Litchi Fruit Research Articles

Effects of hydrogen water treatment on antioxidant system of litchi fruit during the pericarp browning

Litchi fruit were exposed to 0.7 PPM hydrogen water (HW) before storage at 25 ± 1 ℃. HW treatment delayed the pericarp browning and maintained the total soluble solids (TSS) of litchi fruit. Then, a total of 25 antioxidant system-related characters were determined to evaluate the effects of HW on antioxidant system during pericarp browning. Compared with control pericarp, the pericarp of HW-treated litchi fruit exhibited higher levels of superoxide radical (O2−·) scavenging activity, glutathione (GSH), monodehydroascorbate reductase (MDHAR), polyphenol oxidase (PPO) and total flavonoids during whole storage, higher levels of hydrogen peroxide (H2O2), catalase (CAT), glutathione disulfide (GSSG), ascorbate oxidase (AAO) and total phenols only on day 1, and higher levels of ascorbate peroxidase (APX), total anthocyanin, glutathione reductase (GR) and glutathione peroxidases (GPX) at later stage of storage. Those HW-induced antioxidant system-related characters might directly or indirectly enhanced the antioxidant capacity and delayed the pericarp browning of litchi.

Regulation of browning and senescence of litchi fruit mediated by phenolics and energy status: A postharvest comparison on three different cultivars

Abstract Pericarp browning is one of the most important factors limiting the shelf life of litchi fruit. The storage behavior of three cultivars of litchi with different shelf life were studied to comprehensively address the importance of phenolic content and energy status in delaying the development of browning in litchi fruit after harvest. Results revealed that slower changes of browning indices; higher content of EGC, EC, ECG, GCG, PA2, total phenols and anthocyanins; lower activities of ANT, LAC, PPO, POD and PAL were detected in ‘Jingganghongnuo’, as compared to that in ‘Guiwei’ and ‘Nuomici’. The transcript abundant of oxidation-enzyme corresponding genes LcANT, LcLAC, LcPPO, LcPOD and LcPAL exhibited similar trends as changes of phenolics and enzyme activities in three cultivars. The energy status and the relative expression intensity of ATP metabolic-related genes LcATPb, LcSnRK2, LcAAC1, and LcAOX1 differed among the three cultivars and maintained higher levels in ‘Jingganghongnuo’. Accordingly, the development of pericarp browning was significantly related to the content of phenolics, especially ECG and EC, and to the changes in ATP of litchi fruit after harvest. The comparative study on variety of litchi cultivars evident that the phenolics, energy status as well as the transcript abundant of their corresponding genes are potential indicators to mark the browning change in litchi fruit.

Unveiling the complexity of the litchi transcriptome and pericarp browning by single-molecule long-read sequencing

Litchi is a perennial fruit crop with a highly heterozygous genome and complex transcripts. Although fruit senescence and pericarp browning have been extensively studied, the underlying regulatory mechanisms are still poorly understood. In this study, we used long-read sequencing technology in combination with RNA-seq analysis to investigate the diversity and complexity of the litchi transcriptome, as well as differential express of transcripts during litchi fruit storage. We obtained a reference transcriptome with 50,808 unique full-length isoforms, including 41,290 coding sequences (CDS), 1658 transcription factors, 22,100 simple sequence repeats, 2434 long noncoding RNAs, and 151 alternative splicing (AS) events. In addition, 41,290 isoforms had transmembrane helical structure, 33,579 isoforms contained Pfam protein domains, 14,348 isoforms contained SMART protein domains, 4180 isoforms had signal-peptide structure, 19,183 isoforms contained glycosylation sites, and 30,436 isoforms contained furin protease cleavage sites. Using this transcriptome, 1272 isoforms were found to be differentially expressed in litchi fruit pericarp during postharvest storage. The postharvest storage could be divided into a ‘senescence onset’ stage and a subsequent ‘browning’ stage according to RNA-seq data. During the ‘senescence onset’ stage, the expression of isoforms related to senescence and stress response was significantly up-regulated. During the ‘browning’ stage, the expression of isoforms related to cell wall degradation, oxidation, and disease response was significantly up-regulated. In addition, qPCR analysis showed that the expression changes of 30 isoforms during the postharvest storage of both ‘Huaizhi’ and ‘Guiwei’ fruit were consistent with the RNA-seq results, indicating high reliability of our results and inferences.

