Determining the Adaptability and Exploring the Potential of Some Soybean [Glycine max (L.) Merr.] Varieties Advance Lines under the Climatic Conditions of South-Eastern Region of Turkey

A field experiment was carried out to determine yield and yield components of the soybean varieties at Gundas Research Station (Situated on latitude 36°44' N, longitude 36°48' E) of the Directorate of GAP Agricultural Research Institute Sanliurfa, Turkey during 2017 and 2018. The sandy clay soil with pH 7.8 and organic carbon of 1.1% down all profiles (Table 1). Soybean genotypes were used including 9 cultivars (Arisoy, Adasoy, Ataem-7, Sa-88, Atakisi, Umut-2002, Nova, Bravo, Gapsoy-16) and 5 pure lines (KA08-03, Ka08-06, KA08-07, KA08-08,KA08-09). The experiment was laid out in randomized complete block design (RCBD) with 4 replications. The plot size allocated to each treatment was 14 m2 (5 m × 2.80 m). Each plot consist of 4 rows equally spaced at 70 cm. Un-inoculated soybean seeds were sown on May 20 in both years. 
 

 

 
A basal dose of compound fertilizer (20:20:0 NPK) @ 300 kg/ha was spread in experimental field at the time of sowing. After the second irrigation, inter row manual hoeing was carried out followed by application of ammonium sulphate @ 300 kg/ha. The data regarding different parameters including days taken to days taken to flower initiation In this observation, beginning bloom is defined to be when 50% of the plants have an open flower at any node, beginning seed when 50% of the plants have a seed that can be felt when any pod is squeezed, (days), days taken to physiological maturity when 50% of the plants have yellow leaves, (days), growing degree days. Growing degree day was worked by using a base temperature of 100°C. The sums of HTU for particular phenophases of interest determined by multiplying degree days with actual bright sun shine hours (days) Kaushik et al., (2015), plant height at harvest (cm), pods per plant, 1000 grain weight (g), grain yield kg da^-1), crude oil (%) and protein (%) were recorded during the course of study. The research data were analyzed for Analysis of Variance (ANOVA), while the data regarding grain yield kg da^-1), crude oil (%) crude protein (%) were also subjected to combined analysis of variance due to the homogeneity in residual variances of both years. The means were compared through Least Significant Difference (LSD) test and statistical package MSTATC 2.10 was used. For correlation and cluster analysis R versions 3.5.1 (R 2013) was used.

Soybean is a short-day plant and both photoperiod and temperature control the duration of the whole crop cycle (Zhang et al., 2001).  In the Table 3, the variety Adasoy has shortest period (32 days) for flower initiation while the Umut-2002 has longest (38 days). Rest of the material was found intermediate towards flowering habit. David (2010) reported that the flower initiation was more to variety-specific. Physiological maturity is reached when roughly 95% of the pods colour turn to brown, golden, yellow, or gray depending on the variety (Diniz et al., 2013). Adasoy had a shortest time (105 days) of physiological maturity while Atakişi has longest time of 121 days (Table 3). The Adasoy has the least (2133 days) growing degree days while the Sa-88, Umut-2002 and Atakisi were significantly at par with respect to long growing degree days of 2321, 2323 and 2337, respectively. de Wit, 1967 found that the longer growing seasons result in higher potential crop production, when temperature was suitable for plant growth. Similar result were found by Miladinovic et al., (2006) varieties vary in their growing days, longer this duration higher will be the yield and vice versa. Arshad et al., (2006) and Kumar et al., (2019)  also reported significant correlation of grain yield with days to maturity, number of branches per plant and 100-seed weight. The highest number pods per plant in the years’ means i.e. 87.8 and 83.8 were recorded in KA08-06 and KA08-03, respectively. Arslan et al., (2018) reported similar results that in their terms of two-year averages similar results that variety Ataem 7 has lowest number of pod per plant than rest of genotypes studied. The 1000-grain weight particularly explain the thickness and heaviness of the seed produced by each genotype. In the years’ mean Sa-88 has the highest value (184.3) of 1000 grains although same variety was having the least number of pods per plant. It was clearly understood that this variety had bold grain than rest of the genotypes under study. Arslan et al., (2018) reported explained that significant differences in grain size within and between years can be attributed to the effect of different climate conditions between years. These results are  in  agreement  with  the  studies  carried  out  by Yýlmaz et al., (2005), Bayraktar et al., (2007), Copur et al., (2009) and Kai et al., (2020). In Table 3, the years’ mean data showed that the variety Sa-88 and advance line KA08-03 were statically similar with highest yield (3705 and 3660 kg/ha) among the others. It is quite encouraging that new stuff was finding its place among the top existing material.Bravo had the least grain yield (2267 kg/ha) though it was having the highest biological yield. It might be used for other purposes rather grain, in future. Fried et al., (2019) found that genotypes and irrigation had significant effects on seed yield of soybean genotypes.
 

