Background: Dolichos bean (Dolichos lablab L.), 2n = 22 is an important leguminous vegetable crop which provides protein, minerals and vitamins. The exploitation of variability is of great importance and is a prerequisite for the effective screening of superior genotypes. Keeping this in view, the present investigation was carried out to assess the variability and correlation for yield and other components which are useful to select the promising genotypes.&nbsp; 
 
Methods: The study on variability and correlation in Dolichos Bean genotypes for yield and quality was conducted at the College Orchard, Tamil Nadu Agricultural University, Coimbatore. Twenty lablab genotypes, sourced from various locations, were planted in a randomized block design with three replications during the kharif and rabi seasons of 2021 and 2022. Observations on growth, yield and quality traits were recorded and analysed for variance, variability and correlations. 
 
Result: In the kharif season, Ankur Gold yielded the highest green pods per plant (487.50 g), while Acc.7 yielded the lowest (89.59 g). In the pooled analysis, Ankur Gold (469.80 g) had the highest and Acc.6 (87.49 g) had the lowest green pod yield per plant. The study suggests using a selection index based on the number of racemes per plant, raceme length, number of pods per plant, green pod yield per plant and pod length to identify high yielding lablab genotypes.

Variability and Correlation Studies in Dolichos bean (Dolichos lablab L.)

<div>The field experiment was conducted at Kittur Rani Channamma College of Horticulture, Arabhavi, during 2016-17 and 2017-18 to investigate the effect of different levels of nitrogen (0 and 25 kg/ha), phosphorus (0, 50 and 75 kg/ha) and potassium (0, 25 and 50 kg/ha) on growth, flowering, yield and economics of dolichos bean. The experiment was laid out in factorial randomized block design comprising of eighteen treatments replicated thrice. Among indivisual NPK levels, the higher level of nitrogen (25 kg N/ha), phosphorus (75 kg P2O5/ha) and potassium (50 kg K2O/ha) recorded significantly maximum growth (plant height, number of primary and secondary branches, leaf area and dry matter content per plant at harvest), early flowering (except N2 level) and pod yield (162.32, 184.14 and 164.75 q/ha) as compared to lower levels in 2016-17 and 2017-18 growing seasons and pooled data. Similarly, amongst all NPK interaction levels, higher fertilizer dose of 25-75-50 kg N-P2O5-K2O/ha recorded significantly maximum growth parameters however, it was at par with 25-75-25 kg N-P2O5-K2O/ha except dry matter content per plant during both the experimental years. Pooled data followed similar trend. On pooled basis, recommended fertilizer dose (25-50-25 kg N-P2O5-K2O/ha) showed early days to 50 percent flowering whereas pod yield (198.44 q/ha) was recorded maximum at higher fertilizer dose (25-75-50 kg N-P2O5-K2O/ha). Similarly, in case of economics, higher fertilizer dose of 25-75-50 kg N-P2O5-K2O/ha recorded highest benefit: cost ratio (5.27) during both the experimental years as well as in pooled data but it was at par with 25-75-25 kg N-P2O5-K2O/ha. Hence, for profitable cultivation of vegetable type dolichos bean in northern transition zone of Karnataka, NPK fertilizer must be applied at the rate of 25-75-25 kg N-P2O5-K2O/ha.&nbsp;</div>

<div>Effect of Nutrient Levels on Growth, Yield and Economics of Dolichos Bean (Dolichos lablab L.) in Northern Dry Zone of Karnataka, India</div>

<div style="text-align: justify;">Thirty five genotypes of dolichos bean germplasm lines were evaluated for genetic divergence, variability, heritability and genetic advance at Vegetable Research Station, Agriculture Research Institute, Rajendranagar, Hyderabad during August, 2016 to March, 2017. Thirty five genotypes were grouped into six clusters based on the relative magnitude of D2 values. The highest number of genotypes (15) appeared in cluster II. The maximum inter cluster distance was observed between cluster III and cluster VI (D2=1780.19).The minimum inter cluster distance was observed between cluster II and cluster IV (D2 =333.46). Maximum intra cluster distance was in cluster IV (D2=249.64). Among the characters, the maximum contribution towards divergence was made by pod yield per plant (26.21%). High heritability estimates were observed for 15 characters and medium heritability was observed for primary branches per plant, number of seeds per pod, seed breadth and 100 dry seed weight. High genetic advance along with relatively high heritability percent were observed for vine length, days to first flowering, pod length, pod width, pod weight, number of pods per plant, seed length, seed breadth, 100 fresh seed weight, protein content, fibre content and pod yield per plant. Hence, due weightage should be given to the above traits, while selection is practiced for multilocation trails improvement of varieties.</div>