Nutrient components, health benefits, and safety of litchi (Litchi chinensis Sonn.): A review.

Litchi (Litchi chinensis Sonn.) is a tropical to subtropical fruit that is widely cultivated in more than 20 countries worldwide. It is normally consumed as fresh or processed and has become one of the most popular fruits because it has a delicious flavor, attractive color, and high nutritive value. Whole litchi fruits have been used not only as a food source but also for medicinal purposes. As a traditional Chinese medicine, litchi has been used for centuries to treat stomach ulcers, diabetes, cough, diarrhea, and dyspepsia, as well as to kill intestinal worms. Both in vitro and in vivo studies have indicated that whole litchi fruits exhibit antioxidant, hypoglycemic, hepatoprotective, hypolipidemic, and antiobesity activities and show anticancer, antiatherosclerotic, hypotensive, neuroprotective, and immunomodulatory activities. The health benefits of litchi have been attributed to its wide range of nutritional components, among which polysaccharides and polyphenols have been proven to possess various beneficial properties. The diversity and composition of litchi polysaccharides and polyphenols have vital influences on their biological activities. In addition, consuming fresh litchi and its products could lead to some adverse reactions for some people such as pruritus, urticaria, swelling of the lips, swelling of the throat, dyspnea, or diarrhea. These safety problems are probably caused by the soluble protein in litchi that could cause anaphylactic and inflammatory reactions. To achieve reasonable applications of litchi in the food, medical and cosmetics industries, this review focuses on recent findings related to the nutrient components, health benefits, and safety of litchi.

562 Biological evaluation of litchi derived products as dermatological agents

Litchi (Litchi chinensis Sonn.) is a fruit native to South China, and popular for the taste and health benefits. Litchi products, such as litchi juice and vinegar (extracted or fermented from litchi fruit) have potential dermatological benefits. In this paper, we have evaluated litchi vinegar and juice regarding protective effects on HaCaT keratinocytes following either UVB irradiation or poly (I:C) by assessing cell survival (OD, optical density; MTT assay), reactive oxygen species (ROS), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity.

Dielectric properties of litchi fruit (Litchi chinensis Sonn) at microwave frequencies.

The dielectric properties of litchi fruit were determined using the open-ended coaxial probe method. The measurements were performed in the frequency range from 0.5 to 20GHz during 3days of storage at room temperature (~ 24°C). The dielectric properties increased with storage time. Additionally, measurements at different temperatures (24, 30, 40 and 50°C) were determined. The dielectric constant (ε') decreased with increasing temperature in a frequency range of 0.5-5GHz; at higher frequencies, ε' increased with increasing temperature. The loss factor (ε″) value increased at frequencies higher than 2GHz and decreased with increasing temperature. The results will be useful for further applications using microwaves, such as microwave-assisted drying, sensing of quality parameters, modeling, and heating to protect against molds or insects, among other applications.

Choline chloride alleviates the pericarp browning of harvested litchi fruit by inhibiting energy deficiency mediated programmed cell death

Abstract The effect of choline chloride (ChCl) on litchi pericarp browning and the potential regulating mechanism was investigated in this study. Results showed that 1 g L−1 ChCl significantly inhibited the development of pericarp browning and reduced respiration rate of litchi fruit. Meanwhile, choline chloride treatment delayed the programmed cell death (PCD) indicated by lower DNA laddering, inhibition of programmed cell death-related genes expression and higher soluble protein content. Additionally, ChCl treatment maintained higher ATP content and energy charge due to higher level of glycine betaine and regulation of energy metabolism related genes and ATPase activities by ChCl treatment. Finally, higher ATP status in ChCl treated fruit resulted in lower accumulation of reactive oxygen species via enhancing the activities of superoxide dismutase, catalase and ascorbate peroxidase. Taken together, the results obtained in this study suggested that choline chloride reduced pericarp browning of litchi fruit possibly through inhibiting energy deficiency mediated PCD.

