Lemon Cv Research Articles

Melatonin as an Efficient and Eco-Friendly Tool to Increase Yield and to Maintain Quality Attributes during Lemon Storage.

Lemon fruit (Citrus limon (L.) Burm.) is highly appreciated by consumers due to its antioxidant properties and health benefits. However, its shelf life can be limited by various factors, reducing the economy, and thereafter, new strategies to maintain the quality of lemons are necessary. Melatonin is a derivative of tryptamine, which is ubiquitously found in plants and has a wide range of functions regulating numerous physiological processes in plants. During two consecutive harvests, we evaluated the effect of preharvest treatments with melatonin on crop yield and on quality and functional properties of fruit of lemon cv. Verna at harvest and weekly after storage up to 28 days at 2 and 10 °C plus 2 days at 20 °C. Melatonin was applied as foliar spray treatments at dosages of 0.1, 0.3, and 0.5 mM and at three different stages of fruit development. The results showed that melatonin treatment had a positive impact on crop yield as well as in fruit quality parameters, such as firmness, content of bioactive compounds, and antioxidant activity, especially for a 0.5 mM dose. Taking all these effects into account, the application of melatonin along the growth cycle of fruit development could be considered a non-contaminant and eco-friendly tool for improving crop yield and quality of 'Verna' lemons at harvest and during postharvest storage.

Fruit Cracking in Lemon cv. Punjab Baramasi in Relation to Developmental Physiology

Fruit Cracking in Lemon cv. Punjab Baramasi in Relation to Developmental Physiology

Canker and wood rot pathogens present in young lemon orchards in south‐west Arizona

AbstractCanker and wood rots are economically important preharvest diseases of lemons in south‐western Arizona, where commercial lemon production is concentrated. However, the aetiology and epidemiology of canker and wood rots are not well understood. This study comprised a large survey of canker and wood rot incidence and severity in Arizona and the characterization of fungal species associated with the disease. A total of 5431 trees with ages ranging from 1 to 20 years old in 10 lemon orchards were surveyed from 2018 to 2020. Our survey results revealed that canker and wood rot occurred in all 10 lemon orchards studied. Canker and brown rots of twigs, branches, and trunks were the most prevalent symptoms of affected trees ranging from 1 to 20 years old. In contrast, canker and white rots of twigs and branches were observed mostly on 1‐ to 5‐year‐old trees. Disease incidence for both diseases was less than 2% on 1‐ and 2‐year‐old trees. Brown rot increased significantly in older trees, ranging from 62.9% to 100%. Fungi were isolated from canker and wood rot samples and identified based on morphological characters and DNA sequences. Fomitopsis meliae and Hypoxylon macrocarpum were the primary canker and wood rot pathogens isolated from the surveyed orchards, at frequencies of 89% and 11%, respectively. In pathogenicity tests, both fungi were capable of causing canker and wood rots on lemon cv. Lisbon branches and the necrotic length caused by F. meliae was twofold greater than that caused by H. macrocarpum.

Flavedo and albedo of five citrus fruits from Southern Italy: physicochemical characteristics and enzyme-assisted extraction of phenolic compounds

Peels are major byproducts of the juice processing industry. Citrus peels are composed of two tissues, namely the flavedo (outer layer) and the albedo (inner layer). Here, flavedo and albedo were obtained from the peel of grapefruit cv. ‘Star ruby’, lemon cv. ‘Akragas’, and sweet orange cvs. ‘Tarocco’, ‘Sanguinello’ and ‘Moro’. Freeze dried flavedo and albedo were investigated for their functional properties, and subjected to enzyme-assisted extraction with pectinase and cellulase (concentration of 6 U g−1 DW) to extract the phenolic compounds. Albedo showed superior physicochemical characteristics than flavedo. Albedo from ‘Tarocco’ exhibited the maximum water holding capacity (10.9 ± 0.48 g/g). Grapefruit albedo revealed the highest water swelling (13.4 ± 2.62 mL/g) and oil binding (6.31 ± 2.62 g/g) capacities. As regards the enzyme-assisted extraction of phytochemicals, both enzymes enhanced the extraction of phenolics (p < 0.05) compared to the controls. In flavedo, pectinase and cellulase increased the recovery of phenolics by approx. 30%, whereas in albedo the yields were increased above 60%. Results from this investigation suggest that albedo might be used by the food industry as a novel raw material, due to its superior physicochemical properties. Moreover, results provide evidence that the enzyme-assisted extraction is advantageous to recover phenolics from the citrus peels.

