Published Online: 06 Aug 2020 Page range: 125 - 133
Abstract
Abstract
The fruits of myrtle at different stages of development, namely green (G), colour break (C) and mature (M), were used to investigate the changes of fruit quality and anthocyanin composition during its development. Five anthocyanin components, such as delphinidin (Dp), cyanidin (Cy), pelargonidin (Pg), peonidin (Pn) and malvidin (Mv), were detected. Among them, the content of Dp glucoside was the highest (2.12 μg · g−1) and the content of Pn glucoside was the lowest (0.17 μg · g−1) at the green stage. The content of Cy glucoside was the highest (120.94 and 1,200.03 μg · g−1), and the content of Mv glucoside was the lowest (19.50 and 62.72 μg · g−1) at the colour break and mature stages. The single fruit weight, vertical diameter and transverse diameter at the mature stage were significantly higher than those at the colour break and the green stages by 0.87 g, 1.27 mm, 1.53 mm and 1.54 g, 3.4 mm, 3.55 mm, respectively. Fruit quality, the contents of soluble sugar and carotenoids, gradually increased with the development of fruit; and the contents were the highest at the mature stage (17.68% and 16.90 μg · L−1). The contents of titratable acidity, total phenol, flavonoids, chlorophyll a and total chlorophyll gradually decreased with the development of fruit, the content was the lowest at the mature stage (2.71 mmol · 100 g−1, 9.29 μg · g−1, 0.1%, 0.37 μg · L−1, 0.9 μg · L−1) and the content was the highest at the green stage (5.25 mmol · 100 g−1, 21.07 μg · g−1, 0.17%, 8.86 μg · L−1, 15.47 μg · L−1). The difference between the green period and the colour break period was significant.
Published Online: 13 Aug 2020 Page range: 135 - 145
Abstract
Abstract
Excess water in vineyard soils during grapevine growing season is expected to become a critical issue in Japan. The objective of this study was to investigate the effects of constantly high soil water content which was controlled at constantly more than 20% water content in soil on vegetative growth and berry quality of Cabernet Sauvignon over a 3-year growing season. A wireless sensor networking system for real-time monitoring of soil moisture was used to check that the experimental plot had constantly more than 20% water content in soil. Véraison in the experimental plot controlled at constantly high soil water content started 10 days, 4 days and 1 day later than that in the non-irrigated experimental plot in the 2017, 2018 and 2019 growing seasons, respectively. The constantly high soil water content had no notable effects on berry quality, such as berry characteristics and berry composition, at harvest compared with the non-irrigated experimental plot, although there was a certain tendency that constantly high soil water content decreased anthocyanin contents in berry skins compared with those of non-irrigated grapevines during the three growing seasons. We postulated that waterlogging damage due to the increase in soil water content by frequent rainfall would be minimised by the selection of rootstock that confers tolerance to waterlogging stress for scion cultivars and/or viticultural practices to prevent decrease in soil temperature. Also, the introduction of Internet of Things technology for monitoring water status in vineyard soil is expected to contribute to improving practical approaches to vineyard soil water management.
Published Online: 02 Sep 2020 Page range: 147 - 157
Abstract
Abstract
Sweet potato (Ipomoea batatas L.) is a new tuber crop grown in Greece. It constitutes an innovative dietary component for both humans and animals, due to its nutritional properties. The cultivation of sweet potato focuses on the growth of both tubers and plants. Nitrogen is considered an essential element for almost all crops. This study set out to compare the effect of nitrogen inhibitors on yield components of sweet potato. In the literature, it is stated that in sweet potato cultivation nitrogen mainly affects the plants’ growth such as the tuber's yield and some quality characteristics such as dry matter and protein content. To furthermore explore this particular area, field experiments took place in West Greece, during the years 2018 and 2019. Several urea combination treatments were used in the experimental process. The treatments were urea (46-0-0), urea with urease inhibitor (UI), urea with nitrification inhibitor (NI), urea with double inhibitors (UI + NI) and control (without fertilizer) in a randomised complete block design. Leaf area index (LAI) was significantly affected by the fertilizer marking the highest value of 5.35 under urea + UI + NI treatment. Marketable yield was profoundly affected by the fertilizer in the experimental years and ranged from 18,180 to 23,230 Kg · ha−1 whereas non-marketable yield was not affected by the fertilizer. A considerable impact of fertilizers was noticed on yield where the highest value was 30,923 Kg · ha−1 under urea + NI + UI treatment. The percentage of nitrogen on tubers and upper parts was significantly affected by the fertilizers. Nitrogen markers, such as nitrogen use efficiency (NUE), nitrogen harvest index and nitrogen agronomic efficiency (NAE), were used to evaluate nitrogen release. A significant positive correlation was noticed between marketable yield and NUE (0.774). Also, the significant increase in yield showed a positive correlation with NAE (0.727). For yield components of sweet potato, the highest values were observed in urea with double inhibitors treatment in both experimental years.
Published Online: 07 Sep 2020 Page range: 159 - 170
Abstract
Abstract
Two okra cultivars (Chinese green and Chinese red) were subjected to salt stress for 12 weeks. Salt stress treatments T1 (20.8 mM), T2 (103.3 mM), T3 (180.0 mM) and T4 (257.0 mM) were applied with equal proportions of NaCl and CaCl2 in Hoagland nutrient solution. Salt stress significantly affects photosynthesis, transpiration, stomatal conductance, water use efficiency, water potential, plant height, root length, fresh weight and dry weight of both okra cultivars in every salt stress treatment. At T2, T3 and T4, Chinese red plants maintained their physiological and growth traits up to Weeks 9, 6 and 3, respectively; beyond these salt-stress durations, growth reductions were found. Similarly, Chinese green plants maintained their growth up to Weeks 9, 5 and 3, respectively, at T2, T3 and T4 treatments. In comparison, Chinese red showed more tolerance than Chinese green. According to the results, the third and ninth weeks are the tolerance threshold limits for both cultivars to sustain their physiological traits and growth under T4 and T2 salinity treatments. Similarly, Chinese red has the threshold limit to bear T3 treatment up to the eighth week and Chinese green, up to the fifth week. Thus, this study provides a new method to determine the threshold value of crops with respect to duration under salt stress. This finding would be useful in the field of water saving and utilisation of saline water resources.
