Litchi Production Research Articles

Influence of spraying nutrients and bioregulators on vegetative growth, flowering and productivity of litchi

Aim: To investigate the influence of nutrients and bioregulators on the vegetative growth, flowering and productivity of Litchi. Methodology: The vegetative growth, flowering and productivity of litchi cv. Bombai was assessed through application of nutrients and bioregulators. Results: The plants receiving treatment with @ 0.5% Borax (T1) showed the highest percentage increase in canopy volume (7.56 %) and plant height (2.46 %) in litchi, outperforming all other treatments. The maximum productivity (38.69 kg per plant) was registered in plants under treatment T2 (0.3% Borax), which was found to be statistically at par (36.68 kg per plant) with plants treated with 0.1% Seaweed extract (T10) . The percentage increase in the plant height, plant spread in East-West and North-South direction, canopy volume, , fruit weight and fruit set capture positive correlation in both PC-1 and PC-2. The total contribution of PC-1 and PC-2 was 60.857 %. Interpretation: Among all the treatments, T2 (0.3% borax) and T4 (ZnSO4 @ 0.4%) treatments proved superior over other treatements with respect to vegetative growth, flowering and productivity parameters in litchi. However, further investigation need to be carried out with combination of these applied nutrients and bioregulators for getting acceptable results. Key words: Bioregulators, Flowering, Growth, Litchi, Nutrients

Integrative approaches to improve litchi (Litchi chinensis Sonn.) plant health using bio-transformations and entomopathogenic fungi

Bio-transformations refer to the chemical modifications made by an organism on a chemical compound that often involves the interaction of plants with microbes to alter the chemical composition of soil or plant. Integrating bio-transformations and entomopathogenic fungi into litchi cultivation can enhance symbiotic relationships, microbial enzymatic activity in rhizosphere, disease suppression and promote overall plant health. The integration of biological formulations and entomopathogenic fungi can significantly influence growth, nutrient dynamics, physiology, and rhizosphere microbiome of air-layered litchi (Litchi chinensis Sonn.) saplings. Biological modifications included, K-mobilizers, AM fungi, Pseudomonas florescence and Azotobacter chroococcum along with Metarhizium, entomopathogenic fungi have been used. The treatments included, T1-Litchi orchard soil + sand (1:1); T2-Sand + AM fungi + Azotobacter chroococcum (1:2:1); T3-Sand + Pseudomonas florecence + K-mobilizer (1:1:1); T4- AM fungi + K-mobilizers (1:1); T5, P. Florecence + A. chroococcum + K-mobilizer (1:1:1); T6-Sand + P. florecence (1:2) and T7-Uninoculated control for field performance. Treatments T4-T6 were further uniformly amended with drenching of Metarrhizium in rhizosphere. T2 application significantly increased resident microbe survival, total chlorophyll content and root soil ratio in seedlings. A. chroococcum, Pseudomonas, K-mobilizers and AM fungi increased in microbial biomass of 2.59, 3.39, 2.42 and 2.77 times, respectively. Acidic phosphatases, dehydrogenases and alkaline phosphatases were increased in rhizosphere. Leaf nutrients reflected through DOP were considerably altered by T2 treatment. Based on Eigen value, PCA-induced changes at biological modifications showed maximum total variance. The study inferred that the bio-transformations through microbial inoculants and entomopathogenic fungi could be an encouraging strategy to enhance the growth of plants, health and productivity. Such practices align well with the goals of sustainable agriculture through biological means by reducing dependency on chemical inputs. By delving into these aspects, the research gaps including microbial processes, competitive and symbiotic relationships, resistance in microbes and how complex interactions among bio-transformations, entomopathogenic fungi and microbes can significantly impact the health and productivity of litchi. Understanding and harnessing these interactions can lead to more effective and sustainable farming practices.