Impact of integrated nutrient management on fruit quality and leaves nutritional status of lemon (Citrus limon burm) cv. pant lemon-1 in sandy loam soil under western Uttar Pradesh conditions

Impact of integrated nutrient management on fruit quality and leaves nutritional status of lemon (<i>Citrus limon</i> burm) cv. pant lemon-1 in sandy loam soil under western Uttar Pradesh conditions

Effect of integrated nutrient management in relation to vegetative parameters and fruiting behaviour of lemon (Citrus limon burm) cv. pant lemon-1 in sandy loam soil under western Uttar Pradesh conditions

Effect of integrated nutrient management in relation to vegetative parameters and fruiting behaviour of lemon (<i>Citrus limon</i> burm) cv. pant lemon-1 in sandy loam soil under western Uttar Pradesh conditions

Inducing mutations in Citrus spp.: Sensitivity of different sources of plant material to gamma radiation

Gamma radiation represents an alternative for improving genotypes for which breeding through hybridization involves many difficulties because of their complex reproductive biology, as in the case of citrus. In this study in vitro and ex vitro mutagenesis was induced by gamma radiation in several citrus species (‘Alemow’ and sour orange as citrus rootstocks, lemon cv. ‘Fino 49’ and ‘Verna 51’, mandarin cv. ‘Nova’ and lime cv. ‘Bearss’). Three different sources of materials - seeds, budwoods and nodal segments - from in vitro explants, were tested. Seeds and budwoods were germinated or induced to sprout, and de novo regeneration was obtained from in vitro nodal segments from which preexisting buds were previously removed. Budwoods were tested in summer and winter in order to assess their capacity for mutation and further sprouted in different seasons. Seeds were seen to be more resistant to gamma radiation (LD50 of 127 Gy in ‘Alemow and 156 Gy in sour orange) than budwoods (LD50 about 50 Gy for all cultivars) and nodal segments (LD50 about 25 Gy for both lemon cultivars), the last being the most sensitive material tested. Similar LD50 were found for budwoods collected in winter and summer for all the genotypes. All the tested plant material can be considered suitable for gamma irradiation, although budwood is the most widely available and tissue culture material needs the highest degree of expertise.

Soil nutrient status, yield and quality of lemon (Citrus limon Burm.) cv. ‘Assam lemon’ as influenced by bio-fertilizers, organics and inorganic fertilizers

An experiment was conducted at Mizoram University, Aizawl, India during 2015-2017 to study the effect of integrated nutrient management on yield and quality of lemon cv. ‘Assam lemon’ (Citrus limon Burm.). The experiment was comprised of nine treatments viz. T1: 100% recommended dose of fertilizers (RDF) through inorganic fertilizers (IF); T2: 100% N through Farm Yard Manure (FYM); T3: 75% N through FYM + 25% through IF; T4: 50% N through FYM + 50% through IF; T5:75% N through FYM +25% through IF + Azotobacter + phosphate solubilizing bacteria (PSB)+ potash solubilizing bacteria (KSB); T6: 50% N through FYM + 50% through IF+ Azotobacter + PSB + KSB; T7: 75% N through FYM + 25% through IF + Azospirillum + AMF + KSB; T8: 50% N through FYM + 50% through IF+ Azospirillum + arbuscular mychorrhizal fungi (AMF) + KSB; T9: control. Among all treatments, T5 recorded highest value with respect to growth, yield and soil quality. While, T7 showed superiority in quality characters.

