Hot Red Research Articles

'Deep Yellow and Hot Red': Nietzsche's Genealogy of Space

'Deep Yellow and Hot Red': Nietzsche's Genealogy of Space

Plant Growth, Yield, and Quality of Containerized Heirloom Chile Pepper Cultivars Affected by Three Types of Biostimulants

Peppers (Capsicum annuum) are one of the most widely cultivated vegetable crops, with per capita consumption of bell and chile peppers being 11.4 and 7.7 pounds in 2017. Biostimulants are an emerging sustainable alternative to enhance plant health by increasing photosynthetic activity, stress tolerance, and nutrient uptake through various modes of action. The effects of different biostimulant applications largely remain unknown in containerized heirloom pepper production. This study evaluated plant growth, yield, and fruit quality of nine heirloom chile pepper cultivars, including ‘Anaheim Chili,’ ‘Ancho or Poblano,’ ‘Big Jim,’ ‘Cayenne Purple,’ ‘Chile de Arbol,’ ‘Jamaica Hot Red,’ ‘Mulato Isleno,’ ‘Padron,’ and ‘Pasilla Bajio’ in a container production system throughout the years of 2020 and 2021. Each cultivar was treated with three types of biostimulants, including Tribus® Original (a mixture of Bacillus bacterias), Vitazyme (containing plant growth regulators and B vitamins), C-Bio CPS (seaweed extract of Ascophyllum Nodosum), and water as control. Pepper cultivars varied in yield and quality, including fruit length, diameter, single fruit weight, and fruit color in both years. ‘Anaheim Chili,’ ‘Big Jim,’ and ‘Jamaica Hot Red’ produced highest marketable yields similarly, with ‘Chile de Arbol’ and ‘Pasilla de Bajio’ producing the lowest marketable yields in both years. Biostimulant application did not affect marketable yield either in 2020 or 2021 but enhanced fruit quality, including fruit length, diameter, and green coloration.

Plants against pathogens: Effect of significant antimicrobial-producing plants on faecal microbe inactivation throughout the soil profile of stormwater biofilters

Stormwater biofilters have demonstrated promising yet variable removal of faecal microorganisms. Significant antimicrobial-producing plants have been proposed as an inexpensive, safe and easily adaptable component of biofilter design to enhance faecal pathogen treatment. The aim of the present study was to investigate whether significant antimicrobial-producing plants improved faecal bacterial inactivation throughout the biofilter soil profile, focusing on four key treatment zones. These were specifically the top sediment/surface layer; the rhizosphere (soil directly attached to and influenced by plant roots); bulk soil (soil not directly associated with roots); and the submerged/saturated zone. Biofilters were configured with either: (1) no plant; (2) Carex appressa, the most highly recommended plant species in Australian biofilter adoption guidelines; or (3) one of two significant antimicrobial-producing Australian plant species, Melaleuca linariifolia or Melaleuca fulgens (n = 3 each). Following 16 months’ maturation, systems were dosed with semi-synthetic stormwater containing faecal bacteria Escherichia coli and Enterococcus faecalis to monitor their ensuing die-off within all major biofilter treatment zones. Bacterial inactivation was generally more rapid in M. fulgens and M. linariifolia than C. appressa biofilters, with E. faecalis demonstrating an overall enhanced resistance to inactivation. Top sediment tended to exhibit the highest inactivation rates, significantly correlated with sunlight exposure. Conversely, the rhizosphere supported comparatively prolonged faecal bacterial survival. The authors recommend further investigation of melaleucas and similar highly antimicrobial-producing plants for enhanced faecal pathogen treatment within biofilters and related treatment contexts.

Rise of the killer plants: investigating the antimicrobial activity of Australian plants to enhance biofilter-mediated pathogen removal