Published Online: 17 Oct 2020 Page range: 171 - 178
Abstract
Abstract
The ripening process of two grape varieties in the vineyard located in the Sandomierz region was examined. In 2015, the ‘Regent’ and the ‘Sibera’ varieties reached physiological ripeness on 30th September and 3rd October, respectively. On both harvest dates, in addition to soluble solids content, titratable acidity, and pH, the macronutrient content was also determined. In the phase of physiological ripeness, the ‘Sibera’ variety showed higher acidity (1.02 g · 100 mL−1) compared with the ‘Regent’ (0.87 g · 100 mL−1). A higher soluble solids content was found in the ‘Regent’ (20.4°Brix), and slightly lower in the ‘Sibera’ (18.1°Brix). The must of the ‘Regent’ had a higher pH (3.5). This variety also had higher macronutrient contents (K, Ca and Mg). Grapes harvested after 3 weeks (late harvest) showed higher values of sugars, pH, K, and P for both varieties. However, their titratable acidity content, and Ca and Mg contents decreased. Microscopic examination showed differences in mycelial growth of Botrytis cinerea on grape bunches for both of the varieties left for the late harvest. The mycelial growth promoted faster dehydration of the ‘Sibera’ berries. Spot chemical analyses of ‘Sibera’ berry peel performed using EDS (energy dispersive spectroscopy) showed the occurrence of elevated contents of potassium, phosphorus, sulphur, magnesium and silicon. Around skin cracks, sugar crystals as well as hard-to-identify microcrystals were formed containing potassium. On the surface of the ‘Regent’ berries, potassium, and traces of phosphorus, silicon, magnesium, sulphur and calcium were found.
Published Online: 10 Sep 2020 Page range: 179 - 188
Abstract
Abstract
This research was carried out to examine the effects of different doses of bacterial formulation comprised of a mixture of Bacillus megaterium TV-91C, Pantoea agglomerans RK-92 and Kluyvera cryocrescens TV-113C strains on the plant development and bract quality of poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch), which are one of the most important potted plants grown for their fleshy bracts of the horticultural sector. The study was carried out in a climate-controlled research greenhouse from 8 August 2018 to 15 January 2019 in Erzurum (Turkey). Rooted cuttings of poinsettia [E. pulcherrima Willd. ex Klotzsch cv. Christmas Feelings (CvF)] were used as plant materials in the study. Each of the solutions containing bacterial suspensions 52.5 (T1), 105 (T2), 210 (T3), 420 (T4) and 840 (T5) mL · L−1 of water was diluted 5 times with water and 200 mL · pot−1 was applied to the plant rhizosphere. This study revealed that positive changes incurred in plant height, main flower stem length, plant crown width, bract diameter, green leaf and bract leaf area, leaf total nitrogen content and nitrate reductase enzyme activity parameters in poinsettia plants with increasing doses of the bacterial formulation. This effect has reached the maximum level in the number of bracts, main flower stem length, bract diameter, nitrate reductase enzyme activity, plant fresh weight and maximal root length parameters with the T5 application which has the highest bacterial formulation concentration. The most efficient application of glutamine synthetase enzyme activity was determined as T4.
Published Online: 19 Sep 2020 Page range: 189 - 202
Abstract
Abstract
Cornelian cherry fruits are quite rich in bioactive compounds. Natural colour, rich flavonoids and anthocyanins and high antioxidant activity have made the fruits a natural drug. In the present study, antioxidant activity, total flavonoids and total phenolics of naturally growing 18 cornelian cherry genotypes with different phenotypic characteristics were determined. Size and shape parameters of the genotypes were also determined with the image-processing method; sphericity, elongation and shape index were calculated and shapes of two-dimensional fruit images were compared with elliptic Fourier analysis. Antioxidant activity, total flavonoid contents and total phenolic amounts of the genotypes were varied between 55.062 and 152.420 mmol TE · kg−1, 286.40 and 2,882.80 mg QE · kg−1, and 2,644.80 and 12,959.00 mg GAE · kg−1, respectively. Multivariate variance analysis conducted based on physical characteristics revealed that six genotypes were different from the others. Shape analysis with Elliptic Fourier method revealed that the majority of present cornelian cherry genotypes had an oval appearance and a small portion of them had a drop-like appearance. According to discriminant analysis and Hotelling's pair-wise comparison tests, there were five different shape groups for present genotypes. A single genotype was placed into one of these groups, thus it was determined that this genotype was totally different in shape from the others.
Published Online: 30 Sep 2020 Page range: 203 - 219
Abstract
Abstract
Iodine (I) has a beneficial effect on plant growth, development and antioxidant activity. The study aimed to compare iodine uptake after the application of iodobenzoates (2-iodobenzoic acid (2-IBeA), 4-iodobenzoic acid (4-IBeA) and 2,3,5-triiodobenzoic acid (2,3,5-triIBeA)) as well as potassium iodide (KI) to tomato seedlings. One of the main tasks was to evaluate how the tested compounds applied in different concentrations (5, 10, 25 and 50 μM) affect the growth and antioxidative potential of tomato seedlings. Negative effect on growth and development of tomato seedlings was noted for 4-IBeA applied in 10–50 μM I concentrations. The 2,3,5-triIBeA application affected shoot deformation. All tested iodine compounds increased iodine level in leaves and roots of tomato seedlings. Iodine after KI application was accumulated mainly in leaves, while after iodobenzoates treatment in roots of tomato seedlings, which is probably related to their weaker transport to the upper parts of the plant. Tested compounds variously modified the content of ascorbic and dehydroascorbic acids in tomato leaves depending on applied concentration. KI treatment improved ascorbate peroxidase activity, but all iodobenzoates decreased APX and catalase activity in leaves. 4-IBeA (5 μM I) and 2,3,5-triIBeA (25 and 50 μM I) increased guaiacol peroxidase activity in leaves. It can be concluded that mechanisms responsible for plant oxidative metabolism were variously affected by the iodine compounds and its concentration in the nutrient solution.
Published Online: 30 Sep 2020 Page range: 221 - 227
Abstract
Abstract
A good peach fruit should have properties of high quality, as these properties directly affect the shelf life. This study aims to determine the effects of different salicylic acid (SA) treatments in the pre-harvest period on the ‘Cresthaven’ peach cultivar on the fruit quality at harvest and after storage at 2°C (8 days) plus shelf life at 20°C (2 days). Fruits with SA treatments have better characteristics such as fruit weight, fruit flesh firmness, total antioxidant content, total phenol content and titratable acidity level at harvest and after storage plus shelf life. With treatments, no changes were observed in the total soluble solids both at harvest and after storage plus shelf life. SA treatments decreased loss of fruit flesh firmness and loss of acidity after shelf life, compared with the control. In fruits with 2 mM SA acid treatment, the reduction in fruit firmness and acidity loss were the least, and as a result of the study it was determined as the most effective pre-harvest SA concentration that could be used in the ‘Cresthaven’ peach variety.
