Black Gram Research Articles

INFESTATION RATE OF RICE WEEVIL ON SELECTED INDIGENOUS STORED GRAINS

Rice weevil, Sitophilus oryzae Lin. (Coleoptera: Curculionidae) is economically significant and known as a ubiquitous pest in Bangladesh as well as throughout the world. In this study, the infestation rate by this pest was assessed throughout the year on twelve common indigenous cereal grains and pulses, namely boiled and nonboiled rice, wheat, barley, maize, felon, pea, grass pea, lentil, chickpea, black gram and mung bean. There were significant differences in the infestation rate among the months and in the susceptibility among grains over the year. The highest percentage of weight loss over the year was found in chickpea (84.56%) and the lowest percentage of weight loss was found in black gram (7.09%). The chronological position of the experimental grains according to their percentages of weight loss was chickpea > wheat > barley > maize > nonboiled rice > pea > boiled rice > grass pea > lentil ≥ mung bean > felon > black gram. The highest infestation occurs at the temperature range of 32-35o C and during the month of April-June.

Detection and Analysis of melanin pigment in the edible seed coat of some plants

Melanin is a dark phenolic substance present in plants, animals, and microorganisms. The role of melanin in plants is to offer protection against biotic and abiotic conditions. The other possible functions in plants are unknown. Studying the occurrence of melanin in plants is essential to understand the taxonomic evolution of plants and its application in different fields. The deposition and distribution of Phytomelanin in the seed coat was studied using a light microscopy The seed coats of Phaselous vulgaris (Leguminaceae), Vigna mungo (Fabaceae), Linum usitatissimum (Linaceae), Cicer arietinum (Fabaceae), Vigna unguiculata (Fabaceae), Sesamum indicum (padaliaceae) and Macrotylama uniflorum (Fabaceae) showed the presence of melanin. Among the plant studied, S. indicum and V. mungo had a higher yield of melanin per 5 g of seeds. Melanin was extracted, purified and a confirmatory test was also conducted. UV and FT-IR studies were carried out with purified melanin. V. mungo and P. vulgaris showed no absorbance in the UV spectrum. The Maximum absorbance was found at 276 nm for S. indicum, M. uniflorum at 283 nm, L. usitatissimum at 276.5 nm, and V. unguiculata at 286 nm. It is evident from the study that phytomelanin is present in higher concentrations in S. indicum followed by V. mungo.

Influence of climatic factors on spatio-temporal variabilities in the occurrence of aflatoxins in major food grains available at retail shops in Bangladesh

In Bangladesh, little is known about the role of climatic factors influencing spatio-temporal occurrence among different food grains of aflatoxins, which have been linked to liver cancer cases and other health hazards. In this study, 252 food grain samples of 10 types were collected from retail markets at 18 districts, pre-monsoon, monsoon and post-monsoon seasons during February-September, 2018. Occurrence and concentration of total aflatoxins in the samples were analysed by a direct competitive enzyme-linked immunosorbent assay, and compared with climatic data (temperature, humidity, rainfall, and sunshine hours). Contamination of aflatoxins was found in approx. 38% (n=96) of the total samples, with highest occurrence in groundnuts (82%), followed by corn grains (70%), chick pea (54.5%), wheat grain (50%) and green gram (42.9%). Aflatoxins occurrence was moderate in split chick pea (30.8%), yellow pea (28.2%), black gram (27.8%), and lentils (27.6%), while the lowest in grass pea (17.6%). Aflatoxins concentration was found to exceed the European Union permissible limit (≤5 µg kg-1) in 33 (13.1%) samples. Overall, approximately 5.6%, 7.5%, and 25.0% samples were contaminated with high (10-19 ppb), medium (5-9 ppb) and low (1-4 ppb) concentrations of aflatoxins, respectively. High level concentration of aflatoxins was more frequent in groundnut (36%) and wheat grain (20%), in comparison to other types. Occurrence of aflatoxins during pre-monsoon was detected among 21% (19/91) samples, which increased to ca. 30% (36/119) during monsoon, and 98% (41/42) during post-monsoon. However, aflatoxins mean concentration during post-monsoon was comparatively low than the other seasons. Variations in aflatoxins monthly prevalence correlated significantly with relative humidity (p ≤ 0.01) and rainfall (p≤ 0.05), when a 1-month time lag was considered. Therefore, predisposing climatic conditions, i.e., rainfall incidences and persistence of higher relative humidity in the previous month(s), have salient influence on aflatoxins occurrence, potentially impacting both pre-harvest and stored food grains. This study underscores the need of a more holistic monitoring of aflatoxins in agricultural products for a longer term, and adoption of proper intervention measures for food grains while being stored and before consumption. Asian Australas. J. Food Saf. Secur. 2024, 8(2), 32-47

