**4.2 Appropriate grafting age of rootstocks and soybean scions**

## **4.2.1 The grafting age of rootstocks**

Under normal circumstances, the rootstocks are sowed earlier 40-45 days than the scion of soybean. But the climate conditions and the rootstocks types may influence the growth and development of rootstocks, the best age of rootstocks are about 50 days after emergency (DAM) under good growth season.