Effects of ga3 and shoot pruning on flowering and yield in Assam lemon (Citrus limon Burm. f.)

Effect of GA3 and pruning on flowering and yield in Assam lemon (Citrus limon Burm. F.) were studied. Ten treatments were imposed for two seasons (summer and winter) in which significant among the treatments were found for profuse flowering and its yield. Among the different treatments, the pooled data of two seasons showed that G1P1 (GA3 50 ppm single spray plus 15 cm shoot pruning) recorded the highest flower per branch (29.75.), fruitlets per branch (6.4) and yield (10.45 t/ha) as compared to the control plants 26.5 flowers per branch, 5.8 fruitlets per branch and 9.43 mt/ha, respectively. Therefore, combination of GA3 50 ppm single spray + 15 cm shoot pruning is most promising which can be recommended for improvement of yield in lemon cv. Assam lemon.

Effect of integrated nutrient management in relation to vegetative parameters of lemon (Citrus limon burm) CV. pant Lemon-1 in sandy loam soil under Western Uttar Pradesh Conditions

Effect of integrated nutrient management in relation to vegetative parameters of lemon (Citrus limon burm) CV. pant Lemon-1 in sandy loam soil under Western Uttar Pradesh Conditions

Degreening of baramasi lemon {Citrus limon (L.) burm} in response to ethephon application

Harvesting of summer crop of Baramasi lemon (Citrus limon) coincides with the rainy season that leads to low market demand and poor returns to the growers. Therefore, an experiment was planned for post-harvest degreening of lemon fruits to advance the marketing. Fully mature fruits of lemon cv. ‘PAU Baramasi Lemon-1’ were treated with different concentrations of ethephon solution viz., 0, 500, 750, 1000, 1250 and 1500 ppm for 5 min. Treated fruits were packed in CFB boxes with paper lining and kept at room temperature. Experimental fruits were analysed for physicochemical characteristics from 4th to 7th day after treatments at 24 h interval. Results revealed that maximum degreening of fruits occurred with ethephon @ 1500 ppm, which was depicted by ‘b*’ value (49.37, 50.83) of colour flex meter and these results were at par with ethephon @ 1250 ppm treatment. Similar trend was recorded for other parameters viz., physiological loss in weight, sensory quality, juice content, total soluble solids and acid content. It may be concluded that lemon fruits of cv. ‘PAU Baramasi Lemon-1’ harvested in June can be degreened in 6–7 days at room temperature by dipping in 1250 or 1500 ppm of ethephon so as to advance the marketing of summer crop.

Rootstock induced changes in tree physiology and antioxidant enzymes activity in lemon cv. Kagzi Kalan

Lemon cultivar Kagzi Kalan was evaluated on eight rootstocks under Delhi conditions during 2013–14. Rootstocks significantly affected all the physiological and biochemical parameters. Higher transpiration rate (E) and stomatal conductance (gs) were observed in lemon trees budded on sour orange, Jatti khatti (C jambhiri), Troyer citrange (C. sinensis X Poncirus trifoliata) and rough lemon (C. jambhiri) rootstocks. The higher values of photosynthetic rate (A) were observed in trees on sour orange and Troyer citrange rootstocks compared to other rootstocks. Lemon trees budded on Billikhichlli (C. reshni) and Attani-2 (C. rugulosa) had the highest intrinsic water use efficiency (WUEi), while it was lower in trees budded on Jatti khatti and rough lemon rootstocks. Higher relative water control (RWC) was recorded in trees on Troyer citrange and sour orange rootstocks, while highest excised leaf water loss (ELWL) was observed on sour orange followed by trees on rough lemon and Troyer citrange rootstocks. Trees on Billikhichlli rootstock had the highest superoxide dismutase (SOD) activity. However, the highest catalase (CAT) activity was found in the leaves of Kagzi Kalan on Jatti khatti. Leaves of Kagzi Kalan had the highest glutathione reductase (GR) activities on Karna khatta rootstock. The lowest values E, gs, ELWL, and activities of SOD, CAT and GR were observed in the leaves of Kagzi Kalan lemon on Attani-2 rootstock.