Effects of Polypropylene Bag on Storage Properties of Litchi (Litchi Chinensis Sonn.)

The present study was run in the laboratory of the Department of Horticulture, Bangladesh Agricultural University, Mymensingh during the period of 15 May to September, 2016. The objectives of the study were to determine the effects of different postharvest treatments on the storage behaviour of litchi. Eight postharvest treatments viz., control, fruits stored in 50µ polypropylene bag at ambient temperature, fruits stored in 75µ polypropylene bag at ambient temperature, fruits stored in 100µ polypropylene bag at ambient temperature, fruits stored at 4ºC temperature, fruits stored in 50µ polypropylene bag at 4ºC temperature, fruits stored in 75µ polypropylene bag at 4ºC temperature, fruits stored in 100µ polypropylene bag at 4ºC temperature were assigned to the litchi fruits. The single factor experiment was laid out in a completely randomized design with three replications. 75µ polypropylene bag at low temperature (4ºC) caused minimal weight loss, whereas, the untreated fruits exhibited maximal weight loss. The pericarp turned brown within 4 days of storage in the untreated fruits, while polypropylene bags helped keep its bright red colour, but microbial decay was evident at the end of the storage period. Different postharvest treatments showed highly significant variation in the shelf life of litchi. Among the treated and untreated fruits, 75µ polypropylene bag at low temperature (4ºC) treatment exhibited better storage performance. The fruits kept in 75µ polypropylene bag at 4°C showed the highest shelf life (20.67 days) followed by 50µ polypropylene bag at 4°C (20.33 days), and it was the lowest in the untreated fruits (3 days).

Alleviation of pericarp browning in harvested litchi fruit by synephrine hydrochloride in relation to membrane lipids metabolism

Abstract This study investigated the effect of synephrine hydrochloride (Syn-HCl) on litchi pericarp browning and the potential regulating mechanism. Results showed that 0.5 g L−1 Syn-HCl significantly inhibited the development of pericarp browning. Compared to control, Syn-HCl treatment reduced malondialdehyde and H2O2 content and inhibited activities of polyphenol oxidase (PPO) and peroxidase (POD). Meanwhile, Syn-HCl-treated litchi fruit exhibited higher amounts of USFA (unsaturated fatty acids) as well as lower amounts of SFA (saturated fatty acids) through regulating activities of membrane lipids-degrading enzymes: lipase and lipoxygenase. Additionally, higher ratio of USFA to SFA and double bond index were shown in Syn-HCl-treated fruit. Further analysis showed that key genes involved in fatty acid synthesis were also regulated by Syn-HCl treatment. Taken together, these findings indicated that Syn-HCl alleviated litchi pericarp browning resulting from regulation of fatty acid metabolism and maintenance of membrane integrity, which inhibited the enzymatic browning caused by PPO and POD.

Litchi is Safe and Harmless in Normal Individuals

The paper on ‘Determination of tolerable dose of litchi fruit’ by Tripathi et al . 1 confirms the safety of litchi in mice, and by extrapolation, in normal people. In-deed litchi has never been alleged to be unsafe in normal people.

