Control Mango Research Articles

Efficacy of Two Tank-Mix Adjuvants to Control Mango Thrips Using a UAV Sprayer

Thrips have become some of the most challenging pests to control in mango production due to their short developmental time, hidden locations and resistance to pesticides, in the tropical regions of China. To improve pesticides efficacy, the tank-mix adjuvants Qi Gong (QG) and the thrips attractant Lv Dian (LD) were added when using an unmanned aerial vehicle (UAV) to control thrips. The surface tension, contact angle on mango leaves, droplet size, spreading rate, and drying time of the two tank-mix adjuvants were determined. The effects of the two tank-mix adjuvants using a UAV sprayer on the droplet coverage and control efficacy against thrips on mango inflorescences were tested through field trials. The results showed that both QG and LD could reduce the surface tension of the liquid and the contact angle on mango leaves and could increase the spreading performance. The droplet coverage in the upper layer of the canopy was about 2% higher than that in the lower layer, and the coverage at the top of the panicle was 5% higher than that at the bottom. QG improved the deposition coverage of mango inflorescences by about 31.5%. The addition of QG increased the efficacy by 18.24% and 8.03%, respectively, at florescence and the young fruit stage. The addition of the LD increased the efficacy by 24.56% and 14.38%, respectively, at florescence and the young fruit stage. These test results can provide a scientific basis for the control of mango thrips with UAVs.

Evaluation of Some Biocontrol Agents to Control Mango Powdery Mildew Disease and their Effect on Productivity

Evaluation of Some Biocontrol Agents to Control Mango Powdery Mildew Disease and their Effect on Productivity

Effects of Polygonatum cyrtonema extracts on the antioxidant ability, physical and structure properties of carboxymethyl cellulose-xanthan gum-flaxseed gum active packaging films

A novel film composed of Polygonatum cyrtonema extracts (PCE), xanthan gum (XG), flaxseed gum (FG) and carboxymethyl cellulose (CMC) was prepared (XFCP). Addition of PCE has decreased the light transmittance, while enhanced the UV blocking performance, antioxidant activity, tensile strength and elongation at break of XFCP due to polysaccharides, polyphenols, and flavonoid in PCE. Structural analyses by FTIR and XRD indicated the hydrogen-bonding interaction between PCE, XG, FG and CMC. It was found that compared with the control sample, XFCP2.5% with the lowest WVTR was able to prolong the shelf life of mango. The overall quality of mango was also improved in terms of lower decay rate, weight loss rate, total soluble solid, and polyphenol oxidase, higher titratable acidity, Vc, and superoxide dismutase than control mango upon 8 days of storage. This effectively expanded the application of PCE into food packaging in addition to merely as Chinese traditional medicine herbs.

Analysis of the fungicidal efficacy, environmental fate, and safety of the application of a mefentrifluconazole and pyraclostrobin mixture to control mango anthracnose

Mango anthracnose is among the most severe diseases impacting mango yields and quality. While this disease can be effectively controlled through chemical means, it is vital that appropriate field efficacy and fate determination studies be conducted when applying pesticides to crops in order to appropriately gauge the ecological and health risks associated with the use of these agents. GAP field trials were conducted to explore the efficacy, dissipation, and terminal residues associated with the application of mefentrifluconazole and pyraclostrobin to mango crops in six locations throughout China. These analyses revealed that three applications of mefentrifluconazole [160 mg active ingredient (a.i.) kg-1 ] in combination with pyraclostrobin mixture achieved satisfactory disease control efficacy. To simultaneously detect mefentrifluconazole and pyraclostrobin residues on mangoes, a 'quick, easy, cheap, effective, rugged and safe' (QuEChERS) high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)-based approach was established. The initial mefentrifluconazole and pyraclostrobin concentrations ranged from 0.18 to 0.34 mg kg-1 , and these two compounds exhibited respective half-lives of 5.6 to 10.8 days and 5.5 to 9.0 days. At 21 days following foliage application, the terminal mefentrifluconazole and pyraclostrobin residue concentrations were 0.02-0.04 and 0.01-0.04 mg kg-1 , with these concentrations being below the maximum residue limit (MRL) established for pyraclostrobin. Both short-term [acute reference dose percent (ARfD%) 0.78-2.36% and 2.0-6.08%] and chronic [acceptable daily intake percent (ADI%) 0.08-0.47% and 0.09-0.55%] dietary intake risk assessments for mefentrifluconazole and pyraclostrobin indicated that these terminal residue concentrations are acceptable for the general population. Mefentrifluconazole and pyraclostrobin in mango was rapidly degraded following first-order kinetics models. The dietary risk of mefentrifluconazole and pyraclostrobin through mango was negligible to consumers. The application of a 400 g L-1 mefentrifluconazole-pyraclostrobin suspension concentrate mixture represents a highly efficacious fungicidal approach to controlling mango anthracnose that exhibits significant potential for development as it is easily degraded and associated with low residual concentrations after application. © 2022 Society of Chemical Industry.