Physiological, anatomical and transcriptome analyses reveal ‘Huaizhi’ as widely compatible rootstock in Litchi chinensis Sonn. grafting

Litchi chinensis Sonn. cv. ‘Huaizhi’ (HZ) is an ancient cultivar of litchi. It has been used as widely compatible rootstock for litchi grafting for a long time. However, the mechanism of HZ as widely compatible rootstock is still unclear. In the present study, physiology, morphological anatomy, as well as transcriptomics were conducted to reveal the reasons for HZ with wide compatibility in litchi grafting. Field observation were conducted on the grafting combinations of HZ/HZ (homografting as the control), FZX/HZ and MGL/HZ (the scion with good grafting compatibility in production), SYH/HZ, HHDHL/HZ and WHL/HZ (the scion with weak grafting compatibility in production), embodying that HZ as rootstock did show a wide compatibility. The physiological and biochemical indicators of scion new shoot leaves and scion mother tree indicated that nutrients contents (dry matter weight, total soluble sugar, and starch), mineral nutrition (N and P) levels, and antioxidant enzyme (superoxide dismutase and peroxidase) activities, might be related to the wide compatibility of HZ as rootstock. Microscopic observation of the paraffin sections of healing sites at different stages showed that the necrotic layer of three representative litchi grafting combinations of HZ/HZ, WHL/HZ and MGL/HZ basically disappeared from 14 d to 21 d after grafting, and the callus differentiated into a large number of protoxylem cells, indicating a compatible healing dynamics. Subsequently, a total of 14,384 differentially expressed genes (DEGs) were identified by RNA-seq, of which 2,831 DEGs exhibited the same expression trend within three grafting combinations, enriching into phenylpropanoid biosynthesis, plant hormone biosynthesis and signal transduction, sucrose and starch metabolism, MAPK signaling pathway, peroxisome and other metabolic pathways. These results provide a theoretical basis for the adjustment of cultivar structure in litchi production.

Impact of flowering temperature on litchi yield under climate change: A case study in Taiwan

Litchi is a subtropical fruit tree that undergoes flower bud differentiation under low-temperature conditions. However, climate change has affected litchi production in Taiwan, causing litchi farmers to experience economic losses. This study explored the influence of flowering temperature on litchi yield under climate change in Taiwan by analyzing litchi production data from 2001 to 2020 and observation data from meteorological stations in litchi-producing areas. Historical observed data were used to construct several regression models relating temperature to yield, with the performance of the models used to determine critical temperature thresholds for litchi flower bud differentiation. Analytical climate data (CMIP5) were used to project yield changes in Taiwan’s litchi-producing regions under anticipated low-temperature conditions for the mid- (2036–2065) and late- (2071–2100) 21st century. The variable that exhibited the highest correlation with yield changes was the number of days with an average flowering temperature below 16 °C. The production yield, in terms of yield variation per hectare, is expected to decrease by 12 % to 35 % by the end of the 21st century (2071–2100). Given the projected decline in the number of cooler days due to climate change, existing litchi cultivars may become unsuitable for cultivation in production areas in southern Taiwan. Practical ImplicationsSome fruit trees require a period of low temperature before their flowering stage. Climate change is expected to cause warming of winter temperatures in Taiwan, which is likely to lead to reduced litchi flowering. The current study assessed the potential effects of climate change on litchi flowering in the future.Historical observed data were used to establish models, and critical temperature thresholds for litchi flowering were determined on the basis of model performance. Days with average temperatures below 16 °C exhibited the highest correlation with litchi yield among the tested thresholds. According to our results, farmers can use this 16 °C threshold to evaluate the potential effects of future climate change at their current farm locations and to identify other areas with similar or more favorable conditions for litchi cultivation. For agricultural researchers, this temperature threshold could provide a target for new litchi variety breeding and a reference basis for research on optimal cultivation methods.Notably, because climate change projection data have a high degree of uncertainty, the results of this study may differ from those of studies using different databases. In this study, we used an ensemble of CMIP5 projections incorporating data from models from various research centers around the world, which can provide more robust results based on an ensemble mean than those obtainable from a single model or a few models. In addition, rainfall is a crucial factor during the flowering growth stage. Future studies should consider the effects of rainfall and temperature on yield and should consider using a model with yield being considered a function of both of these variables to improve model accuracy.To conclude, the present study provides researchers, policymakers, and other stakeholders with insights into the primary effects of climate change on litchi production. It also lays the groundwork for future climate adaptation strategies in Taiwan’s litchi industry.

