engleski

Changes in seed yield and quality resulting from lodging in Italian ryegrass crop

Rainfall accompanied with winds during seed maturation favour lodging of Italian ryegrass crop, which is commonly observed in farmer fields in north-western Croatia. Thus, the main objective was to determine the changes in seed yield and quality resulting from natural lodging of Italian ryegrass crop. Field trial was carried out during one growing season with three nitrogen (N) fertilization levels (60, 120 and 180 kg/ha) along with unfertilized plots. The onset of considerable natural lodging was observed before crop heading (ZCK 51) at the highest N fertilization, while lodging occurrence was delayed at lower N fertilization rates. In contrast, crop lodging was not observed in unfertilized plots during the whole growing season. Number of seeds per unit area significantly improved with N fertilization up to the rate of 120 kg/ha when crop lodging score averaged 96.2%. Lodging severity was similar (97.5%) at the highest N fertilization rate, but seed number per square meter, and consequently, seed yield was significantly reduced, which was associated with the earliest crop lodging occurrence. At harvest, moisture content in seeds as well as in vegetative parts (straw) was increased with higher N fertilization rate. In spite of higher crop lodging at harvest, the 1000-seed weight tended to increase under more intensive N fertilization. Seeds obtained from less fertilized plots had lower germination rate after 8 days, but these differences were not evident at final seedling count (after 15 days) when germination rate averaged 91.9%.

1000-seed weight, moisture content, nitrogen, seed germination

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