Horticultural Applications Research Articles

A Review of Current and Potential Applications of Remote Sensing to Study the Water Status of Horticultural Crops

With increasingly advanced remote sensing systems, more accurate retrievals of crop water status are being made at the individual crop level to aid in precision irrigation. This paper summarises the use of remote sensing for the estimation of water status in horticultural crops. The remote measurements of the water potential, soil moisture, evapotranspiration, canopy 3D structure, and vigour for water status estimation are presented in this comprehensive review. These parameters directly or indirectly provide estimates of crop water status, which is critically important for irrigation management in farms. The review is organised into four main sections: (i) remote sensing platforms; (ii) the remote sensor suite; (iii) techniques adopted for horticultural applications and indicators of water status; and, (iv) case studies of the use of remote sensing in horticultural crops. Finally, the authors’ view is presented with regard to future prospects and research gaps in the estimation of the crop water status for precision irrigation.

Complete plastome sequence of Hoya carnosa (L. f.) R. Br. (Apocynaceae)

Hoya is a remarkable genus with high horticultural ornamental value. In this study, we report and characterize the complete plastid genome sequence of Hoya carnosa. The complete chloroplast genome was 176,340 bp in length, which includes a pair of inverted repeat regions (IRs) of 41,381 bp separated by a large single copy region (LSC) 91,281 bp and a small single copy region (SSC) 2,297 bp. Interestingly, IRs expanded into SSC, with the result that most of the genes in SSC were duplicated. This chloroplast genome contained 110 genes, including 76 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The complete plastome sequence of H. carnosa will provide some useful information for future phylogenetic study of Hoya and its horticultural application.

Leaf Retention on Stem Cuttings of Two Zamia L. Species With or Without Anti-transpirants Does Not Improve Adventitious Root Formation

Improved horticultural practices may help to reduce demand for wild cycads threatened by unsustainable collection. We determined the influences of leaf retention with or without anti-transpirants on the success and speed of adventitious root development of Zamia furfuracea L.f. and Zamia integrifolia L.f. stem cuttings. Root formation success for both species was greater than 95%. The experimental treatments did not influence the percentage success or the speed of root development for Z. furfuracea or Z. integrifolia. The ending dry weights of the stems, leaves, and roots were also not influenced by the experimental treatments. Our results indicated that adventitious root formation on stem cuttings of these two Zamia species was highly successful with or without retained leaves, and horticultural application of transpiration-reducing products on retained leaves did not improve success. Our findings add to the growing body of evidence that show how the horticulture nursery industry can meet horticultural demands in an effort to stop wild harvesting of threatened plants. Conservation of cycads as a group would benefit from more horticulture studies such as this, especially if the research includes threatened species.

Genetic and environmental factors in the trade‐off between sexual and asexual reproduction of a rare clonal angiosperm

AbstractUnderstanding the factors that influence the trade‐off between flowering and clonal growth in angiosperms is of great interest to botanists, plant ecologists and evolutionary biologists. Being able, ultimately, to manipulate these factors has potentially wide‐ranging applications in conservation biology, horticulture and agriculture. A rare, native Australian species, Melaleuca deanei, displays a low frequency of flowering and failed seedling recruitment, with persistence and expansion in the field predominantly via clonal root suckering. A decade of studies into its reproductive biology and ecology reveal both genetic and environmental factors reducing sexual success within its populations. Five factors influencing the trade‐off from sexual reproduction to clonal propagation are distilled and discussed in this work: 1. environmental constraint on sexual success; 2. small population size/low mate availability; 3. an obligate outcrossing breeding system; 4. somatic mutations in older clones; and 5. phylogenetic constraint. The work is potentially informative to the life cycles and management of other clonal angiosperms, be they rare and endangered; highly fecund weedy species; or economically important species. Methods to test each factor in future studies are proposed.