Evaluation of litchi impact damage degree and damage susceptibility

Mechanical damage induced by impact during shaking harvesting or transportation debases the quantity and shortens the shelf life of litchi fruit. In this paper, ‘Nuomici’ and ‘Guiwei’ litchis were used to study the impact behavior between fruit and a rigid plate with a new measuring method in order to achieve an approach to evaluate the damage degree and the damage resistance. Impact tests were conducted on a pendulum device and the impact force, compressed depth and contact length were recorded with a force sensor and a high-speed camera. Based on these data, a method was introduced to calculate the contact area, average surface pressure and compressed volume at any given moment of the impact. Analysis of the impact process indicated that the end of deformation phase was the most dangerous moment for a fruit during the impact in all cases. For both cultivars, as the drop height increased from 200 mm to 800 mm, the percentage of absorbed energy, the maximum contact area and the damage degree increased, while the contact time decreased. The maximum surface pressure remained stable as the drop height ranged from 400 mm to 800 mm, so that surface pressure was not a main factor affecting the damage degree. The damage degree of ‘Guiwei’ and ‘Nuomici’ were 13.34% and 13.27% at drop height of 200 mm and 27.89% and 23.74% at 800 mm. Respectively, 70% and 79% damage degree happened at drop height of 400 mm. The difference of litchi cultivar has low effect on contact area and contact time, but significant effect on damage degree when drop height was 600 mm and 800 mm. Based on elastic theory, power models with high coefficient of determination were successfully used to fitting the relationship between impact energy and compressed depth for both cultivars. Combined with the good linear fittings between compressed volume and damage degree, the damage degree could then be predicted with impact energy. Furthermore, the damage susceptibility (DS) was introduced to describe the susceptibility of impact damage of litchi fruit. The results show that DS decreased with the increase of drop height. ‘Nuomici’ was more resist to impact damage than ‘Guiwei’ as drop height changed from 600 mm to 800 mm. The new method presented in this study can be used to evaluate the damage of litchi fruit and optimize the design of litchi shakers.

Melatonin Enhances Cold Tolerance by Regulating Energy and Proline Metabolism in Litchi Fruit.

Melatonin (MLT) is a vital signaling molecule that regulates multiple physiological processes in higher plants. In the current study, the role of MLT in regulating chilling tolerance and its possible mechanisms in litchi fruit during storage at ambient temperatures after its removal from refrigeration was investigated. The results show that the application of MLT (400 μM, dipping for 20 min) to ‘Baitangying’ litchi fruit effectively delayed the development of chilling injury (CI) while inhibiting pericarp discoloration, as indicated by higher chromacity values (L*, a*, b*) and anthocyanin levels. MLT treatment suppressed the enhancements of the relative electrical conductivity (REC) and malondialdehyde (MDA) content, which might contribute to the maintenance of membrane integrity in litchi fruit. MLT treatment slowed the decline in cellular energy level, as evidenced by higher adenosine triphosphate (ATP) content and a higher energy charge (EC), which might be ascribed to the increased activities of enzymes associated with energy metabolism including H+-ATPase, Ca2+-ATPase, succinate dehydrogenase (SDH), and cytochrome C oxidase (CCO). In addition, MLT treatment resulted in enhanced proline accumulation, which was likely a consequence of the increased activities of ornithine-δ-aminotransferase (OAT) and Δ1-pyrroline-5-carboxylate synthase (P5CS) and the suppressed activity of proline dehydrogenase (PDH). These results suggest that the enhanced chilling tolerance of litchi fruit after MLT treatment might involve the regulation of energy and proline metabolism.

Involvement of miRNA-mediated anthocyanin and energy metabolism in the storability of litchi fruit

Litchi (Litchi chinensis Sonn.) has a short shelf life and its storability varies greatly among different cultivars. In this study, four litchi cultivars of different storability were used to investigate the possible roles of microRNAs and their targets in litchi fruit senescence. Slower pericarp browning in ‘Jingganghongnuo’ and ‘Huaizhi’ was observed compared with that in ‘Guiwei’ and ‘Nuomici’, which was correlated with higher levels of ATP, energy charge, and anthocyanin but lower activity of anthocyanase that oxidizes anthocyanin. A phylogenic analysis of Arabidopsis, tomato (Solanum lycopersicum), and litchi, using totally 40 LcMYBs, categorized certain LcMYBs into the anthocyanin biosynthesis-related R2R3 MYB subfamilies as previously described in Arabidopsis. In addition, the expression of a group of litchi miRNAs, including miR159/319, miR828 and miR858 that jointly target multiple LcMYB genes, was found to decrease fast in ‘Jingganghongnuo’ and ‘Huaizhi’. A group of R2R3-type LcMYBs was validated as authentic targets of these miRNAs. Accordingly, these MYBs were induced in ‘Jingganghongnuo’ and ‘Huaizhi’ whereas largely suppressed in ‘Guiwei’ and ‘Nuomici’. Moreover, litchi miR2118 targeting energy-related genes displayed a similar expression pattern to those of the MYB-targeting miRNAs in the different cultivars, and two of the miR2118 targets exhibited opposite expression pattern with miR2118. Finally, a miRNA-mediated anthocyanin and energy metabolism network underlying the regulation of cultivar-specific fruit senescence in litchi is proposed. We conclude that miRNA-mediated regulation can account for the differential storability of specific litchi cultivars.

