Forages are Sweden’s most grown crop and consists of a mixture of grasses and legumes. One of the most important legumes is red clover. A perennial crop with high protein content and good nutritional value. Furthermore, red clover provides ecological services such as increased soil health by interacting with nitrogen fixating bacteria in the soil, also, the perennial trait leads to lower soil erosion, higher ground carbon as well as lower nutrient leakage. Red clover is naturally diploid but in the 1970s scientists developed tetraploid varieties. These two ploidy levels differ in important agricultural traits such as yield and persistence, where tetraploids are superior, and seed yield, where diploids are superior. This project is a part of the grogrund project "Genomic selection in Red Clover" and will run models for both genome wide association studies (GWAS) and genomic prediction models (GP). The goal is to apply longitudinal models to find genomic signals for yield over time as well as persistence over time. Hence, we will investigate what effects trends in yield over time, the underlying genetic effect of winter hardiness as well as any plausible genetic effects that differ between diploids and tetraploids.