Intercropping in maize reduces fall armyworm Spodoptera frugiperda (J. E. Smith) infestation, supports natural enemies, and enhances yield

Fall armyworm (FAW) is a multi-generational invasive insect pest of maize. Field experiments were conducted in diverse ecologies at Hyderabad, Telangana (Location 1); Dholi, Bihar (Location 2); Kolhapur, Maharashtra (Location 3) during the rainy season from July-November, 2023 to assess the impact of maize intercropping with legumes and leafy vegetables on FAW damage, abundance of beneficial insects, weed dynamics, and yield. In the present study, location-specific intercrops were selected for the experimentation. In location 1, maize intercropped with cowpea followed by groundnut reduced the level of FAW infestation compared to sole maize. The increased natural enemy population (coccinellids, spiders, earwigs); weed suppression, and higher yields were observed in maize when intercropped with cowpea followed by groundnut and red amaranthus. In location 2, maize intercropped with cowpea followed by green gram and black gram reduced the FAW damage and higher natural enemy population. Maximum yield was obtained in maize intercropped with black gram followed by green gram and cowpea. However, concerning weed suppression and cost-benefit ratio, green gram followed by black gram was found to be superior. Minimum FAW infestation, abundant natural enemy population, weed suppression, and improved economic returns were observed in maize when intercropped with cowpea followed by groundnut and fenugreek in location 3. Each intercrop had its advantages concerning pests, weed suppression, an abundance of natural enemy populations, and higher yields. Therefore, it is suggested that the selection of plants as intercrops with maize should be based on the location-specific importance of particular aspects to attain multifunctional benefits. The present results revealed that crop diversification with location-specific intercrops can reduce significant yield losses caused by FAW and promote higher yields in maize.

Bio-Efficacy of Pre-and Post-Emergence Herbicides on Growth, Productivity, Nodulation of Black Gram (Vigna mungo L.) under Coastal Plain of Odisha

Background: Weeds compete with plants for resources during cultivation and the control of weeds during the critical period of crop-weed competition is crucial to avoid yield loss ranging from 50%-90% in black gram. The first 4-5 weeks are critical for black gram crop-weed competition. The composition of weed flora, the duration of crop-weed competition and its intensity significantly impact yield losses in black gram cultivation. Therefore, the current study aims to evaluate weed management practices in rabi black gram, with a focus on identifying herbicides that enhance weed control, increase productivity and profitability. Methods: A field experiment was conducted during the rabi season of 2021-2022 and 2022-2023 consecutively at Odisha University of Agriculture and Technology, Bhubaneswar. The field experiment comprised of eight treatments on different herbicide applications as T1- Fenoxaprop-p-ethyl @ 65 g a.i. ha-1, T2- Quizalofop-p-ethyl @ 50 g a.i. ha-1, T3-Cyhalofop-butyl @ 75 g a.i. ha-1, T4-Pendimethalin @ 750 g a.i. ha-1, T5- Oxyflourfen @ 50 g a.i. ha-1, T6- Tembotrione @ 120 g a.i. ha-1, T7- Weed check (control) and T8- Weed free, which was laid under randomised block design. Collected samples were analyzed in the field and laboratory for crop-weed competition, herbicide phytotoxicity and yield attributes. Result: The results revealed that weed-free treatment recorded the lowest weed population (5.27-5.45), weed dry weight (1.35g-2.20 g) and lowest weed index (0.00%) at all growth stages followed by pendimethalin (PE) application. Among yield attributes, weed-free treatment recorded the highest plant height (cm) which was at par with pendimethalin (PE) followed by cyhalofop-butyl (PoE) application. The magnitude of seed yield was increased under weed-free (1035.46 kg ha-1) and pendimethalin (PE) and cyhalofop-butyl (PoE) applications by 53.62% and 48.40%, respectively over the weedy check. Application of tembotrione recorded the highest herbicide phytotoxicity (5.3-7.6) over the rest of the treatments. It can be concluded that the application of pendimethalin 30 EC 750 g ha-1 as PE at 2 DAS followed by cyhalofop-butyl 10 EC 75 g ha-1 can be advisable for better weed control, lower herbicide phytotoxicity and higher yield.

