Mango Production Research Articles

Mapping Brazilian Expansion Risk Levels of Mango Weevil (Sternochetus mangiferae Fabricius) Based on MaxEnt.

The mango weevil, Sternochetus mangiferae (Fabricius) (Curculionidae), pest present in Brazil and is restricted to some municipalities in the Rio de Janeiro State. This curculionid attacks the mango crop exclusively and puts mango production globally at risk, especially those destined for export. Using ecological modeling tools, this study is the first to map the potential risk of S. mangiferae in Brazil. We aimed to identify the potential distribution of this pest in Brazilian states, drawing up thematic maps of regions that present suitable and unsuitable climatic conditions for the establishment of the pest using the MaxEnt ecological niche model. The average annual temperature, the annual precipitation, the average daytime temperature range, and the annual temperature range were the variables that contributed most to the selected model. The MaxEnt model predicted highly suitable areas for S. mangiferae throughout the Brazilian coast, especially on the northeast coast. The region responsible for more than 50% of mango production in Brazil, the São Francisco Valley, was classified by the model with suitability for the pest; it can impacts exportations due to the imposition of phytosanitary barriers. This information can be used in strategies to prevent the introduction and establishment of this pest in new areas and monitor programs in areas with recent occurrence. In addition, the model results can be used in future research plans on S. mangiferae in worldwide modeling studies and climate change scenarios.

Comparative transcriptome analysis provides novel insights into molecular response of salt-tolerant and sensitive polyembryonic mango genotypes to salinity stress at seedling stage.

Increased soil salinity in the recent years has adversely affected the productivity of mango globally. Extending the cultivation of mango in salt affected regions warrants the use of salinity tolerant/resistant rootstocks. However, the lack of sufficient genomic and transcriptomic information impedes comprehensive research at the molecular level. We employed RNA sequencing-based transcriptome analysis to gain insight into molecular response to salt stress by using two polyembryonic mango genotypes with contrasting response to salt stress viz., salt tolerant Turpentine and salt susceptible Mylepelian. RNA sequencing by Novaseq6000 resulted in a total of 2795088, 17535948, 7813704 and 5544894 clean reads in Mylepelian treated (MT), Mylepelian control (MC), Turpentine treated (TT) and Turpentine control (TC) respectively. In total, 7169 unigenes annotated against all the five public databases, including NR, NT, PFAM, KOG, Swissport, KEGG and GO. Further, maximum number of differentially expressed genes were found between MT and MC (2106) followed by MT vs TT (1158) and TT and TC (587). The differentially expressed genes under different treatment levels included transcription factors (bZIP, NAC, bHLH), genes involved in Calcium-dependent protein kinases (CDPKs), ABA biosynthesis, Photosynthesis etc. Expression of few of these genes was experimentally validated through quantitative real-time PCR (qRT-PCR) and contrasting expression pattern of Auxin Response Factor 2 (ARF2), Late Embryogenesis Abundant (LEA) and CDPK genes were observed between Turpentine and Mylepelian. The results of this study will be useful in understanding the molecular mechanism underlying salt tolerance in mango which can serve as valuable baseline information to generate new targets in mango breeding for salt tolerance.

AN ECONOMETRIC ANALYSIS FORTHE IMPACT OF CLIMATIC CONDITIONS ON THE PRODUCTIVITY OF MANGO CROPS IN EGYPT BY USING PANEL DATA MODELS

Horizontal agricultural expansion is one of the most important pillars of the national economy in Egypt, so the country makes strenuous efforts to make optimal use of agricultural resources, and despite these efforts, the climate prevents it.Recently, global warming has increased and climate change is expected to worsen the frequency, intensity, and impacts of some types of extreme weather events that affected mango productivity during the last years, which led to a decrease in productivity by about 37%, with a value of financial losses amounting to 4.8 billion pounds in 2021.Therefore, the research aims to estimate the impact of extreme weather on mango productivity during the last three years (2021-2019) at four studied governorates representing 75% of the total area of mango in Egypt. The Fixed Effect Cross of Panel Data Model was adopted as the appropriate model, to illustrate the impact of the phenomena on the productivity of mangoes. The results show that there is a statistical significance and a negative effect for both the minimum and maximum temperatures, as productivity decreases by about 1.05%, and 1.79% with an increase in each of the minimum and maximum temperatures by 1%, respectively. The negative impact has been shown on the governorates of Buhaira and Ismailia. Also, the individual effect was studied for each month,it was found that there was a statistically significant negative effect of the minimum and maximum temperatures for the months of flowering and fruiting.