Published Online: 03 Oct 2020 Page range: 229 - 239
Abstract
Abstract
Progression of the vegetation period and change of year are associated with variations in general climatic parameters, such as temperature, atmospheric pressure, humidity, radiation, precipitation, wind speed and others. Only limited knowledge is available about the effects of these parameters on the characteristics of quality of fruits especially those with successive ripening such as goji berry. In our study, fruits of goji berry were characterised based on physico-chemical properties within four different harvest periods, in two consecutive years. Based on the obtained results, it was found that the pomological characteristics were superior at the beginning of the production season, while the phytochemical properties were better at the end. Fruit length, width and weight characteristics were noted to decrease from the first harvest to the last by 21%, 18% and 33%, respectively, while the total anthocyanin, phenol and antioxidant activity properties increased by 264%, 48% and 105%, respectively. There was a decrease in fruit weight, fruit length and fruit width up to 15.9%, 18.3% and 6%, respectively and were directly associated with yield due to sink competition among fruits. Providing high ripening index that ensures more acceptable fruits, with high soluble solid content (SSC) and titratable acidity (TA) seems to be a very important breeding objective to meet consumer demands thanks to superior organoleptic quality. According to correlations, the synthesis of phenolic compounds increased in parallel with SSC rise and TA, which improved pomological properties too. It is thought that the obtained results may indicate the cultural processes and evaluation methods to be used for the harvested fruits.
Published Online: 07 Oct 2020 Page range: 241 - 254
Abstract
Abstract
Terrestrial plants are constantly exposed to multiple environmental signals that influence their metabolism. Among these signals, nitrogen (N) nutrition and light affect importantly diverse metabolic and physiological processes. Herewith the effects of N nutrition (8.47, 12.71 and 16.94 mg · L−1 N) and shading percentages (0 and 70%) on plant morphology and chemical composition of the essential oil of marigold (Tagetes erecta L.) ‘Inca’ were assessed. Increasing N levels enhanced the number of secondary branches and the flower diameter, while shading reduced height of side branches, number of primary branches and opened flower buds. In leaves, flowers and stems, 15 different compounds were identified. In leaves, low and medium N levels and high light level increased the synthesis of ocimene, limonene and piperitone. As well, medium and high N doses, independently of the light level, stimulated the synthesis of caryophyllene and β-phellandrene in leaves. Nevertheless, increasing N doses and shading level decreased the synthesis of β-myrcene and α-pinene in leaves. In flowers, medium N level and high light intensity increased the synthesis of trans-pinene. Piperitone and verbenone were identified only in flowers of plants with high N doses and lower light intensity. In the stems, caryophyllene, piperitone and β-farnesene were more abundant with medium and high N levels. The interaction of study factors differentially affected both morphological variables and the composition of essential oil among organs studied. Therefore, N nutrition and light intensity are key factors that modify the morphology and composition of the essential oil in T. erecta.
Published Online: 16 Oct 2020 Page range: 255 - 264
Abstract
Abstract
Auricularia cornea, jelly mushroom, is a popular ingredient of traditional Chinese cuisine. This study aimed at evaluating the growth, yield, biological efficiency, total phenolic and flavonoid contents, the antioxidant activity, elemental composition, and molecular structure of the wild and domesticated strain Ac24 and the commercially cultivated edible mushroom A. cornea strains Ac1, Ac3 and Ac15. Based on the weight of the fresh fruiting bodies of A. cornea strains, the maximum yield was obtained from commercial strain Ac1 (237.10 g), followed by Ac3 (224.47 g), Ac15 (158 g) and Ac24 (132.37 g), while the biological efficiency range of A. cornea strains was 52.94–94.84%, with significant differences among the A. cornea strains. Our results revealed that Ac24 contained the highest phenolic content (20.10 mg GAE · g−1), while the highest flavonoid content was found in Ac1 (35.13 mg CE · g−1). The maximum mineral contents and the strains were as follows: copper (7.2 mg · kg−1) and zinc (310 mg · kg−1) in Ac1, manganese (788 mg · kg−1) in Ac3 and iron (310 mg · kg−1) in Ac24. DPPH assay found maximum antioxidant activity in Ac24 (IC50 0.233 mg TX · mL−1), FRAP (591 mg TX · g−1) in Ac15, and erythrocyte haemolysis in Ac24. SEM-EDX and FTIR analyses verified the differences among A. cornea strains. The results revealed that wild, domesticated A. cornea strain Ac24 is a promising dietary source of natural antioxidants and is of high nutritional value, compared to commercially cultivated strains.
Published Online: 17 Oct 2020 Page range: 265 - 278
Abstract
Abstract
No-tillage (UT) and tillage (TL) influence melon (Cucumis melo L.) production. However, the mechanism of improving the soil quality under UT in melon production is still unavailable. In this study, we attempted to explore the effects of UT and TL treatments on soil fertility and the microbial abundance and diversity in planting melon under greenhouse condition. Soil properties were determined and the bacterial v4-v5 16S rRNA and the fungal internal transcribed spacer gene were pyrosequenced by extracting greenhouse soil DNA. Results showed that the two treatments had different effects on nutrient uptake in melon plants under facility conditions. Additional nitrogen (N) was absorbed in the leaves and fruit in UT treatment. However, the N content in the UT treatment was kept as similar to that of the TL treatment. The phosphorus (P) contents in melon plant leaves and fruits in the UT treatment were higher than those in the TL treatment. High potassium (K) contents were observed in fruits and melon stem under the UT and TL treatments, respectively. Soil pH, organic matter and the available N influenced the bacterial and fungal distributions. The total N, total P and total K in melon plants were correlated with the bacterial and fungal groups in facility soils. The UT treatment had a substantial effect on the microbial diversity in soils planted with melon. Our study provided insights into the response of soil fertility and microbial structures to UT and TL treatments under greenhouse soils, which may aid in managing greenhouse soil quality.
Published Online: 06 Nov 2020 Page range: 279 - 290
Abstract
Abstract
Anthocyanins are important bioactive supplements that are consumed from multiple foods and beverage products. Screening tea cultivars producing a high level of anthocyanins can help to enrich the edible bioactive supplements. ‘Zijuan’ (ZJ) is a tea cultivar growing purple shoots rich in anthocyanins, but it is susceptible to freezing winter and sprouts late in spring. Hybridisation using ‘ZJ’ as the female parent and an early sprouting cultivar ‘Wuniuzao’ as the male parent was carried out, and four hybrids with purple leaves were obtained. The quality of anthocyanins, catechins, caffeine and amino acids in shoots with three leaves and a bud of the purple leaf hybrids obtained were determined based on the field investigation on sprouting time in spring, winter resistance and leaf yield. It showed that hybrid ‘B-2’ sprouted earlier in the spring, contained a higher level of anthocyanins and also showed good performance in winter resistance than its female parent ‘ZJ’. It also showed that black tea processing induced a marked decrease in foliar anthocyanins, but green tea processing had little effect on the foliar anthocyanins. Purple tea leaves should be prepared into unfermented green tea instead of fermented black tea to preserve the high level of anthocyanins in the final tea products.
