Horticultural Problems Research Articles

Morphological and Morphometric Identification of Steinernema abbasi (Nematoda: Steinernematidae) from Düzce, Türkiye

Interest in the use of nematodes as biological pest control agents has grown exponentially over the past two decades. Entomopathogenic nematodes (EPNs) (Steinernema and Heterorhabditis) have been particularly successful in managing pest problems in agriculture and horticulture. One of the most important requirements in biological control programmes is the accurate identification of pests and any beneficial organisms with biocontrol potential. The aim of this study was to identify an unknown entomopathogenic nematode that was collected from a hazelnut orchard in Düzce, Türkiye. Our study reports methods for the identification of Steinernema abbasi, based on morphological and morphometric characterization. The unknown entomopathogenic nematode, Strain 1, was identified as S. abbasi.

Vasily G. Trushechkin – founder of Russian berry growing, innovator and scientifi c leader (100 th anniversary of his birth)

The article is dedicated to the 100th anniversary of Vasily Trushechkin – Hero of the Soviet Union, Laureate of the State Prize of the Russian Federation in the field of Science and Technology, corresponding member of the Russian Academy of Agricultural Sciences, Dr. Sci. (Agric.), Professor, Director of the Regional Research Institute of Horticulture in the Non-Black Earth Zone (presently—the Federal Horticultural Center for Breeding, Agrotechnology and Nursery). He was a well-known Russian scientist who made a significant contribution to the theoretical and practical foundations of mechanized cultivation and harvesting of berry crops, as well as the production of healthy planting material of fruit and berry crops. In the years of scientific activity, Vasily Trushechkin supervised 40 candidates and 5 doctors of sciences, published 250 scientific works, as well as obtained 38 inventor’s certificates and two patents for inventions. The scientific legacy of Vasily Trushechkin still finds application today in solving modern horticultural problems.

Effect of potassium humate on the yield and N, P, K content in soil and leaves of cv. Ligol apple in Central Chernozem region

Nutrient management of high-density apple orchards remains to be a serious problem in central Russia. Enhancing apple productivity by applying higher fertilizer rates leads to an increased environmental burden and undesired consequences. Although the transition to organic farming may solve many horticultural problems, conventional methods still produce higher crop yields. One of the most pressing issues consists in reducing mineral fertilizer use by applying more organic substances. This approach allows soil fertility to be preserved while maintaining high levels of plantation productivity. In the present research, particular attention was paid to potassium nutrition of apple trees. During 2020 and 2021, we studied the effect of potassium fertilizers in various standard amounts and silicon-modified potassium humate on the state of apple trees cv. Ligol grafted on 62-396 rootstock in the experimental orchard of I.V. Michurin Federal Research Center. The orchard was planted in 2018 according to a 1.2×4.5 m pattern (1852 trees per hectare). The experimental design was as follows: control (irrigation); full standard amount of N20P6K28 fertilizers; ¾ standard amount of N15P4K21 mineral fertilizers + ½ standard amount of potassium humate, ½ standard amount of N10P3K14 mineral fertilizers + ½ standard amount of potassium humate; full standard potassium humate amount of 10 L/ha. In 2020, the introduction of potassium humate provided the maximum yield, although without significant differences compared to the use of mineral fertilizers. In 2021, the yield was also at the level achieved with mineral fertilizers. Potassium humate provided a higher nitrogen content in the leaves as compared to mineral fertilizers, largely due to a significant increase in the availability of nitrogen and potassium in the soil. The content of available phosphorus was not significantly affected. This assumes that the effectiveness of humates depends on the soil type. The combined application of reduced standard amounts of mineral fertilizers and potassium humate contributed to maintenance of high yields under with a less dramatic increase in soil acidity.

Advances in sequencing and key character analysis of mango (Mangifera indica L.).