Convective drying of mango stone for use as biomass

Mango stone is an interesting biomass by-product with a considerable net calorific value. Mango production has significantly risen in the last few years, meaning that mango waste has increased as well. However, mango stone has a moisture content of about 60% (wet basis) and it is very important to dry the samples for using them in electrical and thermal energy production. In this paper, the main parameters involved in the mass transfer during drying are determined. Drying was carried out in a convective dryer through a set of experiments based on five drying air temperatures (100 °C, 125 °C, 150 °C, 175 °C and 200 °C) and three air velocities (1 m/s, 2 m/s and 3 m/s). Drying times ranged between 2 and 23 h. The drying rate was calculated from the Gaussian model whose values ranged from 1.5·10−6 to 6.3·10−4 s−1. Effective diffusivity was obtained as an overall parameter in the mass diffusion for each test. These values were found between 0.71·10−9 and 13.6·10−9 m2/s. The activation energy was calculated from the Arrhenius law for each test, made at different air velocities. These values were 36.7, 32.2 and 32.1 kJ/mol for 1, 2 and 3 m/s, respectively. This study provides information for future works on design, optimization and numerical simulation models in convective dryers for standard mango stone pieces according to industrial drying conditions.

Trend and Forecasting of Area, Production and Productivity of Mango Crop in Karnataka, India

The current study was carried out to analyze the trend and forecast in area, production and productivity of mango crop in Karnataka. It was determined by using the secondary data of area, production and productivity of mango for the period of 18 years (2000-01 to 2017-18) was collected from Directorate of Economics and Statistics, Karnataka. To estimate the trend and its forecast for the next 5 years, up to 2022-23, linear, quadratic, exponential, logistic and Gompertz models were fitted and the best-fitted model was selected based on lowest MAPE. Result revealed that exponential model was best-fitted for area and production of mango, and the logistic model was found to be the best-fitted model for the mango productivity. The result also explored that the area, production and productivity of mango crop have an upward trend in Karnataka state in above study period. Based on this trend to forecast area, production and productivity of mango crop for the period from 2018-19 to 2022-23.

First Record of Sooty Spot Caused by Cladosporium cladosporioides on Mango (Mangifera indica L.) in Egypt

L.) is an economically important fruit tree belonging to family Anacardiaceae, grown in the tropical and sub-tropical areas of the world. It is usually grown in the nursery and marketed as a scion seedling. Mango fruits are consumed due to their high nutritional values, delicious taste, and excellent flavour. In January 2022, abundant fungal infection appeared in scattered areas on the leaves of mango seedlings at a commercial seedlings production nursery in Ismailia Governorate, which is considered one of the most important districts for mango production.

Forecasting area, productivity and prices of mango in Valsad District of Gujarat: Time series analysis

Mango on an average account approximately 75 per cent of total production quantity. India is the largest mango producer, accounting for about half of the world-wide mango production. Forecasting of area, production and price fluctuations are the key to provide support in decision making and proper planning for sustainable growth of farmers and other people who are dependent on horticulture. The prices of mango are affected by cultivated area and yield of mango but in other ways pre or post-harvest management also affects it. The problems regarding the price fluctuations arise due to seasonality in arrival and its perishable nature. Therefore, the present study was carried out with time series intervention modelling in forecasting area, productivity and prices of mangoes. In the current investigation, simple exponential smoothing (SES) implemented to develop the forecasting models for area and productivity of mango. Under the SES, the error measurements at different values of alpha (a) for forecasting of area and productivity were observed that the value 0.8 and 0.9 of alpha (a) showed minimum Mean Absolute Percentage Error (MAPE) error i.e. 3.11 per cent, and 12.73 per cent, respectively. The study also developed time series ARIMA models for forecasting the prices of the mango (Keshar and Alphonso) for Valsad markets of Gujarat. It was showed that ARIMA (6, 1, 2) and ARIMA (1, 1, 2) were found good models for forecasting the prices of the Keshar and Alphonso, respectively in Valsad district of Gujarat

Two Newly Identified Colletotrichum Species Associated with Mango Anthracnose in Central Thailand

