​Agro-morphlogical and Quality Characters in two Summer Legume Crops: Mung Bean [Vigna radiata (L.) Wilczek] and Guar [Cyamopsis tetragonoloba (L.) Taub] Genotypes Grown in Mediterranean Climate Conditions

Mung bean (Vigna radiata L.) is a pulses crop orginated in Asia. It is widely grown in Asia, Africa, North America, and Australia (Singh et al., 2011). Mung bean seed has high protein, carbonhydrates, vitamin A and B (Gunathilake et al., 2016; Abdul Rahman, 2018). Grain of mung bean can be used as a food for human and feed for livestock and green manure at the world (Nair et al., 2021).
 
Cluster bean (Cyamopsis tetragonoloba) is known commonly guar. Guar or cluster bean is annual legume with tolerant to drought originated from Asia (Singla et al., 2016; Nandini et al., 2017). Guar is generally grown for grain and it has 40-45% of embryo, 14-16% of seed coat and 38-45% of endosperm in total seed (Gresta et al., 2016). Guar gum, which is polysaccharide (glactomannans) provided from seed of guar, is mainly used as a thickening and stabilizing in foods (Jukanti et al., 2015). It is used as a vegetable in human food, green manure, seed for human animal food, paper manufacturing and cosmetics (Mudgil et al., 2014). Yousif et al., (2017) reported that guar lines contain 10.53-11.83% fiber, 25.80-30.52% protein, 43.8-48.7% carbonhydrates.
 
Spreading mung bean and guar cultivation in Turkey is very important for their wider usage area and economical value. The studies on these crops are quite limited in Cukurova region. It is important to evaluate their different cultivars for production potential and nutritional quality. Cukurova region has a typical Mediterranean climate conditions.  Therefore it can be possible to grow mung beanand guar during the spring- summer period in crop rotation.
 
The aim of present study was to investigate grain yield, yield components and quality parameters for some guar and mung bean genotypes.

The field of study for mung bean and guar carried out in the Research Area of Field Crop Deparment, Faculty of Agriculture, University of Cukurova under irrigated conditions (Balcali) in Adana, Turkey, throughout 2016 and 2018. Adana province has typical Mediterranean climate conditions. Total precipitation is 625 mm and mean temperature is 18.7°C according to long-terms in Adana. The experiment soil was sandy-loam type textures. The values of pH and salt were 7.85 and 0.25 mmhos cm^-1, respectively.
 
The field experiment was conducted to randomized complete blocks design (RCBD) with three replications. In this experiment, 5 exotic mung bean genotypes [VC6153 (B6)- Taiwan, NM54-Taiwan, NIMB51- Bangladesh, KPS-1-Thailand and VC6173 (B6)-Taiwan] were used as plant material. These mung bean lines were provided from Field Crop Department, Faculty of Agriculture, University of Ondokuz Mayis. The plots were sown at rows of 4 m and 4 rows. The rows were spaced 45 cm apart and 5 cm plant to plant distance in rows. The experiment was established on 21 April 2016 in the first year and 18 April 2018 in the second year. Field emergences were recorded on 30 April 2016 and on 2 May 2018. The plots were harvested on 1 September 2016 and on 28 Agust 2018. 
 
In this study, 5 guar lines [28 (Pakistan -12), 37 (India- 17), 45 (India Guajerat population No. 5), 76 (India Guajerat population No. 30), 91 (India Guajerat population No. 50] were used as material. These guar lines were selected for seed-type from the guar populations at Field Crop Department, Faculty of Agriculture, University of Canakkale Onsekiz Mart. The field experiment was organized in randomized complete block design (RCBD) with three replications. Each plot was planted in rows of 4 m lenght and 4 rows with a spacing of 45 cm between rows. Plant to plant distance in row was 10 cm. The experiment for guar was established on 19 April 2016 and on 17 April 2018. Field emergences were recorded on 30 April 2016 and on 2 May 2018. The plots were harvested on 4 October 2016 and on 30 Agust 2018. 
         
The fertilizer was applied a rate of 50 kg N ha^-1 and 50 kg P₂O₅ ha^-1 before sowing. 5 kg N ha^-1 as ammonium nitrate (33% N) was also applied in seedling stage and the plots were watered 3 times during the summer in both of the experiment.
       
Plant height (cm), number of branches per plant, number of pods per plant, number of grains per pod and grain weight per plant (g) were recorded on five plants that were randomly selected from each plot. 1000grain weight (g), grain yield (kg ha^-1) and harvest index (%) were also measured. Nitrogen contents were determined by Kjeldahl method (AOAC, 2000). Crude protein, fat, dry matter, ash, ADF and NDF content (%) were also determined by methods (AOAC, 2000; Van Soest et al., 1991).
       