Isolation and expression analysis of differentially expressed genes in stem tissue of the Greek lemon cv. Adamopoulou

ABSTRACTLemon (Citrus limon (L.) Burm. f.) is susceptible to mal secco, a serious vascular disease caused by the fungus Phoma tracheiphila (Petri) Kant. and Gik., as well as low temperatures. The greek lemon cultivar Adamopoulou, thought to be derived from the Portuguese cultivar Lisbon, exhibits enhanced resistance to mal secco and cold as opposed to cv. Lisbon. Suppression subtractive hybridization (SSH) was employed for the isolation of differentially expressed genes in lemon stem tissue. A subtractive cDNA library was constructed and a total of 296 clones were sequenced. The obtained sequences were edited, resulting in 56 non-redundant ESTs. Sequence analysis revealed homology to previously identified genes involved in defense mechanisms against biotic and abiotic stresses, as well as sequences with no significant similarity in the GenBank. Selected ESTs were analyzed by real-time PCR for confirmation purposes. This analysis revealed significant expression differences between the two cultivars for genes expressing allantoinase, ultraviolet-B-repressible protein, 4-coumarate:CoA ligase and other proteins that are known to be upregulated under biotic and abiotic stress conditions.

Effect of rootstocks on tree growth, yield, quality and leaf mineral composition of lemon (Citrus limon (L.) Burm.)

The present study aimed to evaluate the horticultural performance of lemon cv ‘Kagzi Kalan’ on eight rootstocks under typical subtropical conditions for maximizing the production and fruit quality. The experiment was conducted on five years old Kagzi Kalan lemon plants budded on eight rootstocks. The variables collected over two successive years included vegetative growth, fruiting density, fruit quality, and leaf nutrient concentrations. Results revealed a significant effect of rootstocks on all the variables studied. Tree height and canopy volume were found higher on rough lemon and RLC-4 rootstocks, while trunk cross sectional area was higher on Billikichlli and RLC-4 rootstocks than other rootstocks. RLC-4 and Attani-2 rootstocks had higher fruiting density, while it was lowest on Troyer citrange. RLC-4 produced heaviest fruits, while trees on rough lemon and RLC-4 had significantly higher juice recovery. RLC-4 and Karna Khatta improved TSS and acid contents in the fruit juice. RLC-4 and Troyer citrange proved their superiority in terms of higher ascorbic acid content. Foliar N concentration in scion cultivars was found higher on RLC-4, rough lemon and Attani-2 rootstocks, while the foliar K content was higher on RLC-4 and rough lemon. Jatti Khatti was more efficient in accumulating Mg in leaf tissues, whereas Troyer citrange restricted accumulation of Na in leaf tissues. Sour orange was more capable of accumulating Cu and Zn in leaf tissues, while other rootstocks had similar uptake of Cu. Karna Khatta, rough lemon and RLC-4 absorbed more Fe, while the foliar Mn content was highest on rough lemon rootstock. Troyer citrange appeared poor performer in terms of fruiting density and nutrient concentration. A positive significant correlation was found between leaf Ca concentration and canopy volume. Hence, considering growth performance, fruit quality and nutrient concentration, RLC-4, rough lemon and Karna Khatta rootstock could be suggested for lemon under alike ecological conditions.

Impact of Different Pruning Severity and Nutrient Management on Growth and Yield of Lemon cv. Assam Lemon (Citrus limonBurm.)