BackgroundBiofilters are soil-plant based passive stormwater treatment systems which demonstrate promising, although inconsistent, removal of faecal microorganisms. Antimicrobial-producing plants represent a safe, inexpensive yet under-researched biofilter design component that may enhance treatment reliability. The mechanisms underlying plant-mediated microbial removal in biofilters have not been fully elucidated, particularly with respect to antimicrobial production. The aim of this study was therefore to inform biofilter vegetation selection guidelines for optimal pathogen treatment by conducting antimicrobial screening of biofilter-suitable plant species. This involved: (1) selecting native plants suitable for biofilters (17 species) in a Victorian context (southeast Australia); and (2) conducting antimicrobial susceptibility testing of selected plant methanolic extracts (≥ 5 biological replicates/species; 86 total) against reference stormwater faecal bacteria (Salmonella enterica subsp. enterica ser. Typhimurium, Enterococcus faecalis and Escherichia coli).ResultsThe present study represents the first report on the inhibitory activity of polar alcoholic extracts from multiple tested species. Extracts of plants in the Myrtaceae family, reputed for their production of antimicrobial oils, demonstrated significantly lower minimum inhibitory concentrations (MICs) than non-myrtaceous candidates (p < 0.0001). Melaleuca fulgens (median MIC: 8 mg/mL; range: [4–16 mg/mL]), Callistemon viminalis (16 mg/mL, [2–16 mg/mL]) and Leptospermum lanigerum (8 mg/mL, [4–16 mg/mL]) exhibited the strongest inhibitory activity against the selected bacteria (p < 0.05 compared to each tested non-myrtaceous candidate). In contrast, the Australian biofilter gold standard Carex appressa demonstrated eight-fold lower activity than the highest performer M. fulgens (64 mg/mL, [32–64 mg/mL]).ConclusionOur results suggest that myrtaceous plants, particularly M. fulgens, may be more effective than the current vegetation gold standard in mediating antibiosis and thus improving pathogen treatment within biofilters. Further investigation of these plants in biofilter contexts is recommended to refine biofilter vegetation selection guidelines.

Dietary medicinal plants in broiler chickens nutrition in function of meat quality enhancing

The use of nutritional strategies to improve the quality of meat is a relatively new approach that has emerged at the interface of animal science and food science. The effects of dietary medicinal plants ( Allium sativum L., Piper nigrum L., and Capsicum annuum L.) addition to chicken nutrition on quality characteristics of breast and thigh with drumstick meat, as well as caloric value of chicken meat were investigated. Quality measurements included meat sensory (colour, smell, taste, softness, chewiness, juiciness and overall impression), physical (pH, colour – CIE L*a*b* and drip-loss) and chemical (moisture, protein, fat and ash content) characteristics. Herbs showed significant (P < 0.05) influence in altering most examined quality parameters of chicken meat, especially when adding red hot pepper. Caloric value of chicken meat was improved which makes garlic, black pepper and hot red pepper valuable natural feed additives in improvement of meat quality as well as a natural growth promoter. In conclusion, herbs had positive influence on chicken meat quality, however the knowledge of their mode of action is still limited and thus requires further investigation.

Chemical composition, antibacterial and antioxidant activities of essential oils from leaves of three Melaleuca species of Pakistani flora

This study presents essential oil composition of three Melaleuca species namely, Melaleuca bracteata F. Muell, Melaleuca fulgens R. Br. subsp. steedmanii and Melaleuca leucadendron (L.) L. collected from different regions of Pakistan. The chemical composition of essential oils was analyzed by GC-FID and GC–MS. Eugenol methyl ether was identified as a principal component in M. bracteata (82.3%), M. fulgens (87.8%) and M. leucadendron (95.4%) oils. In vitro antibacterial studies were done by agar well diffusion and microdilution method and the tested essential oils exhibited bacteriostatic and bactericidal effects against the tested foodborne pathogens at 4–8µg/ml. Time kill assay showed significant bactericidal effect of oils for four weeks. The antioxidant potential was assessed by free radical scavenging activity and reducing power assay. The oils showed strong antioxidant activity with approximately 89.0–89.5% inhibition of 2,2-diphenyl-1-picrylhydrazyl radical and ferric reducing power in the range of 1.94±0.007–2.04±0.04% at 100µg/ml.

