Heterodera zeae in the rhizosphere of declining almond trees

Abstract

In September 1984, almond trees (Prunus amygdalus Botsch) growing at Quetta, Baluchistan, showed stunted growth. On examination of the soil around the roots, 25-30 lemon shaped cysts/WOg of soil were detected. The cyst cones prepared by the method suggested by Golden (1978) and observed by stereoscopic microscopy had a zig zag pattern, prominent dark brown bullae in the ambifenestrate vulval region. The second stage juveniles, mounted in 3% formalin, were cylindrical, elongate, tapering posteriorly measuring L=0.35-0.44 mm; a= 19.0-23.0; b=4.0-5.0; c=8.0-13.5; stylet = 18-24 pm. The cysts were identified as Heterodera zeae Koshy, Swarup et Sethi, 1971 (Koshy et al., 1971). Heterodera zeae was first discovered on maize, wheat, citrus, pea and garlic from Peshawar and Mardan (Maqbool, 1980) with several additional hosts from Pakistan (Maqbool and Hashmi, 1984). Almond (P. amygdalus) has not previously been reported as a host of H. zeae.