Response of Intercropping Finger Millet on Growth and Yield of Pulses

A field experiment was conducted during kharif season in Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P.) India. The current research aims to evaluate the growth and yield of various pulses namely cowpea (Vigna unguiculata L.), black gram (Vigna mungo L.) and green gram (Vigna radiata L.) and when cultivated as intercrops with finger millet. The soil of the experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.6), low in organic carbon (0.51 %), available N (78.9 kg/ha), available P (32.88 kg/ha) and available K (385.10 kg/ha). The treatments consisted of 3 pulse crops (Cowpea, Black gram and green gram) and 3 row ratios (2:1, 4:1 and 6:1). The experiment was laid out in a Randomized Block Design with 13 treatments and replicated thrice. Maximum plant height and yield attributes was recorded in sole plots of cowpea (treatment 11), Black gram (treatment 12) and Green gram (treatment 13) respectively. Finger millet equivalent yield was recorded high in (treatment 7) where finger millet was intercropped with green gram in 2:1 ratio.

Demand and Supply Projections for Pulses in India

Background: The per capita net availability of pulses in India has been increased from 15.5 kg per year in 2018-19 to 19.6 kg in 2021-22. Efforts made to bridge the gap between demand and supply of pulses in the country has resulted in reducing the gap to some extent in recent years and still country is depended on import to meet the growing demand of the pulses such as pigeon pea, lentils and peas. Few studies predicted the demand and supply of pulses as a whole in the country and no studies analyzed the pulse wise demand supply gap in India. Hence, the present study was proposed to predict the demand and supply of major pulses such as chickpea (Gram/Chana), pigeon pea (Tur/Arhar), black gram (urd bean), mung bean (Green gram) and lentil (Masur) in India for a period, 2024-2030. Methods: The present study has been used the crop data on area, production and yield of major pulses including chickpea (Gram/Chana), pigeon pea (Tur/Arhar), black gram (urd bean), mung bean (Green gram) and lentil (Masur) for a period of 29 years (1985-2024) collected from the Directorate of Economics and Statistics, Government of India, New Delhi. Household consumption expenditure data was collected from the National Sample Survey office for 2011-12 from the Government of India. The supply projection was estimated by using linear regression model and demand projections were done by using behaviouristic approach. Result: Decadal trend in area, production and yield of pulses from 1970-2010 showed mixed trends of increase and decrease, whereas in 2010-2020, chickpea, pigeon pea, mung bean and black gram showed positive trend in area, production and yield but lentil alone showed negative trend in production. Import dependency of the pulses in the total availability has reduced to 8.92 per cent in 2021-22 from 19.42 per cent in 2009-10. Import dependency of the pulses in the total availability has reduced to 8.92 per cent in 2021-22 from 19.42 per cent in 2009-10. The availability of pulses has grown at a rate of 3.73 per cent from 2009 to 2021. Chick Pea, Tur, Mung bean, Urd bean and Lentils together contributed on an average 88.7 per cent to the total pulses production and 83.73 per cent of pulses availability from 2013 to 2021. Production of these five pulses has increased to 23.04 million tonnes in 2020-21 from 17.3 million tonnes from 2013-14. Gram is the single pulse contributed more than 40 per cent of the pulse production of the country in the above period. Demand supply projection showed a net surplus of 0.81-3.89 mt in the case of pulses and 5.64 -7.63 mt in the case of gram and 0.89 to 1.91 mt in Urd and 0.68 to 1.57 mt in Mung bean during 2024-2030. But in the case of pigeon pea and lentil there may be a net deficit in the range of 3-2.42 and 1.13-1.04 mt, respectively, during 2024-2030. Efforts should be made to bridge the gap in demand and supply of pigeon pea and lentil by the way of bringing new areas under pulses and developing the technologies suitable for the clusters.

