of atmospheric volatile organic compounds. The multi-level porous carbon material can enhance the air pollution controlling efficiency and reduce its cost.

Mechanistic insights into the plant biostimulant activity of a novel formulation based on rice husk nanobiosilica embedded in a seed coating alginate film.

Seed coating ensures the targeted delivery of various compounds from the early stages of development to increase crop quality and yield. Silicon and alginate are known to have plant biostimulant effects. Rice husk (RH) is a significant source of biosilica. In this study, we coated mung bean seeds with an alginate-glycerol-sorbitol (AGS) film with embedded biogenic nanosilica (SiNPs) from RH, with significant plant biostimulant activity. After dilute acid hydrolysis of ground RH in a temperature-controlled hermetic reactor, the resulting RH substrate was neutralized and calcined at 650°C. The structural and compositional characteristics of the native RH, the intermediate substrate, and SiNPs, as well as the release of soluble Si from SiNPs, were investigated. The film for seed coating was optimized using a mixture design with three factors. The physiological properties were assessed in the absence and the presence of 50 mM salt added from the beginning. The main parameters investigated were the growth, development, metabolic activity, reactive oxygen species (ROS) metabolism, and the Si content of seedlings. The results evidenced a homogeneous AGS film formation embedding 50-nm amorphous SiNPs having Si-O-Si and Si-OH bonds, 0.347 cm3/g CPV (cumulative pore volume), and 240 m2/g SSA (specific surface area). The coating film has remarkable properties of enhancing the metabolic, proton pump activities and ROS scavenging of mung seedlings under salt stress. The study shows that the RH biogenic SiNPs can be efficiently applied, together with the optimized, beneficial alginate-based film, as plant biostimulants that alleviate saline stress from the first stages of plant development.

Production of strawberry cultivars in a closed system of growing on substrate with transplants of different origins

The growing of strawberries in substrate has grown because it is a profitable way of production, easy to work, and which reduces the occurrence of diseases. Like closed growing systems they have a low environmental impact. The imported strawberry transplants bare root are considered more productive, however they arrive late in Brazil, shortening their production cycle, so transplants produced under local conditions would be an alternative to increase producers' income. Thus, the objective of this work was to evaluate the productive result of strawberry transplants produced under local conditions and imported bare root, growing in a closed growing system soilless, on a carbonized rice husk substrate and with the addition of organic compost. Three experimental factors were evaluated: 1st) substrate: carbonized rice husk (CRH) and CRH with 20% organic compound (OC) (CRH + OC); 2nd) cultivars: ‘Camarosa’ and ‘San Andreas’; and 3rd) transplants origin: bare root imported, and runners plants produced under local conditions. The local runner's plants outperformed imported bare root in relation to the number of fruits, however, the imported bare root provided greater average fresh weight of fruits. The runner’s plants of the cultivar 'San Andreas' produced 732.9 g plant-1, higher than the production of imported bare root, with 44.9% of the harvest harvested in the months of July and August. The 'Camarosa' cultivar didn't show the difference in yield between local and imported transplants. Transplants of cv. 'San Andreas' shallow rooted directly into the slabs under local natural conditions can guarantee earlier harvest, greater production, and higher fruit yield. As for the substrate, plant growth and commercial productivity were not influenced by the addition of OC to CRH. The results indicate that the addition of OC to the CRH has no influence on plant growth and commercial fruit production.

Impact of solid-state fermentation utilizing Saccharomyces boulardii on the chemical composition and bioactive constituents of rice husk

The objective of this study was to evaluate the effect of solid-state fermentation, utilizing Saccharomyces boulardii on brown rice husk, black rice husk, and smoked rice husk substrates in terms of the availability of different compounds. The fermentation process was carried out at 37 °C for a maximum of 12 h, using yeast (2.5 % w/w) and water (25 %). During fermentation, black rice husks (BLRH) exhibited an increase in vitamins, protein, and fiber content, whereas brown rice husks (BRRH) showed an increase in carbohydrate and fiber, and smoked rice husks (SRH) decreased lipid and fiber content. The solid-state fermentation process also enhanced the availability and accessibility of minerals, except for smoked rice husk. The levels of phenolic compounds in fermented black, brown, and smoked rice husks were 1165, 1108, and 1051 μg per gram of sample, respectively. Importantly, black rice husk fermented for 8 h demonstrated the most favorable results in terms of nutrient and bioactive compound availability. Principal Component Analysis (PCA) revealed correlations among the variables, which could be manipulated to improve the accessibility of diverse compounds.