Apple pomace microbiome carrying fungal load against phytopathogens – Considerations regarding application in agriculture and horticulture

This experiment evaluated the taxonomic diversity of the fungal community in conventional (AP) and organic (OAP) apple pomace using high-throughput sequencing, applying fungal genetic barcodes to functional guilds. The most abundant taxonomic groups identified in both AP and OAP were the genera Aureobasidium, Cladosporium, and Alternaria, classified into the pathotroph-saprotroph-symbiotroph guild. The phenotype microarray provided insight into the role of the apple pomace fungal community in the ecosystem. It is theorized that adding apple pomace to the soil may improve the bioavailability of bioresource-based polyols. Evaluation of the antagonistic ability of the AP fungal community and Trichoderma atroviride G79/11 strain against pathogenic fungi was performed. Trichoderma G79/11 developed well on apple pomace and revealed the antagonistic mode against tested fungal plant pathogens. Therefore, it could be applied to soil as a formulation of AP with spores or AP with metaferm biopreparation.

Integrated Metabolome and Transcriptome Analysis Uncovers the Role of Anthocyanin Metabolism in Michelia maudiae.

Michelia maudiae Dunn is one of the important ornamental plants in the Magnoliaceae family, and the color of its flowers usually appears naturally pure white. The discovery of a rubellis flower named M. maudiae Dunn var. rubicunda provides an opportunity to reveal the metabolism of the flavonoids and anthocyanins of this “early angiosperm” plant. Combined metabolome and transcriptome analyses were applied using white and rubellis mutant tepals. Seven stages have been divided for flower development, and forty-eight differentially altered metabolites were identified between white and rubellis tepals at a later stage. The major anthocyanins including peonidin O-hexoside, cyanidin O-syringic acid, cyanidin 3,5-O-diglucoside, cyanidin 3-O-glucoside, and pelargonidin 3-O-glucoside were upregulated over 157-fold in the mutant. Conversely, the highly significant accumulation of the colorless procyanidin or the slightly yellow epicatechin and catechin was found in white flowers. Putative homologues of color-related genes involved in the phenylpropanoid and flavonoid biosynthesis pathway were identified in the transcriptome. The increasing expression of dihydroflavonol 4-reductase (DFR) might play an important role in the occurrence of rubellis pigments, while the overexpression of anthocyanidin reductase (ANR) in white flowers may promote the biosynthesis of proanthocyanidins. Additionally, several coloration-related repressor R2R3-MYB transcription factors showed different expression levels in the tepals of the rubellis mutant. This study provides a comprehensive analysis relating color compounds to gene expression profiles of the Magnoliids plant M. maudiae. The newly generated information will provide a profound effect on horticultural applications of Magnoliaceae.

CHARACTERIZATION OF ALTERED MICA FROM SOKLI, NORTHERN FINLAND

Vermiculite is a mineral with many potential uses in various industrial areas, such as in insulation, horticulture, and environmental applications. The regolith of the Sokli carbonatite intrusion in northern Finland consists of weathered micas which reportedly contain vermiculite. The aim of the present study was to characterize the weathered mica in order to determine if the weathered regolith contains vermiculite. If so, the value of the apatite-rich Sokli intrusion may increase, because the vermiculite could be classified as an ore in Sokli. For the characterization, mica fractions were investigated using electron probe microanalysis (EPMA), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The EPMA results show that the potassium (K2O) content of the mica investigated varies between 6.20 and 0.31 wt.%. The XRD results provided evidence that the interlayer distances in the mica vary between 10.1 and 14.7 Å. The TGA shows that the dehydration of the samples varies between 6 and 12 wt.% for temperatures up to 170°C. Dehydroxylation takes place in three steps, as is characteristic for vermiculite. The results from this study revealed that mica in the weathered parts of the Sokli carbonatite is mostly vermiculite, and that the vermiculite was formed by the weathering of phlogopite. These results can be used to determine whether vermiculite is a possible future commodity at the Sokli carbonatite complex.

Evaluación, Física, Química y Biológica de compostas tipo bocashi elaboradas con estiércol de bovino, ovino, cerdo y conejo más una vermicomposta

Some composts can produce phytotoxins that inhibit the development of plants and the absorption of nutrients by an excess of indoleacetic acid if the compost is not mature. In the present work, the objective is to evaluate the quality of the compost by means of direct tests of phytotoxicity and agronomic quality with different composts. To determine the quality as organic compost and vermicompost fertilizer were considered physical, chemical and biological variables according to existing manuals. The results obtained for these variables were: In the physical, chemical and biological variables, all the parameters are fulfilled according to the norm. Seed germination of vegetables increased with respect to the control in 14.93%, possibly due to the presence of some root development promoter found in the compost. With regard to survival the witness was inferior by 3.08% Although the amount of nutrients found in composts are not so high, they comply with the minimum requirements of the regulations to be used as a substrate in horticultural applications. Conclusion, the results of this study indicate that the compost elaborated with any type of residue can be used as a substrate in seedbeds of chili, onion or other vegetables to induce germination and accelerate the development of plants.