Function of LcAGL19 in the flowering regulation of Arabidopsis and Litchi chinensis

Litchi (Litchi chinensis Sonn.) is an important evergreen woody fruit tree. Appropriate low temperatures during autumn and winter are necessary for floral transition in litchi. However, global warming causes defective flowering, which seriously impedes the production of litchi. AGAMOUS-LIKE 19 (AGL19), a vernalization-related gene, had been found to control flowering time in Arabidopsis thaliana. However, its role in litchi remains unknown. In this study, we performed phylogenetic analysis. The results showed that LcAGL19 belonged to the SOC1/TM3-like protein family. Subcellular localization assay showed that LcAGL19 was localized on the nucleus. Ectopic expression of LcAGL19 in Arabidopsis thaliana resulted in early flowering, active inflorescence growth, and floral defects. Yeast two-hybrid assay and Firefly luciferase complementation imaging (LCI) assays showed that LcAGL19 might interact with MADS-box proteins to determine flowering time and floral organ identity. These results demonstrated that LcAGL19 might play important roles in floral transition, inflorescence and floral organ development in litchi. Our studies provided new insights into the regulation mechanisms of litchi flowering and offered meaningful references for AGL19 functional studies on other woody fruit trees. The functional study of LcAGL19 provided a genetic reference for litchi breeding.

Using slow-release fertilizers ensures the maintenance of litchi (Litchi chinensis Sonn.) production by enhancing soil nutrient supply and optimizing microbial communities

High temperatures and rainy climate conditions result in a very low nutrient utilization rate during crop cultivation in tropical regions. To determine whether slow-release fertilizers could have a positive impact on the yield and quality of litchi, and the soil ecology of orchards while reducing chemical fertilizer application, a field plot experiment with two fertilizer types (chemical fertilizers and lignin-based slow-release fertilizers) combined with a 0 %, 15 % and 30 % reduction of fertilizer application rates was set up from 2018 to 2019. Subsequently, a demonstration trial with an optimum dose of slow-release fertilizers with chemical fertilizers was carried out from 2019 to 2020 in acidic soils. The results demonstrated that all treatments could maintain the yield of litchi between 11,825–13,056 kg/hm2 in 2018–2019. Furthermore, compared to conventional chemical fertilizer treatment, the treatment of lignin-based slow-release fertilizer application with a 15 % fertilizer reduction significantly reduced the concentration of alkaline nitrogen by 19.9 % and available phosphorus by 22.0 % at the 20–40 cm soil layer during the maturity period of litchi growth. The result of the demonstration trial in 2019–2020 further confirmed that a slow-release fertilizer, along with a 25 % reduction in fertilizer application, could maintain high levels of soil alkaline nitrogen and available potassium at the 0–20 cm soil layer without affecting soil bulk density, total soil porosity, and soil aeration. Moreover, the treatment of lignin-based slow-release fertilizer application with a 15 % fertilizer reduction significantly increased the relative abundance of Proteobacteria (1.21 times) and decreased the abundance of Firmicutes (0.81 times) compared to conventional fertilization treatment at the 0–20 cm soil layer. In contrast, it decreased the relative abundance of Firmicutes (0.67 times) and Proteobacteria (0.37 times) at the 20–40 cm soil layer. Meanwhile, the fertilizer application only affected the soil fungi richness but did not increase their diversity. Applying slow-release fertilizers can realize the goal of reducing chemical fertilizers and ensuring excellent litchi production in tropical acidic soils.

Morphological and pathological characterization ofColletotrichumspecies causing anthracnose of litchi leaves in Guangxi, China

AbstractLitchi (Litchi chinensisSonn.) is an evergreen subtropical fruit tree native to southern China. Litchi is vulnerable to a wide range of diseases affecting yield and fruit quality. Anthracnose is one of the main diseases during the period of growth and storage, which has a serious impact on the quality and production of litchi. In December 2020 to May 2021, typical anthracnose symptoms were observed on litchi leaves in different orchards in Qinzhou City, Guangxi Province, Southern China. According to colony features, conidial and appressorial morphology, and sequence analysis of several genomic regions (internal transcribed spacer (ITS) region, chitin synthase (chs‐1), actin (act), calmodulin (cal), glyceraldehyde‐3‐phosphate dehydrogenase (gapdh), β‐tubulin (tub2) and the intergenic region of apn2 and MAT1‐2‐1 (ApMat)), 44 isolates were obtained, and 26 were identified as threeColletotrichumspecies:C. fructicola(50%),C. siamense(42.31%),C. gigasporum(7.69%). The pathogenicity tests were performed with conidial suspension and mycelia plugs to inoculate wounded litchi seedlings. The results of pathogenicity tests showed that the virulence ofC. gigasporumwas the weakest, and the virulence ofC. fructicolawas the strongest. This is the first report ofC. gigasporumcausing anthracnose of litchi worldwide.