Carposome productivity of Pleurotus ostreatus and Pleurotus eryngii growing on agro-industrial residues enriched with nitrogen, calcium salts and oils

The suitability of the abundant agro-industrial residues wheat straw (WS; control), barley and oats straw (BOS) and rice husk (RH), supplemented with various sources of oils (sunflower, corn oil), nitrogen (peptone, yeast extract) and calcium salts (CaSO4·2H2O, CaCl2), as novel substrates in solid-state fermentation of selected Pleurotus ostreatus and P. eryngii mushrooms was investigated. The possible effect of different additives on mycelial growth rate, biomass production and endoglucanase, laccase and lipase biosynthesis were evaluated. Moreover, their impact on essential cultivation aspects (earliness, total mushroom yield, biological efficiency) and carposome quality parameters (weight, morphological characteristics) was assessed. Both fungi showed their highest growth rates on BOS substrates and the most positive implementation was CaSO4·2H2O 6 % w/w (Kr = 9.58 mm/ day; P. ostreatus, Kr = 9.42 mm/ day; P. eryngii), while different additives led to enhancement of biomass production. Pleurotus species demonstrated minimal levels of endoglucanase activity, with values ranging from 0.01 to 0.42 U/g of dry weight, regardless of the substrate and the stage of colonization. On the contrary, the maximum values of laccase activity were observed at 50 % of colonization on BOS and RH, while supplementation with nitrogen and calcium sources positively affected its biosynthesis. P. ostreatus and P. eryngii cultivated on BOS supplemented with peptone at 2 and 5 % w/w, synthesized significant laccase amounts, i.e., 12,165.78 and 8,624.55 U/g d.w., respectively. Satisfactory amounts of lipase were produced, especially in substrates supplemented with sunflower 2 % w/w, in quantities up to 1.42 U/g d.w., whereas the highest lipase activity was achieved by P. eryngii on WS supplemented with corn oil at 2 % w/w, with a value of 4.25 U/g d.w. being recorded. Regarding fermentation of Pleurotus species in polypropylene bags, WS and BOS supported faster colonization and shorter earliness period than RH substrates, whereas supplementation did not seem to affect these culture parameters. Furthermore, oils supplementation had a positive effect on BE of both species, with values up to 100 % for P. ostreatus and 80 % for P. eryngii on WS and BOS, whereas on RH the lowest BE values were detected. Morphological characteristics were not significantly affected by the additives. Results indicate the positive impact that certain additives have on mushroom productivity and production of enzymes with great financial and environmental importance.

Effect of grafting and number of stems on plant growth, yield and fruit quality of soilless tomatoes

Vegetable grafting has grown considerably and has been a management alternative to overcome adverse soil cultivation conditions. However, many growers have used grafted tomato plants in substrate cultivation, claiming greater plant vigor, fruit yield, and longevity. Thus, the work objective is to evaluate the effect of grafting and the number of stems on plant growth, fruit yield, and quality of the Italian tomato, cultivated in a system of troughs filled with raw rice husk substrate. The experiments were conducted in southern Brazil, in the 2017/18 (long cycle) and 2019/20 (short cycle) crop seasons. The cleft grafting was used. The analyzed variables were the number of leaves, leaf area index, vegetative and fruit dry matter production, plant total dry matter, number of fruits, fruit yield, mean fruit weight, and total soluble solids content (ºBrix). The grafted plants had higher LAI, fruit dry matter production, fruit number, and yield (17 and 19%, respectively, in the first and second crop seasons). The quality of the fruits, concerning the concentration of sugars, was not affected by grafting, and the mean fruit size was increased by 7.9 and 8.1 grams (long and short cycle, respectively). In a long cycle, both for grafted and non-grafted plants, single-stem plant cultivation promotes 13.54% more plant growth and is 4.86% more fruit yield than double-stem plants. In a short cycle, from the point of view of reproductive growth and fruit yield, for both types of plants, cultivation with two stems is like that of single-stem plants.