37.1: Invited Paper: Using twin screw extrusion technology for the Inclusion of Phosphors with Polymers to accelerate plant growth under cover

Methods of introducing and dispersing different phosphor particles into polymers using extrusion technology are reported. The extrusion and blending of phosphor/polymer combinations containing different percentages of phosphor and subsequent film blowing was studied. The phosphor/polymer films had their light emitting properties optimised to closely match plant growth requirements. The final films performance was evaluated for horticultural applications.

Formulation of a controlled-release delivery carrier for volatile organic compounds using multilayer O/W emulsions to plant growth

Oil-in-water (O/W) multilayer emulsions have been used to encapsulate volatile organic compounds (VOCs). Nevertheless, research associated with application in horticulture has been poorly studied. The objective of this study was to develop O/W emulsions for releasing VOCs to induce vegetable growth. Emulsions were prepared with vegetable oil, soybean lecithin and polysaccharides to formulate a stable product. The results indicated that O/W emulsions formulated with chitosan and sodium alginate were stable in a wide range of pH, temperature, and ionic strength. Furthermore, a direct relation between emulsions stability and VOC carbon was observed. The 2-nonanone (50–250 ppm) released from O/W emulsions increased the foliar length on L. sativa and S. lycopersicum. Additionally, root lateral number was increased in S. lycopersicum after exposition to released 2-nonanone. Surface elements as carbon, oxygen, and nitrogen were increased on leaves. It empathized that total nitrogen of both vegetables increased with exposition to 2-nonanone. Therefore, O/W emulsions can be an effective tool to microencapsulate VOCs with potential horticulture application.

Coating of sepiolite-chitosan nanocomposites onto urea increases nitrogen availability and its use efficiency in maize

ABSTRACTTo improve the use efficiency of fertilizer and to reduce the rate of nitrogen release, a coated urea was prepared using clay-polymer nanocomposites (CPU). Sepiolite and chitosan were used to form nanocomposites with different clay mineral/polymer ratios. The nanocomposites and CPUs were characterized using several techniques including Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) specific surface area measurement. The FTIR examination revealed functional groups related to chitosan that interacted with sepiolite. The nitrogen release of CPUs was examined in the sand column showing that 75% of nitrogen content of CPU samples released in about 25 d, much longer than that of urea (3 d) and the rate of release of nitrogen was reduced by increasing the proportion of sepiolite in the clay/polymer nanocomposites. The release mechanism of CPUs was evaluated and the results showed the mechanism was not Fickian diffusion but anomalous diffusion. The nutrient use efficiency of CPUs was studied under greenhouse conditions using Zea mays (corn) as the test plant and a significant efficiency improvement was observed. The results showed that the CPUs with slow-release properties could be considered as efficient N fertilizers in agricultural and horticultural applications.

Evaluation of morphological, mechanical, and rheological properties of vulcanized styrene–butadiene rubber/modified corn starch blends

The starch-filled styrene–butadiene rubber (SBR) was prepared using a laboratory-sized two-roll mill. Starch was modified by yeast fermentation for 1 day before it was blended with SBR. The hydrophilicity of SBR was enhanced by grafting with modified starch (MST) by utilizing tetramethyl thiuram disulfide as a catalyst. The effect of modified corn starch loading on morphological, mechanical, and rheological properties of vulcanized SBR blends was investigated. Scanning electron microscope result revealed that the adhesion between the MST and SBR was weak, and the starch pulled out due to poor interfacial bonding. The lowest ultimate tensile strength, elongation at break, and tensile modulus of the SBR- g-MST were found in the sample containing 150 phr of starch. The variation of the percentage elongation of neat rubber and MST/rubber composites was 91.34%. The significant decrease in cure times was observed with the loading of MST in all blends up to 100 phr starch, while no significant change in scorch time was observed. The maximum torque, minimum torque, and cross-linking density increased as the starch loading increases up to 100 phr MST. The water absorption by the composite increases with immersion time and MST loading, although the rate of absorption decreases with increased time. The current product could be especially advantageous in agricultural and horticultural applications as a good controlled fertilizer release and for water retention.