Mango (Mangifera indica L.) is an important fruit crop in tropical and subtropical countries associated with many agronomic and horticultural problems, such as susceptibility to pathogens, including powdery mildew and anthracnose, poor yield and quality, and short shelf life. Conventional breeding techniques exhibit significant limitations in improving mango quality due to the characteristics of long ripening, self-incompatibility, and high genetic heterozygosity. In recent years, much emphasis has been placed on identification of key genes controlling a certain trait through genomic association analysis and directly breeding new varieties through transgene or genotype selection of offspring. This paper reviews the latest research progress on the genome and transcriptome sequencing of mango fruit. The rapid development of genome sequencing and bioinformatics provides effective strategies for identifying, labeling, cloning, and manipulating many genes related to economically important traits. Preliminary verification of the functions of mango genes has been conducted, including genes related to flowering regulation, fruit development, and polyphenol biosynthesis. Importantly, modern biotechnology can refine existing mango varieties to meet the market demand with high economic benefits.

Ozonated water electrolytically generated by diamond-coated electrodes controlled phytonematodes in replanted soil

Phytonematodes cause severe yield losses in horticulture, partly because they are difficult to manage. Compact, energy-efficient generators that electrochemically produce ozonated water by utilizing diamond-coated electrodes have become available. In this study, the application of on-site generated ozonated water to inactivate soil nematodes and to mitigate nematode-mediated apple replant disease was tested. Pratylenchus penetrans was highly susceptible to dissolved ozone (LC50 0.6 mg L−1). In one greenhouse experiment, treatment of P. penetrans in soil with ozonated water (0.27 mg ozone L−1 soil) reduced subsequent invasion of the nematodes into roots by 60%. Growth of apple saplings in soil that was affected by apple replant disease (ARD) was significantly improved following a treatment with 1/10 volume ozonated water compared to the control. In a second greenhouse experiment, one-time drenching of ARD soil with ozonated water was followed by improved growth of apple plants similar to that in autoclaved soil. A second application of ozonated water did not further improve plant growth. The number of active nematodes in replanted soil that moved through a Baermann filter was significantly reduced by all tested concentrations of ozone (0.12–0.75 mg L−1 soil). A fraction of 19–36% of the nematodes survived and slightly recovered after four weeks. In conclusion, on-site generated ozonated water has potential to mitigate nematode problems in horticulture and to expand management options.

Semiochemicals for Thrips and Their Use in Pest Management.

Thrips (Thysanoptera) are small insects that can cause huge problems in agriculture, horticulture, and forestry through feeding and the transmission of plant viruses. They produce a rich chemical diversity of pheromones and allomones and also respond to a broad range of semiochemicals from plants. These semiochemicals offer many opportunities to develop new approaches to pest management. Aggregation pheromones and plant-derived semiochemicals are already available in commercial products. We review these semiochemicals and consider how we can move away from using them mainly for monitoring to using them for control. We still know very little about the behavioral responses of thrips to semiochemicals, and we show that research in this area is needed to improve the use of semiochemicals in pest management. We also propose that thrips should be used as a model system for semiochemically mediated behaviors of small insects that have limited ability to fly upwind.

Coffee Somatic Embryogenesis: How Did Research, Experience Gained and Innovations Promote the Commercial Propagation of Elite Clones From the Two Cultivated Species?

Since the 1990s, somatic embryogenesis (SE) has enabled the propagation of selected varieties, Arabica F1 hybrid and Robusta clones, originating from the two cultivated coffee species, Coffea arabica and Coffea canephora, respectively. This paper shows how mostly empirical research has led to successful industrial transfers launched in the 2000s in Latin America, Africa, and Asia. Coffee SE can be considered as a model for other woody perennial crops for the following reasons: (i) a high biological efficiency has been demonstrated for propagated varieties at all developmental stages, and (ii) somaclonal variation is understood and mastered thanks to intensive research combining molecular markers and field observations. Coffee SE is also a useful model given the strong economic constraints that are specific to this species. In brief, SE faced four difficulties: (i) the high cost of SE derived plants compared to the cost of seedlings of conventional varieties, (ii) the logistic problems involved in reaching small-scale coffee growers, (iii) the need for certification, and (iv) the lack of solvency among small-scale producers. Nursery activities were professionalized by introducing varietal certification, quality control with regard to horticultural problems and somaclonal variation, and sanitary control for Xylella fastidiosa. In addition, different technology transfers were made to ensure worldwide dissemination of improved F1 Arabica hybrids and Robusta clones. Innovations have been decisive for successful scaling-up and reduction of production costs, such as the development of temporary immersion bioreactors for the mass production of pre-germinated embryos, their direct sowing on horticultural soil, and the propagation of rejuvenated SE plants by rooted mini-cuttings. Today, SE is a powerful tool that is widely used in coffee for biotechnological applications including propagation and genetic transformation. Basic research has recently started taking advantage of optimized SE protocols. Based on -omics methodologies, research aims to decipher the molecular events involved in the key developmental switches of coffee SE. In parallel, a high-throughput screening of active molecules on SE appears to be a promising tool to speed-up the optimization of SE protocols.