Growth Rate of Area Production and Productivity of Litchi Fruit in Jashpur District of Chhattisgarh, India

Present study was done to analyse the growth rate of litchi production in Jashpur district of Chhattisgarh. with specific objectives of determining trend in area, production and productivity of litchi. India is the second largest producer of litchi in the world after China. Presently in India, litchi is cultivated in an area about 99170 hectares with total production of 737200 metric tons and productivity of 7.43 metric tons / hectare. Chhattisgarh produces nearly cultivated in an area about 8474 hectares with a total production of 58907 metric tons and productivity of 1.94 metric tons / hectare. It is mainly cultivated in the old district of Surguja, Jashpur, Balrampur and Surajpur. The study revealeds that the growth rates in area, production and productivity was negative and found to be -0.02 %, -0.04 % and -0.02 % respectively in India while, in Chhatisgarh it was recorded -0.05%, -0.05%, and -0.003% In Jaspur district, it was noted to be -0.06%, -0.04%, and 0.01% respectively.

Exploring Lactobacillus plantarum on Fermentation Quality, Gas Emissions, and In Vitro Digestibility of Different Varieties of Litchi Leaves Silage

To investigate the feasibility of developing litchi leaves as silage, we determined the fermentation quality of four varieties of litchi leaves (including “Wanpu”, “Wuyejiu”, “Tongzai” and “Zhuangyuanhong”) ensiled with or without Lactobacillus plantarum on day 3, 7, 14 and 30. The in vitro dry matter digestibility and gas production of litchi leaves silages were also determined after 30 days of ensiling. The results showed that Lactobacillus plantarum significantly reduced pH value (p < 0.01), inhibited coliform bacteria, and reduced the production of ammonia nitrogen (p < 0.01) in all the four kinds of litchi leaves silage. Moreover, Lactobacillus plantarum treated litchi leaves (“Wanpu” and “Zhuangyuanhong”) had lower yeasts than the untreated litchi leaves during ensiling. The number of molds in Lactobacillus plantarum treated groups (“Tongzai” and “Zhuangyuanhong”) was below the detected level after 30 days ensiling, which was lower than that of the untreated groups. The addition of Lactobacillus plantarum also contributed to improving IVDMD and markedly reduced (p < 0.01) gas production of all litchi leaves silages. Conclusions: Lactobacillus plantarum can improve the fermentation quality and in vitro digestion characteristics of litchi leaves silage. Developing litchi leaves as silage material is a feasible way to recycle litchi leaves.

Economic Analysis of litchi Production in Muzaffarpur District of Bihar

"The Study was carried out with an objective to estimate cost and returns of Litchi under different size of sample farms in Muzaffarpur District of Bihar. The empirical data were gathered from agriculture year 2018- 19 during production period of litchi through survey of litchi growers’. The multistage sampling techniques were used to select the location/ area where abundantly litchi orchard occupied and their respondents’ for required information. Thus, a total 90 litchi growers (8 marginal, 18 small, 46 semi- medium and 18 medium) were selected with equal chance or opportunity of all farms categories in groups from 2 blocks from six selected villages of the Muzffarpur district of Bihar. The gross value of the litchi production on overall farms was estimated on an average in ` 2.95 lakhs per hectare against cost C as well as annual maintenance costs was in ` 65.93 thousand per hectare. The costs of production of litchi on overall farms was accounted on an average to be in ` 941.52 per quintal litchi, which were varies from ` 1197.58 per quintal litchi and estimated higher on marginal farms, followed by ` 1045.77 per quintal on small farms, ` 898.75 per quintal on semi-medium farm, and ` 872.97 per quintal on medium farms. Result revealed that cost of production of litchi decreased with increase in land owner farm groups. The establishment (first to fifth year’s i.e. juvenile stage) costs of litchi orchard on overall farms were estimated to be ` 2.56 lakhs and further estimated amortized costs on an average was ` 1329.37 per hectare. The establishment and annual maintenance cost both were included fixed costs increases with increase in land possession of farms groups, but variable cost include in total costs (fixed and variable cost) were reduced with increase in land holding farms groups. The NPV of overall farms were on an average in ` 6.21 lakh, benefit-cost ratio (BCR) in ` 2.77 against one rupee spend. Internal rate of returns (IRR) value was obtained 25.64 percent greater than chosen discount rate as 15 and 20 per cent to make the decision about reinvestment opportunity to prioritize the area of reinvestment by litchi growers."

