Commercial Horticulture Research Articles

Commercial Transition to LEDs: A Pathway to High-value Products

The use of light-emitting diodes (LEDs) to support plant growth is a radical departure from use of gas-discharge lamps, which were developed in mid-19th and widely adopted by the industry during the 20th century. Initial investigation by the National Aeronautics and Space Administration (NASA) in the late 1980s on the use of LEDs to grow plant in space is resulting in an industry-wide transition from gas discharge to solid-state lighting systems. This global transformation is given urgency by national policies to reduce energy consumption and being facilitated by ready access to information on LEDs. The combination of research, government policy, and information technology has resulted in an exponential increase in research into the use and application of LED technology in horticulture. Commercial horticulture has identified the opportunities provided by LEDs to optimize light spectra to promote growth, regulate morphology, increase nutrient content, and reduce operating costs. LED-light technology is enabling the development of innovative lighting systems, and is being incorporated into large-scale plant factories for the production of edible, ornamental, and medicinal plants. An overview of prevalence of readily accessible information on LEDs and implications for future adoption in horticulture is discussed.

Academic Research Perspective of LEDs for the Horticulture Industry

Following is the invited perspective of an academic researcher and director of a multi-institutional research and education project tasked to test the feasibility of adopting light-emitting diode (LED) technology for application by the commercial horticulture industry. Academics researching basic specialty-crop responses to spectra, intensities, and durations of lighting with LEDs often find technical queries from growers, vendors, and entrepreneurs to go beyond the capabilities and scope of systematic research to answer definitively. Differences between commercial and academic research approaches to LED technology development are noted, including legal obstacles to open collaboration. Early generation commercial LED technology for horticultural applications is based on research begun >20 years ago. The basis for selection of various LED wavebands for inclusion in LED plant growth arrays is presented for both commercial as well as research applications. Advantages of light distribution from LED sources for different crop applications are presented, especially including close-canopy and intracanopy lighting, both of which contribute substantially to energy savings. Challenges to providing accurate LED light prescriptions for different crops are discussed, including those for supplemental lighting as well as for sole-source lighting applications. Anticipated trends are projected for horticultural applications of LED technology, including multispectral, individually adjustable, high-intensity arrays; increasing electrical efficacy of future LEDs; and reduced costs of mass production for particular applications.

Educating for food security in the UK: Planning for an uncertain future

The pressures affecting the UK’s food production infrastructure are reviewed, with a conclusion that security of supply is currently unsafe. Planning ahead to improve security of supply is argued as key, especially as we try to cope with an uncertain future. The challenge of planning for uncertainty of food supply leads to a consideration of recent research on risk and the ideas of Taleb about antifragility. This investigation is in the context of Higher Education delivery for the next generation of agriculture and commercial horticulture graduates: the impacts of resource restrictions and opportunities of novel modes of teaching are reviewed as we learn to work with greater uncertainty.

Buchanania lanzanis a Pharmacognostic Miracle Herb

Buchanania lanzan Spreng plant is well known for its medicinal and therapeutic values in Indian folk medicine. However, to be clinically useful, more scientific data are needed. Therefore, in the present study, we investigated the effects of root of Buchanania lanzan. Tribal people of Jharkhand and Chhattisgarh are using Buchanania lanzan Spreng. Mainly for wound healing, anti-diarrhoeal, analgesic and antiulcer activity apart from in other conditions, but no scientific study has been carried out regarding its pharmacological activities. Traditional indigenous knowledge reveals the immense value of almost all parts of the plant i.e. roots, leaves, fruits, seeds and gum for various medicinal uses. Buchanania lanzan, being a vulnerable medicinal plant, is included in the Red Data Book published by International Union for Conservation of Nature and Natural Resources (IUCN). This species has high socioeconomic value providing livelihood to tribal population of the area and has high potential as commercial horticulture species. The present review discusses the need and emphasizes the importance of pharmacognostic study of Buchanania lanzan Spreng.

