Orange Varieties Research Articles

A longitudinal study of sweet orange flowering with grouped count data

The orange variety “x11”, which is a spontaneous mutant of the sweet orange, has a short juvenile period with early flowering. The data used in this paper are from a randomized design experiment that aimed to assess the plants' flowering characteristics when grafted onto two different varieties of lemon rootstock. The plants were pruned in each of the four seasons, and on each pruning occasion, the number of branches on each plant was counted and classified into four mutually exclusive flowering categories. The data presented large variability and many zeros. The statistical analysis included the use of generalized linear mixed models with a Bayesian approach. The results showed that flowering is not equal over the seasons, i.e., there are significant differences in the classification of the branches across the four seasons and the two varieties, with interactions between seasonal and branch effects.

Transcriptome analysis identifies candidate genes associated with skin color variation in Triplophysa siluroides

In vertebrates, skin pigmentation is the most diverse phenotypic trait, and it is produced by a complex biological process that is often genetically controlled. Recently, two different colors (the typical brown and orange varieties) of Triplophysa siluroides, a species restricted to Yellow River drainage in China, were discovered. In the present study, the skin, brain and liver transcriptomes of T. siluroides of both colors were sequenced to search for genes related to skin pigmentation. Transcriptome sequencing generated 1,484,197,774 clean reads, resulting in a total of 222.6 Gb of sequence. The reads were assembled into 470,788 unigenes with a mean length of 1550 bp and an N50 size of 2944 bp. Functional annotation of the unigene dataset showed that 214,507, 304,161, 112,886, 179,074, 180,064, 184,837 and 82,081 unigenes were significantly matched to entries in the Nr protein, Nt, KO, Swiss-Prot, Pfam, GO and KOG databases, respectively. A differential expression analysis revealed that 2774, 3552 and 1529 unigenes were upregulated and 2720, 2663 and 1103 unigenes were downregulated in the skin, brain and liver of orange-skinned T. siluroides, respectively. Several genes that play key roles in pigmentation, i.e., Agouti, Slc45a2, Cbs, Mift and Slc7a11, showed significantly differential expression between brown and orange fish. In addition, we detected 158,863 simple sequence repeats (SSRs) in the T. siluroides transcriptome, and a total of 201,338 single-nucleotide polymorphisms (SNPs) were discovered in the different transcriptomes. The present results will facilitate further study of the molecular mechanisms of skin pigmentation and marker-assisted breeding of fish with valuable skin colors.

The effect of variety and degree of maturity of the fruit on the organoleptic characteristics of candied zucchini

Relevance. Squashes are a promising culture, and the recent work of breeders allow us to uncover large reserves to improve their nutritional and dietary qualities. The dietary value of zucchini is due to the easy digestibility of all carbohydrates, which allows them to be used in the production of canned foods. Canned snacks and candied fruits are produced from zucchini. The most important quality of the varieties we study is their cylindrical shape, allowing mechanization of the cleaning operation.Methods. Therefore, the purpose of this work was to use zucchini of different degrees of ripeness for the preparation of candied fruit with the least loss of products.Results. As a result of research conducted at the All-Russian Research Institute of Irrigated Vegetable and Melon-Growing in the Astrakhan Region, it was found that zucchini fruits of different degrees of maturity can be used to make candied fruits, but the highest yield was obtained from mature squash, and amounted to 654 kg from the Sosnovsky variety , in the Orange variety 696 kg from one ton of prepared raw material, while in the Orange variety of candied fruits it was obtained 42-64 kg more than in the Sosnovsky variety, depending on the degree of ripening STI. The tasting committee rated candied fruits obtained from the fruit of the zucchini of the Orange variety higher by 0.3-0.5 points than from the Sosnovsky variety. In terms of chemical composition, candied fruits prepared from the raw material of ripe zucchini fruits exceeded 1.2-1.5 times - from unripe fruits. Ready candied fruits can be used as an independent form, as well as for the preparation of other types of products in the food industry.

