Maintaining Plant Health Research Articles

Composition and variability of core phyllosphere fungal mycobiota on field-grown broccoli

BackgroundFresh vegetables harbor an assemblage of different microorganisms on their surfaces. The phyllosphere microbiota is important for maintaining plant health and managing crop quality before and after harvest. However, the diversity and ecology of fungal communities are largely unexplored in fresh vegetables. This study investigated the phyllosphere mycobiota of field-grown broccoli florets (n = 66) collected from 22 farms across four regions in Korea, using culturing, amplicon sequencing of the internal transcribed spacer region, and microbial network analysis.ResultsMicrobial network analysis identified core genera (Purpureocillium, Filobasidium, Cystofilobasidium, Papiliotrema, Aureobasidium, and unclassified genera of Capnodiales) specific to the broccoli phyllosphere. The composition and network complexity of core and unique populations varied among farming regions, and was associated with local agro-meteorological conditions. The complexity of microbial associations was higher in mature communities than in immature communities, but complexity was lost upon development of plant pathogenic disease. Broccoli mycobiota were classified according to the dominance of Purpurecillium. While Purpurecillium-type microbiota were prevalent in normal samples, Filobasidium-type microbiota were frequently observed in immature, damaged, or postharvest samples.ConclusionsTogether, fungal communities were important components of phyllosphere microbiota on fresh vegetables, and have substantial potential for exploitation to enhance and stabilize plant health and growth.

Cultural Practices & Beliefs in Abaca Farming of the Indigenous People

Abaca (Musa textilis) is a plant related to the banana, the leaves of which provide one of the strongest natural fibers used by man. Abaca farming is vital in boosting the national economy, and it serves as a potential source of incomefor growers (Biccay,2016). Furthermore, the indigenous knowledge of abaca farming has been proven effective through time and experience. However, there was a scant study about indigenous knowledge on abaca farming and abaca farmers in the Province of Aklan, Philippines. The indigenous people used traditional tools, equipment and ways in phases of producing, processing and marketing abaca fiber. The processes in their production phase were the preparation of the tools, clearing and preparation of the land, preparation of plants, planting, and maintaining plant health. In the processing phase, the processes were: preparation, topping, tumbling, tuxying, extraction, drying and bundling. While in the marketing phase, the processes were: carrying fiber, meeting with the assembler and transporting fiber to the market. The cultural beliefs in abaca farming were drying of suckers, padamguhan (response of deities based on dreams), sonata sa kataeonan (music in the forest), sapat nga pihakan mata (cyclops), prohibition of cooking in the abaca field, and rituals for good luck and thanksgiving for their good harvest. The Aklanon – Bukidnon Indigenous People faced several problems and challenges in abaca farming, and because of their innate positive qualities, they made their own coping mechanisms in order to continue living and avoid delays in their work and income.

Impact of Crop-specific Technologies and Organic Growth Stimulants on Mustard, Black Gram and Green Gram in Sundarban area of West Bengal

The gap between actual and potential crop production can be minimized by maintaining plant health, which needs crop-specific technology interventions. On-farm trials were conducted during 2017-18 and 2018-19 in the farmers’ fields in the Sundarbans to study the impact of crop-specific technologies on crop yields. The yield of mustard can be increased by about 47% with the installation of A. mellifera bee hives @ 3 ha-1 while it was about 40% in the case of A. cerena type @ 5 ha-1. A considerable increase (30.17% and 20.90%) in pod setting was recorded via the installation of mellifera bee hive and cerena type, respectively. Spraying of panchagavya @ 5%, sasyagavya @ 5%, and dasaparni @ 1% at 30 days after sowing (DAS) onwards at 15 days intervals, alternate application with 600 L ha-1 of jeevamrit as soil application at 30 DAS boosted the plant growth attributing characters in black gram. The same treatment recorded the highest yield of black gram (0.95 t ha-1), lowest infestation of pod borer (8.6%) and lowest powdery mildew infestation (21.20%). Application of beejamrit for seed bio-priming and 5% jeevamrit at 30 and 45 DAS as spray and soil application @ 600 L ha-1 also showed potential results with 30% increased yield of black gram over existing farmers’ practices. The integrated approach consisting of the application of T. viride enriched cow dung @ 750 kg ha-1, seed treatment with carboxin 17.5% + thiram 17.5% @ 3 mL kg-1 seed, installation of pheromone trap @ 30 ha-1 and need-based spot application of neemastra @ 3% resulted in highest seed yield of green gram (0.94 t ha-1) and B:C ratio (3.38) followed by chemical management (0.93 t ha-1, 3.23).

