Plum Type Research Articles

Diversity of plums belonging to P. domestica L., P. insititia L. and Prunus × rossica Erem. Tree vigour, yielding and fruit quality attributes

From 2017 to 2022, tree growth, yield components, fruit quality attributes and antioxidant capacity of autochthonous and rare plum cultivars of different genetic origin were investigated. The research was carried out in the environmental conditions of Serbia in orchard where intensive horticultural measures were applied. The results showed a wide variability of the examined parameters among cultivars and among plum types. The ‘Olenka’ plum had the most vigor trees, whereas ‘Saint Julien’ had dwarf trees. The Serbian autochthonous plums ‘Metlaš’ and ‘Crvena Ranka’ had the best yield components (Y, CY, YE). ‘Timočanka’ had the highest FW and fruit size, whereas ‘Metlaš’ and ‘Saint Julien’ had the weakest fruit physical characteristics. Unexpectedly, ‘Saint Julien’ had the highest content of soluble solids, both ripening and sweetness indexes and RS. The highest and similar content of TS was found in the fruits of ‘Crvena Ranka’, ‘Timočanka’ and ‘Obilnaya’. ‘Crvena Ranka’ and ‘Obilnaya’ had the highest content of N-RS. The Czech autochthonous cultivars ‘Durancie’ and ‘Chrudimská’ had a similar and highest content of vitamin C, while the highest TPC and TFC were found in the fruits of ‘Metlaš’ and ‘Olenka’, respectively. The highest amount of anthocyanins had ‘Obilnaya’, whereas the lowest had ‘Saint Julien’. Fruits of ‘Durancie’ had the highest TAC, followed by ‘Timočanka’ and ‘Obilnaya’, whereas fruits of ‘Olenka’ had the poorest antioxidant power. Considering their overall performances, evaluated plums can be grown in production orchards for different purposes or can be an alternative to the leading commercial cultivars in similar ecological conditions. Also, they can be used for breeding programs.

The Domestication and Dispersal of Large-Fruiting Prunus spp.: A Metadata Analysis of Archaeobotanical Material

The Prunus genus contains many of the most economically significant arboreal crops, cultivated globally, today. Despite the economic significance of these domesticated species, the pre-cultivation ranges, processes of domestication, and routes of prehistoric dispersal for all of the economically significant species remain unresolved. Among the European plums, even the taxonomic classification has been heavily debated over the past several decades. In this manuscript, we compile archaeobotanical evidence for the most prominent large-fruiting members of Prunus, including peach, apricot, almonds, sloes, and the main plum types. By mapping out the chronology and geographic distributions of these species, we are able to discuss aspects of their domestication and dispersal more clearly, as well as identify gaps in the data and unanswered questions. We suggest that a clearer understanding of these processes will say a lot about ancient peoples, as the cultivation of delayed return crops is an indicator of a strong concept of land tenure and the specialization of these cultivation strategies seems to be tied to urbanism and reliable markets. Likewise, the evolution of domestication traits in long-generation perennials, especially within Rosaceae, represents awareness of grafting and cloning practices.

The Determination of Pomological and Morphological Properties of The Local Plum Types Grown in Giresun and Districts

Bu araştırma Giresun ili Merkez, Bulancak, Keşap İlçelerinde 2016-2017 yılları arasında yürütülmüştür. Çalışma yapılan alanda 20 farklı isimde anılan yerel erik çeşidi belirlenmiştir. Belirlenen erik çeşitlerinin ağaç özellikleri ve meyve özellikleri tespit edilmiştir. Belirlenen yerel erik çeşitlerinin ortalama meyve ağırlığı 8.02-169.40 g, meyve eni 20.65-42.06 mm, meyve boyu 25.42-42.89 mm, meyve yüksekliği 23.33-43.67 mm, meyve sapı uzunluğu 11.63-17.64 mm, meyve sapı çapı 0.80-2.53 mm, çekirdek ağırlığı 0.31-1.61 g, titre edilebilir asitlik %1.15-2.83, pH 2.13-3.83, suda çözünebilir kuru madde miktarının %7.12-18.47 olarak değişim gösterdiği tespit edilmiştir. Erik çeşitlerinde tomurcuk kabarması 25 Ocak-18 Mart tarihleri arasında, tomurcuk patlaması 8 Şubat-23 Mart tarihleri arasında, İlk çiçeklenme 20 Şubat-27 Mart tarihleri arasında, tam çiçeklenme 1 Mart ile 9 Nisan tarihleri arasında, çiçeklenme sonu 10 Mart-20 Nisan tarihleri arasında gerçekleşmiştir. Eriklerin hasat tarihleri ise 18 Haziran-31 Ağustos tarihleri arasında 75 günlük bir periyotta dağılım göstermiştir. Yaprak döküm tarihi Ekim ayının 4. haftası ile Aralık ayının 3. haftası arasında olduğu gözlenmiştir. Sonuç olarak, yörede farklı bir çeşit zenginliği tespit edilmiştir.

