Studies of red core root disease of the strawberry caused by Phytophthora fragariae Hickman

Abstract

The occurrence of physiologic races of Phytophthora fragariae is demonstrated. A comparison is made of the size of sporangia, zoospores and oospores produced by them, and the temperature relations of the races are determined. The differential response to red core of five varieties of strawberry, namely, Huxley, Oberschlesien, Auchincruive 6, Auchincruive Climax and Auchincruive 11 is studied. The conditions governing the germination of the oospores are investigated