<div style="text-align:justify">Genetic divergence, variability, heritability and genetic advance for growth, pod quality and yield characters in dolichos bean (Dolichos lablab L.var. typicus Prain) germplasm</div>

Background: Dolichos bean [Dolichos lablab (Roxb.) (L) Var. typicus] is one of the most important leguminous vegetable crops cultivated in tropical plains of India. The mature and immature pods are rich in protein, minerals and vitamins. Most of the pole types of dolichos beans are photosensitive in nature, suited for growing in specific season like kharif and not productive when grown in summer season. Different cultivars of Dolichos bean require different seasons for getting maximum yield. With this background, studies on seasonal influence on growth and yield of dolichos bean genotypes were carried out.&nbsp;&nbsp; 
 
Methods: An experiment was conducted to assess the effect of season and genotypes in Dolichos bean. The experiment was laid out in factorial randomized block design with nine treatment combinations and four replications. In this study, three genotypes of dolichos bean viz., CO 1, Dbp-3 and Dbp-4 were sown during kharif, rabi and winter seasons.&nbsp;&nbsp; 
 
Result: The main and interaction effects on genotypes and season of sowing had a significant influence on green pod yield, crude fibre, crude protein and total dry matter production. The genotype Dbp-3 sown during kharif season recorded the highest values for green pod yield (23.43 t.ha-1), crude protein (5.99%), dry matter production at various stages of growth (65.9, 254.3, 305.8, 359.2, 389.8 and 418.0 g.plant-1 at 30, 60,90,120,150,180 days after sowing respectively) and it was significantly different from all other treatments. The same treatment i.e., genotype Dbp-3 sown during kharif season was recorded the lowest amount of crude fibre content (1.53%).

Studies on Seasonal Influence on Yield and Quality of Dolichos Bean Genotypes

<div>A field experiment was conducted to investigate the effect of different N, P and K levels on growth, yield and quality parameters of edible poded dolichos bean at Kittur Rani Channamma College of Horticulture, Arabhavi, during the growing period of 2016-17 and 2017-18. The nitrogen (0 and 25 kg/ha), phosphorus (0, 50 and 75 kg/ha) and potassium (0, 25 and 50 kg/ha) were applied in eighteen different combinations. Among indivisual NPK levels, the higher level of nitrogen (25 kg N/ha), phosphorus (75 kg P2O5/ha) and potassium (50 kg K2O/ha) recorded significantly maximum growth (plant height, number of primary branches, number of leaves), pod yield (162.32, 184.14 and 164.75 q/ha) and quality parameters (fiber, sugar and protein) of dolichos bean compared to lower levels in both the years (2016-17 and 2017-18) and pooled data, respectively. Similarly, among NPK interaction levels, higher fertilizer dose of 25-75-50 kg N-P2O5-K2O/ha (T18) registered the highest value for growth and yield parameters but it was on par with 25-75-25 kg N-P2O5-K2O/ha (T17) for all the characters except number of leaves and days to crop maturity during both the experimental years as well as in pooled data. Therefore, for obtaining high yield with good nutritive value, NPK fertilizer must be applied at the rate of 25-75-25 kg/ha under the Arabhavi (Karnataka) condition.</div>

<div>Studies on Growth, Yield and Quality of Edible Poded Dolichos Bean As Affected By NPK Fertilization</div>

<div>Background: Dolichos bean occupies a unique position among the legume vegetables of Indian origin for its high nutritive value and wider climatic adaptability. Despite its wide genetic diversity, no much effort has been undertaken towards genetic improvement of this vegetable crop. Knowledge on genetic variability is an essential pre-requisite as hybrid between two diverse parental lines generates broad spectrum of variability in segregating population. The current study aims to assess the genetic diversity in dolichos genotypes to make an effective selection for yield improvement. 
 