Community structure of phyllosphere fungi associated with dominant tree species in a broad-leaved Korean pine forest of Changbai Mountain, Northeast China

Forest is the main component of terrestrial ecosystems that harbors about 40% of the existing species on the earth. As a vital component of biodiversity, phyllosphere microbes in the canopy play a critical and unique role in maintaining plant health, improving host resistance, and influencing global biogeochemical cycle. However, the studies on the community structure of phyllosphere fungi in natural forests are scarce as compared to that on rhizosphere microbes. Consequently, we know litter about how phyllosphere fungi associates with leaf traits. In this study, we analyzed fungal community composition of canopy leaves of six dominant tree species (i.e., Pinus koraiensis, Tilia amurensis, Quercus mongolica, Acer mono, Fraxinus mandshurica, and Ulmus japonica), in a broad-leaved Korean pine forest of Changbai Mountain Nature Reserve in Jilin Province, using high-throughput sequencing. We compared the differences of phyllosphere fungal community structure and functional groups of different dominant tree species. Moreover, 14 key leaf functional traits of their host trees were measured to investigate the relationships between fungal community composition and leaf functional traits. We found that the dominant phyla and class of phyllosphere fungi were Ascomycota and Basidiomycota, and Dothideomycetes and Taphrinomycetes, respectively. Results of LEfSe analysis indicated that all the tree species except Ulmus japonica had significant biomarkers, such as the Eurotiomycetes of Pinus koraiensis and the Ascomycetes of Quercus mongolica. The main functional groups of phyllosphere fungi were pathotroph. The results of redundancy and envfit analysis showed that functional traits related to plant nutrient acquisition as well as resistance to diseases and pests were the main factors influencing the community structure of phyllosphere fungi.

Deciphering the microbial diversity associated with healthy and wilted Paeonia suffruticosa rhizosphere soil.

Plant health is closely related to the soil, where microorganisms play a critical and unique role. For instance, Paeonia suffruticosa is an emerging woody oil crop in China with attractive development and utilization prospects. However, black root rot causes wilting of the aboveground plant parts, which significantly affected its seed yield and quality. Studies found that soil microorganisms are critical in maintaining plant health, but how changes in the soil microbial communities affect the healthy and diseased oil peony is unclear. Therefore, our present study used high throughput sequencing and BIOLOG to analyze the rhizosphere soil microbial communities of healthy and diseased oil peonies. Our results revealed that the physical and chemical properties of the soil of the diseased plants had changed, with the ability to metabolize the carbon source being enhanced. Moreover, our research highlighted that the oil peony-infecting fungal pathogenic genus (Fusarium, Cylindrocarpon, and Neocosmospora) was closely associated with oil peony yield reduction and disease aggravation. Further network analysis demonstrated that the bacterial and fungal networks of the diseased plants were more complex than those of the healthy plants. Finally, the inter-kingdom network among the diseased plants further indicated that the lesions destroyed the network and increased the intraspecific correlation between the fungal groups.

Characterization of the belowground microbial community and co-occurrence networks of tobacco plants infected with bacterial wilt disease.

Characterizing the microbial communities associated with soil-borne disease incidence is a key approach in understanding the potential role of microbes in protecting crops from pathogens. In this study, we compared the soil properties and microbial composition of the rhizosphere soil and roots of healthy and bacterial wilt-infected tobacco plants to assess their potential influence on plant health. Our results revealed that the relative abundance of pathogens was higher in diseased plants than in healthy plants. Moreover, compared with healthy plants, there was a significantly higher microbial alpha diversity in the roots and rhizosphere soil of diseased plants. In addition, we detected a lower abundance of certain plant microbiota, including species in the genera Penicillium, Trichoderma, and Burkholderia in the rhizosphere of diseased plants, which were found to be significantly negatively associated with the relative abundance of Ralstonia. Indeed, compared with healthy plants, the co-occurrence networks of diseased plants included a larger number of associations linked to plant health. Furthermore, structural equation modeling revealed that these specific microbes were correlated with disease suppression, thereby implying that they may play important roles in maintaining plant health. In conclusion, our findings provide important insights into the relationships between soil-borne disease incidence and changes in the belowground microbial community. These findings will serve as a basis for further research investigating the use of specific plant-associated genera to inhibit soil-borne diseases.