Postharvest hydrogen sulfide infiltration modulates antioxidative metabolism and increases shelf life of litchi

Litchi fruits are highly perishable in nature and start deteriorating immediately after harvest, which can be characterized by pericarp browning. In this study, the effect of exogenous hydrogen sulfide (H2S) on different biochemical events linked to pericarp browning and oxidative damage in litchi were assessed at 1 day interval during 4 days storage. Fruits were vacuum infiltrated with H2S (1 and 2 mM) at ambient temperature. The untreated control fruits were subjected to dipping in distilled water and were stored at ambient (28 °C, RH 70–75%) conditions. H2S treatment maintained the postharvest quality of litchi fruit during storage by alleviating oxidative damage and modulating enzymatic activities. Control fruits lost their postharvest quality at initial storage with visible pericarp browning and other biochemical degradative changes when compared with treated fruits. Postharvest H2S (2 mM) infiltration significantly reduced weight loss, pericarp browning and ROS production (H2O2 and O2−) as well as suppressed the activity of polyphenol oxidase (PPO) and peroxidase (POD) enzymes and exhibited higher TSS, titratable acidity, total phenolic, anthocyanin, antioxidant activities, membrane integrity, phenylalanine ammonia lyase (PAL) activity and reduced quinone and malondialdehyde (MDA) accumulation. Thus, H2S (2 mM) infiltration treatment could be suggested to enhance the storage life of litchi fruits at ambient storage condition.

Cultivar discrimination of litchi fruit images using deep learning

Litchi (Litchi chinensis Sonn.) originated from China and many of its cultivars have been produced in China so far during the long history of cultivation. One problem in litchi production and research is the worldwide confusion regarding litchi cultivar nomenclature. Because litchi cultivars can be described in terms of cultivar-dependent fruit appearance, it should be possible to discriminate cultivars of postharvest fruits. In this study, we explored this possibility using recently developed deep learning technology for four common Taiwanese cultivars 'Gui Wei', 'Hei Ye', 'No Mai Tsz', and 'Yu Her Pau'. First, we quantitatively evaluated litchi fruit shapes using elliptic Fourier descriptors and characterized the relationship between cultivars and fruit shapes. Results suggest that 'Yu Her Pau' can be clearly discriminated from others mainly based on its higher length-to-diameter ratio. We then fine-tuned a pre-trained VGG16 to construct a cultivar discrimination model. Relatively few images were sufficient to train the model to classify fruit images with 98.33% accuracy. We evaluated our model using images of fruits collected in different seasons and locations and found the model could identify 'Yu Her Pau' fruits with 100% accuracy and 'Hei Ye' fruits with 84% accuracy. A Grad-CAM visualization reveals that this model uses different cultivar-dependent regions for cultivar recognition. Overall, this study suggests that deep learning can be used to discriminate litchi cultivars from images of the fruit.

Energy Consumption, Colour, Texture, Antioxidants, Odours, and Taste Qualities of Litchi Fruit Dried by Intermittent Ohmic Heating.