Evaluation on the Effect of Silica (DE) for Growth and Quality of Mango Kesar

An experiment was conducted during 2012-2014 at Kittur Rani Channamma College of Horticulture, Arabhavi, Gokak (Karnataka), India to study the effect of silicon on yield and quality of mango cv. Kesar. The experiment was laid out in a randomized complete block design with nine treatments replicated five times. The results revealed that, the highest yield per tree (140.93 kg/tree) was recorded in the treatment supplemented in (T5) Half of RDF + DE 600 kg/ha which significantly more than the compared to control during 2012-2013, 2013-2014 and pooled data. It was noticed that the (T7) RDF + DE 300 kg per hectareas RDF + DE 300 kg/ha was best on the basis of physical characteristics like increased in length, diameter and volume of the fruit, and the treatment was significantly higher than the untreated control mango fruits. The treatment also helped in better chemical characteristics like increased TSS, total sugars, and reducing sugars and optimum physiological loss in weight, resulting in improved keeping quality at ambient conditions (25-350C, 50-60% RH). The T7 treatment was judged as the most effective soil application for the mango cv. Kesar that helped in increasing the quality of the mango fruits during storage even after 18 days of storage. The same treatment was also found to be more effective and significantly more than the compared to control during 2012-2013, 2013-2014 and pooled data with respect to organoleptic parameters for the mango cv. Kesar.

First record of Colletotrichum alienum Causing postharvest Anthracnose disease of mango fruit in China.

Mango (Mangifera indica L.) is one of the world's most significant economic fruit crops, and China is the second-largest producer of mango (Kuhn et al., 2017). Postharvest mango anthracnose is caused by Colletotrichum species and reduce the self-life of mature fruit (Wu et al., 2020). Colletotrichum species also cause postharvest anthracnose and fruit rot disease of Apple, Banana and Avocado (Khodadadi et al., 2020; Vieira et al., 2017; Sharma et al., 2017). In July 2019, mango fruits cv. 'Jin-Hwang' were observed at different fruit markets (39°48'42.1"N 116°20'17.0"E) of the Fengtai district, Beijing, China, exhibiting typical symptoms of anthracnose including brown to black lesions in different size (≤ 2 cm) with identified border on the mango fruit surface. Later, the lesions were coalesced and extensively cover the surface area of the fruit. The lesions were also restricted to peel the fruit and pathogen invaded in the fruit pulp. About 30% of mango fruits were affected by anthracnose disease. The margins of lesions from infected mango fruits (n=56) were cut into 2 × 2 mm pieces, surface disinfected with NaClO (2% v/v) for 30 s, rinsed thrice with distilled water for 60s. These pieces were placed on PDA medium and incubated at 25°C for 7 days. Pure culture of fungal isolates was obtained by single spore isolation technique. Initially, the fungal colony was off white, and colony extended with time, turning light gray at the center. The morphological examination revealed that conidia were hyaline, oblong, and unicellular. The conidia were measured from 10 days old culture and dimensions varied from 13.3 to 15.8 µm in length and 4.6 to 6.1 µm in width. For molecular identification, a multi-locus sequence analysis; the Internal Transcribed Spacers (ITS) region, partial actin (ACT) gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene and chitin synthase (CHS-1) gene were amplified by using the primer sets ITS1/4 (White et al. 1990), ACT-512F/ACT-783R (Carbone and Kohn 1999), GDF1/GDR1 (Guerber et al. 2003) and CHS1-79F/CHS-1-354R (Carbone and Kohn 1999) respectively. The partial sequences of MTY21 were deposited to GenBank accessions (MT921666 (ITS), MT936119 (ACT), MT936120 (GAPDH) and MT936118 (CHS-1). All obtained sequences showed 100% similarity with reported sequences of Colletotrichum alienum ICMP.18691 with accessions numbers JX010217 (ITS), JX009580 (ACT), JX010018 (GAPDH) and JX009754 (CHS-1) which represented the isolate MTY21 identified as C. alienum by constructing Maximum Likelihood phylogenetic tree analysis using Mega X (Kumar et al., 2018). For the confirmation of Koch's postulates, the pathogenicity test was conducted on 36 fresh healthy mango fruits for each treatment. Fruits were punctured with the help of a sterilized needle to create 2mm2 wounds and inoculated with 10µL inoculum (107 spores/mL) of MTY21. Control mango fruits were inoculated with 10µL sterilized distilled water and incubated at 25 °C with 90% relative humidity. The lesions appeared at the point of inoculation and gradually spread on the fruit surface after 7 days post inoculation. The symptoms were similar to the symptoms on original fruit specimens. The re-isolated fungus was identified as C. alienum based on morphological and molecular analysis. Mango anthracnose disease caused by several Colletotrichum species has been reported previously on mango in China (Li et al., 2019). Liu et al. (2020) reported C. alienum as the causal organism of anthracnose disease on Aquilaria sinensis in China. C. alienum has been previously reported causing mango anthracnose disease in Mexico (Tovar-Pedraza et al., 2020) To our knowledge, this is the first report of C. alienum causing postharvest anthracnose of mango in China. The prevalence of C. alienum was 30% on mango fruit which reflects the importance of this pathogen as a potential problem of mango fruit in China.