Phytochemicals in Leaves and Roots of Selected Kenyan Orange Fleshed Sweet Potato (OFSP) Varieties

This study reports the inherent phytochemical contents in leaves and roots of nine sweet potato varieties from Kenya. Results indicated that vitamin C content varied significantly (P < 0.05) among the sweet potato varieties regardless of the plant part, leaves having significantly (P < 0.05) higher levels than in the roots. Total flavonoids and phenolic compounds differed significantly (P < 0.05) among varieties, higher values were found in leaves than in roots. Flavonoid contents in roots ranged from below detectable limits (Whitesp) to 25.8 mg CE/100 g (SPK031), while in leaves it ranged from 4097 to 7316 mg CE/100 g in SPK4 and Kenspot 5, respectively. Phenolic content was below detectable limits in the roots of whitesp but it was in substantial amounts in orange fleshed varieties. The β-carotene content was significantly (P < 0.05) higher in leaves (16.43–34.47 mg/100 g dry weight) than in roots (not detected—11.1 mg/100 g dry weight). Total and phytic phosphorus were directly correlated with phytate contents in leaves and the roots. Tannins and soluble oxalates varied significantly (P < 0.05) with variety and plant part being higher in leaves. The current information is important for ration formulations and dietary recommendations utilizing sweet potato leaves and roots. Future studies on effects of processing methods on these phytochemicals are recommended.

Adaptability and Evaluation of Improved Orange Fleshed Sweet Potato (&amp;lt;i&amp;gt;Ipomoea batatas L. &amp;lt;/i&amp;gt;) Varieties in the Mid Altitude of Guji Zone, Southern Ethiopia

"Oromia Agricultural Research Institute, Bore Agricultural Research Center, Bore, Ethiopia Low yields and yield instability due to the use of old land races were limiting sweet potato production by resource-poor farmers in the zone. The Experiment was conducted at Bore Agricultural Research Center during 2018 and 2019 summer cropping season at Adola sub station and on-farm with the objective of identifying the cultivars, which could have wide or specific adaptations, and to select and recommend adaptable, frost and disease tolerant and high yielding orange type sweet potato cultivars for midlands of Guji Zone. To this effect four (Kaboli, Naspot 12, Naspot 13, Kaboli and local) improved orange varieties of sweet potato, <i>Ipomoea batatas</i> L., based on their yield and disease resistance performance were tested in RCBD with three replications with the spacing of 100cm*30cm between rows and plants, respectively. A widely cultivated variety (Local) was included as check. The combined analysis of variance across locations showed significant variation among genotypes and locations interaction for the number of roots, root weight, marketable yield, unmarketable yield and total storage root yield (t/ha). Based on this, the maximum mean value of root number per plot (21.33, 36.66 and 21.33) was recorded from Naspot-13, Naspot-12 and Naspot-13 variety at Dufa, Boke and Gobicha sites, respectively. However the minimum (16.00, 19.33 and 16.00) mean value of root number was recorded from Local Variety across locations. The maximum fresh root weight (670.33g and 444g) was recorded for Kabode and NASPOT-13 Variety over locations. On the other hand, the lowest fresh root weight (447.33, 437.33g and 296.33g) was recorded by Kaboli variety at all locations. The highest mean value of total root yield (65.09 t ha^-1 and 59.88 t ha^-1) was recorded by Naspot-13 at Dufa and Gobicha locations in 2018 and 2019 cropping seasons. While Naspot-12 gave maximum (55.16 t ha^-1) total root yield at Boke location. However Kaboli gave the least (43.09, 27.19 and 37.69 t ha^-1) total root yield over locations and years. Therefore Naspot 13 and Naspot-12 sweet potato varieties were more adaptable, disease tolerant and high yielder and should be promoted to farmers of the study areas for optimum production. "

