Journal of Horticultural Research 31(2) 2023

ABSTRACT

The use of hydrogen peroxide and silver nanoparticles in horticulture

Both hydrogen peroxide and silver can oxidize organic and inorganic molecules, and this causes them to affect the metabolism of living organisms in many ways. The paper presents examples of the impact of H₂O₂ and silver on stimulating plant growth and development and increasing plants' resistance to biotic and abiotic stresses. The most underlined proposal for application in horticulture is the control of microorganisms during cultivating and storing vegetables, fruits, and flowers, aiming to replace synthetic pesticides. Preparations containing H₂O₂, silver, or both components can be widely used in horticulture for plant protection, in the form of spraying and soaking seedlings, to protect them during the time of storage, for disinfecting tubers, bulbs, and rhizomes before planting, for fogging potatoes and root vegetables during storage, for quick healing of wounds on the roots and aboveground parts of plants, after cutting and in the case of frost damage and injuries caused by winds, for disinfecting seeds, and, as stimulants of plant development and inducers of resistance to biotic and abiotic stresses. However, their practical use depends on obtaining the legislator's consent for their broader use in horticultural production.

TRANSLATION

Application of hydrogen peroxide and nanoparticle silver in horticulture

Both hydrogen peroxide and silver can oxidize organic and inorganic molecules, which causes them to affect the metabolism of living organisms in different ways. The paper presents examples of the influence of H2O2 and silver on the stimulation of plant growth and development and increasing plant resistance to biotic and abiotic stresses. The most emphasized proposal for use in horticulture is the control of microorganisms during the cultivation and storage of vegetables, fruits and flowers, in order to replace synthetic pesticides. Preparations containing H2O2, silver or both of these components can be widely used in horticulture for plant protection, in the form of spraying and soaking seedlings, in order to protect them during storage, for disinfecting tubers, bulbs and rhizomes before planting, for fogging potatoes and root vegetables during storage, for accelerated healing of wounds on roots and above-ground parts of plants that intensify after cutting and in the case of frost and wind damage, for seed disinfection and as a stimulant of plant development and an inducer of resistance to biotic and abiotic stresses. However, their practical use in horticultural production depends on obtaining the consent of the legislator.

ABSTRACT

Effects of silver, gold, and platinum nanoparticles on selected nematode trophic groups

As trophic organisms, nematodes play an essential role in the soil environment: they mineralize nutrients into plant-available forms, are a food source for other soil organisms, and feed on pathogenic organisms and plant pests, therefore regulating populations of soil microorganisms. The plant-parasitic nematodes are important pests of crops. Nanoparticles (NP) are increasingly used in agriculture and other production sectors. They are present in the soil, not necessarily in trace amounts, and can affect various soil organisms, including nematodes. In this article, the effects of silver (Ag), gold (Au), and platinum (Pt) nanoparticles on the mortality and reproduction activity of selected nematode species from two trophic groups: entomopathogenic nematodes (EPN) (Heterorhabditis bacteriophora and Steinernema feltiae) and plant parasitic nematodes (PPN) (Xiphinema diversicaudatum, Ditylenchus dipsaci, Heterodera schachtii) were studied under laboratory conditions. All nanoparticles decreased the nematode population to an extent depending on the nematode species, nanoparticle type, and exposure time. AgNP had the greatest nematicidal effect, except for AuNP, which reduced the population of H. schachtii the bridge. The greatest sensitivity to AgNP was observed in X. diversicaudatum (100% mortality), D. dipsacci (90% mortality), and 37 to 13% mortality in other species. Effect of AuNP and PtNP on entomopathogenic nematodes was comparable to the control, not treated with nanoparticles. AuNP and PtNP similarly influenced nematode mortality. However, the effect of nanoparticles on new generations of entomopathogenic nematodes developing in host larvae Galleria mellonella was inclusive. All nanoparticles decreased the number of larvae of S. feltiae and increased the number of H. bacteriophora migrating outside the cadavers compared to the control.

TRANSLATION

The effect of silver, gold and platinum nanoparticles on selected trophic groups of nematodes

As trophic organisms, nematodes play a fundamental role in the soil environment: they mineralize nutrients to forms available to plants, are a source of food for other soil organisms, feed on pathogenic organisms and plant pests, thus regulating the populations of soil microorganisms. Plant-parasitic nematodes are important crop pests. Nanoparticles (NPs) are increasingly used in agriculture and other production sectors. They occur in soil and can affect various soil organisms, including nematodes. This article presents the effect of silver (Ag), gold (Au), and platinum (Pt) nanoparticles on the mortality and reproductive activity of nematode species from two trophic groups: entomopathogenic nematodes (EPNs) (Heterorhabditis bacteriophora i Steinernema feltiae) and plant parasitic nematodes (PPN) (Xipinema diversicaudatum, Ditylenchus dipsacci, Heterodera Schachtia). The studies were conducted in laboratory conditions. All nanoparticles reduced the nematode population, to a degree dependent on the nematode species, type of nanoparticles and exposure time. The greatest nematicidal effect was shown by AgNPs. AuNPs reduced the population the most H. SchachtiaThe highest sensitivity to AgNP was observed in X. diversicaudatum (100% mortality), D. dipsacci (90% mortality) and from 37 to 13% mortality in the remaining species. The effect of AuNP and PtNP on entomopathogenic nematodes was comparable to the untreated control. AuNP and PtNP affected nematode mortality in a similar way. However, the effect of nanoparticles on new generations of entomopathogenic nematodes developing in the host larvae Gallery mellon was not clear. All nanoparticles reduced the number of larvae S. feltiae and increased the number H. bacteriophora migrating from larvae G. mellon compared to control.

