Volume 31 (2019): Issue 2 (December 2019)

The industrial production of citrus plants for ornamental use (ornacitrus) began in Italy at the end of the 1960s due to the need for many citrus nurseries to adapt their activities in a time of crisis for citriculture. Nowadays, the ornamental citrus nursery sector is a well-established industry in many European countries such as Portugal, Spain, Greece, and southern Italy. In Italy, nursery production of ornamental citrus plants has become prominent due to the gradual shutdown of many commercial citrus orchards. Currently, Italy maintains its leadership with more than 5.5 million ornacitrus plants produced annually. Ornamental citrus production regards mainly different cultivars of Citrus and Fortunella species, with lemon as the lead species. In this paper, the contribution of breeding and cultural techniques to the innovation of the sector is reported and discussed. This review aims to give an updated scientific and technical description of a sector with large competitive potential that remains still largely unexplored, pointing out its strengths and weaknesses.

The focus of our research was to evaluate different apples cultivars in terms of their biological properties and bioactive compounds content, and determine the levels of their resistance (or susceptibility) to fire blight. The properties of 10 scab-resistant apple cultivars were examined on the Žiča monastery estate (West Serbia) during the period from 2011 to 2015. The biological and chemical properties such as firmness, maturity stage, total soluble solids, total acids, total and reducing sugars, ascorbic acid content and surface blush of apple fruits were monitored. Various phenolic compounds in the tested samples were tentatively identified by LC-MS analyses. A study of generative properties included: number of flower buds, fruit mass and width, crop load, yield efficiency and yield. During the period of blooming and intensive shoot growth, artificial inoculations were carried out. For each cultivar, a fire blight score was determined by dividing the average length of necrotic tissue by the average total shoot length. In the study period, the cultivars ‘GoldRush’ (41.1 t ha⁻¹) and ‘Florina’ (35.9 t ha⁻¹) produced the highest yields, and the cultivars ‘Discovery’ (19.0 t ha⁻¹) and Selection 25/63 (15.1 t ha⁻¹) the lowest. The cultivar ‘William’s Pride’ produced the largest fruits, with an average fruit mass of 206.8 g. The earliest harvest period was recorded for the cultivar ‘Discovery’ (end of July), and the latest for the cultivar ‘GoldRush’ (beginning of October). The cultivar ‘Enterprise’ had the highest value of total phenols (432.2 mg 100 g ⁻¹ FW), while the cultivar ‘Topaz’ had the highest value of total flavanols (145.2 mg 100 g⁻¹ FW). The highest degree of susceptibility to fire blight was found in Selection 25/63, and the greatest resistance was manifested by the cultivar ‘GoldRush’. In the five-year study period, the cultivars ‘GoldRush’, ‘Rewena’ and ‘Enterprise’ exhibited better bio-chemical properties and higher levels of resistance to fire blight than the remaining cultivars.

The tulip (Tulipa sp.) is one of the most important ornamental bulbous plants, which has been cultivated as a cut-flower, potted, and garden plant, and used for landscaping in Turkey. This study investigated the occurrence of a viral disease in the tulip cultivars Strong Gold, Pretty Woman and Purple Prince that causes striping of the leaves, flames of different colours on the petals and mosaic patterns on the leaves, in Samsun province of Turkey. Surveys of virus-infected tulip plants were carried out in the Middle Black Sea Region of Turkey in 2015-2016. A total of 212 samples were collected from four locations and checked by biological, serological and molecular methods for the presence of the Tulip breaking virus (TBV). TBV was detected in the leaves and flowers by double-antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) in the tulip cultivars (15.5%) tested from Samsun province. TBV infection was found at the highest rate in the cultivar Strong Gold (19.7%), followed by Pretty Woman (14.1%) and Purple Prince (12.8%). The presence of TBV in samples was further confirmed by reverse transcription polymerase chain reaction (RT-PCR) assays. This is the first report on TBV naturally infecting tulips in Samsun province, Turkey.

