GROWTH AND YIELD OF PROGENY OF NITROGEN AND PHOSPHORUS FERTILIZED BARLEY PLANTS

Barley seed samples, obtained from five field locations where N and P fertilizers had been applied in a factorial design, were sorted into size categories. Sorted samples were planted in the greenhouse and in field plots to determine the effects of seed size and parental fertilization on plant growth and yield.N fertilizers significantly increased the proportion of large seeds produced at four of the five field locations. P fertilizers had little influence on seed size. Large seeds produced more vigorous seedlings, more healthy heads per unit area, fewer smutted heads and greater grain and straw yields than did small seeds. Laboratory analyses showed that large seeds contained 1.6–2.3 times as much total available carbohydrates and 1.6–1.9 times as much Kjeldahl-N as did small seeds. It is suggested that the superiority of the large seeds results from the greater amount of stored energy compounds, particularly the carbohydrates. Parental N and P fertilization had little, if any, direct influence on the growth of the subsequent generation if equal-sized seeds were sown. For a given seed size, there was no difference in the amount of total available carbohydrates in seeds from unfertilized or N- and P-fertilized parents. On the contrary, seeds from N-fertilized parents contained 1.1–1.3 times as much Kjeldahl-N as did those from parents receiving no N fertilizer.