Optimisation of the Postharvest Treatment with Thymol to Control Mango Anthracnose

Anthracnose, caused by the fungus called Colletotrichum gloeosporioides, is the main postharvest disease that affects mango production on Reunion Island. Fruits for the export market are always treated with chemicals. The use of chemical treatment is not in adequation with consumer expectations, and the increasing emergence of fungicide-resistant isolates promotes the development of alternatives methods. The principal objective of this work was to use antimicrobial properties of thymol as an alternative postharvest treatment on mango. Thymol diluated in a penetrating agent solution was effective on mango anthracnose. At a concentration of 0.025%, Thymol limited necrosis development due to pathogens during fruit storage. This treatment can stimulate some of polyphenols biosynthesis involved in the fruit resistance to postharvest disease, particularly the synthesis of gallic acid and resorcinol. With this final concentration of 0.025% thymol, the treatment did not affect fruit maturation and quality, especially the peel colour and sugar content. Importantly, the treatment did not show any detectable effect on organoleptic qualities of the fruit.

In Vitro Efficacy of Microbial Antagonists, Botanical Extracts and Synthetic Chemicals against Mango Quick Wilt Pathogen Ceratocystis Manginecans

ABSTRACT Ceratocystis manginecans is a cause of mango quick wilt disease. The pathogen has inflicted significant yield loss to the mango industry of Pakistan. The present study was undertaken to evaluate the inhibitory activity of different microbial antagonists, botanical extracts and fungicides on C. manginecans growth in vitro. Among the three microbial antagonists tested, T. harzianum produced the highest inhibition (87.3%) of the pathogen in dual culture. Allium sativum showed the highest inhibitory (71.5%) activity against C. manginecans, while, Topsin-M (Thiophanate Methyl) was the most effective (84.7%) among fungicides in a poison food assay. This study addresses the gap of information on potential chemical and biological control agents that might find potential application to control mango quick wilt disease. To our knowledge, this is the first report of excellent antifungal activity of A. sativum against C. manginecans. Taken together these findings T. harzianum, A. sativum, and Topsin-M should be tested further at field level so that they can be included as components of integrated management program of mango quick wilt.