Impact of Different Pruning Severity and Nutrient Management on Growth and Yield of Lemon cv. Assam Lemon (Citrus limon Burm.) Like many other citrus species, the lemon (Citrus limon Burm.) presents a number of diverse forms slightly varying from each other. Pruning is one of the important approaches for the canopy management of citrus. The result of pruning on growth parameters have been reported by various workers. It is also a highly nutrient responsive perennial fruit crop and requires adequate nutrition for proper growth and yield of the plants. A field experiment was laid out in two factorial Randomized Block Design with four levels of pruning, seven levels of nutrient, consisting .recommended dose of fertilizers (RDF) and different combinations of organic manure (Vermicompost), inorganic fertilizer, bio-fertilizer (Azotobacter),mycorrhiza (VAM) and their interaction during 2013 to 2015.The investigation revealed that all the vegetative parameters viz. trunk girth (32.74cm, 33.26cm and 33.13cm) and its percentage increase (1.25%, 2.88% and 4.56%), canopy volume (85.22 m3 , 100.03 m3 and 125.84 m3 ) and its percentage increase (31.66%, 56.21% and 114.24%), number of laterals per primary shoot (9.53, 11.87 and 10.80) and its percentage increase (31.65%, 63.64% and 98.25%) and leaf chlorophyll content (1.45%, 1.94% and 2.56%) and its percentage increase (48.61%, 98.41% and 172.80%) was recorded best in highest level of pruning with 75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza at 6th, 12th and 18th month after pruning. Among the three season of cropping Ambebahar recorded the best result in respect to yield (total number of fruits/plant) followed by Mrig and Hasthbahar. .

Enhanced control of postharvest citrus fruit decay by means of the combined use of compatible biocontrol agents

Fourteen Pseudomonas spp. and three Trichoderma spp. strains were tested in vitro for their antagonistic properties against Penicillium digitatum, the causal agent of citrus green mold. Bacterial and fungal strains strongly inhibited the pathogen growth in vitro on PDA and on a citrus-based medium. Inhibitory effects were increased when Pseudomonas and Trichoderma strains were applied in combination. Inhibitory effects were also increased by mixtures of Pseudomonas cells and Trichoderma atroviride P1 culture filtrates. On the opposite, bacterial and fungal filtrates in mixture never induced an improved efficacy, thus indicating that the presence of living bacterial cells was required for a synergistic effect. Accordingly, incidence and severity of disease on orange cv. Tarocco and lemon cv. Femminello were consistently reduced when Pseudomonas and Trichoderma strains were applied 72h before challenging P. digitatum. Pseudomonas syringae strains were the most effective and several combinations had a biocontrol activity higher than one of the each antagonistic microorganism applied alone. The treatments comprising six P. syringae in mixture with Trichoderma strains T22, P1 and T34 were the most effective, with 80–100% control of green mold. The development of green mold decay was also effectively inhibited in small-scale dip-treatments, either by single applications or by their mixtures. These experiments suggest that the combination of Pseudomonas spp. and Trichoderma spp. strains could be considered as a promising mean for the control of citrus green mold decay, supporting the concept that an improved disease control is given by the combined action of the two agents.

Effect of growing media, Pgrs and seasonal variability on rooting ability and survival of lemon (Citrus LimonL.) cuttings

The effect of different growing media (soil, soil+FYM, soil+vermicompost, soil+cocopeat, soil+sand+FYM, soil+sand+vermicompost and soil+sand+cocopeat), hormonal treatments (Control, IBA 500 ppm, NAA 500ppm and IBA+NAA 500ppm each) and growing seasons (rainy and spring) on the number of sprout per cutting, number of primary roots per cutting, number of secondary roots per cutting and survival percentage of cuttings of lemon cv. Pant Lemon-1, was evaluated. Among the different growing medium, number of sprouts per cutting (2.58) with soil+sand+vermicompost, number of primary roots per cutting (9.03) and number of secondary roots per cutting (16.67) with soil+sand+cocopeat and survival percentage (82.23) with soil+sand+FYM, recorded maximum. Growth hormones IBA 500 ppm Hormonal combination of IBA 500 ppm+NAA 500 ppm were resulted maximum number of primary roots (7.74) and secondary roots (16.19) per cutting. Over all compare between spring and rainy seasons, spring season was found superior regarding number of sprout per cutting (2.29) and number of primary roots per cutting (7.30). Whereas, number of secondary roots per cutting (15.30) and survival percentage (77.37), were more in spring season.