Anthracnose caused by Colletotrichum spp. is one of the major problems in mango production worldwide, including Thailand. All mango cultivars are susceptible, but Nam Dok Mai See Thong (NDMST) is the most vulnerable. Through a single spore isolation method, a total of 37 isolates of Colletotrichum spp. were obtained from NDMST showing anthracnose symptoms. Identification was performed using a combination of morphology characteristics, Koch's postulates, and phylogenetic analysis. The pathogenicity assay and Koch's postulates on leaves and fruit confirmed that all Colletotrichum spp. tested were causal agents of mango anthracnose. Multilocus analysis using DNA sequences of internal transcribed spacer (ITS) regions, β-tubulin (TUB2), actin (ACT), and chitin synthase (CHS-1) was performed for molecular identification. Two concatenated phylogenetic trees were constructed using either two-loci of ITS and TUB2, or four-loci of ITS, TUB2, ACT, and CHS-1. Both phylogenetic trees were indistinguishable and showed that these 37 isolates belong to C. acutatum, C. asianum, C. gloeosporioides, and C. siamense. Our results indicated that using at least two loci of ITS and TUB2, were sufficient to infer Colletotrichum species complexes. Of 37 isolates, C. gloeosporioides was the most dominant species (19 isolates), followed by C. asianum (10 isolates), C. acutatum (5 isolates), and C. siamense (3 isolates). In Thailand, C. gloeosporioides and C. acutatum have been reported to cause anthracnose in mango, however, this is the first report of C. asianum and C. siamense associated with mango anthracnose in central Thailand.

Gas exchange and post-harvest quality of ‘Kent’ mango subjected to controlled water deficit in semi-arid region

ABSTRACT Brazil is the seventh largest producer of mangoes in the world, and the São Francisco Valley is the main producing region, with ‘Kent’ as one of the main cultivars. Considering that irrigation management affects physiological events, production and fruit quality, the objective of this work was to evaluate the gas exchange in the leaves and fruit quality of ‘Kent’ mango subjected to controlled water deficit in the semi-arid region. The experiment was carried out in Petrolina-PE, semi-arid region of the São Francisco Valley. The experimental design used was randomized blocks, in a triple factorial scheme, with four irrigation depths (40, 60, 80 and 100% of crop evapotranspiration - ETc), three phenological stages (F1 - flowering, F2 - fruit growth, F3 - fruit maturation) and two production cycles (2018 and 2019), with four replicates. During the phenological stages, the physiological parameters of gas exchange were evaluated. After harvesting, the following parameters were evaluated: soluble solids content, titratable acidity, pH, firmness and peel color. Irrigation with a depth between 79.5 and 83.6% ETc during the evaluated stages promoted greater gas exchange in the leaves, greater firmness and acidity in the fruits. The reduction in irrigation depth in F1 and F3 reduced the soluble solids content, while in F2 the highest soluble solids content was obtained with irrigation between 68.24 and 74.5% ETc. The most suitable irrigation depth for ‘Kent’ mango cultivation depends on the purpose of the producer and on the phenological stage of the crop.

Effect of waste mango silage on the in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics in calf diets.

Mexico is the fifth largest producer of mangoes in the world. For the conservation of agro-industrial waste and crop residues, the ensiling technique has shown good results. This study aimed to evaluate the effect of increasing the level of mango silage (86% waste mango and 14% pangola grass hay) in calf diets on in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics. The diets contained 0 (T0), 30 (T1), 45 (T2), and 60% (T3) mango silage. The partial (24, 48, and 72 h) and cumulative (72 h) biogas, CH4 production, and degradation were determined in the in vitro evaluation. In situ digestibility and estimators of fermentation kinetics of dry matter (DM) and organic matter (OM) were determined. Intake, apparent nutrient digestibility, and rumen parameters of calves (200 kg) were evaluated in a 4 × 4 Latin square design. Response to increased mango silage was calculated by linear and quadratic orthogonal contrasts. In vitro partial and cumulative biogas production decreased linearly (p < 0.05), and the partial and cumulative CH4 production did not show linear or quadratic contrast (p > 0.05); in vitro DM degradation, in vitro neutral detergent fiber degradation, and in vitro acid detergent fiber degradation showed a linear increase (p < 0.05). In situ dry matter digestibility (DMDis), in situ organic matter digestibility (OMDis), b, a + b, c, and effective digestibility (ED) of DMDis, a, a + b, c, and ED of OMDis increased linearly (p < 0.05). Dry matter intake, OM intake, and crude protein intake showed a linear increase (p < 0.05); NDF intake and ADF intake presented a quadratic behavior (p < 0.05). Apparent digestibility of DM, OM, CP, and hemicellulose, pH, N-NH3, total bacterial count, acetate, propionate, butyrate, volatile fatty acids, acetate: propionate ratio, cellulolytic bacteria, and protozoa did not present a linear or quadratic orthogonal effect (p > 0.05). The in vitro, in situ, and in vivo variables demonstrated that up to 60% mango silage can be used for the intensive fattening of calves in confinement.