Supplementary Light Differently Influences Physico-Chemical Parameters and Antioxidant Compounds of Tomato Fruits Hybrids.

One of the challenges for agriculture in the coming years will be producing more food avoiding reducing the nutritional values of fruits and vegetables, sources of nutraceutical compounds. It has been demonstrated that light-emitting diodes (LEDs) used as a supplementary light (SL) technology improve tomato yield in Mediterranean greenhouses, but few data have been reported about SL effects on fruit physio-chemical parameters. In this study, three tomato hybrid (F1) cultivars were grown for year-round production in a commercial semi-closed glasshouse in Southern Italy: red cherry type (“Sorentyno”), red plum type (“Solarino”), and yellow plum type (“Maggino”). From 120 to 243 days after transplant (DAT), Red/White/Blue LEDs were used as SL. The fruits harvested 180 DAT were analyzed and those obtained under LEDs had 3% more dry weight, 15% more total soluble solids, and 16% higher titratable acidity than fruits grown only under natural light. Generally, the antioxidant activity and the mineral profile of the fruits were not negatively influenced by SL. Lycopene content was unchanged and vitamin C content of “Sorentyno” even increased by 15% under LEDs. Overall, LEDs used as SL technology could be one of the tools used by agriculture in Mediterranean basin to produce more food maintaining high quality production.

Design and evaluation of a modular robotic plum harvesting system utilizing soft components

AbstractThe human labor required for tree crop harvesting is a major cost component in fruit production and is increasing. To address this, many existing research works have sought to demonstrate commercially viable robotic harvesting for tree crops, though successful commercial products resulting from these have been few and far between. Systems developed for specific crops such as sweet peppers or apples have shown promise, but the vast majority of cultivar types remain unaddressed, and developing a specific system for each one is inefficient. In this study, an easily modifiable development platform for robotic fruit harvesting is presented, this can be used to test specific design choices on different fruit and growing conditions. The system is evaluated in a commercial plum orchard, with no crop modifications. Both a hard and soft gripper are trialed, along with three object detector approaches and two picking motions. Some existing techniques are found to be counterproductive for plums, while soft robotics and persistent target tracking significantly improve performance. The best harvest success rate of 42%, was observed when using the soft gripper with complex motion. This is lower than expected based on prior testing with apples and indicates the difficulty in moving to new fruit types. Unique challenges specific to the plum type and growing style are examined in the context of system module design choices.

Non-invasive detection of surface features of three plum types

Plums are covered by a layer of epicuticular wax. The purpose of this study was to examine the effect of different surface treatments on the light reflection of three plum types, identify the major drivers of glossiness (luster) changes in time and explain their variation using statistical analysis. Three surface conditions (natural surface, chemically-treated, manually polished) combined with three plum types (blue European plums, yellow mirabelle and greengage) were examined. Light reflection over time was measured with a luster sensor type CH-72H resulting in 860 measurements. The surface treatment affected light reflection and thus luster levels; removal of the wax bloom increased both glossiness and luster level. Statistical analysis has shown that the plum type (blue European plum, mirabelle, and greengage) had negligible influence on the results, whereas 60% of the statistical variation of luster levels was caused by ageing and storage. A model was developed as a first step, opening further possibilities in determining and possibly predicting the freshness of plums.

Fruit Quality and Consumer Acceptability of Three Plum Types and 14 Plum Cultivars Grown in Maine for a Local Market

Fruit quality and consumer acceptance were measured in 14 plum cultivars. In 2015, six cultivars of asian plum (Prunus salicina) and one cultivar of american plum (Prunus americana) were harvested partially ripe and tree-ripe. In 2016, three types of plums, asian, american, and european (Prunus domestica), were harvested tree-ripe. Within most cultivars in 2015, partially ripe fruit were rated as highly as tree-ripe fruit using a hedonic rating from 1 to 9 with 1 being dislike extremely and 9 being like extremely. ‘Obilnya’ and ‘Abundance’ were rated higher than ‘Shiro’ and ‘Methley’ at both stages of ripeness and higher than ‘Vanier’ at the partially ripe stage. ‘Early Golden’ and ‘Spring Satin’ were rated higher than ‘Shiro’ and ‘Methley’ at the tree-ripe stage. In 2016, seven cultivars (Obilnya, Kahinta, Superior, Toka, Castleton, Early Italian, and Rosy Gage) were scored at the desired consumer acceptance level. ‘Shiro’ and ‘Caçak’s Best’ received overall acceptability scores below the level of acceptability. Plum type had minimal effect on scores for texture, sweetness, sourness, and overall liking. European cultivars received lower color scores than american and asian plums. Soluble solids concentration (SSC) ranged from 6.7% to 13.6% in asian plums, from 14.8% to 19.8% in american plums, and from 15.3% to 22.1% in european plums. Overall consumer acceptance of american and european cultivars was as good as for asian cultivars.