The goal of this study was to assess the water needs of elderberry. The investigation included elderberry plants that had been planted in land reclamation areas more than three years earlier. The water needs were evaluated for 5 agro-climatic regions of Poland. The calculations were based on the observation of meteorological conditions in the years 1981-2010 for the period from June 1 to July 31. To determine the water needs, the plant coefficient method was applied. The Blaney-Criddle formula, which was modified for Polish conditions by Żakowicz (2010), was used to calculate the reference evapotranspiration. The plant coefficients of elderberry, adapted to the reference evapotranspiration, were adjusted to Żakowicz’s method. The rainfall deficit with the probability of occurrence: N_50%, N_25% and N_10%, was assessed in accordance with Ostromęcki’s method. The highest water needs of elderberry occurred in central-north-west (264 mm) and central-east (262 mm) Poland, while the lowest (244 mm) in the south-east region. In June, the highest total monthly water needs (119 mm) were noted for south-west Poland, whereas the lowest (107 mm) for the south-east region. In June and July, except for the central-north-west region, an upward time trend of water needs was noted throughout Poland. In June and July, the highest value (135 mm) of rainfall deficit N_50% and N_25% was estimated for the central-north-west region, while the highest rainfall deficit N_10% (269 mm) for central-east Poland. The results of the presented research find application in the planning of irrigation treatments for elderberry in Poland.

Dandelion (Taraxacum spp.) is a widely distributed weed; in China, however, dandelion has been considered to be a kind of medicinal and edible vegetable in recent years. This transition from weed to vegetable requires corresponding cultivation and management. Thus, the production of dandelion on saline land was conducted based on the evaluation of dandelion salt tolerance. Low soil salt content (< 0.3%) did not significantly affect dandelion growth, and the salt tolerance threshold of dandelion ranged from 0.4% to 0.43% according to the correlation between salt content and morphological and physiological parameters, which was for guiding the preparation of saline land for dandelion field cultivation. Different fertilizer treatments significantly affected the leaf yield of dandelion, and the maximum fresh leaf yield of ~10.5 t ha⁻¹ was obtained when urea was applied in batches at a ratio of 2:2:1 in the sowing, seedling and flowering stages, respectively. This research provided the theoretical and technical support for the cultivation on saline land, laying the foundation for further study of quality control for the cultivation of dandelion on saline land.

Quinoa is a gluten-free pseudocereal crop recognized for its exceptional nutritional properties. A 3-year field experiment was conducted to evaluate the influence of soil tillage and fertilization on root growth and productivity of quinoa. The experiment was laid out in a split-plot design with two replicates, two main plots [conventional (CT) and minimum tillage (MT)] and four sub-plots [fertilization treatments: untreated, inorganic fertilization with 100 (N1) and 200 kg N ha⁻¹ (N2), and sheep manure]. Mean weight diameter (MWD) of soil aggregates, total porosity, organic matter and soil total nitrogen increased with the long-term fertilization with sheep manure. The major part of the roots (approximately 70%) is concentrated in the 0-30 cm soil layer. Root length density increased with increased rate of applied nitrogen, and a higher value (1.172 cm cm⁻³) was found in N2 plots. Additionally, higher root mass density (1.114 mg cm⁻³) was observed under MT. Plant height and dry weight were clearly affected by fertilization, with higher values obtained in N2 plots. Moreover, it was observed that quinoa cultivated under CT and N2 treatment produced a higher seed yield (2595 kg ha⁻¹). As a conclusion, increasing the levels of applied nitrogen up to 200 kg N ha⁻¹ improves root growth and consequently the yields of quinoa.

Blue mold rot, caused by Penicillium expansum, is one of the most economically important post-harvest diseases of apple worldwide. The goals of this study were threefold: to evaluate the diversity of P. expansum isolates for mycelial growth, spore production and lesion diameter on apples; to estimate the effects of cold-storage facility conditions on P. expansum population structure; and to investigate the efficacy of three essential oils against P. expansum. The results showed that storage facilities applying fungicides and storing diverse fruit species selected for P. expansum isolates with a larger lesion diameter on apples. In addition, application of fungicides and diversification in stored fruit species significantly select for P. expansum isolates with higher levels of mycelial growth and spore production, respectively. Moreover, the diversity of host species of stored fruit accounted for 38% of the variability observed between storage facilities for the measured fitness parameters in P. expansum isolates and had a stronger effect on P. expansum population structure than fungicide treatment. Essential oils from Mentha pulegium and Syzygium aromaticum significantly decreased mycelial growth and spore production of P. expansum isolates in vitro. Mentha pulegium essential oil also significantly decreased the size of lesions associated with the blue mold rot of apples. Reducing the diversity of stored host species and applying M. pulegium essential oil may be useful in counter-selecting for aggressive P. expansum isolates and reducing losses due to blue mold rot during fruit storage.