Land Suitability Planning for Sustainable Mango Production in Vulnerable Region Using Geospatial Multi-Criteria Decision Model

The land suitability in the Ratnagiri district (India) for mango crop has been assessed using a combination of multi-criteria decision making (MCDM) with GIS-based analytic hierarchy process (AHP), and sensitivity analysis. Five criteria are applied in this study to analyze land suitability affecting the mango production, viz., topography, climate, soil properties, soil erosion risk, and soil and water conservation practices, all affecting mango production. To prepare the land suitability maps for the mango plants, weights of criteria were identified through expert opinions and a pairwise comparison matrix. A weighted overlay tool available in ArcGIS software was applied in this study for the weighted overlay analysis. The most sensitive parameters were identified by developing and testing a total of 26 weighting schemes. After analyzing the sensitivity of parameters, the parameters related to soil and erosion such as terracing, contour trenching, stone bund, etc. were found as the most significant factors, before and after implementing the conservation measures. As a result, it was observed in this study that after conservation practices were implemented, the area in the highly suitable (19.4%) and moderately suitable (68.8%) classes was expected to rise, while the area in the marginally suitable (7%) class was expected to decrease. This research revealed that combining MCDM with GIS-based AHP as well as sensitivity analysis techniques increased the reliability of MCDM output for each criterion.

First report of Lasiodiplodia mahajangana causing canker of mango (Mangifera indica) in Puerto Rico.

Mango originated in the Indo-Burmese region (Alphonse de Candolle, 1885). In the Caribbean, Puerto Rico currently produces and exports mangoes to the United States and Europe. Globally, an important disease affecting mango production is dieback, caused by fungi belonging to Botryosphaeriaceae family. During a one-year survey from 2019 to 2020, conducted at the mango germplasm collection of the Agricultural Experiment Station of the University of Puerto Rico, located at Juana Díaz, PR, symptoms of dieback were observed in shoots, descending towards the woody part, and vascular necrosis. We sampled bimonthly, 35 Keitt trees for one year. At the end of the evaluation, we detected that a 74% disease incidence was caused by Botryosphaeriaceae. Lasiodiplodia mahajangana (syn. L. caatinguensis) was associated with 4% disease incidence. In addition, we identified other Botryosphaeriaceae species causing 70% of disease incidence. To identify the causal agent, sections of symptomatic tissue (4mm2) were surface disinfected by immersion in 70% ethanol, 10% sodium hypochlorite and rinsed with sterile-distilled water for 1 minute at each solution. Sections were transferred to petri dishes containing potato dextrose agar acidified with 85% lactic acid (aPDA). Ten fungal isolates were obtained with similar morphological characteristics such as colony color and texture, after 12 days. Of these, one representative (isolate 17) was selected and identified as L. mahajangana (Lm) using morphological parameters and sequences of four nuclear genes (Zhang, W. et al., 2021). In aPDA, Lm colonies showed sparse and slow-growing aerial mycelium with dark gray-greenish color at the center and light gray edges. Black pycnidia were observed after 15 days of incubation at 28°C and dark conditions. Hyaline, ovoid to ellipsoid immature conidia (n=40) with average size of 22 µm long and 12 µm wide were observed. Mature bicellular pigmented conidia (n=40) had longitudinal striate and its average size was 23 µm long and 12 µm wide. Internal transcribed spacer (ITS), β-tubulin (βtub), elongation factor 1-alpha (EF1-α) and large ribosomal subunit (LSU) genetic regions were amplified by PCR from the original and pathogenicity test recovered isolates. Sequences of PCR products were compared with NCBI database BLAST tool with other Lm sequences. Sequence accession numbers of the four genetic regions of Lm are as follows: OL375401 and OL375402 for the ITS region; OL405579 and OL405580 for β-tubulin; OL455922 and OL455923 for EF1-α; and OL375648 and OL375649 for LSU. All the sequences were grouped with the ex-type CMM1325 of Lm (BS=84). Pathogenicity tests were performed on 6-month-old mango trees of cv. Keitt. Three healthy trees were inoculated with 5 mm mycelial disks of Lm, on stems, with and without wounds. Controls were inoculated with aPDA disks only. Inoculated trees were covered for 3 days with plastic bags, keeping them in conditions of high relative humidity with constant irrigation, temperature of 28°C, and 12 hours of light and 12 hours of darkness for 12 days. Twelve days after inoculation, Lm isolates caused stem necrosis and canker, with differences in lesion severity from 2 to 17 mm2 with wound, and 0 to 6 mm2 without wound. Untreated controls showed no symptoms of canker. Lasiodiplodia mahajangana was re-isolated from diseased stems fulfilling Koch's postulates, and a sequence of the recovered isolate from the pathogenicity test was compared and included in the phylogenetic analysis. Lasiodiplodia mahajangana has been reported to cause stem-end rot of mango in Malaysia (Li, L. et. al., 2021). To our knowledge, this is the first report of Lm causing canker of mango in Puerto Rico. Knowing L. mahajangana as a new pathogen that causes canker of mango is important to establish an adequate and effective control management of this disease in mango producing countries worldwide.