Performance of early ripened varieties of ‘Sweet Orange’ in arid irrigated region of Punjab

Early maturing sweet orange varieties were evaluated during 2014–2018 and the data on leaf nutrient contents, growth, yield and fruit quality were analyzed. Leaf nutrient concentrations varied markedly among different varieties. Early Gold registered significantly higher canopy volume (34.4 m3) over other varieties (22.5–30.8 m3). Fruit yield was also significantly higher in Early Gold (42.3 kg/tree). In general, Early Gold showed overall superiority in term of juice content and quality characteristics over other tested sweet orange varieties, and hence has better perspectives in arid irrigated region of Punjab.

Estimación de máximas densidades para mitigar el impacto de la enfermedad HLB en plantaciones de naranja Valencia

Objectives: This work was carried out to estimate the optimal plant density for 4 Valencia orange varieties and to determine the highest yield potential as a strategic to overlap the yield reduction by citrus HLB disease. Methodology: Tree growth data of nine years [(height, diameter and canopy volume (CV); area of soil covered by canopy (ASC)] and yield in kg/tree (Y) of four varieties were analyzed first by correlation analysis and then submitted to a lineal and multiple regression analysis. Contribution: Correlation values of 0.8 and 0.85 were observed for ASC and CV with Y, respectively. Based on these variables the optimal calculated tree densities by regression for “Pineapple”, “Queen”, “Cutter” and “Campbell” varieties were 900-1000 trees/ha, which can yield 30 to 60 ton/ha/year, from 4th to 9th year.

On-Farm Evaluation of Orange Fleshed Sweet Potato Varieties Under Acidic Soil of North-East Region in Bangladesh

An on-farm trial with four orange fleshed sweet potato varieties viz. BARI Mishti Alu-4, BARI Mishti Alu-8, BARI Mishti Alu-12, BARI Mishti Alu-13 including local check (Muli Alu) were evaluated at farming system research and development (FSRD) site, Jalalpur, Sylhet, Bangladesh during rabi season for two consecutive years (2016-2017 &amp; 2017-2018) under Surma‐Kushiyara Floodplain of Bangladesh. The experiment was laid out in a randomized complete block design (RCBD) with six dispersed replications. The results revealed that the genotypes varied considerably in tuber root yields and yield attributing characters. Considering the average tuber root yield performance orange fleshed sweet potato varieties performed better than local variety (Muli Alu). However, among the varieties under studied BARI Mishti Alu-12 produced higher roots yield (40.63 t ha-1) than the other tested varieties. Considering economic return, the highest gross margin (Tk. 5,65,110 ha-1) and benefit cost ratio (5.50:1.00) was also obtained from sweet potato var. BARI Mishti Alu-12 and the lowest returnfrom var. BARI Mishti Alu-4 with benefit cost ratio of 3.54. Though the local cultivar (Muli Alu) produced lower root yields but it provided considerable gross margin (Tk.3,76,240 )and BCR (3.99:1.00 ) which closed to BARI Mishti Alu-12. It is due to higher demand of local cultivar with high price in the local market. Therefore, the genotypes BARI Mishti Alu-12 and local cultivar (Muli Alu) were found suitable for their better growth and yield under the acidic soils&#x0D; Bangladesh Agron. J. 2018, 21(2): 59-65

Change in taste-altering non-volatile components of blood and common orange fruit during cold storage.