English

The studies on management of fruit cracking were carried out for three consecutive years (2006 to 2008) using integrated approach. The plant material was selected from &quot;Punjab Government Progeny Orchard and Nursery, Attari, Amritsar&quot;. The investigation comprised three sets of experiments during the fruiting years 2006 and 2007. The first experiment comprised irrigation and mulching practices; the second consisted of graded doses of farmyard manure (FYM), inorganic fertilizer and biofertilizer and in the third experiment foliar spray of 1-Naphthaleneacetic acid (NAA), K2SO4&nbsp;and Borax were applied. The statistically best treatments accrued from three different experiments during 2007 and 2008 were combined and tested in 2008. It was revealed that the optimum utilization of different orchard cultural practices viz. proper water management, appropriate fertilizer programme and good preventive spray schedule brought profound changes in fruit cracking intensity. Hence, the consortium of intelligent management practices such as irrigation at 20% available soil moisture depletion (ASMD), mulching with black polythene, application of FYM (75 kg/tree), inorganic fertilizer (Nitrogen 350 g/tree), azotobacter (18 g/tree) and foliar spray of NAA at 40 ppm in lemon cv. Baramasi substantially reduced the cracking losses by 94.5% and resulted in impressive impact on fruit quality. &nbsp; Key words:&nbsp;Irrigation, mulching, organic fertilizer, inorganic fertilizer, biofertilizer, growth regulator, nutrients.

First Report of Citrus tristeza virus in National Germplasm of Citrus in Afghanistan.

Rejuvenation of the horticulture industry is a government priority in Afghanistan. With that purpose, European Commission-supported programs specifically focus on greater access to improved and appropriate planting materials to increase the quantity and quality of more competitive horticultural products. Establishment of a biotechnology laboratory was considered essential support to horticulture sector development. This laboratory has begun screening the health status of the Afghan Germplasm National Collection to ensure multiplication of not only the best selected varieties or ecotypes but also to avoid reproduction and distribution of virus-infected fruit trees. Symptom inspection and sample collection for viral diseases was carried out in the citrus orchard during survey activity at the National Collection Experimental Farm in Jalalabad (Nangarhar Province). Ninety-nine variety plots (one row of five plants) were inspected visually and samples from two plants for each plot were collected and analyzed by double-antibody sandwich (DAS)-ELISA. Plants showing vein flecking, yellowing, and plant decline symptoms were observed in several plots. Four accessions were found to be infected by Citrus tristeza virus (CTV): kumquat cv. Margarita (isolates J4 and J8), orange cv. Mahali (J61), mandarin group cv. Fruter (J76), and rough lemon cv. Mahali (J101). Identified isolates have been characterized molecularly. A 655-nt fragment, corresponding to the major coat protein gene, has been amplified from all ELISA-positive samples by reverse transcription (RT)-PCR using CTVF (5'-TAATGGACGACGAACAAAGA-3') and CTVR (5'-CCAAGCTGCCTGACATTAGT-3') primers. Sequence analysis revealed high similarity, ranging from 91.1 to 99.8%, within CTV isolates detected in Jalalabad. In accordance with the phylogenetic groups previously defined (page 8 in: Proceedings of the 15th Conference of the International Organization of Citrus Virologists, 2002), nucleotide sequences of Afghan CTV isolates investigated in the current work cluster in Group 1 (J4 and J8), Group 4 (J61 and J76), and Group 5 (J101). In particular, J4 and J8 isolates show, respectively, identity of 99.4 and 99.2% with reference isolate T36 (GenBank Accession No. M76485) from the United States (Florida). Moreover, in Group 4, isolate J61 and J76 were more similar to ANO-1 isolate (GenBank Accession No. DQ211658) from Egypt (identity of 98.5 and 98.0%, respectively) than to isolate 443-4 (GenBank Accession No. AY791844) from Croatia (97.4 and 97.5%, respectively). Finally, isolate J101 in Group 5, shows identity of 95.6% with isolates C268-2 (GenBank Accession No. AY750770) and C269-6 (GenBank Accession No. AY750775) from Argentina. To our knowledge, our results identified for the first time CTV-infected plants in Afghanistan. The presence of CTV in four accessions of the national citrus collection is of concern for Afghan horticulture. Implementation of the certification schemes is therefore necessary to guarantee the production and the employment of virus-free propagating material.