The data for morphological and quality traits were analysed according to the RCBD over the years using the MSTAT-C data analysis software. Comparisons among the means were made using LSD multiple range test at 0.05 probability.

Mung bean trial
 
The highest plant height was found for NIMB51 (71.3 cm), while the lowest value was recorded for NM54 (60.8 cm)  in the mean of two years (Table 1). Peksen et al., (2015) reported that plant height varied from 39.95 to 72.08 cm. However, Canci and Toker (2014) found that plant height were between 19.5 and 91.0 cm. Plant height was higher in the first year due to greater rainfall and low temperature in the vegetative stage (May) as compared to the second year.
 

 
Pods per plant ranged between 16.4 and 23.6 as mean of years (Table 1). Pods per plant due to greater rainfall and temperature during the flowering stage (Early June - Early July) in 2016 was slightly lower than 2018. Similar results by Singh et al., (2011) were reported that pods per plant of mung bean genotypes was between 22.8 and 26.3 depending on plant densitity. However, various studies reported that pods per plant varied from 8 to 62 (Taj et al., 2003; Canci and Toker, 2014) depending on genotype and plant densitity. The highest value for grains per pod was obtained from NIMB51 (10.7), while the lowest one was with KPS1 (9.4) (Table 2). Grains per pod due to higher temperature and high rainfall in flowering stage in 2016 were lower than 2018 as in pods per plant. Similarly to our findings, some previous studies reported that grains per pod of the mung bean ranged from 9.3 to 12.0 (Ahmad et al., 2004; Peksen et al., 2015; Khan et al., 2017).   
 

       
As the mean of years, maximum 1000-grain weight was determined in KPS1 (76.6 g), whereas the lowest value was with NIMB51 (51.7 g) (Table 2). Similarly to our study, Canci and Toker (2014) indicated that 100-grain weight varied from 3.1 to 8.6 g. However, 1000-grain weights obtained in this study were greater than values reported by some previous studies. Thus, Taj et al., (2003) found that 1000-grain was weight between 26.42 and 28.09 g. Khan et al., (2017) reported that 1000-grain weight of mung bean genotypes ranged from 42.60 to 55.60 g.        
       
Grain yield varied from 2344 to 3141 kg ha^-1 in the average of years (Table 2). The greatest grain yield was produced by genotype KPS1 and the lowest one was obtained from VC6153(B6) in 2018 and combined year. Previous studies showed that grain yield varied between 793.33 to 3120 kg ha^-1 (Achakzai and Taran, 2011), 2022.2 to 3401 kg ha^-1 (Khan et al., 2017) and 933 to 983 kg ha^-1 (Ahmad et al., 2004). Grain yield is also often limited by temperature and rainfall distribution (Khan et al., 2017).  Present study showed that the genotypes with high 1000-grain weight had higher grain yield capacity. Similarly to our finding, Nandini et al., (2017) indicated that the higher grain yield may be attributed to yield components such as pods number, 100-seed weight and grains per pod.
       
The highest value for crude protein was found by genotype VC6153B6 with 27.4%, 23.3% and 25.3%  in 2016, 2018 and the average years, respectively (Table 3). The lowest value was obtained from NIMB51 with 22.9%, 21.0% and 21.9% in 2016, 2018 and combined years, respectively. Crude protein content in present study was similar to values of 24.52% recorded by Abdul Rahman (2018). However, it is explained in the previous studies that protein contents of mung bean varied from 24.0 to 28.0% (Adel et al., 1980).  
 
        
          
Ash content varied between 2.6% and 3.4% in the average of two years (Table 3). Adel et al., (1980) reported that ash content varied from 3.37% to 4.05%. However, Gunathilake et al., (2016) point out higher ash content (3.96%) than the values obtained in the present study.  Ash content indicates that grain provides essential minerals (Abdul Rahman, 2018).
        
As average of two years, genotypes were found to be significant for ADF content (Table 4). The highest value was achieved by genotype KPS1 (34.6%), followed by NIMB51 and VC6173, while NM54 had lowest value with 30.8% for ADF in combined years (Table 4).
 

     
NDF content ranged between 42.1-51.9% in 2018 and 41.3-49.7% in mean of the years (Table 4). The greatest NDF content was recorded in genotype NIMB51 and the lowest one was obtained from NM54 in 2018 and combined year. Nair et al., (2021) reported that ADF and NDF content of mung bean seed found between 18.3-33.4% and 24.5-45.0%, respectively. This trait was significantly affected by years. NDF content was lower in the first year compared with the second year.