To reduce the cost of dried litchi fruit, the processing characteristics and physicochemical properties of litchi were investigated using drying by intermittent ohmic heating (IOH) (intermittent air drying (IAD)) generated by BaTiO3 resistance. Litchi fruit pulp were dried at 70 °C with an air velocity of 1.8 m/s; the drying intermittent profiles were as follows: (1) 20 min drying-on and 5 min drying-off; (2) 20 min drying-on and 10 min drying-off; and (3) 20 min drying-on and 15 min drying-off, which correspond to pulse ratios (PRs) of 1.2, 1.5, and 1.8, respectively. After drying, the water content, energy consumption, vitamin C content, total phenolic content, colour, taste, and odour qualities were assessed. The results suggested that IOH drying requires lower energy consumption and yields higher quality products. The energy consumption of intermittent air drying ranged from 341 kJ∙g−1 to 427 kJ∙g−1. The IAD of 1.2 and 1.5 PR reduced the browning of litchi fruits and gained better product quality. The major components of odour and tastes were explored in dried litchi. The rising PR of IAD enabled a lower retention of methane and sulphur-organic aroma and a higher assessing value of bitterness taste. This study revealed that BaTiO3 is suitable for IOH drying and it resulted in more merits of dried litchi fruit.

Quality Detection of Postharvest Litchi Based on Electronic Nose: A Feasible Way for Litchi Fruit Supervision during Circulation Process

Susceptibility to mechanical injury and fast decay rates are currently two main problems of litchi fruit after harvesting. To achieve better postharvest management of litchi fruit, this study aimed to find an effective method of litchi fruit supervision during the circulation process that included mechanical injury detection and storage quality detection. For mechanical injury detection, injury-free litchis without any treatment and litchis with mild and severe mechanical injuries were dropped from 80 and 110 cm high, respectively. The electronic nose (E-nose) response, total soluble solid (TSS), and titratable acidity (TA) of samples were tested on days 0, 1, 2, 3, 4, and 5 after injury at room temperature. For storage quality detection, normal litchis were stored in a cold environment. The E-nose response, TSS, and TA of samples were tested on storage days 0, 3, 6, 10, 15, 19, and 24. The experimental results showed that mechanical injury not only accelerated pericarp browning but also accelerated flavor (TA and TSS) loss. The browning index quickly increased during storage, and the TSS and TA of defect-free litchis changed only barely at room temperature and during cold environment storage. After feature extraction, mechanical injury of litchi can be well-detected by E-nose from day 1 to day 4 after injury. The best mechanical injury detection time of litchi fruit is at day 4 after injury under room temperature storage conditions. After singular sensor elimination and comprehensive feature extraction, the storage time and browning degree, but not TSS and TA, of litchi fruit can be detected by E-nose. E-nose data preprocessing should differ according to the litchi variety and detection target.