Central composite design of pressurised hot water extraction process for extracting capsaicinoids from chili peppers

Pressurised hot water extraction (PHWE) was applied to chilies in order to optimise extraction yield of capsaicinoids (capsaicin, dihydrocapsaicin, nordihydrocapsaicin, nonivamide). Determination of the optimum extraction procedure was performed by comparison of the yield of the extracts. Capsaicinoids content was determined by HPLC coupled with mass spectrometry. An optimisation study was performed using water as an extraction solvent at constant extraction pressure (20MPa), extraction temperature ranging from 120 to 240°C and static extraction time ranging from 5 to 60min as independent variables. The optimum PHWE conditions for all response variables were estimated; however, PHWE conditions resulting in the highest recovery of capsaicinoids (20MPa, 200°C and 10+20min of static extraction time) were chosen for comparison with a conventional Soxhlet extraction (SOX) in the case of seven chili pepper fruit samples (chili peppers of species Capsicum chinenses: Trinidad Scorpion Moruga, Jamaican Hot Red, and Yellow Habanero, chilies of species Capsicum annuum: Yellow Bedder, Ring of Fire, and Chiltepin, chili pepper Tabasco of species Capsicum frutescens) and three chili spices (ground spices from Trinidad Scorpion Moruga, Bhut Jolokia, and Fatalii Red, all of species Capsicum chinenses).

Acaricidal and repellent effects of myrtacean essential oils and their major constituents against Tetranychus urticae (Tetranychidae)

Nineteen plant essential oils (EOs) extracted from the family Myrtaceae growing in Australia were screened for their acaricidal and repellent activities against two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), in the laboratory by dipping method and choice- and no-choice tests. Acaricidal bioassays showed that five EOs of Callistemon viminalis, Eucalyptus bicostata, Eucalyptus maidenii, Eucalyptus sideroxylm and Eucalyptus approximans significantly increased the mortality of female adult mites and decreased the total number of eggs. In a choice test, Callistemon sieberi, E. bicostata, Eucalyptus ovata, E. sideroxylm, Eucalyptus mannifera, Eucalyptus dives, Eucalyptus elata, Eucalyptus condonocarpa, Kunzea ericoides, Melaleuca armillaris and Melaleuca fulgens demonstrated good repellency to the mite. In another test, C. sieberi, E. bicostata, E. mannifera, E. condonocarpa, K. ericoides, M. armillaris, and M. fulgens EOs decreased the egg production of the females significantly. In the acaricidal and repellent tests, E. bicostata and E. sideroxylon EOs showed both acaricidal and repellent effects (choice test) and decreased the number of eggs on treated bean leaves. The gas chromatograph/mass spectroscopy analyses revealed that the major components of E. bicostata and E. sideroxylon were 1,8-cineole, limonene, and α-pinene. The 1,8-cineole and limonene showed significant repellent effects on the mites, resulting in reduced numbers of eggs in the choice test. Hence, EOs of E. bicostata and E. sideroxylon and limonene and 1,8-cineole may be potential agents to be used in the sustainable management of T. urticae.

First Report of Crown Rot Caused by Cylindrocladium pauciramosum on Scarlet Honey Myrtle in Italy.

Scarlet honey myrtle (Melaleuca fulgens R. Br.), native to Australia, is an evergreen colorful shrub (Myrtaceae) and grown in Italy as an ornamental plant. During November 2008, a widespread disease was noticed on ~90% of 3,000 6-month-old M. fulgens cv. Red potted plants. Plants were obtained from cuttings and produced by a commercial nursery in Catania Province. Symptomatic plants showed a crown rot and longitudinal sections of tissues revealed a brown discoloration of the basal stem. As a consequence, leaves gradually became necrotic and abscised, followed by death of the entire plant. Root rots and leaf spots were not observed. M. gibbosa, M. ericifolia, M. thymifolia, and M. elliptica, cultivated in the same nursery, did not show disease symptoms. A Cylindrocladium sp. was consistently isolated from the crown and basal stem of symptomatic plants on potato dextrose agar (1). Ten Cylindrocladium isolates obtained from infected basal stems and crowns were selected and cultured for 8 days at 25°C on carnation leaf agar (CLA). Macroconidiophores consisted of a stipe, a penicillate arrangement, and a stipe extension terminating in an obpyriform to ellipsoidal vesicle (6 to 10 μm in diameter). Cylindrical conidia were rounded at both ends, straight, 1-septate, and 42 to 60 × 4 to 5 μm. All single-conidial isolates were mated with opposite tester strains of C. pauciramosum on CLA and produced fertile perithecia (3). Perithecia were solitary or in groups, orange to red-brown, subglobose to ovoid, and 270 to 400 μm high × 180 to 290 μm in diameter. Further confirmation of species was obtained by amplification and sequencing of the intergenic spacer (IGS) region of rDNA with the M13 forward (-20) and M13 reverse primers. On the basis of the complete IGS sequence, two primer sets (218F/218R and 106F/106R) were designed and successfully used in a nested-PCR protocol for the detection of C. pauciramosum from tissues of infected plants (2). On the basis of morphological characters, mating type, and molecular data, the isolates were identified as C. pauciramosum C.L. Schoch & Crous. One representative isolate (DISTEF-MFR2; CBS 124657) was deposited at Centraalbureau voor Schimmelcultures open fungi collection (Fungal Biodiversity Centre, Utrecht, the Netherlands). Pathogenicity tests were performed by adding sterile water to CLA cultures of C. pauciramosum from a single-conidial isolate and incorporating the resulting spore suspension (105 conidia per ml) on the soil surface of 20 3-month-old M. fulgens cv. Red potted plants. The same number of plants served as uninoculated controls. Following inoculation, plants were well irrigated and maintained in a growth chamber at 25 ± 1°C and 90 to 95% relative humidity. All inoculated plants developed crown rot symptoms identical to those observed in the nursery 2 months after inoculation. Control plants remained symptomless. C. pauciramosum was always reisolated from the infected plants and identified as previously described. C. pauciramosum was previously detected in Italy as being responsible for a leaf spot on M. hypericifolia (3). To our knowledge, this is the first record in the world of crown rot of scarlet honey myrtle caused by C. pauciramosum.