Does empowerment influence women’s willingness to pay for integrated pest management practices? A case study of mango growers in Zambia

Mango is an important fruit crop in sub-Saharan Africa (SSA), including Zambia, due to its nutritional value and contribution to food security. However, the invasive and mango-infesting fruit fly is a significant constraint in mango production. Therefore, icipe and partners developed and disseminated the integrated pest management package to curb this menace. The current study uses household-level data from 325 smallholder mango-growing households from selected regions in Zambia to evaluate how empowerment affects women's willingness to pay (WTP) for an Integrated Pest Management (IPM) package for the suppression of mango-infesting fruit flies. We used a double-bounded contingent valuation model to determine the association between Project-Level Women’s Empowerment in Agriculture Index (pro-WEAI), other social-economics factors, and WTP. The results show that women’s empowerment status positively and significantly increased the likelihood of considering a higher bid for the IPM package. Other factors affecting women’s WTP for the IPM package were women's education level, access to extension services, non-farm occupation, and household income from mangoes, with a positive and significant influence on their WTP. However, distance to the input market, perception of the effectiveness of current fruit fly management methods, and level of mango loss due to fruit flies negatively influenced WTP for the IPM package. Empowering women, especially increasing their access to extension services, and providing livelihood alternatives would increase their uptake of pest management technologies. Efforts to lower women’s domestic workloads, boost their finances, and sensitize others in the community to promote women’s freedom of movement would be vital to empowering women hence increasing their uptake of new agricultural innovations.

First Report of Mango malformation disease caused by Fusarium proliferatum in Mexico.

Mango (Mangifera indica L.) is the most economically important fruit in the tropical and subtropical regions of the world. Mexico is ranked the fourth largest mango producer worldwide with an approximate production of 2 396 675 t in 2019 (FAO 2020). Sinaloa is the principal mango production state in Mexico with 410,147 t in 2020 (SIAP 2021). Mango malformation disease (MMD) is one of the main limitations in the production of this crop worldwide, causing serious losses in yield. During December 2017 to April 2018, symptoms of MMD were observed in commercial mango in the municipality of El Rosario (Sinaloa, Mexico). These symptoms included malformed and compacted inflorescences, abnormal development of vegetative shoots with shortened internodes at an incidence of 25 %. Tissue from 15 symptomatic trees were superficially disinfested with 2% sodium hypochlorite and transferred to potato dextrose agar (PDA). Typical Fusarium spp. colonies were obtained from all samples. Fifteen pure cultures were obtained by single spore culturing. White to cream-colored aerial mycelia of typical Fusarium colonies were observed from all samples on PDA (Leslie and Summerell 2006). From 10-day-old cultures grown on carnation leaf agar medium, macroconidia (n = 50) were hyaline, relatively slender with a curve, 4 to 5 septate, and measured 39.5 to 76.8 x 5.7 to 9.5 μm. The microconidia (n = 50) were hyaline and pyriform, without septa, and measured 8.1 to 10.6 x 5.1 to 6.9 μm. Chlamydospores were observed. The EF1-α gene (O'Donnell et al. 1998) was amplified by PCR and sequenced from the isolates. The EF1-α sequence from one representative isolate (128FRSIN) was deposited in GenBank with the accession number MK932806. Maximum likelihood analysis was carried out using the representative EF1-α sequence for F. proliferatum (MK932806) and other Fusarium species. Phylogenetic analysis revealed the isolate most closely related was F. proliferatum (100% bootstrap). The molecular identification was also confirmed via BLAST on the Fusarium ID and Fusarium MLST databases. The pathogenicity tests were carried out on healthy three-month-old mango plants. Twenty plants and five shoots per plant were inoculated with 20 µl of the conidial suspension (1 x 106 conidia/ml) (Freeman et al. 1999). Twenty plants served as noninoculated controls. Plants were maintained for 365 days under greenhouse conditions (25 to 30°C). The assay was conducted twice. Symptoms of multiple vegetative shoots and shortened internodes were observed four months after inoculation on the infected plants with an average disease of 4.5 in the first trial and 4.4 in the second assay according to the disease severity scale outlined by Iqbal et al., (2006). No symptoms were observed on non inoculated control plants after 365 days. One isolate per plant was isolated again from the plants with malformation symptoms (n=20), and identified again as F. proliferatum, by morphological and molecular characteristics. F. proliferatum was identified as the causal agent of MMD in China by Zhan et al. (2010). To our knowledge, this is the first report of F. proliferatum causing MMD in Mexico. The development of management strategies to prevent crop loss is required in this important mango production area.