“The love of enterprise and Nature was born in the woman”: Theodosia Shepherd and the Gendered Garden of California Commercial Horticulture, 1881–1906

“The love of enterprise and Nature was born in the woman”: Theodosia Shepherd and the Gendered Garden of California Commercial Horticulture, 1881–1906

Spatial Distribution of Greenhouse Commercial Horticulture in Kenya and the Role of Demographic, Infrastructure and Topo-Edaphic Factors

Greenhouse commercial horticulture in Kenya started more than two decades ago and has evolved to be a significant sector to the national economy. So far no studies have explored the spatial patterns and dynamics of the area under greenhouse cultivation. Google Earth archives alongside data from various portals provided an opportunity to study those farms’ spatial distribution. The roles of selected topo-edaphic, infrastructure and demographics factors that might influence current location within sub-watersheds in central highlands of Kenya are also examined. Results reveal a non-uniform spread with two high clusters; one in the semi-arid sub-watersheds 3AB shared by Kajiado and Machakos districts and the other is in sub-humid sub-watersheds 3BA shared by Kiambu and Nairobi districts. Multivariate linear regression analysis reveals four statistically significant parameters; population density (p < 0.01), number of dams (p < 0.01), average rainfall (p < 0.01) and average slope (p < 0.05) in predicting the number of greenhouse farms. Soil attributes are not significantly related with greenhouse farming in this study. Findings indicate that greenhouse commercial horticulture is heterogeneous, and rapidly expanding beyond the central highlands towards marginal semi-arid zones in Kenya. These findings are applicable in policy and decision making processes that aid the horticulture sector’s progress in a sustainable manner.

Beyond Crofting: Assessing Change on Scotland's Small-Scale Holdings

In this paper, we go ‘beyond crofting’ to assess the changes to both croft and non-croft small-scale land management in Scotland from 2000 to 2011, through an analysis of agricultural census statistics. We find that although small-scale holdings (defined as holdings of less than 10 ha) occupy a very small percentage of Scotland's agricultural land, they account for 19.6% of Scotland's agricultural labour. Small-scale holdings also play important roles within the commercial poultry and horticulture sectors, and house 35.9% of reported horses. Small-scale land management is increasing throughout Scotland, but with evident regional distinctions. Upland and island holdings (many of which are crofts) have seen substantial reductions in their sheep numbers as part of the wider reduction in agricultural activity associated with 2005 Common Agricultural Policy reforms. In contrast, sheep numbers are growing on small-scale holdings in the lowlands, underpinned by a complex mix of commercial and lifestyle drivers. We highlight that benefits traditionally associated with crofting, such as population retention and rural development, could also be associated with small-scaling holding in general. However, the increase in small-holding and retention of labour in some regions may be evidence of peri-urban gentrification processes, rather than fulfilment of traditional crofting functions in remote areas.

Advancing Wireless Sensor Networks for Irrigation Management of Ornamental Crops: An Overview

Wireless sensor networks (WSNs) transmit sensor data and control signals over long distances without the need for expensive infrastructure, allowing WSNs to add value to existing irrigation systems since they provide the grower with direct feedback on the water needs of the crop. We implemented WSNs in nine commercial horticulture operations. We provide an overview of the integration of sensors with hardware and software to form WSNs that can monitor and control irrigation water applications based on one of two approaches: 1) “set-point control” based on substrate moisture measurements or 2) “model-based control” that applied species-specific irrigation in response to transpiration estimates. We summarize the economic benefits, current and future challenges, and support issues we currently face for scaling WSNs to entire production sites. The series of papers that follow either directly describe or refer the reader to descriptions of the findings we have made to date. Together, they illustrate that WSNs have been successfully implemented in horticultural operations to greatly reduce water use, with direct economic benefits to growers.

Implementation of Wireless Sensor Networks for Irrigation Control in Three Container Nurseries

Water quality and quantity are increasingly important concerns for agricultural producers and have been recognized by governmental and nongovernmental agencies as focus areas for future regulatory efforts. In horticultural systems, and especially container production of ornamentals, irrigation management is challenging. This is primarily due to the limited volume of water available to container-grown plants after an irrigation event and the resultant need to frequently irrigate to maintain adequate soil moisture levels without causing excessive leaching. To prevent moisture stress, irrigation of container plants is often excessive, resulting in leaching and runoff of water and nutrients applied to the container substrate. For this reason, improving the application efficiency of irrigation is necessary and critical to the long-term sustainability of the commercial nursery industry. The use of soil moisture sensing technology is one method of increasing irrigation efficiency, with the on-farm studies described in this article focusing on the use of capacitance-based soil moisture sensors to both monitor and control irrigation events. Since on-farm testing of these wireless sensor networks (WSNs) to monitor and control irrigation scheduling began in 2010, WSNs have been deployed in a diverse assortment of commercial horticulture operations. In deploying these WSNs, a variety of challenges and successes have been observed. Overcoming specific challenges has fostered improved software and hardware development as well as improved grower confidence in WSNs. Additionally, growers are using WSNs in a variety of ways to fit specific needs, resulting in multiple commercial applications. Some growers use WSNs as fully functional irrigation controllers. Other growers use components of WSNs, specifically the web-based graphical user interface (GUI), to monitor grower-controlled irrigation schedules.

Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

Starch metabolism and antiflorigenic signals modulate the juvenile‐to‐adult phase transition in Arabidopsis

Knowledge of how environment influences juvenility could help with crop scheduling in commercial horticulture, decrease time to flowering and reduce waste with resulting benefits for the environment through lower inputs and energy required per unit of marketable product.In the manuscript, using an experimental assay that allows the length of the juvenile phase to be estimated in response to floral competence, and several mutants impaired in different genetic pathways, we show that multiple inputs influence the timing of the juvenile‐to‐adult phase transition in Arabidopsis.

Molecular and morphological analysis of subfamily Alooideae (Asphodelaceae) and the inclusion ofChortolirioninAloe

AbstractAsphodelaceae subfam. Alooideae (Asparagales) currently comprises five genera, four of which are endemic to southern Africa. Despite their importance in commercial horticulture the evolutionary relationships among the genera are still incompletely understood. This study examines phylogenetic relationships in the subfamily using an expanded molecular sequence dataset from three plastid regions (matK, rbcLa, trnH–psbA) and the first subunit of the nuclear ribosomal internal transcribed spacer (ITS1). Sequence data were analysed using maximum parsimony and Bayesian statistics, and selected morphological traits were mapped onto the molecular phylogeny. Haworthia is confirmed as being polyphyletic, comprising three main clades that largely correlate with current subgeneric circumscriptions. Astroloba and Gasteria are evidently each monophyletic and sister respectively to Astroloba and H. subg. Robustipedunculares. Chortolirion is shown to be deeply nested within Aloe and is formally included in that genus. Aloe itself is clearly polyphyletic, with the dwarf species A. aristata allied to Haworthia subg. Robustipedunculares. The taxonomic implications of these findings are examined but branch support at critical lower nodes is insufficient at this stage to justify implementing major taxonomic changes.

Living without Fruit Flies: Biosecuring Horticulture and its Markets

In this paper, informed by more-than-human and biosecurity literatures, I attend a neglected nonhuman considered a serious agricultural pest: the fruit fly. In addressing what it takes to live without fruit flies, biosecurity is theorised as ongoing, enacted achievement sustained (or not) by everyday and eventful interactions of heterogeneous spaces, strategies, and participants—human and nonhuman. Relations of fruits, flies, and people are explored through one vital attempt to biosecure life: Australia's Fruit Fly Exclusion Zone (FFEZ), a tristate pest-free area established to protect commercial horticulture from the fruit fly. Fruit flies become problematised as their appetites and mobilities confound fruit production and marketing, and affiliated biosecurity controls. Making fruit safe enrolls policy and agricultural sectors, but also more dispersed agents (travellers, residents, trees) and management sites (primarily off-farm). Since its introduction, the FFEZ's ongoing biosecuring normalised, with only occasional outbreak events. However, recent unprecedented outbreaks evoke questions about the FFEZ's future status. In such eventful times, it is worth reflecting on what kinds of living are possible in biosecurity zones—for flies, for resident human communities, and for agrifood networks.

Environmental and socio-economic sustainability of chinampas (raised beds) in Xochimilco, Mexico City

The chinampas (raised beds) of Xochimilco, Mexico City, are highly productive, traditional wetland agricultural systems, which were able to feed most of the population in pre-hispanic times. There is a strong trend to substitute chinampas with plastic greenhouses for flower production, which creates negative impacts in the landscape, environment and culture. This study compares the environmental and socio-economic sustainability of chinampas and greenhouses, at both the farm and regional levels, using the MESMIS framework. Even though the results show that greenhouses are more profitable, the contribution of chinampas to ecosystem services cannot be substituted by greenhouses, as tree cover is lost, canals are filled and food is not provided. Greenhouses had a higher diversity, but also a higher agrochemical use and are heavily dependent on external inputs and subsidies. Chinampas have shifted from staple crops to commercial horticulture in order to remain a technically viable and economically feasible option for local farmers. However, compensation mechanisms for the provision of ecosystem services are urgently needed if this ancient system is to be maintained. The framework allowed the integration of indicators at both farm and regional scales, combining on-farm surveys with GIS techniques, which could assist in ecosystem service valuation.