Published Online: 20 Nov 2020 Page range: 291 - 305
Abstract
Abstract
The aim of this study was to examine the influence of shoot age on biological and chemical properties of 11 red currant cultivars (‘Jonkheer van Tets’, ‘Junifer’, ‘London Market’, ‘Makosta’, ‘Mirana’, ‘Redpoll’, ‘Rolan’, ‘Rondom’, ‘Rovada’, ‘Slovakia’ and ‘Stanza’) with different origins and ripening times. Phenological observations and pomological characteristics were studied and chemical analysis was conducted from 2013 to 2018 at experimental fields near Belgrade, Serbia. The total contents of phenols and anthocyanin were estimated spectrophotometrically, while quantitative analysis of anthocyanin aglycones was done using high-performance liquid chromatography. Three-year-old shoots had an earlier start of all examined phenological stages, better generative potential, higher yields, as well as higher total phenol and vitamin C contents in the fruits, compared with 2-year-old shoots, for all cultivars. The contents of total anthocyanins were higher in berries on younger shoots of early-ripening cultivars, while late-ripening cultivars had higher contents of total soluble solids and cyanidin in the berries on 3-year-old shoots. Principal component analysis demonstrated that the most important variables that distinguished 2-year-old shoots from 3-year-old shoots were those related to phenological data, cluster traits, total acids and yields. According to the obtained results, ‘Junifer’ (with the highest number of clusters), ‘Mirana’ (with the highest sugar content and sugar/acid ratio), ‘Redpoll’ (with the highest physical traits of cluster and berry), ‘Slovakia’ (with the highest yield and yield efficiency) and ‘Rovada’ (with the highest level of secondary metabolites) are recommended as the most promising cultivars for growing in the temperate region of Serbia.
Published Online: 20 Nov 2020 Page range: 307 - 317
Abstract
Abstract
Delphinium yunnanense is an endemic species in the Yunnan Province of China, while Delphinium elatum ‘Guardian Blue’ is widespread as cut flowers in the world. They all bloom attractive blue flowers, which are a crucial ornamental trait for floriculture. In this experiment, the cross-compatibility between D. yunnanense and D. elatum was characterised and evaluated. The results showed that a strong cross-incompatibility was observed in D. yunnanense × D. elatum, resulting in hybrid sterility. The F1 hybrid generation produced neither fruits nor seeds. The cross-incompatibility of the hybrids resulted from the disturbed structure of the pollen tubes penetrating pistil style and callose deposits on stigma and in style. Moreover, the germination rate of D. elatum × D. yunnanense F1 seed was lower than their own allogamic crosses, although there was no difference in fruit set rate. The results confirmed the cross-incompatibility between D. yunnanense and D. elatum, suggesting that D. elatum is more suitable as a maternal parent for hybridisation breeding. Our study characterised and evaluated the interspecific cross-compatibility through the pollen–stigma interaction and the reproductive system in Delphinium, which could provide the basis for the development and utilisation of potential ornamental traits in Delphinium.
Published Online: 24 Nov 2020 Page range: 319 - 335
Abstract
Abstract
We determined the abundance, species composition, sex ratio and seasonal dynamics of thrips on one cultivar of Welsh onion (Allium fistulosum) and eight cultivars of onion (Allium cepa) in South Poland within three vegetation seasons (2014–2016). Nine species of Thysanoptera were identified on A. cepa and A. fistulosum. Irrespective of the onion cultivar, Thrips tabaci was the dominant species (64.4% of all collected thrips specimens), while Frankliniella intonsa also occurred in high numbers (28.3%). Conversely, Welsh onion was most often inhabited by F. intonsa (62.7%), although T. tabaci was also numerous (28.3%). The predatory Aeolothrips intermedius accounted for 4.5% on A. cepa and 2.9% on A. fistulosum. In the most numerous species, T. tabaci, F. intonsa and A. intermedius populations were formed mainly by females. The cultivar most colonised by thrips was Kroll of A. fistulosum. The tested cultivars of A. cepa demonstrated varying degrees of attractiveness to thrips in the subsequent years. The relationship between populations of T. tabaci, F. intonsa and A. intermedius changed in the subsequent months of the growing season. In June, mainly T. tabaci and F. intonsa occurred on onion plants, while from July, the percentage shares of F. intonsa and the predatory A. intermedius in the thrips population on many onion cultivars increased. The level of attractiveness of A. cepa related to onion thrips, which is reported as a main pest of onion, varies depending on the year and cultivar.
Published Online: 24 Nov 2020 Page range: 337 - 350
Abstract
Abstract
This research was designed to test the combined efficacy of hot water dipping (HWD) and leaf extracts of Cistus creticus L. subsp. creticus on the storage quality of fresh Valencia oranges. Experiments were laid down according to a completely randomised design with 10 different treatments. Five replications, with five fruits in each replication, were used in the current study, and research was designed to continue for 150 days. Quality characteristics were observed with 30-days interval. The applications of this study were (1) Control [dipping in water at 25°C for 5 min]; (2) HWD at 50°C for 5 min; (3) HWD + Additives (A) [Arabic gum (0.2%), potassium sorbate (0.05%), citric acid (0.05%) and vitamin C (0.05%)] at 50°C for 5 min; (4) Additives alone at 25°C for 5 min; (5) 1.0% C. creticus leaf + HWD + A; (6) 1.0% C. creticus leaf + A; (7) 0.5% C. creticus leaf + HWD + A; (8) 0.5% C. creticus leaf + A; (9) 0.5% C. creticus leaf + HWD and (10) 0.5% C. creticus leaf. According to the results obtained, both the HWD and C. creticus, alone or in combination, were effective in preserving orange weight during storage, preventing pathogenic decay, maintaining visual quality and fruit firmness, delaying the reduction in titratable acidity, increasing ascorbic acid content and reducing respiration rate of the orange fruits. Results also suggested that the combined effect of HWD with C. creticus leaf extracts provided the highest efficacy.
Published Online: 31 Dec 2020 Page range: 351 - 362
Abstract
Abstract
This study aimed to evaluate yield parameters, antioxidant activity (AOA), total polyphenol content (TPC) and total soluble solids (TSS) in beetroot cultivars with different flesh colours. Field experiments were established at the Slovak University of Agriculture in Nitra in 2016 and 2017. Within the study, 16 beetroot cultivars were tested, including 11 red-fleshed (‘Boltardy’, ‘Boro’ F1, ‘Crosby Egyptian’, ‘Cylindra’, ‘Detroit Globe’, ‘Detroit 2’, ‘Egyptian Turnip Rooted’, ‘Opolski’, ‘Pablo’ F1, ‘Renova’ and ‘Taunus’ F1), 2 yellow-fleshed (‘Boldor’ F1 and ‘Golden’), 2 white-flesh cultivars (‘Albino’ and ‘White Detroit’) and 1 red-white fleshed cultivar (‘Chioggia’). All beetroot cultivars with red flesh colour showed higher AOA and TPC than different-coloured beetroot cultivars. The highest root yield was found in the white-fleshed beetroot cultivar ‘Albino’ (37.80–41.91 t · ha−1). The highest root weight was found in the white-fleshed beetroot cultivar ‘White Detroit’ (362.4–412.1 g). The highest AOA (819.19–972.50 mg TEAC · kg−1 d.w.) and TPC (2,387.70–2,731.00 mg · kg−1 d.w.) were found in the red-fleshed beetroot cultivar ‘Pablo’ F1. Different-coloured cultivars of beetroot were characterised by a lower content of TSS (6.4–8.8 ºBRIX) than cultivars with typical, red flesh colour (7.8–10.8 ºBRIX). Results clearly indicate that cultivar, or flesh colour, is showed as a significant factor influencing the quality of beetroot. Knowing of yield potential and quality of beetroot cultivars is important for growers as well as consumers. Results of this study indicate that white-fleshed cultivars of beetroot are characterised by high yield potential but lower quality, including lower AOA, TPC and TSS.