 
According to Cunha et al., (2001) the regions where soils have lower water retention capacity, is the most susceptible to loss of yield due to water deficiency. The advanced soybean line KA08-06 has the highest harvest index (41.72%), while the least value (26.40%) was observed in Arisoy. Rest of the genotypes were intermediate in their performance. The table showed that the highest percentage conversion to yield were recorded in advanced line rather old ones. Krisnawati and Adie (2015) observed the similar results where a huge variation in harvest index (ranging from 31 to 44%) among the soybean genotypes was calculated. Karnwal and Singh, (2009), Namdari and Mahmudi (2013), as well as, Iqbal et al., (2003) also reported the meaningful correlation between seed yield and other four attributions including harvest index. The results in the similar fashion demonstrated that high harvest index is the key high-level of yield soybean with is reachable only by allocation of most of the photosynthaste into reproductive organs (Kumudini et al., 2002; Shadakshari et al., 2014: Jain et al., 2017).In the years’ means value of soybean getnoypes the highest percentage of oil contents (21.43) were observed in KA08-08 statistically at par Bravo (21.16%) and Ataem-7 (21.09). While the least oil contents (18.20%) were recorded in KA08-07. Ilker et al., (2018), the researchers from Turkey, found similar results in the indigenous and exotic genotypes that the average oil content of soybean genotypes ranged between 18-22%. Seed oil and protein contents are dominantly dictated by cultivar selection and maturity group (Kane et al., 1997) and environmental (Robinson et al., 2009) during the reproductive phases of growth, particularly R5 to R6. Similar result were observed by Santos et al., (2010) that there was significant difference between the cultivars in term of protein contents. From the Table 4 it is quite clear that days taken to flowering was positively correlated to the days taken to physiological maturity, growing degree-days and plant height. Moreover, it is was also positively correlated to 1000 grain weight. Days taken to physiological maturity is extremely positively correlated (0.99) to growing degree-days. Astonishingly plant height had negatively correlation with pods per plant. 1000 grain weight was positively correlated to grain yield. The means comparison of genotypes, environment and their interaction is represented in Table 6, after combined analysis. The table showed that experimental years were statistically similar regarding yield, crude oil and protein %. This information depicts that metrological conditions were quite similar during years of study or the variation in meteorological data had non- significant effects on yield and quality of soybean. With respect to grain yield (kg/ha) the cultivar Sa-88 (3705) was at par with the upcoming variety KA08-03 (3660), while the cultivars Ataem-07 (2476) followed by Arisoy (2521) were found least suitable for the region.
 

 
From this study it came to know that the main traits having positive correlation to grain yield are plant height, 1000 grain weight and GDD. Same finding were observed by Copur et al., (2009) and Tayyar (2007). Haliloglu et al., (2007) and Kumar et al., (2019) also reported that seed yield showed positive correlation with days of flowering, plant height and number of grains per plant. The means comparison of genotypes, environment and their interaction is represented in Table 5, after combined analysis. The results showed that experimental years were statistically similar regarding yield, crude oil and protein %. This information depicts that metrological conditions were quite similar during years of study or the variation in meteorological data had non significant effects on yield and quality of soybean. With respect to grain yield kg da^-1) the cultivar Sa-88 (3705) was at par with the upcoming variety KA08-03 (3660), while the cultivars Ataem-07 (2476) followed by Arisoy (2521) were found least suitable for the region. The crude oil (%) was found highest (22.08) in KA08-08, an upcoming variety that might be due to inherit genetic make up to be well expressed under the climatic conditions of Sanliurfa. While the genotype KA08-07 was consistently found least in crude oil (%) i.e. 18.19 and 18.20 for the years 2017 and 2018, respectively. Interestingly the cultivars like Arisoy, Adasoy, Ataem-7, Sa-88, Atakisi and Gapsoy-16 were found high in protein contents (%), as shown in the Table 5, than the upcoming soybean varieties like KA08-09, KA08-08 and others.It was revealed from the above results that ultimate objectives of raising soybean, like yield, crude oil or protein (%), will determine the selection of cultivar/genotype for the region.
 

From the present study it comes to know that the cultivar Sa-88 and an advanced line KA08-03 have proven excellent site specific performance for Sanliurfa the southeast region in Turkey making its confirmation for rural extension to their suitability. And in the grain contributing traits first pod height, plant height, 1000 grain weight and biological yield have the positive correlation.  And the giving special emphasis to these traits in breeding program will be quite encouraging for better outcome in term of grain yield.