First Report of Postharvest Stem End Rot of mango Fruit (Mangifera indica) Caused by Diaporthe pseudomangiferae in China.

Mango (Mangifera indica L.) is considered one of the most important tropical or subtropical fruit crops (Nelson et al.2008). China is the second-largest producer of mango (Kuhn et al. 2017). In June 2021, postharvest stem-end rot disease was observed on Narcissus mango (about 20% of the fruits showed similar symptoms of infections) in local agricultural market of Guangzhou, China. Black rot symptomatic lesions were observed on the fruit surface, which initially started from the stem end and progresses into decay, turning brown. To isolate and identify the pathogen, small pieces (3-5 mm2) were excised from the lesion margins of the fruits (n=54), which were surface sterilized by 1% NaOCl (1 min), 70% ethanol (30 s) and then washed twice with sterile distilled water. After sterilization, the tissues were cultured on potato dextrose agar (PDA). Three morphologically similar isolates (SXM-1/2/3) were obtained and the representative isolate SXM-1 was analyzed. Colonies surface initially had white-gray moderate aerial mycelia, in reverse umber with patches of pale luteous to luteous. On malt extract agar (MEA) surface dirty white, reverse greyish sepia with patches of sienna. Conidiomata pycnidia, black, erumpent to superficial on PDA, globose with neck, ostiole exuding cream conidial droplets; Conidiophores hyaline, smooth, 1-3-septate, branched, densely aggregated, cylindrical, straight to sinuous, 22-42 × 2.8-3.7 µm. Alpha conidia (n = 50) aseptate, hyaline, smooth, fusiform to somewhat short cylindrical, 3.2-11 ×1.3-3.5 µm. Beta conidia (n = 30) hyaline, smooth, curved or hamate 14.8-33.6 × 1.1-2.6 μm. According to morphological characterization, the representative isolate SXM-1 was similar to Diaporthe pseudomangiferae CBS 101339 (Gomes et al. 2013). For molecular identification, the internal transcribed spacer (ITS) region, histone H3 (HIS) and β-tubulin (TUB) genes (White et al. 1990; Carbone et al. 1999; Glass et al.1995) were amplified and sequenced, which were deposited in GenBank (ON243823, ON254656, ON254655). BLASTN analysis revealed that DNA sequences of the isolates (SXM-1/2/3) showed 99% identity with those of D. pseudomangiferae (MG576128.1, KC344149, MN329124.1), respectively. A phylogenetic tree analysis based on the concatenated sequences confirmed the isolates as D. pseudomangiferae. Pathogenicity tests were made with the representative isolate SXM-1. Healthy fruits were inoculated with 5 mm mycelial discs of the representative isolate SXM-1 after being wounded with a needle or non-wounded, control fruits were inoculated with sterilized PDA plugs. All inoculated and control fruits were incubated in the dark at 26°C for 7 days post-inoculation. Control fruits remained asymptomatic, whereas inoculated fruits were dark brown necrotic lesions with a roughly circular shape around the inoculation sites. Pathogenicity tests were performed in triplicate. The pathogenic isolates were successfully reisolated, thus confirming Koch's postulates. D. pseudomangiferae was associated with fruit peel of mango in Mexico and the Dominican Republic, and it has also been reported to cause inflorescence rot, rachis canker, and flower abortion in mango (Gomes et al. 2013; Serratodiaz et al. 2014). To our knowledge, this is the first report of D. pseudomangiferae causing postharvest stem-end rot of mango fruits in China. This finding suggests that D. pseudomangiferae is a potential problem for mango fruit production in China, and it is important to establish an adequate and effective control management of this disease.

