Organic, ecological and biological farming identified as a natural farming system
(Lammerts et al., 2002). The rule in organic agriculture is that no synthetic substance is used during production (such as chemical fertilizers, chemical pesticides). These synthetic substances have negative effects on human health and food safety
(Anonymous, 2021).
Common bean (
Phaseolus vulgaris L.) also known as field bean, dry bean, french bean, kidney bean and green bean which is an important legume around the world
(Camara et al., 2013; Swegarden et al., 2016; Jannat et al., 2019).
Relations of the common bean spad values and biomass yield are important for high yield. But yield parameters are changes due to the different interactions of various factors
(Khan and Dar, 2010).
Correlation coefficient analysis examines the relationship between variables and path coefficient analysis enables the correlation coefficient values to be separated according to the variables and analyzed in more detail. Path coefficient analysis gives information on the common bean yield criteria relations
(Ekinci et al., 2010).
Correlation and path coefficient analyzes of seed yield and bean components have been studied by many researchers
(Agsakalli and Olgun, 2001; Peksen and Gulumser, 2005; Ghobary and Abdallah, 2010; Karasu and Oz, 2010;
Salehi et al., 2010; Sadeghi et al., 2011; Cokkizgin et al., 2013; Prakash et al., 2014; Akhshi et al., 2015; Ejara et al., 2017; Panchbhaiya et al., 2017; Kalauni and Dhakal, 2020). However, little study has been done on the effect of spad values on yield. In addition, researching the subject with organic fertilizers is rarely studied.
This bean study investigated the SPAD-seed yield relationship that was not addressed in other studies. In the study, it was tried to determine the relationship of the spad values measured at three different times to seed yield and biomass yield to seed yield
via correlation and path coefficient analysis.
This study was conducted to Kahramanmaraş Sutcu Imam University, Faculty of Agriculture, Department of Field Crops treatment area (37°35'38.3"N 36°48'46.2"E) in 2021 year from 04 April to 28 July.
Two bean genotypes, one local genotype (Aydintepe) and the other registered variety (Mispir), were used in the study. In the field treatment, leonardite and chicken litter and their mixture were used and their various doses (3,6,9 t ha
-1) were added to the soil. The common bean conventional production method (25 kg ha
-1 N and 64 kg ha
-1 P
2O
5) and the application with no fertilizer were used for control.
The plots were 10 square meters, with 4 rows and the row length was 5 meters. On the other hand, the experiment was established with three replications. Sowing was done on 4th of April and harvesting on 28
th of July 2021. During the growing period, irrigation and weed control were carried out at regular intervals. Organic farming principles were followed during these processes.
Leaf chlorophyll content (SPAD) values, biomass yield and seed yield were measured in the study
(Estrada and Rodriguez-Gonzalez, 2017;
Cokkizgin et al., 2018; Girgel and Cokkizgin, 2019;
Girgel et al., 2019; Ahmadi and Arain, 2021; Amarapalli, 2022). Leaf chlorophyll content was measured in three periods: early leaf stage (SPAD I, 10.May.2021), flowering stage (SPAD II, 31.May.2021), post-flowering stage (SPAD III, 29. June. 2021).
Collected data were subjected to analysis of variance (ANOVA), using SAS 9.1 statistical analysis system
(SAS, 2004). Duncan’s multiple range test (DMRT) was used to compare the means
(Duncan, 1955). Correlation coefficients between all possible combinations of variables were worked out according to
Snedecor (1957). Path coefficient technique (in other words multiple regression analysis) was performed according to the method of
Wright (1934). On the other hand, correlation and path coefficients were determined using Totemstat, the Windows compatible version of the Tarist statistical analysis program
(Acikgoz et al. 1993).
1st SPAD measurement (Early leaf stage)
According to the results obtained, the difference between the cultivars was found to be statistically significant (Table 1).