ABSTRACT

Evapotranspiration estimation using machine learning methods

The study examined the performance of four machine learning algorithms (regression trees, boosted trees, random forests, and artificial neural networks) for estimating evapotranspiration (ET_o) based on incomplete meteorological data. Meteorological variables (mean and maximum air temperature, average air humidity, average level of solar radiation, vapor pressure deficit, extraterrestrial solar radiation, and day number of the year) were used as input. The simulation used two calculation scenarios: data with and without average solar radiation. The performance of the different machine learning models was evaluated using the mean squared error, root means square error, coefficient of determination, and slope of regression forced through the origin between the measured and simulated ET_o. The results demonstrated that the applied models were able to describe nonlinear relationships between weather parameters and evapotranspiration. The accuracy of evapotranspiration estimation depended on the type of input variables and the machine learning model used. The highest level of evapotranspiration prediction was obtained using the artificial neural networks model. Including solar radiation data in the calculations improved the quality of evapotranspiration prediction in all four models. In the absence of data on the actual solar radiation reaching the Earth's surface, it is advisable to supplement the input data with data on extraterrestrial solar radiation and the daily number of the year. Such an approach can be helpful in areas and situations with limited access to meteorological data.

TRANSLATION

Estimating evapotranspiration using machine learning methods

The performance of four machine learning algorithms (regression trees, boosted trees, random forests and artificial neural networks) that allow for estimating evapotranspiration (ET) was investigated._o) based on incomplete meteorological data. Meteorological variables (mean and maximum air temperature, mean air humidity, mean solar radiation intensity, vapor pressure deficit, extraterrestrial solar radiation and the number of the day of the year) were used as input data. Two calculation scenarios were used in the simulation: data containing information on the mean solar radiation intensity and data not containing such information. The performance of different machine learning models was assessed using the mean square error, root mean square error, coefficient of determination and regression slope. The results showed that the applied models are able to describe nonlinear relationships between meteorological parameters and evapotranspiration. The accuracy of evapotranspiration estimation depended on the type of input variables and the applied machine learning model. The highest level of evapotranspiration prediction was obtained using the artificial neural network model. Including solar radiation data in the calculations improved the quality of evapotranspiration predictions in all four models. In the absence of data on the actual solar radiation reaching the Earth's surface, it is advisable to supplement the input data with data on extraterrestrial solar radiation and the day of the year number. This approach can be useful in areas and situations with limited access to meteorological data.

ABSTRACT

Effects of active and passive modified atmosphere packaging on the vase life and quality of narcissus (Narcissus tazetta L.) 'Shahla' cut flowers

The production of ornamental flowers in the horticultural sector is costly; therefore, finding treatments to reduce postharvest losses and extend the vase life of cut flower is essential in this industry. The influence of modified atmosphere packaging (MAP) on the quality parameters of cut flowers of Narcissus tazetta L. 'Shahla' during storage was investigated. The following gas compositions were studied: atmospheric composition (control), vacuum + atmospheric composition, 40% CO₂ +21% About₂, 20% CO₂ +10% About₂, 40% CO₂ +40% About₂, and 0.03% CO₂ +40% About₂. All treatments showed better performance compared to the control. The results showed that 20% CO₂ +10% About₂ most increased the water uptake and relative fresh weight of cut flowers, resulting in the highest level of carbohydrates, extending the appearance quality time and vase life of cut flowers by 60%. The most extended vase life was related to cut flowers stored at 20% CO₂ and 10% O₂ (15.8 days), while the passive-MAP and vacuum packaging did not differ significantly and showed the lowest vase life, 9.2 and 9.9 days, respectively.

TRANSLATION

The effect of storage under modified atmosphere conditions on the durability and quality of cut narcissus flowers (Narcissus tazetta) 'Shahla'

The production of ornamental plants is associated with high costs, therefore it is necessary to find a way to reduce post-harvest losses and extend the life of cut flowers. The effect of storage in a modified atmosphere of cut flowers of narcissus (Narcissus tazetta L.) 'Shahla' on the quality parameters of flowers during storage. The following atmosphere compositions were tested: room conditions, vacuum, vacuum and modified atmosphere: 40% CO₂ +21% About₂, 20% CO₂ +10% About₂, 40% CO₂ +40% About₂ and 0,03% CO₂ +40% About₂. All applied treatments extended the storage capacity compared to storage in room conditions. Storage in vacuum and atmosphere with composition of 20% CO₂ +10% About₂ allowed the highest water uptake and preservation of fresh flower mass, resulting in the highest carbohydrate content, 60% longer vase life and high flower quality. The decorative value in this combination was 15,8 days, while in the passive and vacuum controls it was 9,2 and 9,9 days.

ABSTRACT

The growth activity and productivity of apple trees depending on the form of the crown and the time of pruning

The apple tree is the most common fruit crop in temperate climate zones. Modern intensive fruit cultivation involves using new, highly productive cultivars and cultivation technologies, thanks to the creation of small-sized crown shapes with increased tree numbers per hectare. Reducing planting patterns and creating more dense plantation systems can significantly improve their yields. However, the limiting factor that can reduce tree productivity and deteriorate fruit quality is the degree of crown illumination. Ensuring uniform sunlight access to all crown parts is the main task in tree formation and pruning. The study aimed to determine the effect of crown pruning at BBCH 0 (winter) and BBCH 74 (early summer) and various types of crown formation on the growth activity and productivity of 'Fuji' and 'Honeycrisp' apple trees. A significant decrease (20%) in the number of newly formed shoots in the form of the French axis crown compared to the ballerina and slender spindle crowns was found. However, their length and total growth were significantly higher. The formation of the ballerina crown (with the removal of overgrown wood in the 25 cm zone on the central conductor above the lower tier of semi-cross-branched branches) contributed to a decrease in shoot length and total growth. The introduction of crown pruning in the summer also improved crown illumination – shoot length decreased by 17% and total increase by 12%. The specific productivity per bole cross-sectional and total shoot length were the highest on the trees formed for the ballerina, followed by the slim spindle and pruned in winter and summer.