Investigation of Engineering Properties of Black Gram and Horse Gram for the Design of Hopper and Seed Plate of a Pneumatic Planter

Study presents an in-depth evaluation of the engineering properties of Black Gram (Vigna mungo) varieties VBN-6 and ADT-5, and Horse Gram (Macrotyloma uniflorum) varieties KS-2 and Paiyur-2. This is carried out for the design of a pneumatic seed metering unit viz., seed plate and the hopper. Emphasizing the importance of physical and engineering properties, the investigation on moisture content, axial dimensions, gravimetric properties, and key engineering characteristics such as density, porosity and frictional properties provides critical data for optimizing the design and functionality of the pneumatic seed metering unit, including the seed plate and hopper. For black gram, metering plates with 2.1 mm cell diameter were found optimal, whereas horse gram varieties require 3.5 mm diameter with 26 cells. Hopper of 9100 cm3 capacity made of mild steel of 2 mm thickness was developed according to the seed bulk density and flow characteristics. These properties made the pneumatic metering mechanism compatible with pulse seeds and helped to mechanize the pulse sowing.

Character Association and Path Analysis for Yield and its Attributing Traits in Urdbean Genotypes and its Triple Test Cross F1 Hybrids

This research delves into the association and path coefficient analysis between yield and its attributing traits among 111 diverse lines of urdbean. 27 lines, three testers, and Eighty-one F1 hybrids were grown in a Randomized Block Design (RBD) with three replications during Kharif 2023 at the Crop Experimental Research Farm of Chandra Shekhar Azad University of Agriculture and Technology, Kalyanpur, Kanpur (U.P.). The analysis of variance for parents (27 lines and three testers) and their 81 triple test cross hybrids indicated highly significant genotypic differences across all 12 quantitative traits under study viz., days to 50% flowering (DFF), days to 75% maturity (DM), plant height (cm) (PH), number of primary branches per plant (NPB), pods per plant (NPP), pod length (cm) (PL), seeds per pod (NSP), biological yield per plant (g) (BYPP), seed yield per plant (g) (SYPP), harvest index (%),(HI), 100-seed weight (HSW), and protein content (%) (PC). All the traits studied showed a significant positive correlation with seed yield, except for days to 50% flowering, and days to 75 % maturity at phenotypic and genotypic levels. Path analysis revealed that all the traits had high direct positive effects on seed yield except for days to 50% flowering and days to 75 % maturity at phenotypic and genotypic levels. Therefore, these traits should be the primary focus in black gram breeding programs aimed at yield improvement.

Enhancing salt stress tolerance in black gram (Vigna mungo L.) through the exogenous application of seaweed liquid fertilizer derived from Sargassum sp.

Seaweed extract is being used as an organic biostimulant in agricultural and horticultural crops to reduce chemical fertilizers. This research aimed to determine the importance of seaweed liquid fertilizers (SLFs) derived from Sargassum sp. when given exogenously to black gram (Vigna mungo L.) under saline stress, and growth characteristics were analyzed in the laboratory. The morphological and biochemical characteristics of the plants were studied at the vegetative stage of 30 days after infusion of saline stress (50, 100, and 150 mM, NaCl) and SLF (5 %, 10 %, and 15 %) for five days. Our findings demonstrated a substantial stimulatory effect on black gram growth characteristics. The most effective treatment was a 10 % SLF concentration, which improved the morphology, chlorophyll pigments, RWC, proline, and protein content of black gram under salt stress. The finding was confirmed by LC-MS analysis of seaweed liquid fertiliser, which revealed the presence of growth regulators (alpha-Tocopherol, Isocorydin, 5,6-Dihydroxy-3′,4′-dimethoxyflavanone, Alloxanthin, 6,7,3′,4′-Tetrahydroxyflavanone, Flavanomarein, 3-Hydroxyechinenone, and Zeaxanthin). Thus, these SLF from Sargassum sp. might be exploited as a promising biostimulant in plants that are under abiotic stress, perhaps leading to more ecologically friendly agricultural practices in the future.