Aydıntepe genotype has a higher spad value (40.337) than the Mispir variety (38.957). On the other hand, the Fertilizer X Genotype interaction and the differences in organic fertilizer applications were statistically insignificant. It was found to be statistically insignificant, but leonardite/chicken manure mix. 9 t ha
-1 application had the highest spad value (40.927) among organic fertilizers (Table 2-3).
2nd SPAD measurement (Flowering stage)
The statistical difference between cultivars was also found significant in the second spad measurement. It was determined that the spad value (43.883) of the application without fertilizer was higher than all other applications.
In the first spad measurement, FerXGen. interaction was statistically insignificant. Also, Aydintepe genotype also had a high value (39.677) in the second spad measurement; Mispir variety had lower value (35.144)..
3rd SPAD measurement (Post-flowering stage)
In the third spad measurement, all factors were found to be statistically insignificant. However, Mispir cultivar (32.640) had high value between genotypes and among the fertilizers, control (no fertilizer) got the highest spad value (33.927).
Biomass yield (kg da-1)
All sources of variation in biomass yield were found to be insignificant (Table 4).
However, Aydintepe genotype produced more biomass (491.00 kg da
-1) than Mispir cultivar (439.88 kg da
-1). Leonardite 3t ha
-1 application (520.78 kg da
-1) was also the fertilizer application in which the most biomass was obtained (Table 5-6).
Properties such as biomass yield and yield are highly affected by the environment, climate and soil conditions. Similar views were also reported by
Karavidas et al., (2022). On the other hand, it was reported that there was a strong influence of environmental influences on yield
(Swegarden et al., 2016).
Seed yield (kg da-1)
In terms of seed yield, both the difference between genotypes and the difference between fertilizer applications were found to be statistically significant (Table 4). Between the genotypes, Aydintepe genotype (106.59 kg da
-1) had higher yield compared to Mispir cultivar (68.23 kg da
-1). Considering the fertilizer issue; Chicken Manure 3 t ha
-1 organic fertilizer application (118.79 kg da
-1) was the application with the highest seed yield. However, the following were also included in the same statistical group: Leonardite/Chicken Manure Mix. 9 t ha
-1 (102.83 kg da
-1), Control (Chemical fertilizer) (100.94 kg da
-1), Chicken Manure 6 t ha
-1 (99.70 kg da
-1) and Leonardite/Chicken Manure Mix. 6 t ha
-1 (97.33 kg da
-1) respectively (Table 5-6). The formation of the phenotype; It occurs as a result of genetic factors, environmental factors and the interaction of genetic and environmental factors
(Falconer and Mackay 1996). For this reason, the amount of product we obtained varied according to the region and organic fertilizer. It was reported that the yield of bean varies according to the bean genotypes, fertilizer and fertilization
(Karavidas et al., 2022). It has been reported that environmental factors have a great effect on yield
(Swegarden et al. 2016).
Correlation and path coefficient analysis
Path coefficient analysis is used to examine the correlation coefficient in more detail. And the aim of the path coefficient analysis is the direct and indirect effects of the independent variables on the dependent variable
(Wright, 1918; Wright, 1920; Wright, 1921; Wright, 1934).
When the relationships between the examined features are considered; A positive and significant correlation coefficient was determined between 1
st SPAD and 2
nd SPAD measurement (r=0.523). All correlation coefficients that could be calculated among other features were found to be insignificant. In this study the results obtained were different from other studies due to both genetic and environmental effects (Table 7).
3
rd SPAD had a direct and great negative effect on seed yield and the percentage of effect was 74.4852% (-0.6297). The 1
st SPAD value had the greatest positive direct effect on seed yield and the effect percentage was 63.7681% (p=0.4612). Other direct effects were found positive and the biomass yield was 47.1668% (p=0.2522) and 2nd SPAD 20.6367% (p=0.0944), respectively (Table 8-9).
Falconer and Mackay (1996) reported that genetic and environmental variations inluences physiological mechanisms. Therefore, the the relationships between these studied parameters have changed. For this reason, it is considered as the relationships between the features we examine to change.