Knowledge and Adoption of Good Management Practices Among Litchi Farmers in Muzaffarpur District of Bihar

Litchi is one of the nutritionally rich and economically significant fruit of Indian subcontinent. With the advent of Good Management Practices (GMPs), litchi farming technology has advanced drastically. The study was conducted in 2022 in the Muzaffarpur district of Bihar to assess the level of knowledge and adoption of GMPs among litchi farmers and their relationship with the socio-economic profile of litchi growers. The primary data were personally collected through a well-structured interview schedule from 120 respondents. Knowledge and adoption were determined, practicewise on 19 different parameters of GMPs. The highest number of litchi growers (77.50%) had a medium level of knowledge while 71.67 per cent had a medium adoption level of the recommended GMPs in litchi production. Variables viz., the area under litchi, cosmopolitness, farming experience, risk preference, innovativeness, and attitude towards GMPs were positively and significantly related to knowledge as well as adoption. Primary work and education were positively and significantly related to adoption. Dissemination of information about modern agricultural practices is necessary for the adoption of GMPs in litchi production.

Effect of temperature, flowering time and inflorescence length on yield and productivity of litchi (Litchi chinensis) cv. ‘Shahi’

The present study was carried out in 2017–18 at ICAR-NRC on Litchi, Muzaffarpur to assess the effect of temperature, flowering time and inflorescence length on yield of litchi (Litchi chinensis Sonn.) cv. Shahi. The study revealed that the temperature, flowering stage as well as length of inflorescence were positively correlated with florescence width (0.98) while fruit set was negatively correlated with temperature (-0.863). There was a strong correlation between fruit set and size of the inflorescence. Early-season flowering had higher fruit set (8.56%) as compared to mid (7.58%) and late-season (4.05%) flowering. Fruit set was critically reduced by 50% in late floweringplants resulting in drastic reduction in the total fruit yield. A strong positive correlation (0.84) was found between inflorescence hickness and fruit weight. Fruit and pulp weight were influenced by stage of flowering, as early flowering exhibited highest fruit weight (24.56 g) compared to mid and late flowering in which fruit weight was reduced by 35.42% and 50%, respectively.

LcNAC13 Is Involved in the Reactive Oxygen Species-Dependent Senescence of the Rudimentary Leaves in Litchi chinensis.

Litchi is an important evergreen fruit tree. Floral formation in litchi is induced by low temperatures (LTs). However, unstable flowering is a challenge for litchi production in times of global warming and climate change. Previous studies have shown that the methyl viologen dichloride hydrate-generated reactive oxygen species (ROS) could promote flowering. Leaves in the panicles may affect the development of the inflorescence in litchi under high-temperature condition. In this study, potted litchi trees were transferred to growth chambers at LT and high temperature (HT). From a previous dataset of the RNA sequencing of the ROS-treated rudimentary leaves, a NAC transcription factor-encoding gene LcNAC13 was identified. By genetic transformation of LcNAC13 to Arabidopsis thaliana and tobacco, it was found that the ROS-induced senescence of the leaves was accelerated. Silencing LcNAC13 by virus-induced gene silencing (VIGS) delayed ROS-dependent senescence. Our results suggested that LcNAC13 regulates rudimentary leaf senescence. Our study provided a new target gene for the future molecular breeding of new cultivars that could flower under global warming conditions.

Present Scenario and Problems of Litchi Cultivation in Meherpur District of Bangladesh