Performance of drip fertigation and foliar nutrition on cotton-black gram sequence in subtropics

Field experiments were conducted over two seasons to study the effect of drip fertigation levels and foliar nutrition on the growth and yield of cotton-black gram cropping sequences. The treatments comprised three levels of fertigation viz., 50, 75, and 100% recommended dose of fertilizers (RDF) and nitrogen, phosphorus, and potassium (NPK), combined with and without two levels of foliar spray, drip irrigation with soil surface application of 100% RDF, and surface irrigation with soil surface application of 100% RDF as a control. Drip-irrigated cotton and black gram registered higher yields during both seasons as compared to the surface methods of irrigation. Application of 100% RDF as drip fertigation combined with a foliar spray of 1% urea phosphate registered the highest seed cotton yield of 3598 kg ha−1 and black gram grain yield of 856 kg ha−1, which was significantly superior over the control. Application of nutrients through drip fertigation improved seed cotton yield by 45.2% and blackgram grain yield by 49.8% compared with conventional surface irrigation with soil application of fertilizers. From the results, it could be concluded that drip fertigation at 100% RDF with foliar spray of 1% urea phosphate can be recommended for higher productivity in the cotton-black gram cropping sequence.

Influence of City Waste Manure and Different Levels of Inorganic Fertilizers on Soil Health Parameter, Growth and Yield Attributes of Black Gram (Vigna mungo L.) in Inceptisols

Influence of City Waste Manure and Different Levels of Inorganic Fertilizers on Soil Health Parameter, Growth and Yield Attributes of Black Gram (Vigna mungo L.) in Inceptisols

Evaluation of Blackgram (Vigna mungo L.) Genotypes for Dry Matter Partitioning, Reproductive Efficiency and Yield under High Temperature Stress

Background: In the present climate change scenario, the rising temperatures are imposing severe threat to blackgram production leading to marked reduction in yield potential.The reduction in the yield potential is mainly due to reproductive failures caused by heat stress. Keeping this in view, the present study was carried out to find out the reasons behind reproductive failures and identify the genotypes that yield better under heat stress. Methods: Thirty blackgram genotypes selected from temperature induction response technique were evaluated for reproductive efficiency under natural high temperature conditions. Field experiment was conducted at Agricultural College Farm, Acharya N.G Ranga Agricultural University, Agricultural College, Bapatla. Dry matter partitioning, reproductive efficiency and yield traits were recorded at flowering and the data were analyzed statistically and pooled. Result: Genetic variability was observed among the blackgram genotypes with respect to dry matter partitioning, reproductive efficiency and yield traits under high temperature stress conditions. Among the 30 genotypes tested for thermotolerance, the genotypes TBG-129, PU-1804 and LBG-1015 were found to withstand high temperature stress at reproductive stage by possessing higher dry matter, number of flowers per plant, pollen viability, pollen germination percentage, pollen load on stigma, stigma receptivity, flower to pod setting percentage and higher yield. Correlation analysis revealed a strong positive association of total dry matter and all the reproductive efficiency characteristics with seed yield under heat stress conditions. The PCA results revealed considerable variability among the traits accounting for 86.6% of total variability. The genotypes TBG-129, PU-1804 and LBG-1015 can be potentially used as donors in the breeding programmes for the development of heat tolerant genotypes.

The chemical and microbiological safety of emerging alternative protein sources and derived analogues: A review.

Climate change and changing consumer demand are the main factors driving the protein transition. This shift toward more sustainable protein sources as alternatives to animal proteins is also reflected in the rapid upscaling of meat and dairy food analogues. Such changes could challenge food safety, as new food sources could result in new and unexpected food safety risks for consumers. This review analyzed the current knowledge on chemical and microbiological contamination of emerging alternative protein sources of plant origin, including soil-based (faba bean, mung bean, lentils, black gram, cowpea, quinoa, hemp, and leaf proteins) and aquatic-based (microalgae and duckweeds) proteins. Moreover, findings on commercial analogues from known alternative protein sources were included. Overall, the main focus of the investigations is on the European context. The review aimed to enable foresight approaches to food safety concerning the protein transition. The results indicated the occurrence of multiple chemical and microbiological hazards either in the raw materials that are the protein sources and eventually in the analogues. Moreover, current European legislation on maximum limits does not address most of the "contaminant-food" pairs identified, and no legislative framework has been developed for analogues. Results of this study provide stakeholders with a more comprehensive understanding of the chemical and microbiological safety of alternative protein sources and derived analogues to enable a holistic and safe approach to the protein transition.