The role of seed-vectored endophytes in seedling development and establishment

Seed-vectored endophytes internally colonize plant seeds and remain without eliciting disease symptoms. Microbes are carried by seeds generation after generation to benefit the host during and following seed germination. Seed-vectored endophytes have been poorly investigated and research targeted at understanding their biology will have immense applications in agriculture and horticulture. Some reports are available on the roles of seed endophytes in plant growth promotion via nutrient acquisition and biocontrol of soil borne diseases, but mechanisms of interaction at the endophyte-host interface, especially during seed germination and seedling establishment, have not been explored adequately. The present paper is intended to review the role of seed vectored endophytes in seed germination, seedlings development and in developing the rhizosphere community. The mechanisms of interaction and movement of seed inhabiting endophytic bacteria are explained with the help of pictorial models.

Superabsorbent nanocomposite and its properties

Starch-g-poly (AM-AMPS)/illite superabsorbent nanocomposite was synthesized by grafting copolymerization reaction of starch, acrylamide(AM) and 2-acrylamido-2- methyl propane sulfonic acid (APMS) in the presence of illite micropowder in deionized aqueous solution. The influence factors on water absorbency of the superabsorbent nanocoposite was optimized by single factor experiment. The synthesized superabsorbent nanocomposite exhibited the maximum water absorbency of 1320 g H2O/g in deionized water and 142 g H2O/g in 0.9 wt% sodium chloride (NaCl) solution. FTIR spectra confirmed that the grafting copolymerization between -OH groups on starch and monomers generated during the reaction. XRD analysis confirmed that crystal interlayer of illite was pulled open to 3.61 nm. TEM showed that illite slice layer randomly dispersed in the matrix of superabsorbent nanocomposite. The superabsorbent nanocomposite had a better thermal stability the corresponding superabsorbent material without illite by TGA and DSC analysis. The superabsorbent nanocomposite with excellent water absorbency and water retention could be especially useful in industry, agricultural, horticultural applications.

Biodegradable poly(lactic acid)/cellulose‐based superabsorbent hydrogel composite material as water and fertilizer reservoir in agricultural applications

ABSTRACTThe work presents a fully degradable superabsorbent composite material to be used in agricultural and horticultural applications. It is designed to retain and release fertilizer solutions to the soil in a controlled manner, permitting resource optimization. Because of its ability to absorb and release large amounts of saline water, a natural superabsorbent hydrogel derived from cellulose was chosen. Potassium nitrate was chosen to model the fertilizer. Poly(lactic acid) was added to the final composition in order to delay solution release. The composite material was obtained using easily available and low‐cost starting materials and using a simple manufacturing process, using a standard mixer. After being analyzed for morphological (scanning electron microscopy), physical (X‐ray diffraction), chemical (energy‐dispersive X‐ray spectroscopy), and thermal properties (thermogravimetric analysis and differential scanning calorimetry), the material was tested using two different Mediterranean cultivations (Pomodoro di Morciano di Leuca and Cicoria Otrantina) and two different kinds of soil (red and white soils). The analysis revealed different water release characteristics for different soils. These findings have been confirmed by measuring plant growth for both species, as well as fruit yield of the tomatoes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47546.

Manufacturing of superabsorbent membranes of PVA and rice husk fibres reinforced with nanosilica for agricultural and horticultural applications

ABSTRACTNovel superabsorbent membranes (SMs) consisting of polyvinyl alcohol (PVA), cellulose nanocrystals (CNCs) originated from rice husk (RH), nanosilica, glutaraldehyde and glycerine (G) were manufactured by a compression moulding process. RHs were used to isolate pure CNCs via mechanical and chemical treatments. RHs were used to improve water retention. These SMs were characterised by Fourier-transform infrared spectroscopy, scanning electron microscopy, mechanical testing and differential scanning calorimetry. SMs showed a greater equilibrium swelling capacity than neat cross-linked PVA. Moreover, the water transport mechanism of all SMs was found to follow Fickian diffusion. SMs exhibited good pH-dependent swelling reversibility and high-water retention capacity, making them more efficient water retention materials. The biodegradability of SMs was evaluated under environmental changes. The biodegradability of SMs was evaluated against environmental changes. The SM was also investigated for antimicrobial activity against pathogenic bacteria such as Candida albicans (fungus), Bacillus subtilis (Gram-positive), Staphylococcus aureus (Gram-positive), Proteus vulgaris (Gram-negative) and Erwinia carotovora (Gram-negative). SMs have been found to act as a useful water reservoir, which may make it useful in agricultural applications.Abbreviation: Novel superabsorbent membranes (SMs) consisting of polyvinyl alcohol (PVA), cellulose nanocrystals (CNCs) originated from rice husk (RH), nanosilica (NS), glutaraldehyde (GLA) and glycerine (G) were manufactured by a compression moulding process. RHs were used to isolate pure CNCs via mechanical and chemical treatments. RHs were used to improve water retention. These SMs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Mechanical Testing and Differential Scanning Calorimetry (DSC).