Fludioxonil – A potential alternative for postharvest disease control in mango fruit

Stem-end rot (SER) is one of the most prevalent postharvest diseases of mango fruit grown in the Mediterranean climate, whereas anthracnose disease caused by Colletotrichum gloeosporioides almost never occurs due to the dry environment during fruit development and harvest. SER is caused by a variety of fungal pathogens. The main cause of SER in Israel is Lasiodiplodia theobromae, which is not well controlled by the current fungicide. In the search for potential alternatives to control postharvest SER in mango, we assessed the efficacy of various fungicides and focused on two commercial fungicides — fludioxonil and prochloraz — at controlling postharvest decay of mango fruit. In vitro testing, Fludioxonil was found to be significantly more effective at inhibiting L. theobromae mycelial growth and conidial germination. Subsequent treatments with fludioxonil were also significantly more effective than prochloraz in controlling SER of mango fruit inoculated with L. theobromae. Both fungicides controlled side decay, mainly Alternaria alternata, of mango fruit with similar efficiency. However, fludioxonil treatments significantly changed the stem end microbiome community and reduced SER incidence and severity in mango fruit relative to similar treatments with prochloraz. We suggest fludioxonil as a postharvest treatment to control mango fruit decay in areas that harvest during a dry season.

Stakeholders perception of weaver ants effects on mango fruits quality in Benin

Weaver ant (Oecophylla longinonda) used in biological control of pest, is said to improve the organoleptic quality of protected fruits. This study aims at bringing out stakeholders’ perception of weaver ants effect on mango quality. A survey was performed in Parakou (Benin), with stakeholders to assess their perception of mango quality and their opinion about weaver ant’s effect on mango quality. Then, the taste and the appearance (performed on unwashed and washed fruits) of three categories of mango: Control mango CM (Mango without ants), ants mango without scale insect (AM) and ants mango with scale insects (AMS) were evaluated by 25 panelists. Survey showed that maturity, appearance, size, non-infestation and firmness were the main criteria used by stakeholders to assess mango quality. Differences between protected and non-protected mango were based mainly on taste, appearance and non-infestation (68.8%; 48.4%; 31.3% of respondents, respectively). Most respondents (88.6%), who used taste to differentiate protected mango from non-protected mango, declared that the former is sweeter than the latter. Some respondents (35.5%) negatively pointed out the presence of scale insects and / or ants marks on the peel of protected mango. All respondents stated that protected mango is non-infested by pest. Similarly, sensory test showed that AMS scored the highest grade (4.5) followed by AM (3.9) and CM (2.8) for the taste (for washed fruits), registered the highest score (3.8) ahead AM (3.2) and CM (2.7). This investigation showed that weaver ants improve mango, taste and appearance. Mango quality changes due to the presence of weaver ants should be investigated. Key words: Oecophylla longinoda, biological control, survey, criteria, Parakou, organoleptic quality.

Application of chlorine dioxide microcapsule sustained-release antibacterial films for preservation of mangos

In this study, fresh mangos were packed using a custom-made antimicrobial film coated with sustained-release chlorine dioxide microcapsules. We then compared physical and chemical indexes, such as weight loss rate, firmness, chromatic aberrations, soluble solids, vitamin C, titratable acid, and other nutritional indicators, to examine changes in the mango and film during storage. Our findings revealed that control mango showed loss of edible value and commercial value after 21days of storage, and the chlorine dioxide microcapsule antibacterial film group still retains food value and commercial value. Cross-sectional scanning electron microscopy images of the used film showed that the polylactic acid film was smooth and flat, whereas cross-sections of the antimicrobial film showed that the film was covered with voids due to deliberate release of chlorine dioxide gas during the packaging process. Thus, the antibacterial film exhibited erosion and degradation. These findings provided important insights into the use of antimicrobial films for the packaging of fruits during storage, which is essential for promoting the application of solid chlorine dioxide antimicrobial film in packaging preservation.

Morphological Characterization, Quality, Yield and DNA Fingerprinting of Biofield Energy Treated Alphonso Mango (<i>Mangifera indica</i> L.)