Conditioners for raw rice husk substrate to produce strawberry transplants

The need to produce domestic strawberry transplants leads to the search for low-cost cultivation media in Brazil. Raw rice husk (CAIN) is an abundant and economical material in the south of the country. This study aimed to evaluate three substrate conditioners (35%) [carbonized rice husk (CRH), vermiculite and the commercial substrate S10®] added to RRH (65%) and their effects on growth, production and quality of strawberry transplants grown on benches with recirculation of nutrient solution, in a greenhouse. The experimental design was in causal blocks with three treatments and four replicates. Two mother plants of the Aromas cultivar were grown on each plot between November/2016 and March/2017. Transplants were classified into groups according to crown diameter (Class 1: 3.0-5.0 mm; Class 2: 5.1-8.0 mm; Class 3: >8.1 mm). Similarly, the number of leaves, leaf surface, fresh and dry mass of leaves and crowns of 10 transplants belonging to each class were evaluated. With the addition of CAC and vermiculite to the substrate, the predominance of class 2 transplants was obtained. The addition of S10 to CAIN increased the total number of transplants, as well as the number of leaf surface transplants and the dry mass of the aerial part of plants, in class 3 transplants, as well as S10 and vermiculite, provided a greater number of propagules produced.

Response of germination and seedling growth of Jute plant (Corchorus olitorius L.) on three different substrates in the tilapia aquaponic system

The merging of fish farming and crop husbandry in a mutual system forms aquaponics. In this system, the nature of the planting substrate plays a significant role in the germination, establishment, and growth of the plant. In the current experiment, the germination and growth of the Jute plant ( Corchorus olitorius L . ) in an aquaponics system with tilapia fish was investigated using three different substrate types: gravel, rice husk, and palm kernel shell. Five hundred-liter plastic tanks containing tilapia fingerlings at initial stocking densities of 250 fish m −3 were used. One gram of Jute seed was sown in a 1 m 2 planting trough, which contained the three substrates separately in triplicates. The troughs were flooded with water from fish holdings by an aquarium pump. The germination percentage of the jute plant on gravel substrate (84%) and rice husk (72%) was significantly higher (P < 0.05) compared to the palm kernel shell (55%). A lower velocity of germination was also recorded in the palm kernel substrate. The rates of growth in height (centimeters per day) of jute plant and fresh shoot biomass yield were significantly lower on palm kernel substrate (P < 0.05). Growth and yield parameters of jute showed comparatively higher agronomic efficiency of gravel and rice husk substrates compared to palm kernel substrates in this research. The results indicated that substrate nature significantly affects the germination and productivity of C. olitorius in aquaponic systems and that rice husk has the potential to serve as a planting substrate in aquaponics. • Response of germination and seedling growth of Jute plant ( Corchorus olitorius L.) on three different substrates in the tilapia aquaponic system. • Influence of substrate types on the germination and productivity of C. olitorius in aquaponic systems. • Potentials of rice husks as planting substrate for Jute in the aquaponic system.

Primordial initiation, yield and yield component traits of two genotypes of oyster mushroom (Pleurotus spp.) as affected by various rates of lime

Mushrooms are fleshy fungi valued globally for their nutritional and medical benefits. The study was conducted at Ebonyi State University Mushroom Center, Abakaliki, to determine an optimum level of limestone (CaCO3) on the genotypes for maximum growth and yield. The experiment was carried out as a split-plot experiment in a completely randomized design (CRD) with the use of Oyster mushroom variety. The two genotypes (GI and GII) were placed in the whole plot while limestone was placed in the sub-plot which consisted of five rates of CaCO3(Og,5 g, 10 g, 15 g and 20 g). Sawdust and rice husk substrates were used at the ratio of 60:40 and sterilized for six hours at 121 °C using the steam sterilization cylinder. The media bags were off–loaded after one day and allowed to further cool for another day before inoculation. The cultured spawn was used to inoculate the media upon cooling at room temperature. Data were collected on agro-morphological parameters such as primordial initiation, stalk height, stalk diameter, number of branches, number of fruits, number of productive bags, fresh and dry weights, and subjected to analysis of variance (ANOVA). The result obtained indicated that there was a significant difference (P < 0.05) between the two genotypes studied in all parameters except the dry weight of the mushroom. Also, the various rates of CaCO3 had a significant difference (P < 0.05) in most agro-morphological traits except stalk diameter, number of fruits and fresh weight. However, the interaction of the whole plot (genotype) and sub-plot (lime rates) showed no significant difference (P > 0.05) in all parameters evaluated except the stalk diameter. Genotype I initiated more primordial compared to primordial initiation in genotype II and they differed significantly (p < 0.05) from each other. More so, the result showed that increasing the rate of CaCO3 from 0 to 5 g significantly increased the primordial initiation from 17 to 22. However, further increase in lime rates above 5 g significantly reduced the primordial initiation from 22 to 15. It was concluded that the 5 g rate of limestone produced the best primordial initiation. Therefore, genotype I and 5 g of CaCO3 were recommended. There was also a strong relationship between the primordial initiation and most growth and yield components traits studied. There was a significant positive correlation between primordial initiation and stalk height (r = 0.799*), stalk diameter (r = 0.692*), number of mushroom branches (r = 0.773*), number of productive bags (r = 0.888*), number of fruits (r = 0.810*), fruit weight (r = 0.918*) and dry weight (r = 0.916*). Ideal conditions that would guarantee more primordial initiation for higher yield were recommended.

