Research Notes : India : Genetic variability, interrelationships and path-coefficient analysis of seed technological traits in soybean under different cropping systems

Soybean is generally cultivated in India as a sole or monoculture crop. However, its intercropping with maize is a common practice in some hilly areas of northern India. The practice aims at (1) insuring against total crop fail-ures under abnormal weather conditions, (2) increasing total productivity for unit land area, and (3) equitable and judicious utilization of land resources and farming inputs

Research Notes: Variation for seed yield, its quality and nutritional traits in soybeans

To bring about genetic improvement for any economic trait in economic plants, the foremost prerequisite is the presence of sufficient amount of genetic variability for the trait under improvement in the organism t o be improved. In the present investigation, an attempt has been made to get the information on nature and magnitude of variability for various seed quality traits along with seed yield traits in the soybean germplasm maintained at the Himachal Pradesh Agricultural University, Palampur. Materials and methods: The material for the present study consisted of 250 diverse genotypes of soybeans of both indigenous and exotic origin , and 5 standard checks

Research Notes : Consistency of heritability estimates over environments and crop-ping systems for different groups of traits in soybean

Introduction : Though numerous reports are available on heritability estimates from individual environment, yet information on consistency of heritability over environments is meager (Byth et al., 1969). An attempt has been made in the present communication to understand the influence of en-vironments and cropping system on the heritability estimates in soybean. Materials and methods : The materials and experimental design were same as reported by Gupta et al. (1981)

Research Notes : Genotype X Environment interaction in soybean: I. Individual regression analysis.

In this communication, the results obtained from the material given earlier (Gupta et al., 1981) on the basis of individual regression analysis by using Perkins and Jinks (1968) model, have been presented for different traits groupwise. In the individual regression analysis, genotypes having nonsignificant regression m.s. as well as remainder m.s. against error m.s. were described as exhibiting absence of genotype x environment (g x e) interaction, genotypes having regression m.s. significantly different from error m.s. were designated as showing predictable g x e (linear g x e) interaction, and genotypes having only significant remainder m.s. or significant regression m.s. not significantly different from significant remainder m.s. were categorized as genotypes showing unpredictable g x e (nonlinear g x e) interaction. On the basis of this all 40 genotypes were classified into three groups and their distribution with respect to different groups of characters studied is given in Table 1

Research Notes : Genetic control of productivity, responsiveness and stability for different groups of traits in soybean

In order to breed adaptable varieties, selection is to be based on the above three parameters of adaptability simultaneously, for achieving the de-sired objectives. After understanding the association between these, it is imperative to have information on the gene action or genetic architecture of these three parameters, because in a self-pollinated crop like soybean where end product is homozygous and homogeneous population, selection will be fruitful only if gene action is of additive or additive x additive nature. In the present study, an attempt has been made to infer the genetic control of mean performance (di-productivity), responsiveness and stability with respect to each different group of characters studied, on the basis of segregation pattern observed among 36 F4-derived lines, of the cross Soybean Pb.l x D 60-9647, in relation to their parents

Research Notes : Association among productivity, responsiveness and stability for different groups of traits in soybean

In India, soybean adaptability trials have revealed that, in order to stabilize yield and popularize soybean cultivation, breeders must look for genotypes with good germinability and wider adaptability under diverse geographical and climatological situations (Singh, 1976). Prospects of develop-ing different genotypes having varying degrees of adaptability would depend to some extent on the relationship between various adaptability parameters; namely, di (additive genetic effect-productivity), Si (genotypic regression -a measure of responsiveness), sd2 (deviation from regression - a measure of stability). This has been attempted in the present study on the same material as reported earlier (Gupta et al., 1981) by working out the correlations over all the 40 genotypes between the three parameters which were calculated as per Perkins and Jinks (1968) taken in pairs (Table 1)

Research Notes : Association of leaf and root characteristics among themselves and with seed yield, structural, physiological and phenological traits in soybean

Introduction : The variation present for leaf and root characteristics has been reported earlier and in this communication the association of these traits with seed yield and other traits is being presented. Materials and methods : Materials used in this study and design of experiment were the same as reported by Gupta et al. (1981) and in the earlier communication on variation for leaf and root characteristics. The data were further analyzed for estimating the correlation coefficients at phenotypic and genotypic level

Research Notes: Study on biological measures of environment and its implications on the physical limits to seed yield and other developmental traits in soybean

Since adaptation of soybean and its dependence on various geographical and climatological factors has been a subject of debate (Byth , 1976 ; Summerfield and Minchin, 1976; Whigham , 1976), therefore, in the present study an attempt has been made to measure the environment biologically and to discuss the same in the light of physical limits of environment. Materials and methods : The experimental material consisted of 40 entries, representing 36 F4-derived lines of an inter-varietal cross , two parents involved in this cross, Pb1 and D60-9647, and two standard varieties, \u27 Lee\u27 and \u27D. S. 73-8\u27. The F4-derived lines were selected out of the 74 progenies, raised and evaluated during Kharif, 1977, for seed yield, specific gravity , and hundred- seed weight

Research Notes : Factor analysis in F2 generation of soybean crosses

Factor analysis is a technique of reducing a large number of correlated variables to a few main factors. It has been resorted to to overcome the limi-tations of univariate methods of analysis like correlations, path-coefficient and regression analysis (Wright, 1960; Walton, 1972). Besides, Moreno and Cubero (1978) have used it for estimating diversity

Effects of lubricated surface in the stagnation point flow of a micropolar fluid

In this investigation, we have considered a steady, two-dimensional flow of a micropolar fluid towards a stagnation point over a lubricated plate. A power law fluid is utilized for the purpose of lubrication. To derive the slip condition in the present flow situation, continuity of shear stress and velocity has been imposed at the fluid lubricant interface. The set of nonlinear coupled ordinary differential equations subject to boundary conditions is solved by a powerful numerical technique called the Keller-box method. Some important flow features have been analyzed and discussed under the influence of slip parameter , material parameter and ratio of micro-rotation to the skin friction parameter . The main purpose of the present article is to analyze the reduction in the shear stress and couple stress effects in the presence of lubrication as compared to the viscous fluid that may be beneficial during polymeric processing