Alphonso is the most delicious variety of mango (<i>Mangifera indica</i> L.) known for its excellent texture, taste, and richness with vitamins and minerals. The present study was attempted to evaluate the impact of Mr. Trivedi’s biofield energy treatment on morphological characteristics, quality, yield and molecular assessment of mango. A plot of 16 acres lands used for this study with already grown mango trees. This plot was divided into two parts. One part was considered as control, while another part was subjected to Mr. Trivedi’s biofield energy treatment without physically touching and referred as treated. The treated mango trees showed new straight leaves, without any distortion and infection, whereas the control trees showed very few, distorted, infected, and curly leaves. Moreover, the flowering pattern of control trees did not alter; it was on average 8 to 10 inches with more male flowers. However, the flowering pattern of treated trees was completely transformed into compact one being 4 to 5 inches in length and having more female flowers. Additionally, the weight of matured ripened mango was found on an average 275 gm, medium sized with 50% lesser pulp in the control fruits, while the fruits of biofield energy treated trees showed on average weight of 400 gm, large sized and having 75% higher pulp as compared to the control. Apart from morphology, the quality and nutritional components of mango fruits such as acidity content was increased by 65.63% in the treated sample. Vitamin C content in the treated Alphonso mango pulp was 43.75% higher than the pulp obtained from the control mango farm. The spongy tissue content in pulp of the matured ripened mangoes was decreased by 100% for two consecutive years as compared to the control. Moreover, the yield of flowers and fruits in the treated trees were increased about 95.45 and 47.37%, respectively as compared to the control. Besides, the DNA fingerprinting data using RAPD revealed that the treated sample did not show any true polymorphism as compared to the control. The overall results envisaged that the biofield energy treatment on the mango trees showed a significant improvement in the morphology, quality and overall productivity along with 100% reduction in the spongy tissue disorder. In conclusion, the biofield energy treatment could be used as an alternative way to increase the production of quality mangoes.

Efficacy of Different Fungicides against Mango Anthracnose in Senegalese Soudanian Agroclimate

Anthracnose is the one of the most devastating diseases of mango produced in the southern part of Senegal. The field trials against post harvest rot due to anthracnose took place in three orchards over two production seasons, in 2009 and 2010. Three systemic fungicides (thiophanate methyl, azoxystrobin and myclobutanyl) and one contact fungicide (mancozeb) were tested for their efficacy. The first treatments in 2009 took place in the rainy season, while 20% of mangoes on trees exhibited anthracnose lesions. At ripening stage, 100% of fruits from non treated control mango trees were affected by anthracnose and got rotten, while between 73.2% and 80% of mangoes ripened free of disease when treated with thiophanate methyl. With the treatment with azoxystrobin, between 46.6% and 60% of fruits were not infected. Treatment with myclobutanyl was less effective. This level of effectiveness was clearly improved in 2010 by preventive spraying, days ahead of onset of the rainy season, before the appearance of anthracnose symptoms on fruits. The level of effectiveness was higher respectively for thiophanate methyl (between 96% and 100% of fruits not infected) and azoxystrobin (between 84% and 96% of fruits not infected).

Quality Control of Mango Fruit during Postharvest by Near Infrared Spectroscopy

Near infrared spectroscopy (NIRS) is a prominent technique for non-de- structive fruit quality assessment. This research applied NIRS to control mango quality during postharvest management, harvesting, cold storage and shelf storage. Mango fruits cv. Nam Dok Mai Si Thong were harvested in three stages of fruit maturity; 100, 110 and 120 days after fruit set (DAFS). Mangoes were then divided into three groups. The first group was used to measure the quality at harvest. Mango fruits were measured using short wavelength spectra (700-1100 nm) by NIRsystem 6500 with a fiber optic probe. Physical (color and firmness) and chemical properties (total soluble solids (TSS), tiratable acidity (TA) and dry matter (DM)) were analyzed by conventional methods. The partial least square regression (PLSR) was used to develop the calibration model using The Unscrambler ® version 9.8 (CAMO, Oslo, Norway). The means of the data were compared using the least significant difference (LSD). The second group was used to measure quality after cold storage, and was comprised of mango fruits at two harvesting stages (100 and 110 DAFS). Fruits from each stage were stored in cold conditions (13°C, 80-90%RH) for 21 days before the spectra were measured using the NIRsystem 6500. The physical and chemical properties were analyzed. PLSR model development and study of variance followed the same procedure as with the first group. For the third group, mango fruits at two harvesting stages, 100 and 110 DAFS, were stored in cold condi- tions (13°C, 80-90%RH) for 21 days, after which all samples were kept in the same chamber at 22°C for an additional 4 and 7 days. Spectral data measuring, physical and chemical properties, the PLSR model development and analysis of