The Period of Leaf Level and the Conflict in Efforts to Get the Ordinary Siam Plant

The aim of this research to get a picture of the prolific bud leaves, flowering in the framework of the formation of harvest fruit Siam. Shoots are produced from cultured vegetative vegetation, I e without going through a marriage process because it comes from one parent. The critical point of the formation of the fruit is largely determined by the flowering formation process. Environmental factors and nutritional and hormonal activity in the plant and environmental factors that influence flowering are a mineral nutrient balance, temperature, sunlight intensity and photoperiod. The study was conducted from March to November 2017, in Seming Village, Kerta District, Gianyar Regency of Bali Province. The research is descriptive so there is no special treatment given to the samples. The research is done by the descriptive method that is continuous research so that there is a thorough knowledge about the horticultural cultivation problem of tropical fruit, especially the citrus fruit so that the physiology science of flowering and flowering is obtained in relation get the fruit of the harvest. The citrus varieties used in this research are Siamese orange varieties that have been 6 years old. The number of samples observed as many as 10 plants with the observation of the shoot formation period with the observation once every two days, the percentage of leaf buds, the period of leaf buds, the number of buds that developed. The results showed that the cultivation of Siam plant experienced shoot growth period during one phase of growth 3 times in one period of growth. There are 4 stages of a period of replanting that is 1). Early budgets, 2), full repayment, 3) adult mating and 4) dormancy repayment. Description of flowering development process until the formation of blossom flowers there are 5 important stages traversed by citrus plants are: 1) flower induction, 2) initiation of flowers, 3) development of flower buds towards an thesis, 4) blooming flowers 5) pollination and conception. Siam citrus plants reach the stage of reproductive development, with some or all apical meristem shoots on the branches stop producing leaves and start forming the flower parts according to the typical sequence in the formation of broad flowers apical meristem gradually decreases as the flower parts are formed in sequence. The order of the formation of the flower parts on the citrus plant lasts from the inside out, starting from sepals. Petals, stamens, and pistils. Citrus plant reaches the development stage of reproductive development with a mark of some or all of the apex buds on the branches stop producing leaves and begin to forming parts of the flower according to the typical order. In the formation of broad flowering apical meristem gradually diminishes when the flower is formed in sequence. The sequence of the formations of the flowers on the planting of Siam citrus plant from outside to inside that is ranging from sepal, petal, stamens, and pistils. In contrast to vegetative growth such as the formation of leaves that meristem apex widened again during a period of development.

Chemical quality and nutrient composition of strawberry fruits treated by γ-irradiation

Postharvest quality losses of fruits and vegetables during storage are global horticultural problems. This study evaluates the effect of gamma irradiation doses (0, 300, 600 and 900 Gy) on quality parameters and phytochemical content of strawberry fruits during storage periods at 10 °C. The data revealed the irradiation significantly reduced the fruits weight loss and decay rate at storage periods; in comparison with control (unirradiated sample) which gave the maximum value of these quality parameters. Neither radiation treatment nor storage period had significant effect on titratable acidity and pH of fruits. All treatments decreased vitamin C levels during storage but the anthocyanin contents increased gradually during the storage period and reached its highest values near the end of the storage period. Strawberry fruits treated with 600 Gy had the highest total phenolic content and antioxidant activity followed by 300 Gy. Irradiation stimulated the biosynthesis of some phenolic compounds such as, pyrogallol, gallic, catechol, chlorogenic and ellagic acid.