TRANSLATION

Growth and productivity of apple trees depending on the shape of the crown and the time of pruning

The apple tree is the most commonly cultivated fruit tree in the temperate climate zone. Modern, intensive cultivation of this species involves the use of new, highly productive varieties and technologies that allow for planting a large number of trees on an area of ​​one hectare. In this type of orchard, it is necessary to reduce the span of the crowns and shape them in a way that provides light to all shoots in the crown. The aim of the study was to determine the effect of winter and summer pruning and different types of crowns on the growth and fruiting of apple trees of the 'Fuji' and 'Honeycrisp' varieties. On trees trained in the form of a French axis crown, a 20% decrease in the number of newly developed shoots was observed compared to the ballerina and slender spindle crowns. However, their shoots were longer and had a significantly greater total length. Forming a ballerina crown required removing or shortening many shoots longer than 25 cm, which resulted in inhibiting the growth of entire trees. Summer pruning improved the lighting of the crown because it reduced the average length of shoots by 17% and their total length by 12%. The highest yield coefficient was characteristic of trees trained using the ballerina system, and then the slender spindle method. Regardless of the crown form, trees pruned twice, in summer and winter, were more productive than those pruned only in winter.

ABSTRACT

Detection and molecular characterization of peach latent mosaic viroid isolates infecting stone fruit trees in Poland

Field surveys were carried out to assess the incidence of peach latent mosaic viroid in nine orchards of stone fruit trees in four growing regions of Poland. Forty of 119 peaches, six of 37 apricots, five of eight nectarines and one of four plums trees tested positive by RT-PCR for this viroid. Most of the infected stone fruit trees did not show any symptoms. Leaf yellow mosaic was only noticed on 'Maycrest' peach and 'Saturn' nectarine trees, and additional symptoms of cracked fruits with corky sutures and enlarged pits were observed on one 'Maycrest' tree. One or two isolates from each orchard and each species of infected tree were selected, and together, 11 isolates of peach latent mosaic viroid were used for genetic analyses. The nucleotide sequence similarity of selected isolates found in Poland was 93.6–100%. They shared 82.0–98.8% similarity with the viroid strains from different hosts and geographical regions. The phylogenetic analysis led to the clustering of all isolates detected during this study in the most numerous represented subgroup II-A, composed of peach latent mosaic viroid strains originating from different geographic regions and host plants. Although Polish isolates were clustered in the same subgroup, some differed in length and nucleotide sequences. It was shown that the genetic variability of isolates found in Poland was unrelated to the regions of their origin. A positive signal was obtained in dot-blot hybridization of all analyzed 11 isolates.

TRANSLATION

Detection and molecular characterization of isolates of latent peach mosaic viroid infecting stone fruit trees in Poland

In nine stone fruit orchards located in four regions of Poland, surveys were conducted to assess the occurrence of peach latent mosaic viroid (PLMVd). Leaf samples were collected from 119 peach, 37 apricot, 8 nectarine and 4 Japanese plum trees for RT-PCR testing. PLMVd was detected in 40 leaf samples from peach, 6 apricot, 5 nectarine and one Japanese plum. Most infected stone fruit trees did not show any symptoms. Yellow leaf mosaic was observed only on the 'Maycrest' peach and 'Saturn' nectarine, while on one 'Maycrest' tree, fruit cracking along the corky ventral suture was additionally observed. One or two isolates were selected for further testing from each surveyed orchard and each infected tree species. Nucleotide sequence analysis of 11 PLMVd isolates showed their mutual similarity at the level of 93,6–100%, while the similarity of the sequences of the tested isolates and viroid strains from different geographical regions and host plant species was lower and amounted to 82,0–98,8%. Based on the results of phylogenetic analysis, all isolates detected in Poland were classified into the most frequently represented clade IIA, although some of them were distinguished by the length of the read sequences, as well as the nucleotide sequence. It was shown that the genetic variability of isolates occurring in Poland was not related to their regions of origin. In 11 samples for which a positive result was obtained in the RT-PCR reaction, the presence of latent peach mosaic viroid was confirmed using molecular dot-blot hybridization.

ABSTRACT

Nematicidal effect of eupatorium odor Linn. aqueous extract on burrowing nematodes (Radopholus similis) and its application to control toppling disease on Cavendish banana (Musa acuminate)

Radopholus similis (Cobb 1893) (Rhabditida, Pratylenchidae) is a common and destructive pest that causes significant yield losses in Cavendish bananas. The repeated use of synthetic pesticides to control this nematode has raised concerns about toxicity to users and the environment. An alternative approach to managing this harmful species involves using non-toxic plant-derived extracts that enhance protection against various biological constraints. In this study, aqueous extract from the leaves and stems of Eupatorium odoratum Linn. (EAEO) was used to control R. similis in banana roots under in vitro and on-plant conditions. Through direct contact and penetration experiments on roots, as well as on-plant trials, concentrations of 12500, 6250, 3120, 1560, and 780 mg DW·L^-1 EAEO were used to evaluate nematode mortality rates, infection levels in root segments (in vitro experiment), root infection, root necrosis index, shoot and root fresh weight, and growth parameters such as stem length, diameter, leaf number, and leaf surface area (on-plant experiment). The results revealed that the nematode mortality rate due to EAEO ranged from 35.3% to 90.1%, which is statistically significant compared to the mortality rate in the control treatment (16%). Significant nematode inhibition was observed in banana roots infected with R. similis and exposed to EAEO for 48 h. There were no statistically significant differences in root infection, root necrosis, and plant fresh weight between plants treated with fenamiphos and EAEO. Maximum effectiveness was observed at the 12500 mg DW·L^-1 EAEO concentration. These findings provide valuable insights into the nematicid metabolites of EAEO against R. similis. Thus, the potential of EAEO as a biocontrol agent against R. similis has been demonstrated. For future research, investigations will expand to elucidate the mechanisms of action of the essential compounds in EAEO against nematodes, determine the optimal EAEO dosage for nematode control without harm to banana plants and the environment, assess the long-term effects of EAEO on banana plants and the environment, explore the ecological impact of EAEO use in agricultural ecosystems, study the effectiveness of EAEO on various plant species, and consider the development of commercial products or formulations based on EAEO.

