Sources of Variation in Shelling Percentage in Peanut Germplasm and Crop Improvement for Calcium Deficiency-Prone Soils1

Abstract

Calcium (Ca) deficiency causes peanut pegs and pods to abort, resulting in decreased shelling percentages and yields. Environmental factors influencing calcium avail ability include soil Ca content and soil moisture. Genetic attributes that influence the sensitivity of cultivars to soil Ca supply include pod size, soil volume per pod (varied by plant growth habit), and pod wall attributes. Where Ca fertilization is not possible, genetic solutions to Ca deficiency are important, and breeders need informa tion on the relative importance of these attributes. The objective of this research was to quantify the relative importance of these three sources of variation. Data from three trials were used to evaluate the relative importance of these attributes. The trials, sited on Cadencient alfisols, used between four and 12 germplasm lines with varied Ca sensitivity-determining attributes. Lines differed in growth habit (spreading or bunch), pod volume, pod yield, shelling percentage, and seed yield. The trial treatments and environments (sites and sea sons) also varied Ca supply through soil type, fertiliza tion, and water supply. Assuming that Ca supply has little impact on crop growth rates (CGR), a physiological model was used to set aside the contributions of CGR to yield differences between treatments. The three trials were analyzed separately and then combined for further regression analysis by defining each site and treatment combination as an environment. Within trials, variations in shelling percentage accounted for up to half the variations in seed yield between Jines. In the combined analysis, easily selected attributes-pod volume (58% of germplasm sums of squares) and plant habit (8%) and their interaction (14%)-accounted for much of the variation in shelling percentage. The interaction was due to shelling percentage being less influenced by pod volume in spreading than in the bunch types. Thus, in Ca-limiting situations, the spreading growth habit al lowed larger seeded peanuts to be grown than the bunch growth habit because of the greater pod dispersal of this type. Assuming that the lines tested typified peanuts for tneir relation between attributes and Ca deficiencybased shelling percentage variations, breeders should place the greatest emphasis on small pod size to decrease peanut sensitivity to Ca deficiency. Increased soil avail able to each pod by pod dispersal decreases the need for small pods to decrease sensitivity to Ca-deficient soils.

Influences of genotype and location interactions on oil, fatty acids and agronomical properties of groundnuts

“…The highest number of pods was observed for ACG 14 which also had very high pod yield in L1 and this type of positive correlation was also obtained by Jiang et al, (2014) for the Chinese groundnut collection. Shelling percentage is strongly influenced by genotype (Hartmond et al, 1996), locational differences (Padi, 2008) and positively related to pod yield in groundnuts (Anothai et al, 2008). In the present study, the genotypes showed significant differences for shelling percentage in L2.…”

Effect of Seed Fungicide Treatment, Microelement Fertilizer and Mepiquat Chloride Applications on Yield and Yield Components of Peanut

“…In the second year of the study, application of Pix + Fertilon Combi application after flowering (T 12 ) had the highest shelling rate at 65.2%, and the treatment T 10 (Pix application at the beginning of the flowering and after flowering) had the lowest shelling rate with 57.2%. The shelling percentage of peanut genotypes was increased with the addition of plant nutrients (Williams 1987;Hartmond et al, 1996). When mean shelling percentage was considered, year and treatment were significant while year x treatment interaction was not significant.…”

Physical and Mechanical Properties of Some Peanut Varieties Grown in Mediterranean Environment

“…It is reported that shelling percentage is an important parameter for seed yield and has a highly significant negative correlation between pod volume and shelling percentage (Keisling et al, 1982). Hartmond et al (1996) observed that shelling percentage of the peanut lines was strongly influenced by germplasm lines and the largest pod lines gave the lowest shelling percentage among the lines. Significant variations between peanut cultivars and the shelling percentage was observed by Calıskan et al (2008).…”