The fruits of myrtle at different stages of development, namely green (G), colour break (C) and mature (M), were used to investigate the changes of fruit quality and anthocyanin composition during its development. Five anthocyanin components, such as delphinidin (Dp), cyanidin (Cy), pelargonidin (Pg), peonidin (Pn) and malvidin (Mv), were detected. Among them, the content of Dp glucoside was the highest (2.12 μg · g−1) and the content of Pn glucoside was the lowest (0.17 μg · g−1) at the green stage. The content of Cy glucoside was the highest (120.94 and 1,200.03 μg · g−1), and the content of Mv glucoside was the lowest (19.50 and 62.72 μg · g−1) at the colour break and mature stages. The single fruit weight, vertical diameter and transverse diameter at the mature stage were significantly higher than those at the colour break and the green stages by 0.87 g, 1.27 mm, 1.53 mm and 1.54 g, 3.4 mm, 3.55 mm, respectively. Fruit quality, the contents of soluble sugar and carotenoids, gradually increased with the development of fruit; and the contents were the highest at the mature stage (17.68% and 16.90 μg · L−1). The contents of titratable acidity, total phenol, flavonoids, chlorophyll a and total chlorophyll gradually decreased with the development of fruit, the content was the lowest at the mature stage (2.71 mmol · 100 g−1, 9.29 μg · g−1, 0.1%, 0.37 μg · L−1, 0.9 μg · L−1) and the content was the highest at the green stage (5.25 mmol · 100 g−1, 21.07 μg · g−1, 0.17%, 8.86 μg · L−1, 15.47 μg · L−1). The difference between the green period and the colour break period was significant.
Excess water in vineyard soils during grapevine growing season is expected to become a critical issue in Japan. The objective of this study was to investigate the effects of constantly high soil water content which was controlled at constantly more than 20% water content in soil on vegetative growth and berry quality of Cabernet Sauvignon over a 3-year growing season. A wireless sensor networking system for real-time monitoring of soil moisture was used to check that the experimental plot had constantly more than 20% water content in soil. Véraison in the experimental plot controlled at constantly high soil water content started 10 days, 4 days and 1 day later than that in the non-irrigated experimental plot in the 2017, 2018 and 2019 growing seasons, respectively. The constantly high soil water content had no notable effects on berry quality, such as berry characteristics and berry composition, at harvest compared with the non-irrigated experimental plot, although there was a certain tendency that constantly high soil water content decreased anthocyanin contents in berry skins compared with those of non-irrigated grapevines during the three growing seasons. We postulated that waterlogging damage due to the increase in soil water content by frequent rainfall would be minimised by the selection of rootstock that confers tolerance to waterlogging stress for scion cultivars and/or viticultural practices to prevent decrease in soil temperature. Also, the introduction of Internet of Things technology for monitoring water status in vineyard soil is expected to contribute to improving practical approaches to vineyard soil water management.
Sweet potato (Ipomoea batatas L.) is a new tuber crop grown in Greece. It constitutes an innovative dietary component for both humans and animals, due to its nutritional properties. The cultivation of sweet potato focuses on the growth of both tubers and plants. Nitrogen is considered an essential element for almost all crops. This study set out to compare the effect of nitrogen inhibitors on yield components of sweet potato. In the literature, it is stated that in sweet potato cultivation nitrogen mainly affects the plants’ growth such as the tuber's yield and some quality characteristics such as dry matter and protein content. To furthermore explore this particular area, field experiments took place in West Greece, during the years 2018 and 2019. Several urea combination treatments were used in the experimental process. The treatments were urea (46-0-0), urea with urease inhibitor (UI), urea with nitrification inhibitor (NI), urea with double inhibitors (UI + NI) and control (without fertilizer) in a randomised complete block design. Leaf area index (LAI) was significantly affected by the fertilizer marking the highest value of 5.35 under urea + UI + NI treatment. Marketable yield was profoundly affected by the fertilizer in the experimental years and ranged from 18,180 to 23,230 Kg · ha−1 whereas non-marketable yield was not affected by the fertilizer. A considerable impact of fertilizers was noticed on yield where the highest value was 30,923 Kg · ha−1 under urea + NI + UI treatment. The percentage of nitrogen on tubers and upper parts was significantly affected by the fertilizers. Nitrogen markers, such as nitrogen use efficiency (NUE), nitrogen harvest index and nitrogen agronomic efficiency (NAE), were used to evaluate nitrogen release. A significant positive correlation was noticed between marketable yield and NUE (0.774). Also, the significant increase in yield showed a positive correlation with NAE (0.727). For yield components of sweet potato, the highest values were observed in urea with double inhibitors treatment in both experimental years.
Two okra cultivars (Chinese green and Chinese red) were subjected to salt stress for 12 weeks. Salt stress treatments T1 (20.8 mM), T2 (103.3 mM), T3 (180.0 mM) and T4 (257.0 mM) were applied with equal proportions of NaCl and CaCl2 in Hoagland nutrient solution. Salt stress significantly affects photosynthesis, transpiration, stomatal conductance, water use efficiency, water potential, plant height, root length, fresh weight and dry weight of both okra cultivars in every salt stress treatment. At T2, T3 and T4, Chinese red plants maintained their physiological and growth traits up to Weeks 9, 6 and 3, respectively; beyond these salt-stress durations, growth reductions were found. Similarly, Chinese green plants maintained their growth up to Weeks 9, 5 and 3, respectively, at T2, T3 and T4 treatments. In comparison, Chinese red showed more tolerance than Chinese green. According to the results, the third and ninth weeks are the tolerance threshold limits for both cultivars to sustain their physiological traits and growth under T4 and T2 salinity treatments. Similarly, Chinese red has the threshold limit to bear T3 treatment up to the eighth week and Chinese green, up to the fifth week. Thus, this study provides a new method to determine the threshold value of crops with respect to duration under salt stress. This finding would be useful in the field of water saving and utilisation of saline water resources.