Genetic resources of Chironji (Buchanania lanzan Spreng.): a socio-economically important tree species of central Indian tribal population

Buchanania lanzan Spreng. (Chironji) is a socio-economically important underutilized fruit and life support species of tribal populations of north, west and central India. A survey and germplasm collection programme undertaken in the Indian states of Rajasthan, Gujarat and Madhya Pradesh observed that B. lanzan is found as natural wild in the forest, marginal lands and occasionally in farmer’s fields. A total of 72 diverse accessions of this important tree species were collected from the diversity–rich areas of India having wide range of variation in agro-morphological traits among the accessions. This species has high socio-economic value providing livelihood to tribal population of these areas and has high potential as commercial horticulture species. Fresh ripen fruits and extracted seed kernels have several nutritional and medicinal properties. Seed kernel and extracted kernel oil is used for the preparation of several Indian dishes. Traditional indigenous knowledge revealed immense importance of almost all parts of plant like roots, leaves, fruits, seeds and gum for various medicinal applications like cure for blood disorder, fever, ulcers, burning sensation of body, diarrhoea, dysentery, asthma, snakebite, etc. Due to direct harvesting of economically important parts of tree from natural habitat, genetic resources of B. lanzan are facing severe threat of extinction and need immediate conservation efforts.

Determination of Major Viral and Sub Viral Pathogens Incidence in Apple Orchards in Himachal Pradesh

Apple is the major commercial horticulture crop in Himachal Pradesh and other hill states of Jammu & Kashmir, Uttarakhand and some parts of Northeastern states of India. In order to gather data on health status and incidence of virus and virus-like pathogens in apple orchards, survey was conducted in the month of June and September, 2010 in Hatkoti, Rohru, Kuthara, Jubbal and Khadapathar areas of major apple producing Shimla district of Himachal Pradesh. A total of 250 samples were collected and analyzed by DAS-ELISA, NASH and RT-PCR. NASH results indicated that a total of 117 samples were infected with Apple chlorotic leaf spot virus (ACLSV), Apple mosaic virus (ApMV), Apple stem grooving virus (ASGV), Apple stem pitting virus (ASPV) and Apple scar skin viroid (ASSVd). Results showed that ASSVd is predominant in these areas with highest infection rate of 27.6% followed by ASPV (17.2%), ACLSV (16.8%), ApMV (15.2%) and ASGV (12%). Mixed infection of these viruses and viroid was frequently detected in apple trees in Himachal Pradesh. The trees, which were positive for viruses and viroids, showed a variety of fruit deformation and rusting symptoms besides leaf deformation, mosaic and chlorosis.

Assessing Economic Impacts and Benefits of Commercial Horticulture Extension Programs

As fiscal pressures increase from federal and state government agencies to spend public dollars more effectively, it is imperative that the outcomes from educational efforts be clearly documented in terms of measurable changes in knowledge and behavior of clientele or stakeholders. This 5-page fact sheet presents a standardized approach for evaluating the economic impacts of extension educational programs in commercial horticulture in Florida, with which impacts are quantified in terms of measurable changes in revenues, income, or jobs. Written by Alan Hodges, Shawn Steed, Jane Morse, Peggy Dessaint, Donald Rainey, and Charles Vavrina, and published by the UF Department of Food and Resource Economics, September 2011. (AP Photo: Thomas Wright, University of Florida/IFAS)