ECONOMICAL EVALUATION OF MANGO (CV. KEITT) TREES UNDER COLOURED SHADE NETS

This study explored the economical viability of five different coloured shade nets (White, yellow, red, blue and black) on mango production (Mangifera indica L. cv. Keitt). This study investigated the climatic parameters in terms of light intensity, minimum and maximum air temperature, relative humidity and plant growth across 2019 and 2020 seasons. When compared to open field conditions, coloured shade nets resulted in higher maximum temperatures and relative humidity. The black net cover and open field treatments gave the lowest mango yield compared to all greenhouse net cover. When compared to the other treatments, the use of white or yellow nets resulted in a considerable increase in the number of fruits and total yield per plant. According to prevailed conditions, it could be concluded that optimum microclimate for growing mango in similar conditions could be obtained under white and yellow nets compared to the other net covers. Black greenhouse net cover gave the lowest productivity during the experimental duration. Production costs, total revenue, net return and ratio of total revenue to cost for Keitt mango in Egypt are presented in this study. The result shows that the net return for white net reached 15777 Egyptian pound (LE) and LE 15270 per m2 in 2019 and 2020 respectively, which was 2.63 times those grown in the open field (LE 5980 and LE 5081 per 2000 m2) in 2019 and 2020 respectively. However, Revenue to cost ratio was found higher in white net in both seasons which were 1.9 and 1.8 respectively.

PRODUCTION, MARKETING AND ECONOMIC DYNAMICS OF MANGO AT BHERIGANGA MUNICIPALITY, SURKHET, NEPAL

The present study was carried out to assess the production, marketing and economic dynamics of mango in Bheriganga Municipality of Surkhet district in 2022. Purposefully, 81 mango growers having minimum mango orchards of 1 hectare in size and 10 to 15 years old were selected. A pre-tested and standard interview schedule was employed for a household survey to collect primary data. The findings of the study revealed that mango farming has a major contribution to household income. Dashari variety of mango was very popular among farmers and gradually changed the production system from subsistence to market oriented. The mango growers in the study area contributed an average NRs 189286.4 in cost of production/ha with average productivity of 11383.2 kg/ha. Gross revenue and net incomes were 628352.64 Rs/ha and 439066.24 Rs/ha respectively. BC ratio, profit-to-revenue ratio and input-output ratio were 2.32, 69.88 and 3.32 respectively. However, all the findings revealed with mango production were significant, but marketing is not well-organized, and the prices offered by each channel vary. In addition, farmers were more likely to exclude from market information due to long value chains, a lack of transparency and the presence of too many players. Despite serious irrigation, disease and insect problems, farmers were still able to produce a significant number of mangoes. However, due to the monopolized market system of middlemen and negligible efforts for value-addition practices, farmers were forced to accept lower farm gate prices while retail prices of those products were high. It was necessary to strengthen the marketing system, establish processing industries, and mobilize resources to give more negotiating power to the farmers because there was so much potential for value addition.

Comparative assessment of soil degradation potentials of commodity crops grown in Nigeria

Abstract Comparative assessment of land degradation potential of commodity crops grown in Jaba Local Government Areas of Kaduna State, Nigeria was investigated to provide evidence for crop-specific land management practices in the area. Soil samples collected from plots of four (maize, ginger, mango, and oil palm) main crops grown within three (Ungwan Rana; Kurmin Kwara, and Kyari) communities were analysed for relevant physico-chemical variables using standard laboratory procedures. The preliminary results of laboratory analyses showed that soils, where annual crops were grown had a higher content of sand particles, higher bulk density, pH(water), mineralization (lower carbon content), and gravimetric water content when compared to soils where permanent crops were found growing. Soils, where tree crops were growing, had a higher silt, clay, and organic matter content. Results from the erodibility factor (k) estimation indicated that ginger production in Kurmin Kwara had the greatest impact of all three sites and crops investigated with an annual soil loss of 12 kg/ha/annum. Mango production in Ugwan Rana resulted in the least impact with an estimated loss of 9 kg/ha/annum of soil to erosion. Evidence of two-way analysis of variance of land degradation (erodibility) data at a 95% confidence level in SPSS version 21 indicated that the impacts resulting from the cultivation of different crops in various communities are not significantly different from one another. Therefore, soil conservation measures such as mulching, composting, land fallowing, and cover cropping would be helpful in eliminating the emerging land degradation owing to the cultivation of commodity crops in the study area.