Observations on Manganese Deficiency and Toxicity in Some Australian Native Plants

Analysis and research on the nutrition of some Australian native plants as well as diagnostic analysis of failed native plant gardens reinforces the view that manganese (Mn) availability is a major factor in the edaphology and cultivation of Australian native species. Yellow Kandosol soils on sandstone show a unique endemic floral assemblage. These soils show low total soil Mn levels of only 20–30 mg/kg. Despite this, endemic species such as Eucalyptus haemastoma and Acacia suaveolens show greater foliar Mn levels (around 291 and 389 mg/kg, respectively) than iron (Fe) levels, with Fe/Mn ratios as low as 0.14 and 0.27. During pot trial work on artificial soils created from crushed sandstone and green waste compost that were designed to research phosphorus (P) and calcium (Ca) nutrition, some interesting data on Mn uptake were collected. Levels of foliar Mn as high as 1250 and 389 mg/kg, respectively, accumulated in E. haemastoma and A. suaveolens when soils were artificially acidified to pH 4.7 (CaCl2) using ferrous sulfate. These Mn levels were associated with visible toxicity symptoms in foliage of E. haemastoma but not in A. suaveolens. Foliar Mn in both species showed a strong inverse correlation (R2 > 0.93) with soil pH. Previous research has shown that eucalypts from this floral assemblage are prone to Mn toxicity when grown in conditions of high soil Mn availability. Diagnostic analysis of soils and foliage for a client with horticultural problems in a native plant landscape showed severe chlorosis in a wide range of native species due to Mn deficiency induced by neutral soil pH (around 7.0 in CaCl2). Such soil pHs are considerably greater than those of the plant’s natural distribution. Despite apparently elevated soil P and the appearance of what looked like P toxicity, foliar P levels were not sufficiently elevated to conclude acute P toxicity but rather simple and severe Mn deficiency. The work suggests that induced Mn deficiency and toxicity may be underdiagnosed problems in the cultivation of many Australian native plants.

Incorporating Individual Teachings (aka Individual Contact Teaching Methods) into a Sustainable Landscaping Extension Plan of Work and Report of Accomplishments

Many horticultural Extension professionals conduct numerous consulting phone calls, send e-mails, visit offices, conduct research, and visit landscapes to solve horticultural problems and concerns. Although many Extension faculty members are initially unaware that they are educating clients when providing these services, these activities should be considered major educational methods. The activities should also be planned by Extension faculty and reported in an Extension plan of work and in their annual report of accomplishments. When planned thoughtfully, communicated clearly, and evaluated appropriately, these methods of individual contact teaching can become a substantial part of an Extension program. This 4-page fact sheet was written by Laura Sanagorski, and published by the UF Department of Agricultural Education and Communication, November 2013. http://edis.ifas.ufl.edu/wc157

A Survey on Cut Flower Cultivar Trends and Horticultural Status of Lilies (Lilium Hybrids) in South Korea

This study investigated trends in lily (Lilium hybrids) cultivars and challenges for growing cut lily flowers using a survey of producers in the South Korean lily industry. A questionnaire requested information on various topics including the total growing area, length of farming experience, cultivars grown, factors considered when purchasing bulbs, cultivation systems, horticultural practices, disease and pest problems, and horticultural problems. The survey targeted the membership of the Korea Lily Producer Association and the number of respondents corresponded to 43% of all lily farmers in the country. Oriental-Trumpet (OT) hybrid ‘Yelloween’ and Oriental hybrids ‘Siberia’, ‘Medusa’, and ‘Sorbonne’ were mainly cultivated in South Korea. The main flower colors were yellow, white, and pink. Factors considered in choosing cultivars were the prices of bulbs and cut flowers affecting income of the farm. More than 90% of respondents used soil culture in a greenhouse to grow cut flowers. There were various horticultural practices used from planting to harvest. The main pests harming bulb and flower productivity were fungus gnat (Bradysia difformis) and bulb mite (Rhizoglyphus robini), and the most common horticultural problem was leaf scorch. Overall, the survey suggested that the stable production of lily bulb with low cost and high quality was required and practical techniques should be developed for increasing the cut lily production efficiency. In addition, the pests, diseases, and horticultural problems in the given local environmental conditions should be considered when breeding new cultivars and developing production technology.