TRANSLATION

Nematicidal activity of the aqueous extract eupatorium odor Linn. against root nematodes (Radopholus similis) and an attempt to use it against the Cavendish banana blight (Musa acuminate)

Banana root, Radopholus similis (Cobb 1893) (Rhabditida, Pratylenchidae), is a common pest that causes significant yield losses in Cavendish bananas. The repeated use of synthetic pesticides to control this nematode raises concerns about toxicity to humans and the environment. An alternative approach to control this harmful species involves the use of non-toxic plant extracts. An aqueous extract of leaves and stems was used in this study Eupatorium odoratum Linn. (EAEO) for combating R. similis in banana roots in vitro and on plants. Nematode mortality, root infection rate, root dieback index, fresh weight of shoots and roots, and plant growth parameters such as stem length, diameter, number of leaves, and leaf area were assessed. Nematode mortality caused by EAEO ranged from 35,3% to 90,1%, which is statistically significant compared to the mortality in the control group (16%). Significant inhibition of nematode numbers was observed in infected R. similis banana roots exposed to EAEO for 48 hours. No statistically significant differences were found in root infection, root necrosis and fresh plant weight between fenamiphos and EAEO treated plants. Maximum efficacy was observed at a concentration of 12500 mg DW·L^-1 EAEO. These findings provide valuable information on the nematicidal metabolites of EAEO against R. similis. In this way, the potential of EAEO as a biocontrol agent against R. similis. Future studies will be expanded to elucidate the mechanisms of action of the key compounds in EAEO against nematodes, determine the optimal dose of EAEO to control nematodes without harming banana plants and the environment, assess the long-term impact of EAEO on banana plants and the environment, investigate the impact of EAEO use on agro-ecosystems, investigate the efficacy of EAEO on different plant species, and consider commercialization of EAEO-based products.

ABSTRACT

Changes of postharvest nutritional quality and antioxidant enzymes in 'Haribhanga' mango by Aloe true gel with chitosan and coconut oil coating during ambient storage

Mango is a well-known tropical climacteric fruit that decays rapidly. Thus, a postharvest management strategy utilizing natural and biodegradable materials is necessary to minimize crop losses. The study evaluated the coating effects of A. true gel with chitosan and coconut oil on postharvest features and mango shelf life throughout 15 days of storage at room temperature (25 ± 2 °C). Fruits were treated with the following six coatings: control (distilled water), 1.5% chitosan solution (CH) (w/v), Aloe vera gel (AV) (1 : 1, v/v), coconut oil (CO) (1 : 1, v/v), 1.5% chitosan solution + A. true gel (CH + AV) (1 : 1, v/v), and coconut oil + A. true gel (CO + AV) (1 : 1, v/v). The findings showed that the coating with A. true gel and chitosan significantly decreased decay, weight loss, respiration rate, and ethylene production compared to control. This coating improved fruit quality indicators like acidity, total soluble solids, pH, fruit firmness, and ascorbic acid content. Additionally, the phenol content and antioxidant activity decreased slightly during storage, while the control fruits demonstrated a rapid decrease in phenol content and antioxidant activity. Coated fruits significantly reduced the activity of polyphenol oxidase, whereas control fruits had the lowest catalase and peroxidase activity throughout the storage period. Coated fruit skin showed higher L* and b* values ​​than the control fruits throughout storage. These findings suggested that A. true gel with chitosan coating might preserve bioactive components and postharvest 'Haribhanga' mango fruit quality under ambient storage

TRANSLATION

The influence of gel coatings with Aloe true, with chitosan and coconut oil on the nutritional quality and antioxidant enzyme content of 'Haribhanga' mango fruit during storage at room temperature

Mango is a well-known tropical climacteric fruit that quickly loses its utility value after harvest. To minimize yield losses, a management strategy using natural and biodegradable materials is necessary. The study evaluated the effect of gel coatings with Aloe vera with chitosan and coconut oil on the durability of mango fruits stored for 15 days at room temperature (25 °C ± 2). The fruits were covered with one of five coatings: 1,5% chitosan solution (w/v), gel Aloe vera (1:1, v/v), coconut oil (1:1, v/v), 1,5% chitosan solution + gel A. vera (1:1, v/v) and coconut oil + gel A. vera (1:1, v/v). Fruits immersed in distilled water served as the control. Gel coating A. vera with chitosan significantly reduced fruit decay, weight loss, respiration rate and ethylene production compared to the control. This coating improved fruit quality parameters such as acidity, soluble solids, pH, fruit firmness and ascorbic acid content. Additionally, phenolic content and antioxidant activity decreased slightly during storage, in contrast to the control. The coated fruit showed significantly lower polyphenol oxidase activity, while the control fruit showed the lowest catalase and peroxidase activity during the entire storage period. The skins of coated fruit showed higher color index values ​​(L* and b*) during storage than the control fruit. Gel coating A. vera with chitosan proved to be the most effective in protecting bioactive components and extending the shelf life of 'Haribhanga' mango fruit during storage at room temperature.

ABSTRACT

Influence of a preharvest melatonin application on postharvest chilling injury in basil (Ocimum basil L.)