TRICHODERMA SP. AS A BIOLOGICAL CONTROL AGENT IN THE POSTHARVEST TREATMENT OF MANGO STEM-END ROT

Stem-end rot caused by Botryodiploidia theobromae is one of the most economically important diseases of mango. Currently the disease is controlled by fungicides. Due to the residual effect and biosafety issues to the health and environment caused by fungicides, this study was initiated to investigate the potential use of fungal antagonist (Trichoderma sp.) against B. theobromae and its effectiveness as compared to fungicides. The mango cuultivar ‘Sala’ was used in this study. Treatments applied were propiconazole sprayed at 500 ppm and three different spore concentrations at 1×10(3), 1×10(6) and 1×10(8) conidia/ml of Trichoderma sp. with and without inoculation of B. theobromae. The severity of the disease was determined at 0, 2, 4, 6 and 8 days post inoculation based on disease lesion. When B. theobromae inoculated on mango, spore concentration of Trichoderma 1×10(6) and 1×10(8) conidia/ml showed good potential to control stem-end rot but control levels was not as high as using propiconazole. All the fruits without inoculation with B. theobromae did not develop any disease symptom until day 4 for all treatments. Treating the mangoes by spraying with three different spore concentrations of Trichoderma sp. and 500 ppm propiconazole did not have significant effect as compared to untreated (control) mango. Disease started to develop at day 6 for fruit sprayed with all the three concentrations. All treatments including control showed that the percentage of lesion had a value ranging from 0-2%. This study revealed that fungal antagonist of Trichoderma sp. with spore concentration of 1×10(8) and 1×10(6) conidia/ml has the potential for postharvest disease control and thus needs further evaluation.

Total Phenolics, Carotenoids, Ascorbic Acid, and Antioxidant Properties of Fresh‐cut Mango (Mangifera indica L., cv. Tommy Atkin) as Affected by Infrared Heat Treatment

Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh-cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh-cut cubes from 'Tommy Atkin' mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4-d intervals during 16-d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh-cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (μM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16-d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh-cut mangoes with minimal effect on the visual appearance. Various methods/treatments are in use for extending the quality of fresh-cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh-cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16-d storage. This is the first study reporting on the use of IR heat in fresh-cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh-cut mango cubes with minimal effect on the visual appearance.

Evaluating sago as a functional ingredient in dietetic mango ice cream.

A low fat mango ice cream (2.4% milk fat) was prepared in a mechanized 'ice and salt' type freezer using powdered sago at 2.5% as a natural bulking agent along with sodium alginate at 0.025% as adjunct. The low fat mango ice cream was compared with control mango ice cream having 10% milk fat and 0.15% sodium alginate as stabilizer. Both control as well as experimental ice creams contained 20% mango pulp solids. To impart richness to low fat mango ice cream, flavour enhancers like Cream Plus and Butter Buds were used at levels of 0.2% and 0.05%, respectively. The dietetic low fat ice creams compared well in sensory colour and appearance, flavour, body and texture, and melting quality to that of control ice cream. Incorporation of 2.5% powdered sago and 0.2% Cream Plus as flavour adjunct is recommended in the manufacture of 'low-fat' mango ice cream. The energy values for control and dietetic mango ice cream was 202.8 and 142.9kcal/100g, respectively, which represents about 30% reduction in calorie. The cost of ice cream per liter was Rs 39.9, Rs 37.6 and Rs 49.7 for experimental ice creams containing Cream Plus and Butter Bud, and control, respectively.