Synthesis of a superabsorbent hydrogel from Artocarpus heterophyllus Lam seed polysaccharides and its application in relieving drought stress in plants

AbstractSustainability in agriculture can only be achieved by protecting important resources, one of them being water. Availability of water in the soil greatly influences agricultural productivity. Hydrogels play a key role in ensuring water availability and achieving agricultural sustainability. A novel superabsorbent hydrogel was synthesized from Artocarpus heterophyllus Lam seed polysaccharides. The synthesized hydrogel was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Swelling capacity of the hydrogel in different solutions, water retention duration, its influence on the soil water holding capacity (SWHC), and degradation in soil were assessed. The hydrogel absorbs up to 326 g/g and degrades naturally at around 1.4 wt% daily. The hydrogel improved the SWHC by 34% at a concentration of 0.3% w/w. Further pot experiments with black gram (Vigna mungo (L.) Hepper) plants showed that the superabsorbent hydrogel ensured water availability for 35 days and relieved the plants from drought‐induced stress. The data presented here indicates that the synthesized hydrogel can potentially be used as a soil conditioner for the sustained release of water and fertilizer.

Multi-GWAS reveals significant genomic regions for Mungbean yellow mosaic India virus resistance in urdbean (Vigna mungo (L.) across multiple environments.

Unraveling genetic markers for MYMIV resistance in urdbean, with 8 high-confidence marker-trait associations identified across diverse environments, provides crucial insights for combating MYMIV disease, informing future breeding strategies. Globally, yellow mosaic disease (YMD) causes significant yield losses, reaching up to 100% in favorable environments within major urdbean cultivating regions. The introgression of genomic regions conferring resistance into urdbean cultivars is crucial for combating YMD, including resistance against mungbean yellow mosaic India virus (MYMIV). To uncover the genetic basis of MYMIV resistance, we conducted a genome-wide association study (GWAS) using three multi-locus models in 100 diverse urdbean genotypes cultivated across six individual and two combined environments. Leveraging 4538 high-quality single nucleotide polymorphism (SNP) markers, we identified 28 unique significant marker-trait associations (MTAs) for MYMIV resistance, with 8 MTAs considered of high confidence due to detection across multiple GWAS models and/or environments. Notably, 4 out of 28 MTAs were found in proximity to previously reported genomic regions associated with MYMIV resistance in urdbean and mungbean, strengthening our findings and indicating consistent genomic regions for MYMIV resistance. Among the eight highly significant MTAs, one localized on chromosome 6 adjacent to previously identified quantitative trait loci for MYMIV resistance, while the remaining seven were novel. These MTAs contain several genes implicated in disease resistance, including four common ones consistently found across all eight MTAs: receptor-like serine-threonine kinases, E3 ubiquitin-protein ligase, pentatricopeptide repeat, and ankyrin repeats. Previous studies have linked these genes to defense against viral infections across different crops, suggesting their potential for further basic research involving cloning and utilization in breeding programs. This study represents the first GWAS investigation aimed at identifying resistance against MYMIV in urdbean germplasm.

Efficacy of combined seed dressing and foliar application of seaweed extract on yield and yield parameters of black gram (Vigna mungo L.)

Efficacy of combined seed dressing and foliar application of seaweed extract on yield and yield parameters of black gram (Vigna mungo L.)

Assessment of genetic variability in blackgram (Vigna mungo) under rainfed conditions of Jammu and Kashmir

Assessment of genetic variability in blackgram (Vigna mungo) under rainfed conditions of Jammu and Kashmir

Effect of urdbean (Vigna mungo) cultivars and phosphorus levels on dynamics of soil phosphorus fractions and enzyme activity

Effect of urdbean (Vigna mungo) cultivars and phosphorus levels on dynamics of soil phosphorus fractions and enzyme activity

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis

Selection efficiency of molecular markers associated to Yellow Mosaic Virus (YMV) tolerance and identification of donors for earliness, yield and YMV tolerance in blackgram (Vigna mungo (L.) Hepper) using GT Biplot analysis