Effects of Packaging and Low Temperature on Shelf Life and Quality of Litchi

Litchi is a non-climacteric fruit (Wills et al. 2004) and it deteriorates very fast after harvest. Various technologies have been devised to minimize the post-harvest losses of litchi, one of such technologies is the use of PP bag & low temperature. The objectives of the study were to evaluate the effects of thiLitchi is a non-climacteric fruit and it deteriorates very fast after harvest. Various technologies have been devised to minimize the post-harvest losses of Litchi; one of such technologies is the use of Polypropylene bag and low temperature. The objectives of the present study were to evaluate the effects of thickness of polypropylene bags and low temperature on the storage behavior of Litchi (Litchi chinensis Sonn, var. Bombai). The experiment consisted of two factors including temperature (T1: Ambient temperature, T2: 4oC temperature); and Polypropylene bags (P1: Control (unwrapped), P2: 50 μm Polypropylene bag, P3: 75 μm Polypropylene bag, P4: 100 μm Polypropylene bag. The experiment was conducted in completely randomized design (CRD) with three replications. The postharvest treatments caused highly significant variation in the shelf life of Litchi. Among the treated and untreated fruits, 75 μm Polypropylene bags at low temperature (4 oC) exhibited better storage performance. The fruits wrapped in 75 μm Polypropylene bag at 4 °C showed the longest shelf life (23.67 days) followed by 50 μm and 100 μm Polypropylene bags at 4 °C (23.33 days). The shortest shelf life was obtained in the untreated fruits (3 days). It may be concluded that keeping Litchi in 75 μm Polypropylene bag and stored in low temperature (4 oC) is the best postharvest approach to extend Litchi shelf life without considerable negative effects on fruit quality. For short-term storage of Litchi fruits 75 μm Polypropylene bag at ambient temperature is recommended.ckness of polypropylene bags and low temperature on the storage behaviour of litchi (Litchi chinensis Sonn, var. Bombai). The experiment consisted of two factors. Factor A: Temperature viz. T1: Ambient temperature, T2: 4oC temperature; Factor B: PP bags (Polypropylene bag) viz. P1: Control (unwrapped), P2: 50 micro meter (µm) PP bag, P3: 75µmm PP bag, P4: 100µm PP bag. The experiment was conducted in completely randomized design (CRD) with three replications. The postharvest treatments showed highly significant variation in the shelf life of litchi. Among the treated and untreated fruits, 75µm pp bag at low temperature (4oC) treatment exhibited better storage performance. The fruits wrapped in 75µm pp bag at 4°C showed the longest shelf life (23.67 days) followed by 50µm & 100µm pp bag at 4°C (23.33 days) and it was the lowest in the untreated fruits (3 days). More research should be conducted by using other litchi cultivar like Bedana, China-3 etc. It may be concluded that keeping litchi in 75µ PP bag and stored in low temperature (4oC) is the best to extend its shelf life without affecting the quality. For short-term storage of litchi fruits 75µ PP bag at ambient temperature would be recommended.

Evaluation of Insecticides for the Management of Litchi Fruit and Shoot Borer

Litchi is an important subtropical evergreen fruit crop grown in Nepal, which have high nutritive value and refreshing taste. The Litchi growers are experiencing severe loss every year with the damage caused by several insect pests. Among them fruit and shoot borer Conopomorpha sinensis Bradley (Lepidoptera: Gracillariidae) is the one of the important insect pest. Experiments were conducted at RARS Tarahara on existing litchi orchard in RCBD design with four replication and five insecticides (Azadiractin, Chlorantraniliprole, Flubendiamide, Lambda cyhalothrin, and Dimethoate) with recommended doses in litchi orchard against C. sinensis during 2015 and 2016 AD to find out the efficient one. Among the tested insecticide chlorantraniliprole (18.5% w/w SC) and flubendiamide (39.35% m/m SC) each were found to be most efficient against C. sinensis and could be applied at the rate of 1 ml per 3 liter of water when fruit size was about pea and applied 3 times with 10 days interval. This result suggested that these two insecticides could be used for the management for C. sinensis. Farmers may reduce the losses and increase their income with the application of these insecticides

Alleviation of enzymatic browning and maintenance of postharvest quality of litchi (Litchi chinensis) fruit with packaging films

The present study was carried out during the years 2016–17 and 2017–18 to evaluate the effect of different packaging films for control of pericarp browning and maintenance of postharvest quality of litchi (Litchi chinensis Sonn.) fruits during cold storage. Litchi fruits of cultivar Dehradun were harvested at physiological mature stage and de-stalked. The fruits were packed in low density polyethylene film (LDPE, 25 μ), high density polyethylene film (HDPE, 10 μ) and heat shrinkable film (15 μ). The control fruits were packed with in gunny sack with litchi leaves as per traditional technique.The fruits were then stored in walk-in-cold store (2-3°C and 90-95% RH) for 4 weeks. The results revealed that LDPE packaging film proved to be the most effective in minimizing the pericarp browning of litchi fruits. LDPE film resulted in reducing the weight loss, browning index and maintained, organoleptic quality, TSS, acidity, ascorbic acid and gave the best browning inhibition during the storage by reducing the activities of polyphenol oxidase and maintained a higher level of total anthocyanin. The data revealed that litchi fruits packed in LDPE films can be stored successfully up to three weeks with acceptable marketable quality.