Cold storage may cause changes in the volatile and non-volatile components of orange fruit, in association with the decrement of the characteristic fruit flavour and sensory acceptability. The aim of this work was to evaluate the changes of some non-volatile taste-altering components (total and individual sugars, acids, anthocyanins, putrescine and limonin) that may affect the organoleptic perception of cold-stored orange fruit. Three blood orange varieties ('Tarocco TDV', 'Tarocco Gallo', and 'Moro') and a common variety ('Washington navel') were stored at 6±1°C and 90-95% Relative Humidity (RH) for 60 d. Chemical and sensory assessments were performed during fruit storage at 15 d intervals. During storage, no dramatic change of the physicochemical parameters was recorded and the ascorbic acid content remained almost unchanged in all varieties. As expected, total anthocyanins significantly increased during storage. Limonin significantly decreased in all varieties. A consistent and significant increase in putrescine occurred during storage in the fruit of the pigmented varieties, not recorded in the common orange variety. Putrescine behaviour showed direct correlation with the accumulation of off-flavour in cold-stored 'Moro' and 'T. TDV' fruit, showing a clear influence of its relative concentration on the sensory perception of fruit. Finally, principal component analysis showed that the complete quality profile of the four investigated varieties represented clear differentiation without overlapping clusters. Our results suggest that the arise of a negative sensory perception in cold stored blood orange fruit might be linked to their accumulation of putrescine.

Production of antifungal compounds by Bacillus spp. isolates and its capacity for controlling citrus black spot under field conditions.

Orange juice is a major agricultural product, and oranges are among the most widely sold fresh fruits in several countries. Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, affects almost every species of citrus, causing aesthetic depreciation of the fruit and fruit drop, with consequent financial loss for its in natura commercialization. Fungicides are the major control measure for CBS, but have limited efficiency and high cost, and give rise to fungal strains resistant to these products. This work assayed the production of antifungal compounds by Bacillus spp. isolates and tested the potential of two isolates from B. subtilis (ACB-AP3 and ACB-83) for controlling CBS under field conditions with two previously untested orange varieties. A total of 15 isolates produced cell-free, thermostable or volatile compounds effective in suppressing P. citricarpa growth in vitro. It was possible to detect the production of two antibiotics (iturin and surfactin) by B. subtilis ACB-83. Additionally, B. subtilis isolates ACB-AP3 and ACB-83 displayed significant effects in controlling the disease under field conditions.

Extraction of essential oil from Citrus reticulate Blanco peel and its antibacterial activity against Cutibacterium acnes (formerly Propionibacterium acnes)

Citrus is one of the largest output fruits in the word. In China, the major orange variety is the Citrus reticulate Blanco (Ponkan). The peels are discarded as waste material, its comprehensive utilization is urgently needed. In this work, hydrodistillation method was developed to extract citrus essential oil (EO) from Blanco peel. With the optimal extraction conditions, the EO yield was more than 3%. By GC-MS analysis, 53 compounds were identified from the citrus EO. Terpenes compounds accounted for 71.2%, especially d-limonene (major composition) accounted for 58.9%. The obtained citrus EO showed remarkable antibacterial activity against Cutibacterium acnes (C. acnes, Formerly P. acnes) and common microorganisms such as S. aureus, B. subtilis, and E. coli. Even compared with the common antibiotics (such as erythromycin, clindamycin, and tetracycline) for acne therapy, its antibacterial activity against C. acnes is more excellent. This work provides a potential therapy material for the treatment of acne.

A three-variety automatic and non-intrusive computer vision system for the estimation of orange fruit pH value

An automatic 3-variety computer vision orange fruit pH value assessment system in the visible-range is presented, including each 100 different color images from Bam, Blood and Thomson orange of which the true pH has been measured and is known in advance. A total of 452 features are extracted from segmented orange color images. Results with repeated trials include: true versus estimated mean pH values, true minus estimated pH values boxplots, fitness regression dispersion plots and various error measure boxplots, for both single orange variety as well as the three-orange varieties altogether (test set), showing consistent results over all three orange varieties. Regression coefficient for pH estimation in Bam, Blood and Thomson orange varieties, were 0.950, 0.935 and 0.957, respectively. Results show that the hybrid ANN-ABC estimates pH values in orange quite similarly among orange varieties, implying that properly pH values estimation is possible for different orange varieties, regardless of orange type.

