Report on Two Little-Known Poplar Diseases

Studies of microconidia of Marssonina brunnea and apothecia of Drepanopeziza tremulae

“…Numerous microconidia form prior to leaf fall and the relatively mild New Zealand winters should not preclude apothecial development. The perfect form of M. brunnea has been reported from Holland (CREMMEN 1965), Italy (CASTELLANI 1966), Yugoslavia (GOJKOVIC 1970), England (BYROM and BURDEKIN 1970), France (MORELET 1971) but not Japan (KOBAYASHI and CHIBA 1962).…”

The identification of poplar mosaic virus in Canada

“…angulata Ait. and the hybrids and cultivars associated with this subspecies appeared most susceptible to the virus in Europe, which causes (in addition to green-yellow mottling) veinal necrosis, precocious leaf fall, witches broom, reduced growth, and dieback (3,8,9,14). The other native species of North America, P. candicans, is also severely affected, the symptoms being necrosis of the veins and petioles and deformation and rolling of the blade (3,14).…”

“…Since that time it has been intensively investigated in a number of European countries (2)(3)(4)(5)(6)(7)(8)(9)(11)(12)(13)(14)(15)(16), especially those in which poplars have been cultivated. At present, eradication is the best means of control of the disease and rigid precautions are taken in countries such as ~zech6slovakia and the Netherlands to mevent the dissemination of infected stock.…”