Postharvest chilling injury is a physiological disorder detrimental to produce quality and shelf-life. Basil (Ocimum basilicum L.) is susceptible to postharvest chilling injury at temperatures below 12 °C, manifesting as leaf lesions and discoloration. Melatonin, a growth regulator, has reduced postharvest chilling injury severity in produce, but its effect on basil is unknown. Here, we evaluated the impact of an exogenous preharvest melatonin application at 400 µM on basil leaves stored at 3.5 °C for 12 days. Visual parameters, including objective color descriptors, chilling injury index, and damaged surface area, as well as biochemical (total soluble solids, malondialdehyde, and total polyphenol content) and physiological (electrolyte leakage and fresh weight loss) markers for cold stress, were assessed. Melatonin-treated leaves showed reduced symptoms (15–22%) relative to the untreated control after cold storage. The biochemical and physiological parameters displayed subtle changes between treatments after storage. However, melatonin induced alterations before storage (70–90%), suggesting it acted as a stressor.

TRANSLATION

The effect of pre-harvest melatonin application on basil leaves (Ocimum basil L.) for damage caused by cooling

Cold damage during storage is a physiological disorder that negatively affects the quality and shelf life of products. Basil (Ocimum basilicum L.) is susceptible to chilling damage during storage at temperatures below 12 °C, which manifests itself as leaf spots and discoloration. The growth regulator melatonin reduces the severity of chilling damage, but its effect on basil plants is not known. In this study, the effect of pre-harvest melatonin application at a concentration of 400 µM on basil leaves was assessed. Leaves were then stored at 3,5 °C for 12 days. Visual parameters (including color descriptors, damage index, and damaged area) as well as biochemical markers (total soluble solids, malondialdehyde, and polyphenols) and physiological markers (electrolyte leakage and fresh weight loss) were assessed. Leaves treated with pre-harvest melatonin after cold storage showed 15–22% less damage compared to the untreated control. Biochemical and physiological parameters after storage showed subtle differences. Melatonin, however, induced adverse changes even before harvest in 70–90% of leaves, suggesting its action as a stressor.

ABSTRACT

Response of fresh-cut iceberg lettuce to fumigation with botanical essential oils

The study was conducted on iceberg lettuce 'Ice Wave F₁'. The effect of prestorage treatment with seven essential oils (EOs) of rosemary, peppermint, basil, thyme, marjoram, lemon, and oregano on the quality of cut lettuce was evaluated. The lettuce was fumigated with EOs for two hours in airtight containers. Two concentrations of EOs were used: 16.7 µL·L^-1 and 33.3 µL·L^-1. Fumigation with rosemary and thyme EOs lowered the browning of fresh-cut iceberg lettuce and thus the deterioration of its appearance during six days of storage. Lettuce fumigated with thyme EO scored relatively high in sensory quality and consumer acceptability. Lettuce fumigated with rosemary EO was characterized by high intensity of aroma and herbal flavor, significantly lowering its sensory rating. Marjoram EO at a dose of 16.7 µL·L^-1 resulted in the fastest browning of lettuce cut surface and relatively reduced the market value during storage. Other EOs had no significant effect on the quality of cut lettuce during shelf life. It was also found that fumigation did not change bacteria, fungi, and mold populations on fresh-cut iceberg lettuce during short-term storage. The results obtained in the study showed that fumigation with thyme oil at a concentration of 33.3 µL·L^-1 is most recommended for use in the storage of fresh-cut iceberg lettuce, but implementing these results into practice requires further research.

TRANSLATION

Response of freshly cut iceberg lettuce heads to fumigation with vegetable oils

The research was conducted on the 'Ice Wave F' iceberg lettuce.₁'. The effect of fumigation with seven types of essential oils (EO) from rosemary, peppermint, basil, thyme, marjoram, lemon and oregano on the quality of fresh-cut lettuce was assessed. Lettuce was fumigated with EO in airtight containers for two hours. Two concentrations of oils were used: 16,7 µL·L^-1 and 33,3 µL·L^-1. Fumigation with rosemary and thyme oils significantly inhibited the browning of cut iceberg lettuce, thus maintaining its better appearance during six-day storage. Lettuce fumigated with thyme oil achieved high sensory quality and a high consumer acceptance index. In lettuce fumigated with rosemary oil, an intense herbal aroma and taste were found, which significantly reduced the sensory assessment. Marjoram oil at a dose of 16,7 µL·L^-1 caused the fastest browning of lettuce edges and reduced its commercial value during storage. Other EOs had no significant effect on the quality of cut lettuce. It was found that fumigation did not cause changes in the populations of bacteria, fungi and molds isolated from freshly cut iceberg lettuce during short-term storage. The results obtained in the study showed that for the storage of freshly cut iceberg lettuce, the most beneficial is the use of thyme oil fumigation at a concentration of 33,3 µL·L^-1.

ABSTRACT

Varietal differences in wet damage of broccoli (Brassica oleracea L. var. italica) under waterlogging conditions

Broccoli is a typical wet-sensitive vegetable. Recently, precipitation levels have been unusually high in Japan, so the wet tolerance of broccoli is of great interest to farmers. The purpose of this study is to gather basic information to help with broccoli cultivation in unusual wet circumstances by investigating the varying responses of different cultivars to wet conditions. In two years of pot experiments, the early growth stage of broccoli was compared using cultivars which exhibit unique characteristics in their ability to tolerate wet conditions, and the differences in the yield were also confirmed at harvest season in a field experiment. Broccoli plants subjected to three days of waterlogging treatment exhibited wilting, yellowing, and reduced biomass. Significant interactions between the treatment and cultivar were also detected in biomass, water content, and photosynthetic ability. The 'Shigemori' cultivar showed less susceptibility to wet damage compared to the other cultivar. The trend could be observed in the head yield of a field experiment. The unique cultivars shown in this study may be helpful in broccoli cultivation and may be candidates for use as parent materials for breeding. Furthermore, the short-term pot experiment can help evaluate broccoli wet tolerance during the early growth.