Toropical Fruit Tree—Problems in Horticulture Under Plastic House—

Toropical Fruit Tree—Problems in Horticulture Under Plastic House—

Biotechnological advances in guava (Psidium guajava L.): recent developments and prospects for further research

Guava (Psidium guajava L.), an important fruit crop of several tropical and sub-tropical countries, is facing several agronomic and horticultural problems such as susceptibility to many pathogens, particularly guava wilting caused by Fusarium oxysporium psidii, low fruit growth, short shelf life of fruits, high seed content, and stress sensitivity. Conventional breeding techniques have limited scope in improvement of guava owing to long juvenile period, self incompatibility, and heterozygous nature. Conventional propagation methods, i.e., cutting, grafting or stool layering, for improvement of guava already exist, but the long juvenile period has made them time consuming and cumbersome. Several biotechnological approaches such as genetic transformation may be effective practical solutions for such problems and improvement of guava. The improvement of fruit trees through genetic transformation requires an efficient regeneration system. During the past 2–3 decades, different approaches have been made for in vitro propagation of guava. An overview on the in vitro regeneration of guava via organogenesis, somatic embryogenesis, and synthetic seeds is presented. Organogenesis in several different genotypes through various explant selection from mature tree and seedling plants has been achieved. Factors affecting somatic embryogenesis in guava have been reviewed. Production of synthetic seeds using embryogenic propagules, i.e., somatic embryos and non-embryogenic vegetative propagules, i.e., shoot tips and nodal segments have also been achieved. Development of synthetic seed in guava may be applicable for propagation, short-term storage, and germplasm exchange, and distribution. An initial attempt for genetic transformation has also been reported. The purpose of this review is to focus upon the current information on in vitro propagation and biotechnological advances made in guava.

PRODUCTION AND MARKETING PROBLEMS IN SMALL SCALE HORTICULTURAL FARMING IN BOTSWANA

PRODUCTION AND MARKETING PROBLEMS IN SMALL SCALE HORTICULTURAL FARMING IN BOTSWANA

Control of apple russeting in a warm and dry climate

SummaryRusseting is one of the more important horticultural problems in apple (Malus × domestica) production worldwide. ‘Smoothee’ (cv. Golden Delicious), the major commercial strain grown in Israel, is susceptible to russeting. Israel’s apple growing season is characterised by having a warm, dry climate, particularly during fruit set and the putative cell division stages of development. Treatment with gibberellins A4 and A7 (GA4+7) plus 6-benzyladenine (6-BA) to control russet formation has long been questioned, due to poor results in Israel. The efficacy of this hormonal treatment was re-evaluated following the induction of skin russeting by fogging trees and exposing fruit to high humidity. Fruit were most susceptible to fog-induced russeting up to 50 d after petal fall. GA4+7 plus 6-BA treatment did not reduce fruit russeting dramatically. Multiple applications, beginning at petal fall, were effective only on fruit with slight russeting. Crop marketability was not significantly improved. Growers in a warm and dry climate, similar to Israel, should give serious consideration to the costly application of GA4+7 as a routine procedure to reduce or control russet on apples.

A Comparison of Return Bloom and Nonstructural Carbohydrates, Nitrogen, and Potassium Concentrations in Moderate and Severe Alternate-bearing Pecan Cultivars

The most significant horticultural problem facing pecan producers is alternate bearing. Four pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars were chosen, two with low to moderate and two with severe alternate-bearing tendencies, to compare selected characteristics related to irregular bearing. The cultivars were Colby and Peruque (low to medium alternate-bearing tendency) and Osage and Giles (high alternate-bearing tendency). Vegetative shoots and fruit-bearing shoots in the terminal and lateral position on 1-year-old branches were tagged in October, and flowering was determined the next spring. Shoot and root samples were collected while dormant and then analyzed for organically bound nitrogen (N), potassium (K), and nonstructural carbohydrate concentrations. As expected, ‘Colby’ and ‘Peruque’ had a lower alternate-bearing tendency than ‘Giles’ and ‘Osage’. Cultivars with a low alternate-bearing tendency had a larger return bloom on the bearing shoots in the terminal position than the other shoot types. Cultivars with a high alternate-bearing tendency had a lower return bloom on bearing terminal shoots than vegetative shoots. Bearing shoots in the lateral position usually had a lower return bloom than the other shoot types regardless of cultivar. Neither root nor shoot N, K, or nonstructural carbohydrate concentrations appeared to be closely related to the alternate-bearing characteristics of the four cultivars. The unique characteristic identified for low alternate-bearing cultivars was their ability to produce as many or more flowers and flowering shoots the next year on previously bearing terminal shoots compared with previously vegetative shoots. In high alternate-bearing cultivars, return bloom of bearing terminal shoots was suppressed relative to their vegetative shoots.