Steeping of Biofortified Orange Maize Genotypes for Ogi Production Modifies Pasting Properties and Carotenoid Stability

Biofortified orange maize open-pollinated varieties and hybrids with higher provitamin A carotenoids (pVACs) have been released in sub-Saharan Africa and will be introduced throughout the local food systems. This study assessed the impact of steeping, a traditional processing method, on retention of carotenoids and starch pasting properties of porridges made from select biofortified maize genotypes. Steeping had a modest effect (&lt;9% loss) on total carotenoid stability during relatively shorter steeping periods (&lt;72 h). However, more extended steeping periods (up to 120 h) had a detrimental effect on total carotenoid recovery (61% loss). Xanthophylls showed greater stability (82% retention) compared to carotenes (30% retention) during subsequent wet cooking of fermented flours. Interestingly, steeping of maize did modify pasting properties, with peak viscosities increasing from 24–72 h of steeping potentially impacting cooking stability. These results suggest that steeping can impact carotenoid retention and potentially optimal steeping times would be 24–72 h for acceptable carotenoid retention.

Inhibitory Effects of Different Varieties of Sweet Potato (Ipomoea batatas L.) Tubers Extracts on Lipoxygenase Activity

Background: Sweet potatoes (Ipomoea batatas L.) with purple, orange and white varieties can be differentiated by their skin and flesh tubers’ colors. Research on anti-inflammatory activity of this plant is still limited although has been used traditionally. Objective: This study aimed to determine IC50 value of sweet potato tubers extracts in inhibiting lipoxygenase activity. Methods: Dried tubers of sweet potato were macerated with ethanol 70%. Each extracts were tested for soybean lipoxygenase inhibitory activity, phytochemical screening and total flavonoid contents. IC50 value and total flavonoid contents obtained from each extracts were analyzed statistically. Results: IC50 value of purple, orange and white sweet potato tubers extracts are 46.09, 52.12 and 63.69 μg/mL respectively. Each extracts contain alkaloids, flavonoids, saponins, tannins and glycosides. Total flavonoid contents in purple, orange and white sweet potato extracts are 8.45±0.41; 7.57±0.03; and 6.12±0.14 mgQE/g extract respectively. Conclusion: Total flavonoid contents and IC50 values of each extracts are strongly correlated and inversely proportional with significance value of 0.026 and correlation value of -0.999 which indicate that the higher total flavonoid contents, the stronger inhibitory activity.

Effects of Storage Conditions, Storage Duration and Post-Harvest Treatments on Nutritional and Sensory Quality of Orange (Citrus sinensis (L) Osbeck) Fruits

ABSTRACT The fruits of Msasa and Jaffa orange varieties were harvested and subjected to post-harvest treatments namely; dipping in hexanal, dipping in calcium chloride and compared with untreated control; and they were stored at ambient (28 ± 2°C) and reduced temperatures (18 ± 2°C) conditions. Data were collected on the 0, 4th, 8th, and 12th days from the date of fruit harvest. Chemical analyses were conducted to determine vitamin C content, total sugars, reducing sugars and total flavonoids. Post-harvest treatments had a significant effect on vitamin C and total flavonoids of Jaffa orange fruit. Hexanal treated fruit had higher values of total flavonoids, vitamin C, and total sugars compared to calcium chloride treated and control fruit. The storage durations showed significant effects on the vitamin C content of Jaffa, total flavonoids, the total and reducing sugars of both fruit varieties. Vitamin C and total flavonoids decreased with increasing storage duration of fruit. The significant interactions of factors were observed on total sugar which was increasing with increasing storage duration, but higher in hexanal treated and ambient stored fruit. Based on consumer acceptance test, the hexanal treated fruits were the most liked followed by calcium chloride treated and untreated fruits based on the appearance, taste, texture and overall acceptability.

THE INFLUENCE OF GENOTYPE AND STORAGE CONDITION ON THE CONTENT OF SELECTED BIOACTIVE SUBSTANCES IN THE FRUIT OF PUMPKIN (CUCURBITA MOSCHATA DUCH.)