First Report of Shoot Blight, Canker, and Gummosis Caused by Neoscytalidium dimidiatum on Citrus in Italy.

In September 2008, a new disease was noticed in eastern Sicily, Italy in a 2-year-old regrafted citrus orchard with approximately 1,500 plants of sweet orange (Citrus sinensis (L.) Osbeck cv. Tarocco Scirè) on sour orange rootstock. Symptoms on the sweet orange scion consisted of blight of vigorously growing shoots and a sooty canker on shoots and rootstock trunks, resulting in shoot dieback to the cankered area. Masses of black fungal spores appeared under the bark and on the canker surface. Abundant gummosis was frequently associated with the affected tissues. Of the 1,500 plants surveyed, 12% were infected. A Scytalidium-like fungus was isolated consistently from symptomatic tissues on 2% potato dextrose agar (PDA). Conidia were ellipsoid to ovoid, hyaline, with an acutely rounded apex, truncate base, initially aseptate, becoming brown and two-septate at maturity, (10-) 12 to 13 (-14) × (4-) 5 (-6) μm. Mycelium was branched with septate, brown hyphae that disarticulated into 0- to 1-septate phragmospores (toruloid state). Genomic DNA was extracted from mycelia of single-conidial isolates cultivated on malt extract agar. Primers V9G and ITS4 were used to amplify the nuclear rRNA operon spanning the 3' end of 18S rRNA gene, the internal transcribed spacers, the 5.8S rRNA gene, and a part of the 5' end of the 28S rRNA gene (1,2). Both PCR primers were used to sequence directly the entire amplicon. DNA sequences of two isolates (CBS 124887 and 124888) were deposited in GenBank (Accession Nos. GQ330902 and GQ330903, respectively). These sequences were 100% identical in more than 545 nt to GenBank Accession Nos. AY213688 and FJ648577. On the basis of morphological characters and molecular data, the fungal isolates were identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers (2,3). Pathogenicity tests were conducted on five 2-year-old potted plants of sweet orange cv. Tarocco Scirè and lemon cv. Femminello Zagara Bianca, both grafted on sour orange. Eight 5-cm mycelial plugs of a single-conidial isolate were placed in wounds made with a sterile blade in the inner bark of plant stems and branches. Inoculation wounds were wrapped with Parafilm. The same number of plants inoculated with sterile PDA plugs served as controls. Inoculated plants were maintained in a growth chamber at 25 ± 1°C and 90 to 95% relative humidity. After 2 weeks, all inoculated plants developed gummosis originating from the inoculation point. Shoot blight and death of the entire plant were observed within 6 months on all inoculated plants. No differences were observed among the two citrus species. Control plants remained healthy. N. dimidiatum was reisolated from the infected plants and identified as described. To our knowledge, this is the first record of a disease caused by N. dimidiatum on citrus in Italy. The pathogen has been previously observed to infect freeze-damaged limbs of citrus in California, inducing a disease named Hendersonula branch wilt (4). This pathogen on citrus is important mainly as a wound-invading pathogen, therefore posing a serious threat to regrafted citrus orchards.