The ripening process of two grape varieties in the vineyard located in the Sandomierz region was examined. In 2015, the ‘Regent’ and the ‘Sibera’ varieties reached physiological ripeness on 30th September and 3rd October, respectively. On both harvest dates, in addition to soluble solids content, titratable acidity, and pH, the macronutrient content was also determined. In the phase of physiological ripeness, the ‘Sibera’ variety showed higher acidity (1.02 g · 100 mL−1) compared with the ‘Regent’ (0.87 g · 100 mL−1). A higher soluble solids content was found in the ‘Regent’ (20.4°Brix), and slightly lower in the ‘Sibera’ (18.1°Brix). The must of the ‘Regent’ had a higher pH (3.5). This variety also had higher macronutrient contents (K, Ca and Mg). Grapes harvested after 3 weeks (late harvest) showed higher values of sugars, pH, K, and P for both varieties. However, their titratable acidity content, and Ca and Mg contents decreased. Microscopic examination showed differences in mycelial growth of Botrytis cinerea on grape bunches for both of the varieties left for the late harvest. The mycelial growth promoted faster dehydration of the ‘Sibera’ berries. Spot chemical analyses of ‘Sibera’ berry peel performed using EDS (energy dispersive spectroscopy) showed the occurrence of elevated contents of potassium, phosphorus, sulphur, magnesium and silicon. Around skin cracks, sugar crystals as well as hard-to-identify microcrystals were formed containing potassium. On the surface of the ‘Regent’ berries, potassium, and traces of phosphorus, silicon, magnesium, sulphur and calcium were found.
This research was carried out to examine the effects of different doses of bacterial formulation comprised of a mixture of Bacillus megaterium TV-91C, Pantoea agglomerans RK-92 and Kluyvera cryocrescens TV-113C strains on the plant development and bract quality of poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch), which are one of the most important potted plants grown for their fleshy bracts of the horticultural sector. The study was carried out in a climate-controlled research greenhouse from 8 August 2018 to 15 January 2019 in Erzurum (Turkey). Rooted cuttings of poinsettia [E. pulcherrima Willd. ex Klotzsch cv. Christmas Feelings (CvF)] were used as plant materials in the study. Each of the solutions containing bacterial suspensions 52.5 (T1), 105 (T2), 210 (T3), 420 (T4) and 840 (T5) mL · L−1 of water was diluted 5 times with water and 200 mL · pot−1 was applied to the plant rhizosphere. This study revealed that positive changes incurred in plant height, main flower stem length, plant crown width, bract diameter, green leaf and bract leaf area, leaf total nitrogen content and nitrate reductase enzyme activity parameters in poinsettia plants with increasing doses of the bacterial formulation. This effect has reached the maximum level in the number of bracts, main flower stem length, bract diameter, nitrate reductase enzyme activity, plant fresh weight and maximal root length parameters with the T5 application which has the highest bacterial formulation concentration. The most efficient application of glutamine synthetase enzyme activity was determined as T4.
Cornelian cherry fruits are quite rich in bioactive compounds. Natural colour, rich flavonoids and anthocyanins and high antioxidant activity have made the fruits a natural drug. In the present study, antioxidant activity, total flavonoids and total phenolics of naturally growing 18 cornelian cherry genotypes with different phenotypic characteristics were determined. Size and shape parameters of the genotypes were also determined with the image-processing method; sphericity, elongation and shape index were calculated and shapes of two-dimensional fruit images were compared with elliptic Fourier analysis. Antioxidant activity, total flavonoid contents and total phenolic amounts of the genotypes were varied between 55.062 and 152.420 mmol TE · kg−1, 286.40 and 2,882.80 mg QE · kg−1, and 2,644.80 and 12,959.00 mg GAE · kg−1, respectively. Multivariate variance analysis conducted based on physical characteristics revealed that six genotypes were different from the others. Shape analysis with Elliptic Fourier method revealed that the majority of present cornelian cherry genotypes had an oval appearance and a small portion of them had a drop-like appearance. According to discriminant analysis and Hotelling's pair-wise comparison tests, there were five different shape groups for present genotypes. A single genotype was placed into one of these groups, thus it was determined that this genotype was totally different in shape from the others.
Iodine (I) has a beneficial effect on plant growth, development and antioxidant activity. The study aimed to compare iodine uptake after the application of iodobenzoates (2-iodobenzoic acid (2-IBeA), 4-iodobenzoic acid (4-IBeA) and 2,3,5-triiodobenzoic acid (2,3,5-triIBeA)) as well as potassium iodide (KI) to tomato seedlings. One of the main tasks was to evaluate how the tested compounds applied in different concentrations (5, 10, 25 and 50 μM) affect the growth and antioxidative potential of tomato seedlings. Negative effect on growth and development of tomato seedlings was noted for 4-IBeA applied in 10–50 μM I concentrations. The 2,3,5-triIBeA application affected shoot deformation. All tested iodine compounds increased iodine level in leaves and roots of tomato seedlings. Iodine after KI application was accumulated mainly in leaves, while after iodobenzoates treatment in roots of tomato seedlings, which is probably related to their weaker transport to the upper parts of the plant. Tested compounds variously modified the content of ascorbic and dehydroascorbic acids in tomato leaves depending on applied concentration. KI treatment improved ascorbate peroxidase activity, but all iodobenzoates decreased APX and catalase activity in leaves. 4-IBeA (5 μM I) and 2,3,5-triIBeA (25 and 50 μM I) increased guaiacol peroxidase activity in leaves. It can be concluded that mechanisms responsible for plant oxidative metabolism were variously affected by the iodine compounds and its concentration in the nutrient solution.
A good peach fruit should have properties of high quality, as these properties directly affect the shelf life. This study aims to determine the effects of different salicylic acid (SA) treatments in the pre-harvest period on the ‘Cresthaven’ peach cultivar on the fruit quality at harvest and after storage at 2°C (8 days) plus shelf life at 20°C (2 days). Fruits with SA treatments have better characteristics such as fruit weight, fruit flesh firmness, total antioxidant content, total phenol content and titratable acidity level at harvest and after storage plus shelf life. With treatments, no changes were observed in the total soluble solids both at harvest and after storage plus shelf life. SA treatments decreased loss of fruit flesh firmness and loss of acidity after shelf life, compared with the control. In fruits with 2 mM SA acid treatment, the reduction in fruit firmness and acidity loss were the least, and as a result of the study it was determined as the most effective pre-harvest SA concentration that could be used in the ‘Cresthaven’ peach variety.