Study of the effect of pyrite and alkali-modified rice husk substrates on enhancing nitrogen and phosphorus removals in constructed wetlands.

The combined effects and respective advantages of using pyrite and alkali-modified rice husk (RH) were studied as substrates for nitrogen and phosphorus removal from constructed wetlands, and the effects of the carbon to nitrogen (C/N) ratio and the tidal flow mode on system performance were explored. The results showed that alkali-modified RH, which enhances heterotrophic denitrification, had far more advantages than pyrite, which enhances autotrophic denitrification, and alkali-modified RH can be used for the treatment of sewage containing low C/N ratios. At a C/N ratio of 1.5, the total nitrogen (TN) removal rates exceeded 95%. However, the removal efficiency of the system with only pyrite only reached 76.90% when the influent C/N ratio was 6. Pyrite achieved a total phosphorus (TP) removal 10-20% higher than that of the control group. The tidal flow CWs showed enhanced nitrification, and the NH4+-N removal rates increased by approximately 10%, but the increase in dissolved oxygen (DO) was still insufficient to meet the needs of the systems, leading to limited TP removal. The combination of pyrite and alkali-modified RH was optimal for improving the ability of constructed wetlands to treat wastewaters, simultaneously removing nitrogen and phosphorus from sewage containing low C/N ratios. Combined with the tidal flow mode strategy, the use of pyrite and alkali-modified RH as substrates showed substantial advantages for improving water quality.

Evaluation of agronomic descriptors of two cassava varieties (Manihot esculenta Crantz) on ten innovative substrates in Daloa (Côte d'Ivoire)

In Côte d'Ivoire, cassava production is carried out by small-scale planters who use very few technical means and local cultivars that are not very productive and susceptible to diseases. The objective of this study is to maximize the recovery of cassava cuttings after planting. To this end, ten substrates of single, double, triple and quadruple composition were made from soil supplemented with sawdust, chicken droppings, carbonized rice husks and NPK 10 18 18 to regenerate dehydrated cassava Bocou 1 and Yavo mini-cuttings. The recovery rate of the mini-cuttings was evaluated as well as the agro-morphological parameters of the seedlings for 21 days. Results showed that the recovery rate was very high on the carbonized rice husk substrate (86.5% in Bocou 1 and 85.5% in Yavo). In addition, the substrates significantly influenced the growth parameters of the seedlings. Thus, the substrate composed of carbonized chicken-bale soil had the highest number of leaves, with 6 leaves per plant in Bocou 1 and 10 leaves in Yavo, with an average height ranging from 10.99 ± 1.22 (Bocou 1) to 20.23 ± 1.16 (Yavo). The results of this study will help orient the actors of the cassava sector towards a new cultivation technique.

Potentials of Acremonium butyri fungus in pre-treatment and hydrolysis using Rice husk substrate for biofuel production: A short communication

There is increasing interest in the area of biofuel production due to fear of fossil fuel extinction as a result of over exploitation and crises. During biofuel production, substrate needs to undergo pre-treatment and hydrolysis where acids and alkali are mostly used. In this study, Acremonium butyri was used for both pre-treatment and hydrolysis. Structural compositions of the rice husk were determined. Extractives, hemicellulose and Lignin content was determined via extraction using Soxhlet extractor while cellulose was determined as the difference from the extractives, hemicelluloses and lignin. Acremonium butyri was isolated from dried roots of Piliostigma reticulatum (Kalgo) by keeping the roots in a clean plastic for a period of 7 days on moist environment after which fungal growth appeared. The growth was aseptically transferred on to prepared S.D.A plate and kept at room temperature. The fungal growth was identified as based on the physical and microscopic characteristics. About 50g of rice husk was mixed with 500 ml of distilled water in the ration of 1:10 to obtain homogenous slurry and then inoculated with 2ml of prepared Acremonium butyri solution and incubated at room temperature for up to&#x0D; 3 weeks with frequent shaking at certain intervals. Reducing sugar test was carried out to determine the reducing sugar released with UV-VIS spectrophotometer. The results obtained indicate that rice husk contained 32%, 30%, 29% and 8.4% of cellulose, hemicelluloses, extractives and lignin respectively. And a total of 0.936g/l of reducing sugar was released after 3 weeks of pre-treatment. The results implies that Acremonium butyri separated the component of rice husk (pre-treatment) as well as break down cellulose and hemicelluloses into its monomers (hydrolysis) thereby releasing sugar. Hence, Acremonium butyri is a good microorganism for biological pre-tretment and hydrolysis.

