Dj. Moot et Dl. Mcneil, YIELD COMPONENTS, HARVEST INDEX AND PLANT TYPE IN RELATION TO YIELD DIFFERENCES IN-FIELD PEA GENOTYPES, Euphytica, 86(1), 1995, pp. 31-40
The effectiveness of yield components, harvest index and morphological
characteristics as selection criteria among four field pea (Pisum sat
ivum L.) genotypes was examined. Genotypes were grown at a wide range
of plant populations (9 to 400 plants m(-2)) to maximise environmental
diversity. Both biological and seed yields approximately doubled from
9 to 100 plants m(-2). This response flattened from 100 to 400 plants
m(-2). Differences among the genotypes were found only at 225 and 400
plants m(-2). Analysis of the yield components highlighted the plasti
city and large genotype by environment interactions of field peas. The
numbers of pods per plant and peas per pod were maximised when each g
enotype was grown as spaced plants, but the low plant numbers meant se
ed yields per unit area were at their lowest. Genotypic differences fo
r plant harvest index (PHI) were also only found at 225 and 400 plants
m(-2). Broad sense heritability estimates indicated that direct selec
tion for PHI was not feasible. The inference from the yield component
and pill results was that alternative selection criteria such as physi
ological or morphological characteristics may be necessary for improve
d yield potential. Classification of each genotype indicated that low
seedling vigour may be a positive attribute for crop plants of semi-le
afless and conventionally leafed field peas. Selection based on any si
ngle plant attribute is unlikely to lead to dramatic improvements in t
he yield potential of field peas. Selection should be based on plant c
haracteristics rather than on differences in yield components.