Nitrate control using LED lights

Light emitting diodes (LEDs) have become very efficient light sources for application in horticulture. Light sources based on LEDs are relatively easy to control in intensity and spectrum. Light-source optimization allows growth efficiency and quality of leafy greens to be influenced, especially the nutrient content. Leafy green vegetables contain relatively high concentrations of nitrate compared with other foods, and constitute a significant source of dietary nitrate to the consumer. Because of health concerns, nitrate content is regulated in Europe. Nitrate levels in vegetables grown in plant factories or greenhouses can be reduced significantly with an appropriate light strategy. In this paper, we present such a strategy, as well as results that show that, with optimized light recipes, the level of nitrate at harvest can be controlled, while the growth efficiency can be kept high. When grown in a closed environment without daylight, we have found that the daily light integral has a strong influence on the final nitrate level. For an optimum daily light integral, we have found that using a continuous pre-harvest light treatment for 2-5 days before harvesting can significantly reduce the nitrate level in lettuce. Light composed of red and blue or red and white can achieve a similar reduction of the nitrate level for various cultivars of baby-leaf lettuce. We present several results on lettuce, spinach and rocket. We also discuss how to achieve extremely low nitrate levels (<500 mg kg-1) and how to find the optimum light sum and spectrum during growth or pre-harvest treatment in combination with an adapted irrigation strategy. Finally, we applied our findings in a greenhouse trial during winter and compare the results with those obtained under plant factory growth conditions.

A light salad [LED lighting applications in horticulture

The article shows that with their low energy usage, reduced heat output and the ability to control the light colour they emit, LEDs are poised to revolutionise the horticulture industry.

Challenges – the impact of climate change on the nutritional management of Hungarian orchards

The agricultural sector is increasingly exposed to both environmental and economic risks due to the phenomena of climate change and climate variability. Fruit growth and productivity are adversely affected by nature’s wrath in the form of various abiotic stress factors. Climate change and extreme climatic events are predicted to increase in intensity, frequency, and geographic extent as a consequence of global climate change. It is no doubt that frequency of unexpected climatic events and their growing rate result in an increasing amount of problems for fruit growers globally. Today, climate change impacts are the most serious problems for Hungarian fruit growers as well. It can be stated that the nutrient demand of fruit trees can be supplied only under even worse conditions.&#x0D; Therefore, it is so important to know and apply adaptation and mitigation strategies in horticulture to improve fruit quality and yield. In the last ten years, at the Faculty of Agricultural and Food Sciences and Environmental Management at University of Debrecen expanded studies have been made to prove the importance of groundcover management in horticultural applications. In this mini review paper, is presented, how the university's researches contributed to the expansion of knowledge of preservation of soil moisture and what advice we can provide for fruit growers to face the challenges of climate change.

Common Green Plants Recognition Based on Wavelet Transformation and Varied Local Edge Patterns

Green plant species identification plays an important role in so many aspects, such as ecological environment protection, Chinese medicine preparation, agricultural and horticultural application, etc. A method on green plants recognition based on wavelet transform and variable local edge patterns (VLEP) is proposed in this paper. Firstly, the original image is decomposed by wavelet transformation. Then texture features are extracted using VLEPs. At the same time, block-based and multi-resolution ideas are considered together to extract features after images are transformed by wavelet. Finally, the fused texture features are classified by the nearest neighbor method. The experimental results show that the proposed method is a promising method for recognizing the common green plants with the natural and complex background compared with the other state-of-the-art methods, and combination of block-based and multi-resolution ideas can further improve the accuracy rate effectively.