Effects of tetracycline on the secondary metabolites and nutritional value of oilseed rape (Brassica napus L.).

Secondary metabolism, which helps a plant cope with external stress, is sensitive to environmental changes and plays a prominent role in maintaining plant health. However, few studies of the effects of tetracycline on the relationships between secondary metabolism and plant stress responses have been performed. Here, secondary metabolism, nutritional value, and oxidative stress responses in oilseed rape (Brassica napus L.) exposed to tetracycline for 14days were investigated. Tetracycline inhibited growth and biomass accumulation and decreased the chlorophyll content. The sinapine, phenol, and flavonoid contents were 118.46%, 99.67%, and 93.07% higher, respectively, but the carotenoid content was 76.47% lower in plants exposed to 8mg/L tetracycline than the control plants. Tetracycline affected the nutritional value of oilseed rape. Tetracycline decreased the dietary fiber, soluble sugar contents, and microelement (Fe, Mn, and Zn) contents. The antioxidant system also responded strongly to tetracycline. The catalase and peroxidase activities were increased and the superoxide dismutase activity was decreased by tetracycline. Tetracycline caused oxidative damage and secondary metabolite disturbances and adversely affected oilseed rape growth and quality. The results provide a new perspective on the effects of tetracycline on plants in relation to secondary metabolites and improve our understanding involved in the toxicity of tetracycline.

Advances in Soil Engineering: Sustainable Strategies for Rhizosphere and Bulk Soil Microbiome Enrichment.

The preservation of natural ecosystems, as well as the correct management of human societies, largely depends on the maintenance of critical microbial functions associated with soils. Soils are biodiversity rich pools, and rhizosphere soils can be associated with increased plant functions in addition to the regulation of nutrient cycling, litter decomposition, soil fertility and food production by agriculture systems. The application of biocontrol agents or plant growth-promoting bacteria has been tested in order to colonize roots at initial stages and offer advantages by promoting healthier and higher-yielding crops. In this review we describe the efforts to develop more sustainable systems that seek to minimize environmental disruption while maintaining plant health. Particular emphasis is given in this review to soil improvement strategies and the taxonomic groups involved in plant growth and protection against biotic stresses. It is important to define the impacts of land management and crop production practices on the structure and composition of soil bacterial communities. By promoting, monitoring and controlling the plant microbiome, and understanding the role of certain biocontrol agents within the plant throughout the lifecycle of the plant, we may substantially improve nutritional and environmental standards and reduce the negative impact of some agrochemicals. The integration of biological alternatives with traditional strategies may be critical to improve the sustainability of agriculture systems.

Mixture compatibility of Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) with pesticides used in soybean

ABSTRACT: Anticarsia gemmatalis (Hübner: 1818) (Lepidoptera: Erebidae) is one of the main pests that affect soybean crops, causing defoliation. In the vegetative stages, defoliation occurs together with weeds, and in the reproductive stages with pathogens. In this sense, to maintain plant health, it is necessary to carry out the combined use of pesticides. Thus, this research determined the compatibility of the entomopathogenic virus AgMNPV with the main herbicides and fungicides used in soy at different times of the mixture. The artificial diet was immersed in the solutions of the pesticides and their mixtures and supplied to A. gemmatalis caterpillars, immediately and after one and two hours of mixing. The evaluation was performed by quantifying the number of dead caterpillars by mixing the AgMNPV virus with herbicides and fungicides, even after two hours of mixing if compatible. The observed scenarios showed a compatibility of the virus with the herbicides and fungicides, with mortality rates between 70 to 99% for A. gemmatalis.