TRANSLATION

Varietal differences in broccoli sensitivity (Brassica oleracea L. var. italica) for flooding

Broccoli is a typical vegetable that is sensitive to flooding. Due to the increasing rainfall in some areas, the tolerance of broccoli to excessive moisture is very important for production. The aim of this study was to collect information on the response of different broccoli varieties to flooding. In two years of pot experiments and in a field experiment, the early growth phase of broccoli and the yield of varieties with different tolerance levels were compared. Wilting, yellowing and reduced biomass were observed in broccoli plants subjected to a three-day flood treatment. Significant interactions between irrigation and variety were detected in terms of biomass, water content and photosynthetic capacity. The variety 'Shigemori' showed less susceptibility to flood damage compared to the other varieties. This trend was observed in the yield of broccoli heads in the field experiment. A short-term pot experiment can help to assess the tolerance of broccoli to flooding in the early growth phase and can be helpful in selection for breeding purposes.

ABSTRACT

Biological control efficiency of potato bacterial wilt (Ralstonia solanacearum) using selected plant extracts

The current study evaluated the effect of methanol and water extracts of tobacco (Nicotiana tabacum L.), wild marigold (Tagetes minutes L.), and garlic (Allium sativum L.) at 50 mg·mL^-1 applied at different frequencies (weekly, biweekly, and monthly) on the control of potato bacterial wilt under field conditions (two growing seasons in 2021). Weekly and biweekly application of methanol extracts from tobacco and wild marigold showed higher efficacy of biological control of the pathogen (58% and 57%) on aerial parts of potato plants than monthly application (48%). In potato tubers, weekly and biweekly application of methanol extracts caused higher biological control efficacy (75.92% and 67.39%) than monthly application (52.49%). Weekly and biweekly application of methanol extracts of tobacco and wild marigold also reduced postharvest infection and postharvest yield losses caused by potato bacterial wilt during the storage period, among other treatments. These experiments conclude that weekly or biweekly application of methanol extract from tobacco and wild marigold at 50 mg·mL^-1 is a practical approach to control potato bacterial wilt in the field and storage.

TRANSLATION

Efficiency of biological control of potato bacterial wilt (Ralstonia solanacearum) using plant extracts

The effect of methanol and aqueous tobacco extracts was assessed (Nicotiana tabacum L.), wild marigold (Tagetes minutes L.) and garlic (Allium sativum L.), at a dose of 50 mg·mL^-1, applied with different frequency (weekly, biweekly and monthly) on the control of bacterial wilt of potato in field conditions. The application of methanol extracts of tobacco and wild marigold every week and every two weeks showed higher efficacy in controlling the pathogen in the above-ground parts of plants (58% and 57%) and in tubers (75,92% and 67,39%) compared to monthly application (48% and 52,5%). Methanol extracts of tobacco and wild marigold applied every week and every two weeks reduced infections and post-harvest losses of tubers during storage. These experiments show that the application of methanol extract of tobacco and wild marigold at a dose of 50 mg·mL^-1 at weekly or fortnightly intervals can be a practical way to control bacterial wilt of potatoes during field cultivation and storage.

ABSTRACT

Effect of nutrient solution concentration on growth, yield, and fruit quality of tomato grown hydroponically in single-truss production system

The single-truss production system for tomatoes (Solanum lycopersicum L.) is a relatively new developed cultivation technology that guarantees high yields and high-quality fruit throughout the annual cycle. In this study, we examined the impact of electrical conductivity (EC) of nutrient solutions on the growth, yield, and fruit quality of tomatoes grown in a single-truss system in a hydroponic culture. Plants were supplied with nutrient solution at the following EC values: 0.8, 1.0, 1.2, and 1.4 mS·cm^-1 in the spring and summer cycles, and at 1.0, 1.2, 1.4, and 1.6 mS cm^-1 in the winter cycle. In the spring cycle, the EC of the nutrient solution increased in all treatments, particularly after pinching the main stem. Increased EC values ​​of nutrient solutions were also recorded at the 1.2 and 1.4 EC in the summer cycle and the 1.4 and 1.6 EC in the winter cycle. The leaf number per plant did not differ between treatments in all production cycles. The largest leaf area was found at the 1.2 and 1.4 EC in the spring cycle and the 1.0 and 1.2 EC during the summer. During the winter cycle, no differences in leaf area between treatments were observed. In spring, plants at the 1.2 and 1.4 EC had the highest yields and largest fruits, while during the summer, plants at the 1.0 and 1.2 EC produced the most fruit. In winter, the highest yield was found at the 1.4 EC. The soluble solids concentration (SSC) of fruit was increased at the 1.4 EC both in the spring and summer cycles, while in the winter cycle, there was no difference between the treatments. Only fruit at the 1.4 EC in the summer cycle had an increased acidity. The findings indicate that under greenhouse conditions, tomato cultivation in a single-truss system can be successful if the plants are supplied with a nutrient solution at an EC value of 1.2–1.4 mS·cm^-1.