Litchi is a popular summer fruit in Bangladesh and the production of litchi is increasing day by day. However, the production procedure of litchi is not a problem free venture. The Meherpur district of Bangladesh is a suitable place for commercial cultivation of litchi. Thus, the present study was conducted to determine the status of litchi cultivation and to identify the problems confronted by the litchi growers of Meherpur Sadar and Mujibnagar upazila of Meherpur district, Bangladesh. Data were collected through a pre-tested interview schedule from 60 respondents selected by accidental sampling during May to June, 2019. Majority of the respondents (58.3%) belong to early initiation category of litchi cultivation (during 1996 to 2012) with early (3-5 years) fruit collection (51.7%). Most of the respondents (80.0%) allotted small area (up to 0.5 ha) of land for litchi cultivation; and 41.7% used low extent for litchi cultivation i.e., 40% of the potential area; and all the respondents belonged to continuous adoption category. Most of the respondents (80.0%) cultivate Bombai variety and 73.3% had moderate number (86-135) of plants in their orchard; and about one-third of the respondents (30.0%) maintain a spacing of 4.65m×6.20m in their litchi orchard. Two-fifth (40.0%) of the respondents harvested a moderate yield (1,00,001-2,00,000 fruits ha-1), however, most of the respondents (81.67%) argued that they get low price (up to 1,25,000 BDT ha-1) from their litchi orchards . Majority of the respondents (68.33%) reported that litchi fruit and shoot borer infest their orchard while the orchards of 45% respondents were infested by fruit rot disease. Majority of the respondents (68.3%) confronted medium extent of problems followed by low (18.3%) and high (13.4%) extent of problems. The most severe problems were lack of training on litchi cultivation and low shelf life of litchi as reported by all (100%) of the respondents. Among eleven selected socioeconomic characteristics of the respondents’ only farm size, annual income, cosmopolitanism and knowledge on litchi cultivation showed significant negative relationship with their problem confrontation. It might be concluded that proper, adequate and timely extension activities would minimize the extent of problems in litchi cultivation to ensure sustained higher yield in Bangladesh. South Asian J. Agric., 8(1&2): 20-28

Effects of reducing chemical fertilizers combined with organic fertilizers on soil microbial community in litchi orchards

Organic fertilizer application can replace a part of chemical fertilizer (CF) to improve the quality and efficiency of litchi production. To further explore the soil microbiological mechanism, with 19-year-old 'Feizixiao' litchi trees as the research objects, we examined the effects of two consecutive years of reduced CF applications (average 21.5% of total nutrients) combined with sheep manure (OF) and bio-organic fertilizers (BIO) on soil microbial diversity, community composition and differential microorganisms. The results showed that reducing the application of chemical fertilizers and combining it with the application of sheep manure and bio-organic fertilizer for two consecutive years could significantly improve yield and quality. The average increase of yield in the two years was 23.1% and 39.0%, respectively. Soil organic matter content and pH increased significantly in response to the combination treatments. Compared to that in the chemical fertilizer treatment, the contents of soil available phosphorus, potassium, calcium, magnesium, iron, manganese, copper, and zinc displayed an increasing trend in the combination treatments. The application of organic fertilizer increased the diversity of bacteria and fungi in rhizosphere soil, but not in non-rhizosphere soil. Both treatments significantly changed soil microbial community structure, increased eutrophic bacterial groups such as Bacteroides, Proteobacteria, and Bacillus phylum, and reduced anatrophic bacterial groups such as Acidobacteria and Chloroflexus. Compared with CF, the relative abundances of MND1 under OF and TK10, Gemmatimonas, Pseudolabrys, Trichoderma and Botryotrichum under BIO were significantly increased, which was positively correlated with yield. In conclusion, reducing CF and applying organic ferti-lizer for two consecutive years could effectively improve soil pH and nutrient availability, increase rhizosphere microbial richness and diversity, change soil microbial community structure, and shape microbial communities being more conducive to yield and quality improvement.

Impact of smartphone use on production outsourcing: evidence from litchi farming in southern China

There is a great deal of evidence suggesting that information and communication technology (ICT) and agricultural production outsourcing can improve farm productivity and farmers’ welfare. However, less is known about the relationship between modern ICT use and agricultural production outsourcing. Drawing upon a survey of 855 litchi growers from southern China, this study estimates the effect of smartphone use on farmers’ decisions regarding agricultural production outsourcing. A novel genetic matching method is employed to mitigate the selection bias associated with self-selected smartphone use. Our result confirms the positive role of smartphone use in increasing the number of production tasks outsourced by litchi growers. Moreover, smartphone users are more likely to outsource both labor-intensive and technology-intensive tasks than nonusers. In addition, the treatment effect of smartphone use varies with each specific litchi production task. Our findings highlight the importance of improving smartphone adoption among farmers to promote agricultural production outsourcing.