A reduction in crop spoilage and an increase in shelf-life is the goal of effective disease control methods. This study aimed to assess ZnO-nanoparticles (ZnO-NPs) as a safe, new protectant against Rhizopus soft rot of sweet potato. ZnO-NPs had a fungicidal effect against Rhizopus stolonifer when used at concentrations above 50 ppm. The results showed that tubers treated with ZnO-NPs exhibited fewer fungal populations (1.2 CFU per segment) than those that did not receive the treatment. Tubers infected with Rhizopus stolonifer and treated with ZnO-NPs showed no visible decay for up to 15 days, indicating that ZnO-NPs act as a coating layer on tuber surface. The greatest weight loss after 15 days of storage was reported in infected tubers (8.98%), followed by infected tubers treated with ZnO (6.54%) and infected tubers treated with ZnO-NPs (3.79%). The activity of cell-wall degrading enzymes, α-amylase and cellulase, were significantly increased in both infected tubers and those treated with ZnO, compared to the tubers treated with ZnO-NPs. These results confirm that coating with ZnO-NPs is an effective method of protecting sweet potato tubers from infection, maintaining their quality and increasing their shelf-life for up to 2 months in storage.

Mexico is the centre of origin and domestication of the dahlia, which has the widest distribution worldwide as an ornamental plant; however, due to changes in eating habits in some sectors of the population (vegetarians and vegans), it has also been incorporated as an ingredient in the gastronomic field. The aim of this research was to determine the attributes of physicochemical quality, antioxidant capacity and nutritional value of ligulate flowers of some wild dahlia species. A completely randomized experimental design with five repetitions was used. Fresh weight, total titratable acidity (TTA), total soluble solids (TSS), ascorbic acid (AA), colour, total phenols (TP), total flavonoids (TFl), total anthocyanins (TAn), antioxidant capacity (AC) and proximate composition were evaluated. The highest fresh weight was observed in D. × hortorum, with similar values among its different flower colours. Likewise, D. merckii and D. coccinea stood out for their high TTA value; however, D. coccinea also had the highest AA content (0.77-0.9 mg g⁻¹ FW), TP (12.87-19.92 mg GAE g⁻¹ FW), TFl (6.78-11.32 mg QE g⁻¹ DW) and AC (47.28-60.43 mg AAEVC g⁻¹ FW). On the other hand, D. campanulata was notable for its high levels of moisture, fat and raw fibre; similarly, D. coccinea stood out for its high amounts of dry matter and total carbohydrates. The ligulate flowers of wild dahlias have a high concentration of bioactive compounds and a nutritional composition with beneficial contributions to health care, so they could be used for consumption as fresh products.

Due to the remarkable health benefits of celery (Apium graveolens), its consumption has increased over time. A partial substitution of NO₃⁻ with NH₄⁺ is recommended to limit the accumulation of NO₃⁻ in leafy vegetables. Hence, a factorial experiment with two factors, consisting of six treatments as combinations of three NH₄:NO₃ ratios (0:100, 20:80 and 40:60) in nutrient solutions and two harvesting times (in the morning and in the evening), was conducted on celery plants in a soilless culture system. The results showed that 100% NO₃ as a sole N source significantly increased plant height, leaf number, chlorophyll, fresh weight, N, K, Ca, Mg, Fe, Mn, Zn, protein, dietary fibre, soluble sugars, nitrate, vitamin C, α-carotene, β-carotene and lutein of celery plants compared to either 80 or 60% NO₃. However, this increase was not significant compared to 20% NH₄:80% NO₃ in terms of leaf number, fresh yield, N, Mg, Mn, protein, soluble sugars, vitamin C and α-carotene. Harvesting in the evening significantly increased K, Mg, Fe, soluble sugars, α-carotene and β-carotene, and lowered the nitrate level in celery plants. In conclusion, partial replacement of 20% NO₃-N with 20% NH₄-N and evening harvesting are recommended for a greater fresh yield, higher quality, and lower nitrate level.

