99 Richter is aV. berlandieri x V. berlandieri hybrid created by Franz Richter in 1889 and used as a rootstock. Its natural vigour means it should not be used on fertile sites or–according to Dr Richard Smart (2015, p.628)–cool regions as this can delay ripening. In Roussillon, Gérard Gauby of Domaine Gauby told me he found 99 Richter’s deep root system useful in drought conditions. It has high phylloxera resistance and moderate nematode resistance too. 

Other V. berlandieri x V. berlandieri rootstocks: 110 Richter. | 1103 Paulsen. | 140 Ruggeri. | 775 Paulsen. 

Bibliography

Dr Richard Smart in the Oxford Companion to Wine 4th edition ed. Jancis Robinson MW and Julia Harding MW (Oxford University Press, 2015, p628.