Food Security Under The Era Of Climate Change Threat

Food Security Under The Era Of Climate Change Threat

Evaluating the lettuce metatranscriptome with MinION sequencing for future spaceflight food production applications

Healthy plants are vital for successful, long-duration missions in space, as they provide the crew with life support, food production, and psychological benefits. The microorganisms that associate with plant tissues play a critical role in improving plant health and production. To that end, we developed a methodology to investigate the transcriptional activities of the microbiome of red romaine lettuce, a key salad crop that was grown under International Space Station (ISS)-like conditions. Microbial transcripts enriched from host–microbe total RNA were sequenced using the Oxford Nanopore MinION sequencing platform. Results show that this enrichment approach was highly reproducible and could be an effective approach for the on-site detection of microbial transcriptional activity. Our results demonstrate the feasibility of using metatranscriptomics of enriched microbial RNA as a potential method for on-site monitoring of the transcriptional activity of crop microbiomes, thereby helping to facilitate and maintain plant health for on-orbit space food production.

Contrasting Patterns of the Resident and Active Rhizosphere Bacterial Communities of Phragmites Australis.

Rhizosphere microbes play a key role in maintaining plant health and regulating biogeochemical cycles. The active bacterial community (ABC) in rhizosphere, as a small fraction of the rhizosphere resident bacterial community (RBC), has the potential to actively participate in nutrient cycling processes at the root-sediment interface. Here, we investigated the ABC and RBC within the rhizosphere of Phragmites australis (P. australis) subjected to different environmental conditions (i.e., seasons and flooding conditions) in Lake Taihu, China. Our results indicated that RBC exhibited significantly higher alpha diversity as well as lower beta diversity than ABC. The active ratios of 16S rRNA to 16S rDNA (also RNA/DNA) of the bacterial communities in summer and winter suggested a lower proportion of potential active taxa in the rhizosphere bacterial community during summer. Network analysis showed that negative correlations in each network were observed to dominate the species correlations between the rhizosphere and bulk sediment bacterial communities. Our results revealed that niche differentiation and seasonal variation played crucial roles in driving the assembly of ABC and RBC associated with the rhizospheres of P. australis. These findings broaden our knowledge about how rhizosphere bacterial communities respond to environmental variations through changing their diversity and composition.

A Digital Framework to Predict the Sunshine Requirements of Landscape Plants

Knowledge of the sunshine requirements of landscape plants is important information for the adaptive selection and configuration of plants for urban greening, and is also a basic attribute of plant databases. In the existing studies, the light compensation point (LCP) and light saturation point (LSP) have been commonly used to indicate the shade tolerance for a specific plant; however, these values are difficult to adopt in practice because the landscape architect does not always know what range of solar radiation is the best for maintaining plant health, i.e., normal growth and reproduction. In this paper, to bridge the gap, we present a novel digital framework to predict the sunshine requirements of landscape plants. First, the research introduces the proposed framework, which is composed of a black-box model, solar radiation simulation, and a health standard system for plants. Then, the data fitting between solar radiation and plant growth response is used to obtain the value of solar radiation at different health levels. Finally, we adopt the LI-6400XT Portable Photosynthetic System (Li-Cor Inc., Lincoln, NE, USA) to verify the stability and accuracy of the digital framework through 15 landscape plant species of a residential area in the city of Wuhan, China, and also compared and analyzed the results of other researchers on the same plant species. The results show that the digital framework can robustly obtain the values of the healthy, sub-healthy, and unhealthy levels for the 15 landscape plant species. The purpose of this study is to provide an efficient forecasting tool for large-scale surveys of plant sunshine requirements. The proposed framework will be beneficial for the adaptive selection and configuration of urban plants and will facilitate the construction of landscape plant databases in future studies.

Ground pearls (Hemiptera: Margarodidae) in crops and pastures: biology and options for management

Ground pearls (Hemiptera: Margarodidae), so called for their shiny spherical cyst stage, are important root-feeding pests of a broad range of plants predominantly belonging to the family Poaceae. In the tropical and subtropical regions of eastern Australia, ground pearl species cause significant damage on sugarcane and turf grasses and have been identified at multiple sites of pasture dieback in Queensland. The potential impact of ground pearls on pasture production in Australia and elsewhere is largely unknown. This paper reviews Australian and international literature on the biology and management of this poorly understood group of pests. Ground pearls have several features that make control difficult, including a resilient cyst which provides resistance to drought and excessive moisture, a relative impermeability to insecticides, and ease of dispersal through movement of soil. Ground pearls can also modulate the period of encystment to survive adverse environmental conditions, with some species capable of surviving for years while disassociated from a host. No insecticide effectively controls ground pearl cysts. Biological control agents have been identified for some species; however, these pathogens are relatively ineffective on subterranean ground pearl cysts. Cultural control methods such as cultivation and fallowing have helped to reduce ground pearl populations in sugarcane. In turf, practices that maintain plant health such as adequate irrigation and nutrition can mask signs of ground pearl infestation. The paucity of research conducted on the biology and impact of ground pearls represents a constraint to improving management of this pest.