The quality of tomato fruits is influenced by preharvest factors. Trichoderma are considered biostimulants with potential to improve growth and development in plants, as well as the quality of the fruits. The objective of this study was to evaluate the effect of foliar application of Trichoderma on the quality of tomato fruits at different cluster levels on the same plant in two commercial hybrids using three different substrates in a greenhouse. Six foliar applications of a liquid biological preparation of Trichoderma were performed at a dose of 4 mL L⁻¹ every 15 days after transplanting. The results show that the foliar application of Trichoderma increased the ratio of soluble solids to titratable acidity of the fruits at different cluster levels, which was mainly due to the decrease in acidity rather than the increase in soluble solids. The decrease in titratable acidity is in accordance with the increase in the pH of the fruits. Trichoderma have a positive effect on titratable acidity, pH and electrical conductivity of fruits. In the Cid hybrid grown in the tezontle substrate, the application of Trichoderma increased the ratio of total soluble solids to titratable acidity. At the same time, sand increased the percentage of juice in the fruits. Foliar application of Trichoderma increases the quality of tomato fruits, and as such, should be considered as a crop management option.

The aim of this work was to evaluate the yield parameters (number of fruits per plant, total yield per plant and average fruit weight), level of ascorbic acid, and pungency (SHU units) of different genotypes of chilli pepper in protected cultivation in the Czech Republic in order to identify a suitable and prospective chilli cultivar which could be recommended to the Central European growers. The experiment took place in two years (2016 and 2018) in a plastic greenhouse with 17 genotypes of the species Capsicum chinense Jacq., C. annuum L., C. baccatum L. and C. pubescens Ruiz. & Pav. From the viewpoint of yield parameters and stability of yield, ‘Habanero Red’, ‘Jamaican Yellow’, ‘Jwala’ and ‘Rocoto Orange’ can be recommended for Czech conditions. The majority of the tested cultivars were a good source of vitamin C (mostly reaching a value of at least 800 mg kg⁻¹). From the perspective of pungency, the following cultivars can be recommended: low pungency – Fish, Jalapeño, Jwala, Pimiento de Padrón and Rocoto Orange; medium pungency – Cayenne Gold, NuMex Piñata and Scotch Bonnet Orange; and high pungency – Aji Lemon Drop, Cayenne Purple, TMSR and Tricolor Variegata.

The Actinidia genus includes a number of commercial fruit species with a wide range of countries of origin. Some species such as A. arguta or A. kolomikta are characterized by a high level of resistance to frost. The aim of this study was to compare the fruit of selected cultivars of kiwiberry. In the kiwiberry fruit, sucrose was the predominant type of sugar. Citric acid was dominant in all samples; it was most represented in the pulp of kiwiberry seedlings and in the skin of kiwiberry ‘Issai’. Kiwiberry fruits feature a higher ascorbic acid content in the skin in comparison with the commercial A. chinensis cultivars. Antioxidant activity of kiwiberry fruit skin was up to 18 times higher than that of the pulp. In view of the kiwiberry fruit having no hair, it is possible to eat the whole fruit, including the skin containing substances beneficial to health.

Iodine is considered as a beneficial element for plants. As compared to the mineral form of iodine, the effect of organoiodine compounds on physiological and biochemical processes in plants is weakly recognized. This study describes the influence of different forms of iodine – mineral as KI and organic as iodosalicylates and iodobenzoates on the antioxidative and sugar metabolism of tomato plants. Plants were treated with KI and with the following organoiodine compounds: 5-iodosalicylic acid (5-ISA), 3,5-diiodosalicylic acid (3,5-diISA), 2-iodobenzoic acid (2-IBeA) and 4-iodobenzoic acid (4-IBeA). The effect of salicylic acid (SA) and benzoic acid (BeA) on plants was also tested. The plants revealed a lower tolerance to 3,5-diISA, 4-IBeA and slightly to BeA as compared to control. Tested compounds did not affect the content of ascorbic (AA) and dehydroascorbic (DHA) acid. All tested compounds, with the exception of 2-IBeA, did not affect the content of phenols, phenylpropanoids and anthocyanins in leaves. Tested compounds variously modified the activity of catalase (CAT), ascorbic peroxidase (APX) and peroxidase (POX) in leaves and roots. The content of soluble sugars in tomato leaves and roots varied depending on the combination, with a noticeable tendency to increase after the application of organoiodine compounds.