Why do Wineries plant a Rose bush at the end of the row of grape vines?

The rose bush and grape vine share a close relationship. Some places that vineyards are planted are humid and the vines are susceptible to diseases. Fungus is a main concern to the vineyard which is due to humidity. Black spots will appear on the left of the rose indicating rot on the vines. The rose bush will show an early warning of the disease which appear two weeks earlier. Both the grape vine and rose bush grow in very similar ways and are affected by many of the same diseases and problems.