Butternut squash (Cucurbita moschata) is a significant crop in terms of the content of bioactive substances with antioxidant properties – vitamin C, vitamin E, carotenoids, polyphenol compounds – as well as B-complex and potassium vitamins are appreciated by the consumer both raw and heat treated. It is suitable for storage, consumption in the fresh state or heat treatment thanks to its interesting sensory properties. The aim of the thesis was to evaluate the influence of genotype and storage conditions on the content of selected bioactive substances in the fruit of these six varieties: Liscia, Matilda F1, Orange, Serpentine, UG 205 F1 and Waltham F1. From bioactive substances we determined the content of total carotenoids and total polyphenols in the flesh of the fruits before and after storage. The total carotenoid content in the fruit before storage was in the range of 40.62 mg.100 g-1 DS (dry substance) to 76.78 mg.100 g-1 DS, after storage the range transformed into 50.58 mg.100 g -1 DS to up to 109.81 mg.100 g-1 DS. The total polyphenol content before storage ranged from 109.95 mg GAE.100 g-1 DS to 198.96 mg GAE.100 g-1 DS, after storage in the range of 152.51 mg of GAE.100 g-1 DS to 199.83 mg of GAE.100 g-1 DS. The results show that the highest content of total carotenoids in fresh fruits after harvest was determined in the pulp of the varieties UG 205 F1 (76.78 mg.100 g-1 DS), Orange (71.40 mg.100 g-1 DS), and high content of total polyphenols was determined in the Matilda F1 strains (198.96 mg GAE.100 g-1 DS) and Orange (166.09 mg GAE.100 g-1 DS). After two months of the fruit’s storage, the total carotenoid content significantly increased in Liscia by 91%, Orange and Waltham F1 both by 54%. The total polyphenol content considerably rose in Liscia and UG 205 F1 varieties by 39%. The highest content of total polyphenols after storage was found in Serpentine fruit (199.83 mg GAE.100 g-1 DS). It follows that from the point of view of the content of total carotenoids it makes sense to store the fruits of the Orange and Waltham F1 varieties and, in terms of total polyphenols content, the fruits of the Serpentine variety. Taking into account the development of the contents of both groups of bioactive substances, storage of the Liscia variety is recommended. The effect of genotype on total carotenoid and polyphenol content in fruit was statistically significant. Storing these pumpkin varieties resulted in an increment of their total carotenoid and polyphenol content, but it did not have any statistical significance.

Assessment of Orange (Citrus Sinensis) Supply Chain Activities in Kano State

The study focused on the handling system of orange in Yanlemo Market of Kano State. A field study was conducted with structural questionnaires that targeted the orange supplies, traders and agricultural equipment suppliers/fabricators. Result obtained reveals that the orange handling activity is dominated by male traders. Average of 2 to 5 bags of oranges are usually handled by about 53.3% of the respondents, while 8.3% handle more than 10 bags of the oranges daily. Dan Tivi was found to be the commonest orange variety in the study area. Some other varieties established in the study area are; Dan Nassarawa, Dan Ondo and Dan Delta representing about 8.3, 1.7 and 1.7% of the varieties handled in the study area respectively. The mode of transportation, sorting, and washing was found to be manual with a lot of challenges. The predominant manual handling of the orange established in the study area could be amongst the major reasons for the high losses usually recorded by the traders on a daily basis. Thus, useful suggestions that could be employed by researchers and policymakers to provide improvements in the supply chain activities to prevent such losses are presented. Keywords— Orange, Assessment, Supply Chain, Handling

Genetic, morphological and chemical investigations reveal the genetic origin of Pompia (C. medica tuberosa Risso & Poiteau) – An old endemic Sardinian citrus fruit