Cultivar Evaluation and Yield Performance of Tomato in an Organic Management System

This paper presents evaluation of organic tomato cultivars on yield performance in local climatic conditions. Field research trials were conducted from April to October in 2015 and 2016 growing seasons at the Tennessee State University organic farm. Differences occurred in number of marketable fruit, fruit weight and total soluble solids. ‘Arbason F1’ (28.67 Mt·ha-1), ‘Gold Nugget’ (26.08 Mt·ha-1), ‘Roma’ (25.65 Mt·ha-1) were the high yielding and ‘Pink Bumblebee’ (2.61 Mt·ha-1), ‘Hillbilly’ (3.10 Mt·ha-1), ‘Cherokee Green’ (5.99 Mt·ha-1) had the lowest marketable yield. ‘Mountain Prince’ (57.68%), ‘Pink Brandywine’ (52.32%) and ‘Black Prince’ (44.74%) had the most culls and ‘Pink Bumblebee’ (1.80%), ‘Rutgers VF’ (4.98%), and ‘Hillbilly’ (5.02%) had the fewest cull fruit. ‘Bing Cheery’ and ‘Cheery Sweetie’ ranked highest in taste among cherry types. All twenty six cultivars did set fruits during the growing seasons in local climatic conditions. Results suggest that ‘German Johnson’ and ‘Pink Brandywine’ (beefsteak type), ‘Gold Nugget’, (cherry type), and ‘Roma’, (plum type) were top performers in higher yields and brix.

Assessment of genetic diversity and relationships among wild and cultivated Tunisian plums (Prunus spp) using random amplified microsatellite polymorphism markers.

The usefulness of random amplified microsatellite polymorphism markers to study the genetic diversity and relationships among cultivars belonging to Prunus salicina and P. domestica and their wild relatives (P. insititia and P. spinosa) was investigated. A total of 226 of 234 bands were polymorphic (96.58%). The 226 random amplified microsatellite polymorphism markers were screened using 15 random amplified polymorphic DNA and inter-simple sequence repeat primers combinations for 54 Tunisian plum accessions. The percentage of polymorphic bands (96.58%), the resolving power of primers values (135.70), and the polymorphic information content demonstrated the efficiency of the primers used in this study. The genetic distances between accessions ranged from 0.18 to 0.79 with a mean of 0.24, suggesting a high level of genetic diversity at the intra- and interspecific levels. The unweighted pair group with arithmetic mean dendrogram and principal component analysis discriminated cultivars efficiently and illustrated relationships and divergence between spontaneous, locally cultivated, and introduced plum types. These procedures showed continuous variation that occurs independently of the status of the species and geographical origin of the plums. In this study, random amplified microsatellite polymorphism was found to be as a reliable molecular marker for fingerprinting and for examining the diversity study of the plum and its relatives.

High-quality and Multiple disease Resistant Cherry Tomato ‘Titi Chal’

‘Titi Chal’ with elite characteristics and high fruit yield was developed from a cross between ‘MS-BGT’ and ‘NHMF’ in 2009. The cultivar has multiple disease resistances against Tobacco mosaic virus, Tomato yellow leaf curl virus, Tomato spotted wilt virus and Leaf mold disease. The early and medium-maturing variety can be transplanted on July to September. The cherry tomato presents longer shelf-life due to higher fruit firmness and also has high eating quality with 9~10 brix of sugar content. The fruit shape is red plum type with an average fruit weight of 23~25 g. The ‘Titi Chal’ is more reliable to be cultivated because of medium-strong plant-vigor and low occurrence of creased stem.