발병 조건에 따른 살균제들의 배추 뿌리혹병 방제효과

배추 뿌리혹병에 대한 효율적인 살균 활성 검정법을 확립하기 위하여, 배추 품종, 기주 식물의 생육 시기, 접종원 농도, 토양 종류 등의 발병 조건에 따른 살균제 fluazinam, ethaboxam 및 cyazofamid의 배추 뿌리혹병에 대한 방제 효과를 온실에서 실험하였다. 배추의 생육 시기에 따른 살균제들의 방제효과는 파종 7일 및 14일 유묘에서는 21일 유묘보다 더 높은 방제효과를 보였다. 그리고 토양종류에 따른 살균제의 방제효과는 원예용 상토보다 혼합토양에서 더 높은 방제효과를 나타냈다. 무처리구의 뿌리혹병 발생은 배추가 커질수록 증가하였으며, 혼합토양보다 원예용 상토에서 병 발생이 더 많았다. 그러나 배추품종에 따른 살균제들의 방제효과 차이는 거의 없었다. 한편 P. brassicae 포자 농도가 100배 증가하여도 무처리구의 뿌리혹병 발생은 거의 차이가 없었으나, 살균제들의 배추 뿌리혹병 방제효과는 크게 감소하였다. 이상의 결과로부터 살균제 fluazinam, ethaboxam 및 cyazofamid는 토양 종류, 배추 생육시기 및 접종원 농도 등의 발병 조건에 따라 배추 뿌리혹병에 대하여 다양한 방제효과를 보였으며, 이들 중 포자 농도가 살균제의 방제효과에 가장 큰 영향을 미친다고 생각되었다. To develop the efficient screening methods for antifungal compound active to Chinese cabbage clubroot caused by Plasmodiophora brassicae, the control efficacy of three fungicides fluazinam, ethaboxam, and cyazofamid on the disease was tested under several conditions such as soil types, cultivars of Chinese cabbage, growth stages of the host, and inoculum concentrations. The in vivo antifungal activities of the fungicides on clubroot of two Chinese cabbage cultivars were hardly different. At 7- and 14-day-old seedlings, the fungicides were more effective to control of clubroot than at 21-day-old seedlings. In a commercial horticulture media soil (CNS), disease severity of untreated controls was higher and control activity of the fungicides was less than in a mixture of CNS and upland soil (1:1, v/v). Disease development of the seedlings inoculated with P. brassicae at <TEX>$1.8{\times}10^7$</TEX> spores/pot to <TEX>$1.1{\times}10^9$</TEX> spores/pot was almost same, but control efficacy of the fungicides was negatively correlated with inoculum dosages. To effectively select in vivo antifungal compound on Chinese cabbage clubroot, 14-day-old seedlings need to be inoculated with P. brassicae by drenching the spore suspension to give <TEX>$1{\times}10^8$</TEX> spores/pot 1 day after chemical treatment. To develop clubroot, the inoculated plants are incubated in a growth chamber at <TEX>$20^{\circ}C$</TEX> for 2 days, and then cultivated in a greenhouse (<TEX>$20{\pm}5^{\circ}$</TEX>) for four weeks.

The intersection of conservation and horticulture: bird-pollinated Lotus species from the Canary Islands (Leguminosae)

This paper critically reviews the status of the “lotus vines” (Lotus section Rhyncholotus) in the wild and in cultivation. The literature concerning the conservation status of this group is scattered and in many places is not updated. Besides, the most recent efforts in conservation on this group have not been published in widely available sources and are mainly published in Spanish. Our aims in this paper are to compile the most recent information regarding the conservation status, studies on genetic diversity and the latest strategies for the conservation of this group. The four species are all critically endangered in the wild. Two species (Lotus berthelotii and L. maculatus) are widely cultivated in Europe and North America but the range of genotypes in cultivation is likely to be small, as the plants are propagated by cuttings. Hybrids between these two species are also in cultivation, and some have been patented. Commercial horticulture has considerable implications for overall conservation strategies, and these implications are discussed. We suggest that a circa situm conservation could improve the conservation strategies of these four species in the Canary Islands.

Plastic films for polytunnels can prolong the effective residual life of cypermethrin to over 6 months

SummarySynthetic pyrethroid insecticides are degraded almost entirely by ultraviolet (UV)-catalysed oxidation. A bioassay using the beetle Tribolium confusum duVal caged on bandages soaked in 0.04% a.i. cypermethrin showed large differences in residual insecticide-life under three plastic films available for cladding polytunnels. Cypermethrin exposed to a UV film that transmitted 70% of UVB and 80% of UVA killed all beetles for 8 weeks, compared to only 3 weeks for cypermethrin exposed in a clear plastic envelope. Cypermethrin under a UV-absorbing film that reduced the transmission of UVB and UVA to 14% and 50%, respectively, gave a complete kill for 17 weeks. Reducing the transmission of UVB to virtually zero, and that of UVA to only 3%, using a UV-opaque film prolonged the effective life of the cypermethrin residue to 26 weeks, and some beetles were still killed for a further 11 weeks. Even after this time, beetles exposed to cypermethrin from the UV-opaque treatment were still affected by the insecticide, and only showed near-normal mobility after 24 months of pesticide exposure to the UV-opaque film. These results have implications for the recommended intervals between cypermethrin treatment and crop harvest, and on the time of introduction of insect-based biological control agents, when UV-opaque films are used in commercial horticulture.