Evaluación de sustratos bajo un sistema hidropónico en un cultivo de fresa con variables de calidad

This project was carried out at the Centro Internacional de Producción Limpia Lope of Servicio Nacional de Aprendizaje SENA, Regional Nariño, to evaluate two types of substrates as alternatives that improve the quality of the strawberry (Fragaria ananassa Duch) variety Albión under an open hydroponic system. Coconut fiber and rice husk substrates were used, alone and in a mixture (70 % - 30 %, 50 % -50 %, 30 % - 70 %), compared with a control in soil with plastic cover. The physical and chemical variables of the fruit such as weight, diameter, length, soluble solids content, titratable acidity, and firmness were evaluated. A Random Complete Blocks design with 6 treatments and 4 repetitions was used. The mixtures of the substrates obtained a better response for the firmness variable than the soil treatment, also, the 100 % rice husk treatment obtained a superior response in the variables of Brix degrees and titratable acidity, allowing the generation of an innovative and competitive proposal for strawberry production in reduced areas in Nariño. &nbsp

Constructed Wetland with Rice Husk Substrate as Phytotechnology Treatment for Sustainable Batik Industry in Indonesia

This study aims to determine the vegetation efficiency of Canna indica plants and rice husk as a VFCW substrate in the batik wastewater treatment process. The VFCW pilot is made of acrylic with a length, width and height of 0.5 x 0.5 x 0.5 m respectively. Rice husk is filled as substrate to a depth of 0.3 m. Canna indica is cultivated and acclimatized then be planted in VFCW with 6 plants / units. Batik liquid waste is flowed with a hydraulic loading rate of 0.15 m3/d and variations in hydraulic retention time for 3 days, 7 days, 15 days, 21 days, and 30 days using an intermittent system. The results showed Canna indica proved to have a significant effect (p <0.05) on the removal of all parameters consisting of pH, BOD, COD, TSS, ammonia, and heavy metals Cr. Optimal efficiency for all parameters occurred at 21 days HRT which obtained TSS removal values of 91.25%, BOD5 of 91.82%, COD of 89.15%, ammonia of 96.2%, and heavy metals Cr of 81.8%. Effluents produced through the construction of VFCW with rice husks as a substrate and vegetation of Canna indica are able to meet the standards set out in East Java Governor Regulation No. 72/2013.

Indole butyric acid application methods in ‘Brite Blue’ blueberry cuttings collected in different seasons

The cultivation of temperate fruits such as blueberries is expanding in Brazil. However, lower technical information on plant cultivation and difficulties in propagation are among the limiting factors in the expansion of the blueberry cultivation. The objective of this study was to evaluate the influence of different methods of indole butyric acid (IBA) application on the rooting of ‘Brite Blue’ blueberry herbaceous cuttings, with and without lesions, collected in two different seasons. The experimental design was completely randomized, with five replicates, each consisting of 10 cuttings, in a 3x2x2 factorial arrangement. Two IBA application methods (talc and alcohol) and control (no application), with two collection seasons (autumn and summer), and cuttings with and without basal injury, consisted of two superficial cuts on the basal part, on opposite sides, were evaluated. The cuttings were put in carbonized rice husk substrate, inside perforated plastic boxes (44x30x7 cm), and maintained in a mist chamber with intermittent regime. After 200 days, it was verified that the ‘Brite Blue’ blueberry was influenced by the cutting collection season, with higher rooting percentage when basal lesion was performed in cuttings collected in the summer. The IBA application of 1000 mg L-1 does not influence the rooting and root development of the cuttings.