Methods: Twenty genotypes collected from different regions were evaluated during year 2016-17 and 2017-18. Data on twelve quantitative traits was analysed using principal component analysis and single linkage cluster analysis for estimation of genetic diversity. 
 
Result: Principal component analysis revealed that first five principal components possessed Eigen value &gt; 1, cumulatively contributed &gt; 82.53% of total variability. The characters positively contributing towards PC-I to PC-V may be considered for dolichos improvement programme as they are major traits involved in genetic variation of pod yield. All genotypes were grouped into three clusters showing non parallelism between geographic and genetic diversity. Cluster-I was best for earliness and number of cluster/plant. Cluster-II for vine length, per cent fruit set, pod length, pod width, pod weight and number of seed /pod, cluster III for number of pods/cluster and pod yield /plant. Selection of parent genotypes from divergent cluster and component having more than one positive trait of interest for hybridization is likely to give better progenies for development of high yielding varieties in Dolichos bean.</div>

<div>Genetic Diversity Assessment in Dolichos Bean (Lablab purpureus L.) Based on Principal Component Analysis and Single Linkage Cluster Analysis</div>

<div>Background: Legume pod borer, Maruca vitrata (Fabricius), infests the Dolichos bean throughout the cropping season. However, there is no information on the seasonal abundance of M. vitrata over different seasons on Dolichos bean, which is an essential tool for forecasting and developing integrated pest management strategies.&nbsp; 
 
Methods: The seasonal abundance of M. vitrata on Dolichos bean were studied during three consecutive cropping seasons of 2019 Summer, Kharif and Rabi. The larval population in flowers and pods and the number of larval webbings and weather parameters were recorded and subjected to correlation and multiple linear regression analysis. 
 
Result: The overall larval abundance was observed to be higher in flowers than in pods. The highest larval abundance in flowers and pods was 14.60 and 13.40 during the 48th and 50th standard meteorological week (SMW) of Rabi 2019 respectively, which corresponds to 8 to 10 weeks after sowing (WAS) in flowers and 10 to 12 WAS in the case of pods. The number of larval webbings was higher, with 18.76 during the 49th SMW of Rabi 2019. The maximum temperature had a significant negative correlation with the larval abundance in flowers (r= -0.570), pods (r= -0.523) and the number of active webbings (r= -0.477). At the same time, the regression coefficient shows that rainfall had a significant negative influence on the larval abundance in pods (B= -1.26).</div>

Influence of Weather Parameters on the Seasonal Abundance of Legume Pod Borer Maruca vitrata (Crambidae: Lepidoptera) on Dolichos Bean (Lablab purpureus var. typicus)

<div>Background: Dolichos bean is one of the important vegetable legume crops. During storage, protection of seed from bruchid attack is a major problem worldwide. Once the bruchid attacks, the extent of damage could be up to 100%, leading to both quantitative and qualitative loss by making it unfit for consumption. Existing traditional methods are less effective or impractical and the use of chemical methods can be harmful to the farmers and consumers. So, there is urgent need of hermetic storage method for seed quality maintenance. Keeping in view, the present study was carried out to investigate on hermetic storage practices for seed quality maintenance. 
 
Methods: Triple-layer PICS technology, a chemical-free hermetic storage was evaluated for storage of dolichos bean to moisture content, germination and quality. Four different types of storage bags viz., jute bags, polythene bags, triple layer PICS bags and jute bags treated with chlorpyrifos were used for evaluating their efficacy in managing dolichos bean seed attributes. The data on various parameters pertaining to seed characteristics and changes in biochemical composition of dolichos bean seeds stored in different bags was recorded at every two month intervals for 3 times (2,4, and 6 months) by using standard protocols. Complete Randomized Design (CRD) (Snedecor and Cochran, 1967) was used for the data analysis. The data was subjected to statistical analysis as per the methods suggested by Panse and Sukhatme (1985).&nbsp; 
 