TRANSLATION

The effect of nutrient concentration on the growth, yield and quality of tomato fruit grown in a single-shoot hydroponic system

Single-drive tomato production system (Solanum lycopersicum L.) is a relatively new cultivation technology that guarantees high yields and high fruit quality in year-round cultivation. The influence of the electrical conductivity (EC) of the medium on plant growth, yield and fruit quality of tomato in hydroponic cultivation, in the single-shoot system, was studied. In the spring and summer cycles, the plants were supplied with medium with EC values ​​of 0,8, 1,0, 1,2 and 1,4 mS cm^-1, and in the winter cycle: 1,0, 1,2, 1,4 and 1,6 mS cm^-1. In the spring cycle, especially after pinching the main shoot, the salinity of the medium increased at all initial EC values. In the summer cycle, EC values ​​increased in combinations with initial levels of 1,2 and 1,4 EC, and in the winter cycle at initial levels of 1,4 and 1,6 EC. In all production cycles, the number of leaves per plant was the same, regardless of the initial EC. The largest leaf area was observed at 1,2 and 1,4 EC in the spring cycle and 1,0 and 1,2 EC in the summer cycle. In the winter cycle, no differences in leaf area were observed depending on the EC value. In the spring cycle, the highest yields and the largest fruits were recorded in plants grown in media with initial values ​​of 1,2 and 1,4 EC, while in the summer cycle, the plants grown in media with initial values ​​of 1,0 and 1,2 EC produced the most fruit. In the winter cycle, the highest yield was obtained from plants grown in a nutrient solution with an initial value of 1,4 EC. The concentration of soluble solids (SSC) in fruits increased at an initial value of 1,4 EC, both in the spring and summer cycles, while in the winter cycle the EC of the nutrient solution did not affect this feature. Fruits on plants grown in a nutrient solution with an initial value of 1,4 EC in the summer cycle were characterized by increased acidity. The results indicate that in greenhouse conditions, tomato cultivation in a single-shoot system can be effective if the plants are supplied with a nutrient solution with an EC of 1,2–1,4 mS cm^-1.

ABSTRACT

Comparative effect of dichlorvos and ginger (Zingiber officinale L.) on the Indian meal moth (Plodia Interpunctella Hubner) feeding on Zea mays grains

Synthetic and natural insecticides have successfully controlled the Indian meal moth (Plodia Interpunctella Hübner). However, little is known about how Indian meal mothreacts in a stressed environment caused by synthetic and botanical insecticides. Therefore, this study compared the effects of dichlorvos (DDVP) and ginger (Zingiber officinale L.) rhizome extract oil on larval and adult mortality, hatchability and adult emergence, and on neurotransmitters and digestive enzymes of Indian meal moth under laboratory conditions of 75 ± 5% relative humidity and 25 ± 5 °C. The insects were exposed to different concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5% of dichlorvos and ginger extract oil for 96 h. Ginger rhizome extract oil caused 100% mortality in newly emerged adult Indian meal moths within 96 h at all concentrations. DDVP and gingerextract oil were ineffective against the third instar larval stage of the Indian meal moth, at varying concentrations that caused adult mortality. DDVP and ginger rhizome extract oil significantly affected digestive enzymes and acetylcholinesterase activities at lethal concentrations used in treatment. Protease activity was significantly increased in larvae exposed to extract oil than DDVP. Acetylcholinesterase activities in the adult insects exposed to maize grains treated with DDVP were higher than those exposed to maize treated with ginger extract oil. DDVP and the gingerextract oil have significant effects on the digestive enzymes. Nevertheless, ginger extract oil increased larval protease activity more than DDVP.

TRANSLATION

Comparison of the effectiveness of dichlorvos and ginger (Zingiber officinale L.) in the control of the granary borer (Plodia Interpunctella Hübner) feeding on corn grains

Synthetic and natural insecticides are effective in controlling the granary borer (Plodia punctella Hübner). However, little is known about its response in the stressful environment induced by the use of synthetic and plant-based agents. In this study, the effects of dichlorvos (DDVP) and ginger rhizome oil extract (Zingiber officinale L.) on the mortality of larvae and adults, hatching of larvae and emergence of adults, and on neurotransmitters and digestive enzymes of the granary borer under laboratory conditions (relative air humidity 75 ± 5%, temperature 25 ± 5 °C). The insects were exposed for 96 hours to dichlorvos and ginger oil extract at concentrations of 0,1, 0,2, 0,3, 0,4 and 0,5%. Ginger rhizome oil extract at each concentration caused 96% mortality of freshly hatched granary borer adults within 100 hours. DDVP and ginger oil extract at concentrations that caused mortality of adults were ineffective in controlling the third larval stage. DDVP and ginger rhizome oil extract at concentrations causing lethality in the experiment significantly affected digestive enzymes and acetylcholinesterase activity. Protease activity was significantly higher in larvae exposed to oil extract than to DDVP. Acetylcholinesterase activity in adult insects reared on corn grain treated with DDVP was higher than in adults reared on corn treated with ginger oil extract. DDVP and ginger oil extract had significant effects on digestive enzymes. Ginger oil extract increased larval protease activity more than DDVP.