Growth and quality of lisianthus [Eustoma grandiflorum (Shinn.)] cultivated in rice husk substrates in troughs with leaching recirculation

This study aimed to evaluate the growth and quality of lisianthus cultivated in different rice husk substrates. The evaluated substrates were: carbonized rice husk (CRH; 100%); raw rice husk (RRH; 100%); CRH (70%) + S10 Beifort® commercial organic compost (30%); and RRH (70%) + S10 Beifort® commercial organic compost (30%). Plant dry mass (DM) production and partitioning, plant leaf area and shoot/root DM ratio were analyzed. Quality parameters of the flower stems were also evaluated (length; diameter and number of flowers and buds). The RRH substrate at 100% reduced plant growth and prevented flower development. This modified dry mass partitioning among the plant organs. The substrates RRH + S10 and CRH provided quality flower stems. Thus, both substrates can be used to produce cut lisianthus flowers in recirculating nutrient systems. However, the RRH + S10 substrate stood out because it increased plant growth. This result is ascribed to the improvement of the physical and chemical properties of substrate RRH + S10 as a result of the presence of both the organic compost, which benefited the water holding capacity, and the RRH, which guaranteed high porosity to the substrate.

New Media Components and Fertilization to Accelerate the Growth of Citrus Rootstocks Grown in a Greenhouse

In Puerto Rico, oranges made up $6,452,000 of the agricultural gross income for 2014–2015. Today, citrus greening (CG) is the most aggressive disease affecting the citrus industry in the whole world. This disease causes dieback of the plant, among other symptoms, which is resulting in the reduction of citrus trees in the field across the world. Currently, it is recommended to grow citrus rootstocks in nurseries to produce disease-free trees. The objective of this investigation was to evaluate (before and after grafting) the effect of different substrate mixes and quantities of fertilizers on the rootstocks Carrizo citrange and Swingle citrumelo in order to accelerate their development inside of a protected structure. The treatments were: Promix + sand (control) (1:1), Promix + sand + coco peat (1:1:1), Promix + sand + coffee compost (1:1:1) and Promix + sand + rice husk (1:1:1). Two 18-6-2 fertilizer treatments were also evaluated: 5.6 g and 8.5 g. The substrate that contained 33% rice husks negatively influenced every parameter evaluated for both rootstocks. Carrizo presented better development on the coffee compost mix, while Swingle did not exhibit significant differences among any substrates, except on rice husk, for most of the parameters. “Rhode Red Valencia” presented better results for dry weight when grafted on Carrizo with the coffee substrate. The rice husk substrate is not recommended for the citrus tree production at the nursery level.

Rice husk substrates and pruning time for gypsophila production

This research evaluated the growth, yield and quality of gypsophila New Amore® variety grown in gutters filled with substrate in a system with leaching recirculation in southern Brazil. The treatments were the result of the combination of four substrates [carbonized rice husk (CRH100%), raw rice husk (RRH100%), CRH + organic commercial substrate S10 (Beifort®) (15%) and RRH+S10 (15%)] with two pruning times (early and late). The substrates did not affect the dry matter partitioning between the flowers and vegetative organs or the balance between the shoot and root growth. However, RRH100% reduced the shoot growth, flower stem yield and quality. The CRH100% and RRH+S10 substrates can be indicated for gypsophila cultivation once, in a general way, they presented promising results. The late pruning increased the gypsophila growth and yield and benefited the quality of the stems. The gypsophila plants adapted well to the employed crop system.

Effect of Different Proportions of Agrowaste on Cultivation Yield and Nutritional Composition of the Culinary-Medicinal Jelly Mushroom Auricularia polytricha (Higher Basidiomycetes)

In this study, Auricularia polytricha was cultivated on a sawdust basal substrate supplemented with different proportions (30%, 45%, and 60%, respectively) of agrowastes-sugarcane bagasse (SB), rice straw (RS), and rice husk (RH)-to evaluate the alternative substrates. The mycelial growth rate, total colonization time, time to first primordia, biological efficiency, and chemical composition of the fruiting bodies were determined. Results indicated that the 60% SB substrate was the best substrate for mycelial growth of A. polytricha, with a corresponding total colonization period of 35.2 days, followed by the control (35.5 days) and 45% SB (36.2 days) substrates. The most suitable substrate with a high biological efficiency was 60% RS substrate (159.14%), followed by the 45% SB (128.45%), and 20% RH (124.47%) substrates. The nutrient values of fruiting bodies showed the largest amounts of ash, protein, fat, carbohydrates, and energy cultivated on 60% SB, 60% SB, 30% SB, 30% RH, and 30% RH/the control substrates, respectively. The results indicated that 60% RS was an appropriate substrate for A. polytricha cultivation.