Seed Storage Reserves and Glucosinolates in Brassica rapa L. Grown on the International Space Station

Although plants are envisioned to play a central role in life support systems for future long-duration space travel, plant growth in space has been problematic due to horticultural problems of nutrient delivery and gas resupply posed by the weightless environment. Iterative improvement in hardware designed for growth of plants on orbital platforms now provides confidence that plants can perform well in microgravity, enabling investigation of their nutritional characteristics. Plants of B. rapa (cv. Astroplants) were grown in the Biomass Production System on the International Space Station. Flowers were hand-pollinated and seeds were produced prior to harvest at 39 days after planting. The material was frozen or fixed while on orbit and subsequently analyzed in our laboratories. Gross measures of growth, leaf chlorophyll, starch and soluble carbohydrates confirmed comparable performance by the plants in spaceflight and ground control treatments. Analysis of glucosinolate production in the plant stems indicated that 3-butenylglucosinolate concentration was on average 75% greater in flight samples than in ground control samples. Similarly, the biochemical make-up of immature seeds produced during spaceflight and fixed or frozen while in orbit was significantly different from the ground controls. The immature seeds from the spaceflight treatment had higher concentrations of chlorophyll, starch, and soluble carbohydrates than the ground controls. Seed protein was significantly lower in the spaceflight material. Microscopy of immature seeds fixed in flight showed embryos to be at a range of developmental stages, while the ground control embryos had all reached the premature stage of development. Storage reserve deposition was more advanced in the ground control seeds. The spaceflight environment thus influences B. rapa metabolite production in ways that may affect flavor and nutritional quality of potential space produce.

POLLEN DISPERSION IN RABBITEYE BLUEBERRY

Poor fruit set is one of the most important horticultural problems of the rabbiteye blueberry industry. Rabbiteye blueberries require cross-pollination and several bee species are expected to transfer pollen from one cultivar to another. A novel method was developed to measure bee-mediated pollen dispersion in rabbiteye blueberry. Pollen diameters were used to predict the proportion of cross-pollen in bumble bees' pollen load. Bumble bees visiting blueberry flowers had low proportions of cross-pollen. It is proposed that inadequate levels of cross-pollination play a major role in the failure of rabbiteye blueberries to set adequate commercial crops. The composition of bees' pollen load changed with the phenology of the crop. Data indicate that the greatest likelihood for cross-pollination occurred around the time of maximum bloom overlap of the two studied cultivars.

Absorption of Nutrient Elements on Single-node Cutting Rose `Versillia' as Affected by Mineral Nutrient Control in a Closed Hydroponic System

The application of a closed hydroponic system for rose poses some horticultural problems. The nutrient uptake by the plants changes constantly depending upon environmental conditions and growing stages, which results in the imbalanced composition of the drained solution and aggravates root environmental conditions. This research was aimed to observe the effect of mineral nutrient control method on the nutrient solution management in a closed hydroponic system. Single-node cutting rose `Versillia' was grown in aeroponics and DFT system and was irrigated with the nutrient solution of the Univ. of Seoul (NO3 -N 8.8, NH4 -N 0.67, P 2.0, K 4.8, Ca 4.0, and Mg 2.0 me·L-1). Recirculated nutrient solution was managed by five different control method: macro- and micro-element control in aeroponic system (M&M); macroelement control in aeroponic system (M); nutrient solution supplement in aeroponic system (S); electrical conductivity (EC) control in aeroponic system (EC-A); EC control in deep flow technique system (EC-D). In the EC control method, the concentration of NO3 -N exceeds optimal range whereas P and Mg decreased at the later stage of plant growth. The overall mineral nutrient content increased with S. On the other hand, the nutrient content of root environment was maintained optimally with M&M and M.