Guar trial
 
The highest plant height was obtained from genotype 37 (110.1 cm), while the lowest one was found in genotype 91 (80.2 cm) in combined years (Table 4). Mahmood et al., (1988) reported that plant height was between 163.8 cm and 168.63 cm, but Khalid et al., (2017) indicated from 72.0 to 234.4 cm. This showed that plant height can vary according to the genotypes and environmental conditions.
       
Pods per plant varied from 39.6 (genotype 37) to 71.2 (genotype 28) in 2018 and from 32.2 (genotype 37) to 48.6 (genotype 91) in the average of years (Table 5). The pods per plant recorded in the second year were significantly higher the first year. The pods per plant in guar genotypes are in agreement with the values recorded by Singla et al., (2016) (34.9-49.3 pods plant^-1).  However, Mahmood et al., (1988)  indicated in the range of 55.93-77.63 pods plant^-1 for this trait. Grains per pod varied between 6.8 (genotype 28) and 7.7 (genotype 37) in combined years (Table 6). Genotype 37, 76 and 91 had higher grains per pod as compared to another genotypes in both of the years. However, the lowest value was obtained from genotype 28 in both of the years. Earlier studies revealed that grains per pod of guar genotypes varied from 5.2 to 11.4 (Khalid et al., 2017) and 3.7 to 4.4 (Singla et al., 2016). Higher temperature and rainfall during the flowering stage in June and July in the first experimental year may have decreased the grains per pod.      
 

 

    
1000-grain weight varied from 31.5 to 38.0 g in 2018 and 31.0 to 35. 9 g in combined years (Table 6). The highest value was indicated from genotype 37, while the lowest one was obtained from genotype 91 in 2018 and combined years. Similarly results to our study, Ton and Anlarsal (2018)  exhibited that 100-grain weight was ranging from 3.4 to 3.5 g. Mahmood et al., (1988)  indicated that 1000-grain weight was ranging from 33.50 to 35.30 g. 1000-grain weight may decrease depending on higher temperature occured during the seed filling stage in July of 2016.
       
Grain yield varied from 1561 to 2354 kg/ha in combined year (Table 6). Genotype 45 had the highest grain yield followed by genotype 91, while the lowest grain yield was found for genotype 37 in both the years. Previous studies reported that grain yield was recorded between 1117-1162 kg ha^-1 (Singla et al., 2016) and 1650-2065 kg ha^-1 (Mahmood et al., 1988). However, some studies indicated that lower grain yield was obtained in guar. Thus, Ton and Anlarsal (2018) reported between 569-678 kg ha^-1 and Nandini et al., (2017) exhibited between 524.50-743.89 kg ha^-1. It was shown that grain yield was might be due to different environmental conditions, genotypes and growing techniques. The grain yield may decrease depending on the higher temperature and rainfall during the flowering stage (June and July) in 2016 as in other yield components (Singla et al., 2016).               
    
Dry matter was affected by genotypes in the first year, but not in the second year and combined years (Table 7). The effect of genotypes was not significant on crude ash in both of the years and combined years. According to combined years, dry matter and crude ash in guar ranged from 90.3% to 90.7 and 4.8 to 5.0%, respectively.                           
          
In the guar genotypes crude fat content ranged from 3.8% (genotype 37) to 4.6% (genotypes 76 and 91) and crude protein content was varied from 33.2% to 35.3% in the average years (Table 8). The effects of years and genotype × year interaction were not significant for crude fat and protein content. In this study, protein content was slightly higher than the values found by Nandini et al., (2017), who explained a range from 29.75% to 30.75%. The chemical composition contents obtained in the present study are slightly higher than the range of 25.80-30.52%  protein, 1.93-2.47 oil, 8.37-8.80% moisture, 3.33-3.80% ash reported by Yousif et al., (2017). Sharma et al., (2017) reported that maximum protein and ash content in guar genotypes were 26.78 and 5.29% respectively. The differences in the chemical composition may be affected by genetic factors and environmental conditions as in reported by Yousif et al., (2017).

The results of present study showed that mung bean genotypes KPS1, VC6173, NM54 and guar genotypes 45, 91 had a great grain production potential and high quality traits for growing in summer period under in the Mediterranean climate conditions. The mentioned promising genotypes should be tested in diverse environment of Mediterraenean region in Turkey. Further, the studies relation to growing techniques should be carried out in mentioned mung bean and guar genotypes. Another genotypes also should be tested in this region.