Nondestructive Identification of Litchi Downy Blight at Different Stages Based on Spectroscopy Analysis

Litchi downy blight caused by Peronophythora litchii is the most serious disease in litchi production, storage and transportation. Existing disease identification technology has difficulty identifying litchi downy blight sufficiently early, resulting in economic losses. Thus, the use of diffuse reflectance spectroscopy to identify litchi downy blight at different stages of disease, particularly to achieve the early identification of downy blight, is very important. The diffuse reflectance spectral data of litchi fruits inoculated with P. litchii were collected in the wavelength range of 350–1350 nm. According to the duration of inoculation and expert evaluation, they were divided into four categories: healthy, latent, mild and severe. First, the SG smoothing method and derivation method were used to denoise the spectral curves. Then, the wavelength screening methods competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were compared to verify that the SPA method was more effective. Eleven characteristic wavelengths were selected, accounting for only 1.1% of the original data. Finally, the characteristic wavelengths were tested by six different classification models, and their accuracy was calculated. Among them, the ANN model performed best, with an accuracy of 90.7%. The results showed that diffuse reflectance spectroscopic technology has potential for identifying litchi downy blight at different stages, providing technical support for the subsequent development of related automatic detection devices.

Management of Litchi Fruit and Shoot Borer (Conomorpha sinensis) in Three Litchi Varieties in Samtenling, Bhutan

In Bhutan, litchi production is constrained by insect pest damage. Among insect pests, the litchi fruit and shoot borer (Conopomorpha sinensis Bradley) is an emerging pest of economic importance in the subtropical regions of Bhutan. Up until now, there is documented research on its biology and management in Bhutan. Therefore, this study was undertaken to study the efficacy of two different management methods against litchi fruit borer infestation in three litchi varieties (Bhur litchi 1, Bhur litchi 2 & Hong houy). The management methods consisted of three treatments; T1-Azadirachtin followed by Imidacloprid, Azadirachtin and Cypermethrin; T2-Azadirachtin followed by Imidacloprid, Azadirachtin and Azadirachtin; T3-Untreated control. The result showed that the fruit infestation at harvest was significantly lower in management method T1 (34.74%) as compared to T2 (78.07%) and untreated control (89.98%). In terms of the variety, the lowest fruit infestation at harvest was observed for Hong houy (56.02%) as compared to Bhur Litchi 1 (73.28%) and Bhur Litchi 2 (73.45%). There were no significant differences in fruit drop percent and percent infestation of dropped fruits between the treatments and varieties tested. Heavy fruit drop was observed in the third week, due to unknown reasons, which then decreased over the fruit development stages. Fruit borer infestation seems to increase rapidly after the fifth and eighth weeks indicating that most of the fruit borer damage occurs at the fruit maturity stage after fruit colour break. Therefore, the last application of cypermethrin 10% EC at the fruit colour break stage was found necessary to reduce fruit infestation during this vulnerable pest infestation period besides scheduled application of Azadirachtin and Imidacloprid at the early fruit development period.

A REVIEW ON MANAGEMENT OPTIONS FOR LITCHI FRUIT AND SHOOT BORER, CONOPOMORPHA SINENSIS

Under changing climatic condition, litchi fruit and shoot borer is becoming a major threat to quality litchi production and leading to more than 70% borer infested fruit in unmanaged orchard. Different management methods viz., physical, mechanical, cultural, biological, innovative, chemical and integrated pest management approach have been adopted to manage fruit and shoot borer. Based on various management strategies, integrated pest management approach with the use of green label insecticides and pheromones traps has huge potential for pest management and preservation of non-targeted species. Therefore, an attempt has been made to review management options for litchi fruit & shoot borer, Conopomorpha sinensis.

Supply Chain Management of Litchi: A Case Study in Sonitpur District of Assam

Litchi (Litchi chinensis Sonn), an important sub-tropical evergreen fruit crop belonging to family Sapindaceae, is believed to have originated in China, where it has been grown in Southern Guangdong state for thousands of years. It is highly specific to climatic requirements and probably due to this reason its cultivation is restricted to few countries in the world. In India, litchi was introduced in the 18th century through Burma, and from there, it spread to many countries. India and China account for 91 percent of the world litchi production. Litchi is one of the important fruit crop commercially grown in Assam. Due to its perishable nature and having very short shelf life, Supply Chain Management (SCM) plays a vital role. Though India is an agrarian economy the business faces various challenges in terms of infrastructure facilities. The present article is an attempt to explain the production, distribution and Supply chain management of Litchi in Sonitpur District of Assam. Most of the litchi growers belong to marginal and small category. Hence, the involvement of marginal farmers is more in Litchi plantation as compared to other category of farmers. Major share of produce traded through market intermediaries. The linear trend model was used to check the dynamicity of the area and production data of Litchi in India. Due to perishable in nature, the litchi farmers are suffering severely due to wastage of litchi throughout the intermittent steps in existing supply chain of litchi.