Phytoremediation of nutrients and organic carbon from contaminated water by aquatic macrophytes and the physiological response

In the current study, the integrated influence of four concentration levels of pollutants (COD, TN, NH 4 + -N and TP) in contaminated water on phytoremediation efficiency by aquatic macrophytes community (emergent, floating-leaved and submerged species) and physiological responses in submerged macrophyte were investigated in microcosms. The removal efficiency of COD elevated as the increase of pollutants concentration and reached a maximum value (92.4 %). Moreover, the purification efficiencies of TN, NH 4 + -N and TP elevated within a certain pollutant concentration range, however inhibited in high concentration levels. Furthermore, Chlorophyll content, malondialdehyde (MDA) content, Catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) activities in submerged macrophyte were explored as physiological characteristics to estimate correlation among them and pollutants concentrations. Significant positive correlations were found except for chlorophyll. Oxidative stress was proved by the consistently higher MDA content as increasing of pollutant concentrations. In addition, antioxidant enzyme responses were induced to remove reactive oxygen radicals which damage plant structure, and maintain plant health. Nonetheless, the adaptive physiological regulations were inhibited in high pollutant concentration levels, and unhealthy symptoms of plants were also spotted. Considering both the physiological response and pollutant removal efficiency, the range level of COD, TN, NH 4 + -N and TP that suitable for phytoremediation was within 75 mg L −1 ,15 mg L −1 , 13 mg L −1 and 3.5 mg L −1 , respectively. And the related maximum removal rates were 90.3 %, 76.0 %, 95.9 % and 77.4 %. These findings suggested that pollutant concentrations significantly affect phytoremediation efficiency, and excessive concentrations of organics and nutrients may be partly responsible for macrophytes recession and phytoremediation efficiency reduction by inhibition of adaptive physiological regulations. • Range of nutrients and organic carbon suitable for phytoremediation. • In high nutrients and organic carbon concentration chlorophyll content decreased. • Excessive nutrients and organic carbon inhibited plant antioxidant enzyme defense. • Phytoremediation efficiency is related to physiological characteristics.

Influence of biochar and organic soil amendments on bioavailability and immobilization of copper and lead to common cocklebur in acidic sandy loam soil

Application of amendments may help to alter soil physicochemical properties and the bioavailability of metals. A pot experiment was carried out using a metal accumulator plant common cocklebur (Xanthium strumarium L.). The plant was grown in contaminated soil with copper (Cu) and lead (Pb) at four different concentrations of each metal (150, 250, 300, and 350 mg kg−1 soil). Soil amendments hardwood biochar (HWBC), farmyard manure (FYM), and vermicompost (VC) were applied at 2.77 g kg−1 rate. The amendments were effective in maintaining plant health under metal exposure. VC improved the chlorophyll stability index and dry biomass of plants, which was followed by FYM and HWBC. Decreased in peroxidase activity and metal concentration in plant tissues under the amendments disclosed their effectiveness to reduce metal toxicity. VC application reduced Pb concentration in plant up to 52.94%, while FYM reduced Cu uptake up to 30.03 % by the plant. The speciation study revealed the potentiality of the tested amendments to cause a reduction in bioavailable form of the metals. The order of efficiency to reduce exchangeable fraction of Cu was HWBC (29.2–69.0 %) > FYM (5.9–44.5 %) > VC (5.7–33.8 %). However, to reduce exchangeable fraction of Pb the order was VC (41.8–74.9 %) > FYM (30.2–60.0 %) > HWBC (18.5–26.9 %). Less bioavailable fractions (excluding exchangeable and carbonate bound) of Cu and Pb was found maximum at FYM and VC amendment respectively indicate higher efficacy of them to immobilize Cu and Pb in acidic sandy loam soil inducing reduce possibility of metal contamination in the food chain.