EVOLUTION OF PLUM CULTURE; CONSTRAINS AND PERSPECTIVES

European plum (Prunus domestica) and Japanese plum (Prunus salicina and hybrids) culture are facing a relative critical period world wide. In the last two decades the annual world plum production went up to more then 7 million tones, which has 2 to 5% increase over the 1970-1990 period, although large variation from one year to another were recorded. The European plum type production is 5.5 to 5.6 million tons per year and the Japanese type plums represent 1.5 to 1.6 million tons (21 to 23% of the total plum production). The plum culture situation is dependent on the human society demands either for fresh consumption plums or processed plums. Decrease of demands for plums are due to the competitively with other fruits (apples, peaches, oranges, bananas, etc.) and availability of those all year long as result of trade globalization. The morphological characteristics of plum fruits (size, shape, and color), taste, storage ability, etc., are only several elements that contribute to decrease of demand. Advertising and information on plum consumption benefits for healthy and balanced diet are less and less present. Investments in new plum orchards in the traditional plum growing countries like Romania, Serbia, Bulgaria, Hungary and Moldova or in Greece are very low; this can be explained by the last period economical situation of these countries which is continuing due to the financial crisis. In order to have perspectives in favor of plum culture improvements have to be done regarding cultivar assortment and behavior to virus diseases, rootstocks and orchard management. The cultivar assortment needs commercial valuable and productive genotypes, which produce large and tasty fruits that can be stored and shipped extensively. Plum rootstocks are necessary to be more available, especially those of low vigor and having good compatibility with many cultivars. Issues regarding virus infection and their reaction on plums have to be solved as soon as possible. Plum orchard management requires modernizing from all points of vue especially for the super-intensive culture.

S-GENOTYPING IN JAPANESE PLUM BY PCR AND CAPILLARY GEL ELECTROPHORESIS DETECTION

In this work a PCR S-genotyping method using capillary electrophoresis detection was assayed in Japanese plum. Sweet cherry primers designed for S-RNase and SFB intron length polymorphism detection by capillary electrophoresis were evaluated in Japanese plum cultivars. Amplification of both genes was successful and amplified sizes were correlated with Japanese plum S-alleles. The S-RNase genotype of 58 Japanese plum type cultivars previously determined by other methods was confirmed using this technology and the SFB alleles of these cultivars were also determined. Allele sizes of both genes are reported for 13 different S-alleles found in Japanese plum and will allow efficient S-genotype characterization in this species.

A SURVEY OF SELF-ROOTED OLD PLUM TYPES IN NORWAY

A large diversity of plums from the species Prunus insititia L. and Prunus domestica L. is present in semi-wild growing stands in Norway, but the species are not regarded as autochtonous in Norway. However these species have been present in the country for centuries and have been spread at least up to 64 degrees North. The climatical conditions in the districts where plums are present are highly different, and over several generations one might expect response to natural selection in the borderline of the species adaptational limit. These old plum types are regarded as a part of the genetical plant heritage in Norway, and the Norwegian Genetic Resource Centre supported projects to map the old self-rooted types in 2005 and 2007. More than 50 different sources from South to North were reported, and nearly 50 genotypes will be established for further study. Most of the types reported were yellow or blue, but red types are also represented, and the majority of the found types are probably Prunus insititia.

POMOLOGICAL STUDIES OF PLUM-APRICOT HYBRIDS

The plum-apricot hybrids, numbers 16-19, 16-22, 16-23, 16-25, 16-26 and 16-29, were established in 1989 from crossings of the plum cultivar 'Stanley' of Prunus domestica L. species with the apricot cultivar 'Modesto' of Prunus armeniaca L. species. They can be attributed to a separate botanical species with the working name Prunus domestiaca. The plum-apricot hybrid No. 23-128 was established by crossing the plum 'Green gage' of P. domestica species with the apricot 'Melitopolskij tchjornij' of the purple apricot species Prunus dasycarpa (Ehrh.) Borkh. We think that hybrid 23-128 can be attributed to a separate botanical species with the working name Prunus domesticarpa. All the hybrids obtained had dark coloured fruits and fine pubescence over the fruit skin. Only hybrid No 16-26 had yellow coloured fruits. The plum type dominated in the shape of the fruits, stones and leaves.

EVALUATION OF AGRONOMICAL PERFORMANCE OF SEVERAL PEACH ROOTSTOCKS IN LLEIDA AND GIRONA (CATALONIA, NE-SPAIN)

