Agronomic performance of dwarf and standard height sunflower hybrids grown in Tuscan Maremma flatland and hillside environments at different planting densities

摘要

In field trials in 1992-93 on the coastal plain near Grosseto and on a hill farm in the municipality of Manciano, Italy, the very early dwarf sunflower hybrid Granosol was grown at densities of 6, 12, 18, 24 or 30 plants/m2, while the standard height, medium duration cycle hybrid Gloriasol was grown at densities of 4, 6 or 8 plants/m2. Results for Granosol confirmed its short cycle (roughly 25 days shorter than that of Gloriasol), shortness (between 56 and 80 cm in height) and lodging resistance. Plant height, seed oil content, LAI, seeds/m2, grain yield and oil yield of both genotypes generally increased with increasing plant density, while head diameter, seed number/head, 1000-seed weight, seed hull percentage and harvest index generally decreased. In Granosol, seed hull percentage was positively correlated with 1000-seed weight, while oil content was negatively correlated both with 1000-seed weight and hull content. LAI and harvest index values were higher in Granosol than Gloriasol. Granosoloil content was low (33.7-42.2%).