Boron, zinc and manganese suppress rust on coffee plants grown in a nutrient solution

Providing adequate nutrition to coffee plants is required to maintain plant health. The effect of five doses (0.05, 0.25, 0.50, 1.0, 2.0 and 4.0 mg L−1) of boron (B), zinc (Zn) and manganese (Mn) on the severity of rust on coffee plants grown in nutrient solution was evaluated. Micronutrients were supplied to seedlings having two pairs of fully developed leaves. The seedling plants were inoculated with spores (106 ml−1) of the coffee rust pathogen (Hemileia vastatrix). Five assessments of the severity of the rust symptoms were made starting on the 43rd day after inoculation. The area under the disease progress curve for severity (AUDPCS) was calculated. There was a statistical difference in AUDPCS (p < 0.05) with all micronutrients tested. With B and Mn, there was a 15.1% and 52.3% reduction in severity of coffee rust at doses of 4.00 and 0.25 mg L−1, respectively. With Zn there was a 78.0% decrease in AUDPCS. The three micronutrients significantly affected the concentration of total soluble phenols, nevertheless, only Mn influenced the concentration of lignin.

Corroboration That Highly Resistant Impatiens Cultivars Are Not Immune to Downy Mildew Disease: A Report of Crop Losses from Two California Producers

Two new series of Impatiens walleriana (impatiens) cultivars, Beacon and Imara XDR, were released to commercial growers in the United States in 2019 to 2020. Field trials show these new cultivar series are highly resistant to impatiens downy mildew (IDM). However, neither of these two impatiens series are completely immune to the disease, and preventive fungicide programs are still recommended for use throughout production to maintain plant health. Here we report two destructive outbreaks of IDM from Imara XDR in two commercial production facilities in California, one in 2019 and one in 2020. The disease outbreaks were caused by a known rDNA genotype of Plasmopara destructor (synonym = P. obducens). Modified Koch’s postulates showed that the pathogen could infect and cause disease in both Beacon and Imara XDR plants. Mefenoxam applied by both growers may have been ineffective due to resistance in P. destructor populations, which has been demonstrated on several previous occasions. Given these findings, fungicide programs intended to supplement genetic resistance should not be overly reliant upon application of mefenoxam and should utilize effective materials from different mode of action groups, in rotation. Fungicides to supplement genetic resistance are particularly appropriate in frost-free areas or in any circumstances that provide a potential inoculum source.

Rhizobacterial community structure in response to nitrogen addition varied between two Mollisols differing in soil organic carbon

Excessive nitrogen (N) fertilizer input to agroecosystem fundamentally alters soil microbial properties and subsequent their ecofunctions such as carbon (C) sequestration and nutrient cycling in soil. However, between soils, the rhizobacterial community diversity and structure in response to N addition is not well understood, which is important to make proper N fertilization strategies to alleviate the negative impact of N addition on soil organic C and soil quality and maintain plant health in soils. Thus, a rhizo-box experiment was conducted with soybean grown in two soils, i.e. soil organic C (SOC)-poor and SOC-rich soil, supplied with three N rates in a range from 0 to 100 mg N kg−1. The rhizospheric soil was collected 50 days after sowing and MiSeq sequencing was deployed to analyze the rhizobacterial community structure. The results showed that increasing N addition significantly decreased the number of phylotype of rhizobacteria by 12.3%, and decreased Shannon index from 5.98 to 5.36 irrespective of soils. Compared to the SOC-rich soil, the increases in abundances of Aquincola affiliated to Proteobacteria, and Streptomyces affiliated to Actinobacteria were greater in the SOC-poor soil in response to N addition. An opposite trend was observed for Ramlibacter belong to Proteobacteria. These results suggest that N addition reduced the rhizobacterial diversity and its influence on rhizobacterial community structure was soil-specific.

Flavonoid Profile of the Cotton Plant, Gossypium hirsutum: A Review.

Cotton, Gossypium hirsutum L., is a plant fibre of significant economic importance, with seeds providing an additional source of protein in human and animal nutrition. Flavonoids play a vital role in maintaining plant health and function and much research has investigated the role of flavonoids in plant defence and plant vigour and the influence these have on cotton production. As part of ongoing research into host plant/invertebrate pest interactions, we investigated the flavonoid profile of cotton reported in published, peer-reviewed literature. Here we report 52 flavonoids representing seven classes and their reported distribution within the cotton plant. We briefly discuss the historical research of flavonoids in cotton production and propose research areas that warrant further investigation.