ABSTRACT

Diptera pests occurring on vegetable crops in Poland

In Poland, the share of Diptera in the species composition of the harmful entomofauna occurring on vegetable crops ranges from 20 to 25%. They occur on all vegetables grown in Poland (over 80 species and botanical varieties). Since the systematic registration of pests inhabiting crops in Poland in 1919, over 70 species of flies have been listed as pests of vegetable plants. Species from three families dominate in terms of population and numbers: Anthomyiidae with 12 species (Delia radicum, on early and late cultivars of cruciferous vegetables, mainly broccoli, cauliflower, white cabbage, kohlrabi, and radishes; Delia platura occurs annually on beans and cucumber; old delia on onion and garlic; and Pegomya hyoscyami on beetroot), Cecidomyiidae with 10 species (two species dominate, Contarini nasturtiums and Design daily, on cruciferous vegetables), and Agromyzidae with 23 species (Liriomyza bryoniae on cucumbers, tomatoes, and peppers, and Phytomycosis gymnostoma he leeks). Short-term, gradational occurrence of some dominant species was found, including Botanophila gnava (lettuce), Chamaepsila rosae (carrot, parsley), Delia platura (asparagus, bean), Delia radicum (broccoli, cauliflower, kohlrabi, radishes, white cabbage), Phytomyza gymnostoma (leek), Oscinella frit (corn), and Suillia lurida (garlic). However, they did not affect the level of plant production in the following years of cultivation. Apart from phytophagous species, taxa with a different trophic structure are common. These are copro-, necro-, sapro-, and zoophagous species. The most were numerous flies from the Drosophilidae family (Drosophila busckii, Drosophila limbata, Scaptomyza pallida, Fanniidae (Fannia canicularis, Fannia scalaris), Heleomyzidae (Tephrochlamys tarsalis), and Muscidae (Muscina levida, Muscina stabulans, Phaonia trimaculata). Natural enemies of insects play an important role in vegetable agrocenoses. Species belonging to the order of Coleoptera beetles (Carabidae and Staphylinidae), Syrphidae, Tachinidae, and Muscidae, mainly Phaonia trimaculata larvae, play the most important role in reducing the number of Diptera. In addition, the number of phytophages is limited by other organisms, eg, Diplopoda, Nematoda, Arachnida, and pathogens of viral, bacterial, and fungal origin.

TRANSLATION

Diptera pests occurring on vegetable plants in Poland

In Poland, the share of flies (Diptera) in the species composition
The number of harmful entomofauna occurring on vegetable crops ranges from 20 to 25%. They occur on all vegetables grown in Poland (over 80 species and botanical varieties). Since 1919, when pests were systematically registered on agricultural crops in Poland, over 70 species of harmful flies have been recorded on vegetable plants. In terms of numbers, species from three families dominate. Of the 12 species of the Anthomyiidae family, the most common are Delia radicum – on early and late varieties of cruciferous vegetables (cruciferous – mainly broccoli, cauliflower, cabbage, kohlrabi and radishes), Delia platura occurs annually on beans and cucumbers, old delia – on onion and garlic and Pegomya hyoscyami – on beets. Among the 10 species of the Cecidomyiidae family (midges) on cruciferous vegetables, two predominate – Contarinia nasturtii i Dasineura will write. Among the 23 species of the Agromyzidae family (mineralocybins), the most important are Liriomyza bryoniae on cucumbers, tomatoes and peppers and Phytomyza gymnostoma on leeks. Periodic occurrence of some dominant species was noted, including Botanophila gnava on lettuce, Chamaepsila rosae on carrots and parsley, Delia platura on asparagus and beans, Delia radicum on broccoli, cauliflower, kohlrabi, radishes and white cabbage, Phytomyza gymnostoma on time, Oscinella frit on corn and Suillia lurida on garlic, but they did not affect plant production in subsequent years of cultivation. In addition to phytophagous species, taxa with different trophic specificity are found. These are copro-, necro-, sapro- and zoophagous species. The most numerous were flies from the family Drosophilidae (damp flies) – Drosophila busckii, Drosophila limbata, Scaptomyza pallida, Fanniidae (broodworms) – Fannia canicularis, Fannia scalaris, Heleomyzidae (marsh flies) Tephrochlamys tarsalis and Muscidae (flies) – Muscina levida, Muscina stabulans i Phaonia trimaculata. In reducing the number of flies, the most important role is played by insects from the order of beetles (Coleoptera), from the families Carabidae (ground beetles) and Staphylinidae (rove beetles), Syrphidae (hoverflies), Tachinidae (tachinidae) and Muscidae (flies). In addition, the number of phytophages is limited by other organisms, e.g. Diplopoda (dwarf flies), Nematoda (nematodes), Arachnida (arachnids), and pathogens of viral, bacterial and fungal origin.

ABSTRACT

Flowering phenology of shrub roses as a sensitive indicator of meteorological variability in Central Europe

Climate change and warming affect the development cycle of ornamental plants and, thus, their quality and ornamental value. The study aimed to investigate the flowering phenology of 37 cultivars of shrub roses in response to meteorological conditions based on eight years of observations. Based on 14,800 field records, we grouped shrub rose cultivars according to their dominant flowering stage as a sensitive indicator of variability in weather conditions. We also selected the rose cultivars that would retain the highest ornamental value even at increasing temperatures. The total flowering duration of the cultivars ranged from 31 to 115 days (mean 90.4 days) and was significantly positively correlated with temperature. Meteorological conditions significantly influenced individual flowering stages (FS) and a trend of changes concerning the long-term gradient was observed: the increase in temperature extended FS10 and shortened FS25, FS50, and FS75 but did not affect FS100. If the warming trend continues, the abundant flowering of roses may be shortened significantly. Rose cultivars with the longest flowering period at FS10 abundance may adapt better to rising temperatures, and, therefore may be more useful in landscape planning and management.

TRANSLATION

Flowering phenology of shrub roses as an indicator of meteorological variability in Central Europe

Climate change and warming affect the development cycle of ornamental plants, and thus their quality and ornamental value. The aim of the study was to investigate the flowering phenology of 37 park rose cultivars in response to meteorological conditions based on eight years of observations. Based on 14 field records, park rose cultivars were grouped according to the dominant flowering phase, which is a sensitive indicator of weather condition variability. Rose cultivars were also selected that retain the highest decorative value even at increasing temperatures. The total flowering time of cultivars ranged from 800 to 31 days (average 115) and was significantly positively correlated with temperature. Meteorological conditions significantly affected individual flowering stages (FS). A trend of changes was observed in the long-term gradient: temperature increase extended FS90,4 and shortened FS10, FS25 and FS50, but did not affect FS75. If the warming trend continues, the abundant flowering of roses may be significantly shortened. Rose varieties with the longest flowering period at FS100 abundance may adapt better to rising temperatures and therefore may be more useful in landscape planning and management.