Coupling of regulated deficit irrigation at maturity stage and moderate fertilization to improve soil quality, mango yield and water-fertilizer use efficiency

• Underground continuous fertigation was applied to mango cultivation in the dry-hot region. • Regulated deficit irrigation could increase soil nutrient content, but reduce soil enzyme activity and microbial quantity. • Regulated deficit irrigation at maturity stage and medium fertilization increased mango yield by improving soil quality. Reasonable irrigation and fertilization practices can not only improve soil quality, but also increase crop yield, and water-fertilizer use efficiency. However, it is still unclear that the micro-irrigation and fertilization mode is conducive to improving the soil comprehensive environment, the mango yield and water-fertilizer use efficiency in the dry-hot region. The effects of regulated deficit irrigation (RDI) and fertilization levels on soil enzyme activity, soil microbial quantity, soil nutrient content, yield, water use efficiency (WUE) and partial fertilizer productivity (PFP) of mango in dry-hot region were studied. A randomized block design study with four irrigation levels [full irrigation throughout the growth period (FI), RDI during flowering (RDI FS ), RDI during fruit expansion (RDI ES ), and RDI at maturity (RDI MS )] and three fertilization levels [F H , a water-soluble compound fertilizer (N:P 2 O 5 :K 2 O = 12:8:40) applied at 129.0 kg ha −1 ; F M , 103.2 kg ha −1 ; and F L , 77.4 kg ha −1 ] was implemented in 2018 and 2019. The results showed that RDI reduced soil enzyme and microbial quantity, but increased nutrient content. With the decrease of fertilizer application rate, soil nitrate nitrogen, available phosphorus, available potassium content, urease, fungi and actinomycetes quantity decreased, while soil catalase, phosphatase activity and bacteria quantity increased first and then decreased. RDI reduced soil quality comprehensive index (SQI), and SQI decreased with the reduction of fertilization. Compared with FI, RDI FS and RDI ES reduced mango yield and PFP, RDI FS reduced WUE, while RDI MS increased WUE and PFP. Compared with F H , F M increased mango yield, WUE and PFP, F L increased PFP. The yield, single fruit weight and PFP increased first and then decreased with the increase of SQI at different growth stages. RDI MS F M obtained the maximum mango yield and WUE. Thus, the treatment of regulated deficit irrigation at maturity stage and moderate fertilization (103.2 kg ha −1 ) was the suitable mode of water and fertilizer management for mango, which could realize water-saving and high yield of mango simultaneously in the dry-hot region of Southwest China.

The use of toxic baits for the suppression of Mediterranean fruit fly in mango orchards.

Ceratitis capitata (Wiedemann, 1824) is an insect of major economic importance in the mango orchards of the submedium of the São Francisco River Valley, the main area of mango production and exportation in Brazil. To provide alternatives for the management of C. capitata, toxic baits based on alpha-cypermethrin (Gelsura®) and spinosad (Success® 0.02 CB) were evaluated in three commercial mango experiments during two consecutive harvests: 2016/2017 (experiment 1 - area 1) and 2017/2018 (experiment 2 -area 2 and experiment 3 - area 3). According to the results, there was a large reduction in the infestation of C. capitata after five sequential applications of the alpha-cypermethrin (6 g.ha-1) and spinosad (0.38 g.ha-1) toxic baits performed at seven-day intervals during mango fruit ripening in all experiments and years (harvest) evaluated. Compared with the untreated plots, the plots with alpha-cypermethrin and spinosad applications showed a significant reduction in the damage induced (fallen fruits and/or on trees) by C. capitata. The management of C. capitata in mango orchards can include the use of the toxic bait based on alpha-cypermethrin, which represents an alternative to rotate with spinosad toxic bait in the São Francisco River Valley.