Evaluation of pre-harvest Bacillus licheniformis sprays to control mango fruit diseases

Bacillus licheniformis was evaluated as a pre-harvest spray treatment either on its own or alternated with copper oxychloride to control mango fruit diseases. Prior to initiating the spray trials, in vitro and in vivo studies were done to determine the effect of stickers, spreaders, a biostimulant and a copper fungicide on the biocontrol agent's ability to effectively attach to and colonise the mango leaf surface. Bioboost, Nufilm-P, Biofilm and Agral 90 did not affect antagonist growth in vitro. However, copper oxychloride and Supafilm inhibited the in vitro growth of B. licheniformis, more pronouncedly after 8 h. The in vivo study showed that stickers and spreaders did not improve the ability of B. licheniformis to attach to and colonise the leaf surface. Pre-harvest B. licheniformis applications alone and alternated with copper sprays applied at 3-weekly intervals from flowering until harvest controlled moderate levels of anthracnose, bacterial black spot and soft rot.

EFFECT OF FRUIT DROPPING ON POSTHARVEST QUALITY OF MANGO ‘ROSA’ AT TWO MATURITY STAGES

The aim of this research work was to evaluate the effect of fruit dropping from the tree on postharvest conservation of mango fruit (Mangifera indica L.) cv. Rosa, in the green-yellowish (mature-green) and yellow-greenish (pre-climacteric maturity stages. The treatments were: fruits dropped from an average height of 5-m and the control (mango harvested using a 6-m rod provided with a 20x40-cm cloth basket at the end), for each maturity stage. Mangoes of each treatment were kept at room temperature (24 ± 2 °C). Fruit weight loss, total soluble solids (TSS), total titratable acidity (TTA), skin color, and external and internal appearances were evaluated. As measured by external appearance, mango harvested in yellow-greenish maturation stage was much more affected by dropping. For green-yellowish fruits, the symptoms resulting from dropping were impaired or uneven ripening, followed by decay. For yellow-greenish mango fruits, the impacts resulted in an accentuated rate of weight loss, darkened skin, pulp browning, fungi infection, and soaked areas. Skin black spots were observed in dropped yellow-greenish fruits four days after harvesting, paralleled by an increased pulp's TTA, and presence of fermentative off-flavor. Dropping mango cv. Rosa from the tree reduced the shelf life by about four days for yellow-greenish, as compared with green-yellowish non-dropped fruits. Fruit dropping resulted in acceleration of the senescence process, mainly for mango harvested at pre-climacteric, yellow-greenish maturity stage.

Effect of partial pressure infiltration of calcium into ‘Kensington’ mango fruit

Summary.‘Kensington’ mango fruit harvested at the mature green stage were partial pressure (vacuum) infiltrated with calcium (4 g Ca 2+/L as CaCl2) at 3 reduced pressure levels (–33, –66 and –99 kPa). Concentrations of Ca2+ in unripened calcium-treated fruit were about 1-, 2- and 3-fold higher, respectively, than Ca2+ concentrations in the skin and flesh of control (untreated; i.e. not vacuum infiltrated) fruit. For example, skin tissue Ca2+ concentrations of control fruit and of those treated at –33, –66 and –99 kPa were 1.51, 1.93, 3.42 and 5.01 mg Ca2+/g dry weight, respectively. Concentrations of Ca2+ in the skin of both control fruit and of Ca2+ -treated fruit were consistently higher, by about 2-fold, than those in the fruit flesh. Compared with the –33 kPa infiltration treatment, Ca2+ levels in the fruit flesh were increased by only about 2-fold by further reductions in the partial pressure infiltration levels to –66 or –99 kPa. Infiltration of Ca2+ into mango fruit was apparently via lenticels and along xylem conduits open at the cut pedicel. These infiltration pathways were revealed by inclusion of Brilliant Blue dye in the Ca2+ solution. Undyed and dyed lenticels were separately excised for Ca2+ analysis. Dark (dyed) lenticels had higher Ca2+ concentrations (1.86 ± 0.11 mg Ca2+/g dry weight) than light (undyed) lenticels (0.83 ± 0.19 mg Ca2+/g dry weight). Partial pressure infiltration of Ca2+ at any of the 3 subatmospheric pressure levels did not result in shelf life extension. Fruit infiltrated at –66 and –99 kPa exhibited injuries, which included exacerbated lenticel blackening and anaerobic off-odour and taste evident at the end of shelf life. In comparison, both control (untreated) mango fruit and those infiltrated with Ca2+ at –33 kPa ripened normally.