The Effects of Processing Methods on Some Properties of Hot Red and Red-blackish Ground Peppers

The Effects of Processing Methods on Some Properties of Hot Red and Red-blackish Ground Peppers

Fumigant toxicity ofEucalyptus blakelyi andMelaleuca fulgens essential oils and 1,8-cineole against different development stages of the rice weevilSitophilus oryzae

Essential oils extracted fromEucalyptus blakelyi (1,8-cineole, 77.5%),Melaleuca fulgens (1,8-cineole, 56.9%) and 1,8-cineole were shown to have fumigant toxicity against different development stages ofSitophilus oryzae. The eggs ofS. oryzae were the most tolerant, followed by pupae, larvae and adults in that order.M. fulgens oil,E. blakelyi oil and 1,8-cineole at 100 µl per liter of air gave, respectively, LT50 values of 16.2, 17.4 and 9.1 h for adults, 31.1, 19.3 and 17.5 h for larvae, 55.6, 75.2 and 39.7 h for pupae, and required >7 days for eggs. Only 1,8-cineole (200 µl −1 air) gave a significant egg kill by 7 days and the LT95 was 134.5 h. 1,8-Cineole could be a useful new fumigant.

Fumigant toxicity of essential oils from the Myrtaceae family and 1,8-cineole against 3 major stored-grain insects

Six out of 42 essential oils extracted from species of the family Myrtaceae found in Australia were shown to have potent fumigant toxicity against three major stored-grain insects: Sitophilus oryzae, Tribolium castaneum and Rhyzopertha dominica. These were the essential oils from Eucalyptus nicholii, E. codonocarpa, E. blakelyi, Callistemon sieberi, Melaleuca fulgens and M. armillaris. The LD 50 and LD 95 of the selected essential oils against S. oryzae adults were between 19.0–30.6 and 43.6–56.0 μl/l air, respectively. Also, these oils were approximately twice as toxic to T. castaneum and R. dominica at the LD 95. Fumigant effects of the essential oils rich in 1,8-cineole were considered to warrant further research into their potential for commercial use.

Contributions to a revision of Melaleuca (Myrtaceae): 7&amp;ndash;10

7. The Melaleuca fulgens species group is revised and found to comprise 11 species, of which M. adenostyla and M. apostiba are described as new. Subspecies recognised include M. fulgens subspp. corrugata, based on M. corrugata J. Black ex Eardley, and steedmanii, based on M. steedmanii C. Gardner; and M. macronychia subsp. trygonoides and M. coccinea subspp. eximia and penicula, which are described as new. 8. The Melaleuca laxiflora species group is revised and found to comprise 10 species, of which M. camptoclada and M. ctenoides are described as new. The only subspecies recognised are in M. armillaris (Sol. ex Gaertner) Smith, in which subsp. akineta is described as new. 9. The taxonomy of Melaleuca diosmifolia Andrews, a systematically isolated species, is discussed. 10. A brief summary is presented for the Melaleuca symphyocarpa group which is misplaced in Melaleuca and correctly belongs in Asteromyrtus Schauer.