Progression of the vegetation period and change of year are associated with variations in general climatic parameters, such as temperature, atmospheric pressure, humidity, radiation, precipitation, wind speed and others. Only limited knowledge is available about the effects of these parameters on the characteristics of quality of fruits especially those with successive ripening such as goji berry. In our study, fruits of goji berry were characterised based on physico-chemical properties within four different harvest periods, in two consecutive years. Based on the obtained results, it was found that the pomological characteristics were superior at the beginning of the production season, while the phytochemical properties were better at the end. Fruit length, width and weight characteristics were noted to decrease from the first harvest to the last by 21%, 18% and 33%, respectively, while the total anthocyanin, phenol and antioxidant activity properties increased by 264%, 48% and 105%, respectively. There was a decrease in fruit weight, fruit length and fruit width up to 15.9%, 18.3% and 6%, respectively and were directly associated with yield due to sink competition among fruits. Providing high ripening index that ensures more acceptable fruits, with high soluble solid content (SSC) and titratable acidity (TA) seems to be a very important breeding objective to meet consumer demands thanks to superior organoleptic quality. According to correlations, the synthesis of phenolic compounds increased in parallel with SSC rise and TA, which improved pomological properties too. It is thought that the obtained results may indicate the cultural processes and evaluation methods to be used for the harvested fruits.
Terrestrial plants are constantly exposed to multiple environmental signals that influence their metabolism. Among these signals, nitrogen (N) nutrition and light affect importantly diverse metabolic and physiological processes. Herewith the effects of N nutrition (8.47, 12.71 and 16.94 mg · L−1 N) and shading percentages (0 and 70%) on plant morphology and chemical composition of the essential oil of marigold (Tagetes erecta L.) ‘Inca’ were assessed. Increasing N levels enhanced the number of secondary branches and the flower diameter, while shading reduced height of side branches, number of primary branches and opened flower buds. In leaves, flowers and stems, 15 different compounds were identified. In leaves, low and medium N levels and high light level increased the synthesis of ocimene, limonene and piperitone. As well, medium and high N doses, independently of the light level, stimulated the synthesis of caryophyllene and β-phellandrene in leaves. Nevertheless, increasing N doses and shading level decreased the synthesis of β-myrcene and α-pinene in leaves. In flowers, medium N level and high light intensity increased the synthesis of trans-pinene. Piperitone and verbenone were identified only in flowers of plants with high N doses and lower light intensity. In the stems, caryophyllene, piperitone and β-farnesene were more abundant with medium and high N levels. The interaction of study factors differentially affected both morphological variables and the composition of essential oil among organs studied. Therefore, N nutrition and light intensity are key factors that modify the morphology and composition of the essential oil in T. erecta.
Auricularia cornea, jelly mushroom, is a popular ingredient of traditional Chinese cuisine. This study aimed at evaluating the growth, yield, biological efficiency, total phenolic and flavonoid contents, the antioxidant activity, elemental composition, and molecular structure of the wild and domesticated strain Ac24 and the commercially cultivated edible mushroom A. cornea strains Ac1, Ac3 and Ac15. Based on the weight of the fresh fruiting bodies of A. cornea strains, the maximum yield was obtained from commercial strain Ac1 (237.10 g), followed by Ac3 (224.47 g), Ac15 (158 g) and Ac24 (132.37 g), while the biological efficiency range of A. cornea strains was 52.94–94.84%, with significant differences among the A. cornea strains. Our results revealed that Ac24 contained the highest phenolic content (20.10 mg GAE · g−1), while the highest flavonoid content was found in Ac1 (35.13 mg CE · g−1). The maximum mineral contents and the strains were as follows: copper (7.2 mg · kg−1) and zinc (310 mg · kg−1) in Ac1, manganese (788 mg · kg−1) in Ac3 and iron (310 mg · kg−1) in Ac24. DPPH assay found maximum antioxidant activity in Ac24 (IC50 0.233 mg TX · mL−1), FRAP (591 mg TX · g−1) in Ac15, and erythrocyte haemolysis in Ac24. SEM-EDX and FTIR analyses verified the differences among A. cornea strains. The results revealed that wild, domesticated A. cornea strain Ac24 is a promising dietary source of natural antioxidants and is of high nutritional value, compared to commercially cultivated strains.
No-tillage (UT) and tillage (TL) influence melon (Cucumis melo L.) production. However, the mechanism of improving the soil quality under UT in melon production is still unavailable. In this study, we attempted to explore the effects of UT and TL treatments on soil fertility and the microbial abundance and diversity in planting melon under greenhouse condition. Soil properties were determined and the bacterial v4-v5 16S rRNA and the fungal internal transcribed spacer gene were pyrosequenced by extracting greenhouse soil DNA. Results showed that the two treatments had different effects on nutrient uptake in melon plants under facility conditions. Additional nitrogen (N) was absorbed in the leaves and fruit in UT treatment. However, the N content in the UT treatment was kept as similar to that of the TL treatment. The phosphorus (P) contents in melon plant leaves and fruits in the UT treatment were higher than those in the TL treatment. High potassium (K) contents were observed in fruits and melon stem under the UT and TL treatments, respectively. Soil pH, organic matter and the available N influenced the bacterial and fungal distributions. The total N, total P and total K in melon plants were correlated with the bacterial and fungal groups in facility soils. The UT treatment had a substantial effect on the microbial diversity in soils planted with melon. Our study provided insights into the response of soil fertility and microbial structures to UT and TL treatments under greenhouse soils, which may aid in managing greenhouse soil quality.
Anthocyanins are important bioactive supplements that are consumed from multiple foods and beverage products. Screening tea cultivars producing a high level of anthocyanins can help to enrich the edible bioactive supplements. ‘Zijuan’ (ZJ) is a tea cultivar growing purple shoots rich in anthocyanins, but it is susceptible to freezing winter and sprouts late in spring. Hybridisation using ‘ZJ’ as the female parent and an early sprouting cultivar ‘Wuniuzao’ as the male parent was carried out, and four hybrids with purple leaves were obtained. The quality of anthocyanins, catechins, caffeine and amino acids in shoots with three leaves and a bud of the purple leaf hybrids obtained were determined based on the field investigation on sprouting time in spring, winter resistance and leaf yield. It showed that hybrid ‘B-2’ sprouted earlier in the spring, contained a higher level of anthocyanins and also showed good performance in winter resistance than its female parent ‘ZJ’. It also showed that black tea processing induced a marked decrease in foliar anthocyanins, but green tea processing had little effect on the foliar anthocyanins. Purple tea leaves should be prepared into unfermented green tea instead of fermented black tea to preserve the high level of anthocyanins in the final tea products.