Citrus fruits have been introduced to the Mediterranean area from Asia for centuries and spontaneous crosses have generated several hybrid forms, some of which have had agricultural or industrial success while others have remained niche food or ornamental products, or have disappeared. Pompia (C. medica tuberosa Risso & Poiteau) is an old endemic citrus fruit from Sardinia of unknown genetic origin. Initial phenotypic and molecular characterizations revealed a high degree of similarity with lemon (C. limon (L.) Burm.) and citron (C. medica L.). To identify the ancestors of Pompia, 70 citrus species of the Citrus genus were genotyped with 36 codominant molecular markers (SSR and InDel) of nuclear and cytoplasmic genomes. Diversity analysis and allelic comparisons between each citrus species at each locus indicated that Pompia resembles lemon and limonette of Marrakech, i.e. the result of a cross between sour orange (C. aurantium L.) and citron, where citron was the pollinator. Two Italian citron varieties were identified as potential male parents, i.e. Diamante and Common Poncire. However, we were unable to differentiate varieties of sour oranges because varietal diversification in this horticultural group resulted from DNA sequence variations that SSR or InDel markers could not reveal. Rhob el Arsa and Poncire de Collioure were found to be two synonyms of Pompia. Pompia appeared to be equally distinct from citron, lemon and sour orange based on the overall analysis of the fruit, leaf and seed phenotype, and juice chemical composition. At the leaf level, the Pompia essential oil (EO) composition is close to that of citron whereas the zest is much closer to that of sour orange.

Differences between sun and shade habitats on the invasive shrub Lantana camara and its biocontrol agent Teleonemia scrupulosa

The sap-sucking lace bug, Teleonemia scrupulosa (Hemiptera: Tingidae), was released as a biocontrol agent against the invasive shrub Lantana camara (Verbenaceae) in South Africa in 1961. Like many agents released against the weed in South Africa, success has been varied, largely attributed to the sheer number of L. camara varieties involved and the habitat types they invade. This study assessed the effects of L. camara variety (floral colour) and light microhabitat (sun/shade) on the preference, proliferation and feeding damage of T. scrupulosa. Using a cage choice test, varietal preference of T. scrupulosa between two of the most abundant (invasive) L. camara varieties (pink and orange) was assessed under both shaded and well-lit conditions. Secondly, the effect of T. scrupulosa chlorotic feeding damage on leaf physiology was evaluated. Results indicated that T. scrupulosa preferred the orange flower variety in high light environments but did not proliferate on either variety in the shade. At approximately 20% herbivory damage, photosynthesis declined by 90%, which was primarily attributed to the rapid increase in stomatal resistance. These results indicate that microhabitat, particularly sunlight intensity, is more important than L. camara variety to T. scrupulosa host preference. Mass release strategies should therefore consider microhabitat, prioritising releases on plants in open sunny locations to encourage agent persistence and proliferation.

Occurrence of Colletotrichum fruticola along with C. gloeosporioides in causing anthracnose disease on Citrus sinensis in Tunisia

Information on the Colletotrichum species associated with Citrus anthracnose was lacking. Surveys were conducted from January 2012 to February 2013 on different citrus species and varieties orchards in the Cap-Bon region (Tunisia) to investigate the prevalence of Colletotrichum species. Typical anthracnose symptoms such as dieback and wither-tip of twigs were noticed. The fungi associated with anthracnose were isolated and studied. Morphological features (mycelial and sporulation characterization), molecular identification by using ITS1 and ITS2 primers were done along with pathogenicity test monosporic cultures. Eight Colletotrichum isolates were collected from infected fruits, leaves and twigs and were identified as Colletotrichum gloeosporioides (seven isolates) and Colletotrichum fructicola (one isolate). All eight Colletotrichum isolates were pathogenic on Thomson, Malti and Meski orange varieties, Lunari lemon variety and sweet lime Bergamot detached fruit and leaves. This investigation revealed the prevalence, for the first time of C. fructicola, on Citrus in Tunisia.