Plant immunity as a factor suppressing plant combined wilts under urbinized conditions

Abstract

Objective of investigation is to assess role of mycoses at suppression of normal development of potato haulm. Phytopathological (mycological) investigation of samples of wilted plants and trees as well soils collected in urbanized conditions of Moscow in 2012-2018. Conducted investigations at principally different plants revealed currently polluted urbanized conditions and contrasting meteorological conditions (periods with strong rains and dried periods) provide specific inoculums potential as natural provocative infection. This infection is very strong, not homogeneous and in general is able to essentially influence plant routs, stems and leafs. Infective complex includes rather similar facultative parasites of fungal nature from genera Alternaria, Fusarium, Cladosporium, Aspergillus as well as different nematodes. Potato combined wilt (PCW) should be classified as extremely bad infection which leads to crucial yield loss as well as negative phytosanitary and sanitary situation. Protective measures against PCW must be directed to the escaping mechanical injuries and immunity losses of rout system and potato foliage. Combined wilt of arboreal foliage (CWAF) is a serious disease of tree stands, including two stages. At a first stage, immunity of stems and leave buds essentially become weakened, what is caused with polluted aggressive external environment and development of some infective dangerous diseases. At a second stage, mycosis affects weakened leave buds, after this foliage of trees is developing unequally or is not developing at all.