Result: Results on moisture content showed that, in case of storage in PICS bags, there was no decrease in seed moisture content at 2, 4 and 6 months respectively and germination percent in triple-layer PICS bag at 2, 4 and 6 months storage was highest among all bag types. Test weight (g), protein content (%) and&nbsp; carbohydrate content (%) at 2, 4 and 6 months storage respectively were higher in triple layer PICS bag. The mean fat content recorded was highest in jute bag (1.25%) and lowest in triple layer PICS bag (0.63%). Our study concludes that the triple layer PICS bags hermetic technology is efficient in managing maintaining same level of moisture content percent, germination percent and test weight compared to other bags over 3 different periods of storage. The triple layer PICS bags are also highly useful for retaining carbohydrate percent and protein percent at almost the same levels compared to initial values.&nbsp;</div>

​​Effect of Hermetic Storage on Seed Quality Maintenance of Dolichos Bean [Lablab purpureus (L.) var Typicus Prain]

<div>Background: Assessment and molecular characterization of genetic diversity among the Dolichos lablab (L.) have huge implication in scheming strategies for breeding. In India, there is less comprehensive information on the potential genetic diversity of lablab bean and this is a major challenge for systematic use of lablab bean in genetic breeding programs. To exploit the available trait of interest, the genetic diversity of the locally available genotypes must be known. The PCR-based SSR approach requires just nanogram amounts of template DNA, subjected to quick detection and less influenced by environment. In this manner SSR have been utilizing broadly to study hereditary assorted qualities of yields. 
 
Methods: In this study, genetic diversity on ten Indian Dolichos lablab (L.) genotypes were surveyed utilizing SSR markers at Department of Botany, Bundelkhand University, Jhansi during 2019-20 got from Indian gene bank. For SSR analysis, 5 primers were used for checking the diversity in Dolichos lablab (L.) and the performance of markers were measured by using 4 parameters (1) PIC, (2) Mean resolving Power, (3) Resolving Power and (4) MI.&nbsp; 
 
Result: SSR (05) markers produced a total of 51 bands, out of which 45 bands (88.23%) were polymorphic which varies from 6 (Primer-111) to 15 (Primer-AGB-9) with mean of 10.5 bands per primer. The polymorphic information content value ranges from 0.265 to 0.488 with a mean value of 0.390. The value of Matrix index is 3.2. The value of resolving power ranges from 2.2 to 12.60 with a mean value of 7.40. In the UPGMA dendogram, the 10 genotypes were separated into two main clusters with all the primers used. Our present examination uncovered that genetic markers might be effectively used for deciding hereditary variety and connections in Dolichos lablab (L.) genotypes and could be utilized as a part of breeding programs.</div>

<div>Simple Sequence Repeats Marker based Detection of Genetic Diversity of Indian Bean Dolichos lablab (L.) of Family Fabaceae</div>

<div>Background: Dolichos bean is an important leguminous vegetable having a wide range of variation in different quantitative characters. Assessing genetic diversity among dolichos bean accessions can ensure development of suitable high-yielding and adapted varieties with suitable maturity period.&nbsp; 
 
Methods: Fifteen genotypes were evaluated for different characters in Dolichos bean at two locations of Dr. Rajendra Prasad Central Agricultural University viz. Vegetable Research Farm, Pusa and Krishi Vigyan Kendra, Birauli, Samastipur, Bihar during the year 2018-19 and pooled data was analyzed. The genotypes were evaluated for genetic variability and genetic divergence for 14 characters. For the assessment of genetic diversity among the fifteen genotypes of dolichos bean, Mahalanobis (D2) statistic (Mahalanobis, 1936) was used, following the procedure given by Rao, 1952. Grouping of genotypes into clusters was done using Tocher&rsquo;s method as described by Rao, 1952. 
 
Result: Phenotypic Coefficient of Variation (PCV) was slightly higher than Genotypic Coefficient of Variation (GCV) for all the characters indicated that the characters were less influenced by environment. The characters having high heritability and high genetic advance include harvesting duration, number of pods per plant, pod length, pod diameter, individual pod weight, weight of seeds per pod, 100 fresh green seed weight, pod yield and percent incidence of yellow mosaic virus. Therefore, selection for above characters is highly effective. Genetic diversity analysis evaluated that all genotypes could be placed into 6 clusters. Genotypes grouped in Cluster III and I have highest mean value for all characters as well as highest inter-cluster distance.&nbsp;&nbsp;</div>

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