Agronomical behaviour of 23 peach rootstocks grafted with the cultivar 'Elegant Lady®' (Merdame) has been evaluated over a six-year period (1996-2001) at IRTA’s Experimental Station of Lleida and Experimental Station of Mas Badia (Girona). Bloom time has not been significantly affected by the rootstock while differences in harvest date based on fruit firmness and IR have been observed. In general, the lowest values of IR have been obtained on plum rootstock species. Significant differences have been observed on vigour with Felinem (GxN22), Garnem (GxN15), GF-305, Titan and GF-677 being the most vigorous and Jaspi® (Fereley) and GF655/2, Montizo and Nemaguard the weakest ones. Highest cumulative yields per tree were recorded on Barrier, GF-677 and Montclar® (Chanturgue) and the lowest on GF-655/2 and Nemaguard. When cumulative yields were adjusted by rootstock vigour and converted to tons/ha, highest yield was obtained on GF655/2, Adesoto 101, Jaspi® (Fereley) and Isthara® (Ferciana), all weak rootstocks. Tree vigour and cumulative yields on all the rootstocks have always been higher in Lleida than in Girona. GF 655/2, Isthara® (Ferciana) and Jaspi® (Fereley) have shown the highest efficiency (kg/cm2). Largest fruit size has been obtained on Rubira, Barrier and Adesoto 101 in Lleida, and on the plum types or some interspecific rootstocks in Girona. Presence of suckering has been observed only on plum rootstocks species, especially GF 655/2, Adesoto 101, Julior® (Ferdor) and Monpol, with small differences between them. Nemared, Nemaguard and Myran® (Yumir) showed maximum sensitivity to iron chlorosis, and intermediate values were recorded on GF 305, Montclar, PSB2, PSA6, PSA5, Rubira, Jaspi® (Fereley), GF 655/2 and Barrier. The lowest was obtained on Garnem (GxN 15), Felinem, Isthara®, MRS 2/5 and Adesoto 101. GF 677 was the only rootstock without iron chlorosis.

First Report of Powdery Mildew of Tomato Caused by an Erysiphe sp. in Connecticut.

In 1995 and 1996, powdery mildew was observed on several samples of field-grown tomato foliage (Lycopersicon esculentum Mill.; various cultivars) submitted to the CAES Plant Disease and Information Office. Symptoms included gray superficial mycelium with abundant sporulation on adaxial and abaxial leaf surfaces, followed in the field by dessication of the foliage and rapid defoliation. No cleistothecia were observed, and single-celled, hyaline, ellipsoidal conidia occurred, usually singly, on unbranched conidiophores. Pyriform conidia occurred at a frequency of less than 1%. Conidia ranged in length from 25.6 to 43.2 μm (mean = 33.6, SE = 0.4) and in width from 13.1 to 23.1 μm (mean = 18.2, SE = 0.2; n = 500). Fibrosin bodies were not observed, and vacuoles were present. Based on conidial characteristics, the fungus was identified as an unknown Erysiphe sp. To confirm pathogenicity, 2-week-old tomato seedlings (cv. Rutgers) were inoculated by shaking dry conidia onto the leaves and placed within plastic tents on a greenhouse bench. Control plants were treated identically but not inoculated. The inoculated plants developed foliar powdery mildew symptoms, and sporulation was observed. Susceptible cultivars that were naturally infected included Better Boy, Better Beef, Celebrity, Rutgers, Ultra Magnum, Ultra Sweet, Whopper, Yellow Brandywine; cherry type tomatoes Matts Wild Cherry and Sweet Chelsea; and plum type tomatoes Roma and Super San Marzano. Eastern black nightshade (Solanum ptycanthum Dunal), eggplant (S. melongena L. 'Black Pride'), and tobacco (Nicotiana tabacum L. 'C9') were also naturally infected under greenhouse conditions. However, conidia size and number of conidia per conidiophore differed between hosts. Conidia from tobacco, eggplant, and nightshade averaged 37.8 × 19.1 μm (SE = 0.5 and 0.2, respectively) with a 95% CI of 35.5 to 40.0 × 18.1 to 20.3 μm (n = 300). Conidia from tomato were smaller, averaging 33.6 × 18.2 μm (SE = 0.3 and 0.2, respectively) with a 95% CI of 32.7 to 34.4 × 17.5 to 18.9 μm (n = 300). Factorial inoculation experiments between tomato and other hosts demonstrated cross-infectivity, but isolates originally from tobacco had significantly larger conidia when infecting tomato than isolates originally from tomato infecting tobacco. Powdery mildew isolates on tomato had fewer (P = 0.001) conidia per conidiophore (mean = 1.39, range = 1 to 4) than isolates infecting tobacco inoculated at the same time and held under the same conditions (mean = 2.54, range = 1 to 6). These results demonstrate considerable morphological variation in the powdery mildew fungus, perhaps associated with hosts such as tomato or other solanaceous plants. This is the first report of powdery mildew of tomato and tobacco in Connecticut. Powdery mildew of tomato has been reported to occur in the field in California, and in greenhouse tomatoes in New York (2). Powdery mildew of tobacco has only been reported on artificially inoculated plants in California (1).