The aim of this study was to examine the influence of shoot age on biological and chemical properties of 11 red currant cultivars (‘Jonkheer van Tets’, ‘Junifer’, ‘London Market’, ‘Makosta’, ‘Mirana’, ‘Redpoll’, ‘Rolan’, ‘Rondom’, ‘Rovada’, ‘Slovakia’ and ‘Stanza’) with different origins and ripening times. Phenological observations and pomological characteristics were studied and chemical analysis was conducted from 2013 to 2018 at experimental fields near Belgrade, Serbia. The total contents of phenols and anthocyanin were estimated spectrophotometrically, while quantitative analysis of anthocyanin aglycones was done using high-performance liquid chromatography. Three-year-old shoots had an earlier start of all examined phenological stages, better generative potential, higher yields, as well as higher total phenol and vitamin C contents in the fruits, compared with 2-year-old shoots, for all cultivars. The contents of total anthocyanins were higher in berries on younger shoots of early-ripening cultivars, while late-ripening cultivars had higher contents of total soluble solids and cyanidin in the berries on 3-year-old shoots. Principal component analysis demonstrated that the most important variables that distinguished 2-year-old shoots from 3-year-old shoots were those related to phenological data, cluster traits, total acids and yields. According to the obtained results, ‘Junifer’ (with the highest number of clusters), ‘Mirana’ (with the highest sugar content and sugar/acid ratio), ‘Redpoll’ (with the highest physical traits of cluster and berry), ‘Slovakia’ (with the highest yield and yield efficiency) and ‘Rovada’ (with the highest level of secondary metabolites) are recommended as the most promising cultivars for growing in the temperate region of Serbia.
Delphinium yunnanense is an endemic species in the Yunnan Province of China, while Delphinium elatum ‘Guardian Blue’ is widespread as cut flowers in the world. They all bloom attractive blue flowers, which are a crucial ornamental trait for floriculture. In this experiment, the cross-compatibility between D. yunnanense and D. elatum was characterised and evaluated. The results showed that a strong cross-incompatibility was observed in D. yunnanense × D. elatum, resulting in hybrid sterility. The F1 hybrid generation produced neither fruits nor seeds. The cross-incompatibility of the hybrids resulted from the disturbed structure of the pollen tubes penetrating pistil style and callose deposits on stigma and in style. Moreover, the germination rate of D. elatum × D. yunnanense F1 seed was lower than their own allogamic crosses, although there was no difference in fruit set rate. The results confirmed the cross-incompatibility between D. yunnanense and D. elatum, suggesting that D. elatum is more suitable as a maternal parent for hybridisation breeding. Our study characterised and evaluated the interspecific cross-compatibility through the pollen–stigma interaction and the reproductive system in Delphinium, which could provide the basis for the development and utilisation of potential ornamental traits in Delphinium.
We determined the abundance, species composition, sex ratio and seasonal dynamics of thrips on one cultivar of Welsh onion (Allium fistulosum) and eight cultivars of onion (Allium cepa) in South Poland within three vegetation seasons (2014–2016). Nine species of Thysanoptera were identified on A. cepa and A. fistulosum. Irrespective of the onion cultivar, Thrips tabaci was the dominant species (64.4% of all collected thrips specimens), while Frankliniella intonsa also occurred in high numbers (28.3%). Conversely, Welsh onion was most often inhabited by F. intonsa (62.7%), although T. tabaci was also numerous (28.3%). The predatory Aeolothrips intermedius accounted for 4.5% on A. cepa and 2.9% on A. fistulosum. In the most numerous species, T. tabaci, F. intonsa and A. intermedius populations were formed mainly by females. The cultivar most colonised by thrips was Kroll of A. fistulosum. The tested cultivars of A. cepa demonstrated varying degrees of attractiveness to thrips in the subsequent years. The relationship between populations of T. tabaci, F. intonsa and A. intermedius changed in the subsequent months of the growing season. In June, mainly T. tabaci and F. intonsa occurred on onion plants, while from July, the percentage shares of F. intonsa and the predatory A. intermedius in the thrips population on many onion cultivars increased. The level of attractiveness of A. cepa related to onion thrips, which is reported as a main pest of onion, varies depending on the year and cultivar.
This research was designed to test the combined efficacy of hot water dipping (HWD) and leaf extracts of Cistus creticus L. subsp. creticus on the storage quality of fresh Valencia oranges. Experiments were laid down according to a completely randomised design with 10 different treatments. Five replications, with five fruits in each replication, were used in the current study, and research was designed to continue for 150 days. Quality characteristics were observed with 30-days interval. The applications of this study were (1) Control [dipping in water at 25°C for 5 min]; (2) HWD at 50°C for 5 min; (3) HWD + Additives (A) [Arabic gum (0.2%), potassium sorbate (0.05%), citric acid (0.05%) and vitamin C (0.05%)] at 50°C for 5 min; (4) Additives alone at 25°C for 5 min; (5) 1.0% C. creticus leaf + HWD + A; (6) 1.0% C. creticus leaf + A; (7) 0.5% C. creticus leaf + HWD + A; (8) 0.5% C. creticus leaf + A; (9) 0.5% C. creticus leaf + HWD and (10) 0.5% C. creticus leaf. According to the results obtained, both the HWD and C. creticus, alone or in combination, were effective in preserving orange weight during storage, preventing pathogenic decay, maintaining visual quality and fruit firmness, delaying the reduction in titratable acidity, increasing ascorbic acid content and reducing respiration rate of the orange fruits. Results also suggested that the combined effect of HWD with C. creticus leaf extracts provided the highest efficacy.
This study aimed to evaluate yield parameters, antioxidant activity (AOA), total polyphenol content (TPC) and total soluble solids (TSS) in beetroot cultivars with different flesh colours. Field experiments were established at the Slovak University of Agriculture in Nitra in 2016 and 2017. Within the study, 16 beetroot cultivars were tested, including 11 red-fleshed (‘Boltardy’, ‘Boro’ F1, ‘Crosby Egyptian’, ‘Cylindra’, ‘Detroit Globe’, ‘Detroit 2’, ‘Egyptian Turnip Rooted’, ‘Opolski’, ‘Pablo’ F1, ‘Renova’ and ‘Taunus’ F1), 2 yellow-fleshed (‘Boldor’ F1 and ‘Golden’), 2 white-flesh cultivars (‘Albino’ and ‘White Detroit’) and 1 red-white fleshed cultivar (‘Chioggia’). All beetroot cultivars with red flesh colour showed higher AOA and TPC than different-coloured beetroot cultivars. The highest root yield was found in the white-fleshed beetroot cultivar ‘Albino’ (37.80–41.91 t · ha−1). The highest root weight was found in the white-fleshed beetroot cultivar ‘White Detroit’ (362.4–412.1 g). The highest AOA (819.19–972.50 mg TEAC · kg−1 d.w.) and TPC (2,387.70–2,731.00 mg · kg−1 d.w.) were found in the red-fleshed beetroot cultivar ‘Pablo’ F1. Different-coloured cultivars of beetroot were characterised by a lower content of TSS (6.4–8.8 ºBRIX) than cultivars with typical, red flesh colour (7.8–10.8 ºBRIX). Results clearly indicate that cultivar, or flesh colour, is showed as a significant factor influencing the quality of beetroot. Knowing of yield potential and quality of beetroot cultivars is important for growers as well as consumers. Results of this study indicate that white-fleshed cultivars of beetroot are characterised by high yield potential but lower quality, including lower AOA, TPC and TSS.