Factors influencing the incidence of Rosellinia necatrix Prill. in poplars¹

Abstract

Tests were carried out m controlled environments to ascertain the effects of some physical, chemical and biological characteristics of soil on the spread o\ Rosellinia necatrix and on the development of its infection in poplars. Following the results obtained, cultivation techniques have been suggested which could prevent the diffusion of the fungus or reduce the damage it causes.

The effect of fungal metabolites on leaves as detected by chlorophyll fluorescence

“…Current evidence suggests that R. necatrix infection may be most damaging to a plant when other stress conditions, such as drought, are present (Teixeira de Sousa, 1985). Anselmi & Giorcelli (1990) in a study of factors influencing the incidence of Rosellinia infection in poplars found that R. necatrix spread rapidly on loose soil with a high sand content. They also noted that soil moisture close to field capacity encouraged mycelial spread from tree to tree but that dry conditions predisposed the trees to attack.…”

Developing tools to unravel the biological secrets of Rosellinia necatrix, an emergent threat to woody crops

“…The development of the R. necatrix mycelium and mycelial strands depends on temperature, oxygen, moisture and organic matter contents, pH and soil microflora. In vitro studies have shown that the optimal growth temperature is 22–24 °C; it does not grow below 4 °C or above 32 °C (Abe and Kono, 1953; Anselmi and Giorcelli, 1990; Araki, 1967; Mantell and Wheeler, 1973; Pérez‐Jiménez, 1997). Unlike most fungi, R. necatrix is not inhibited by high pH; in vitro growth occurs over a pH range of 4–9 (Makambila, 1978; Pérez‐Jiménez, 1997; Ruano‐Rosa, 2006), and growth in soil occurs over a pH range of 6–8 (Anselmi and Giorcelli, 1990; Gupta and Gupta, 1992).…”

“…In vitro studies have shown that the optimal growth temperature is 22–24 °C; it does not grow below 4 °C or above 32 °C (Abe and Kono, 1953; Anselmi and Giorcelli, 1990; Araki, 1967; Mantell and Wheeler, 1973; Pérez‐Jiménez, 1997). Unlike most fungi, R. necatrix is not inhibited by high pH; in vitro growth occurs over a pH range of 4–9 (Makambila, 1978; Pérez‐Jiménez, 1997; Ruano‐Rosa, 2006), and growth in soil occurs over a pH range of 6–8 (Anselmi and Giorcelli, 1990; Gupta and Gupta, 1992). Soil moisture is the most important factor influencing the growth of the fungus and, in sandy–silt soils, the optimal growth of the mycelium is obtained at field capacity and is reduced when moisture approaches the wilting point (Anselmi and Giorcelli, 1990).…”

“…Unlike most fungi, R. necatrix is not inhibited by high pH; in vitro growth occurs over a pH range of 4–9 (Makambila, 1978; Pérez‐Jiménez, 1997; Ruano‐Rosa, 2006), and growth in soil occurs over a pH range of 6–8 (Anselmi and Giorcelli, 1990; Gupta and Gupta, 1992). Soil moisture is the most important factor influencing the growth of the fungus and, in sandy–silt soils, the optimal growth of the mycelium is obtained at field capacity and is reduced when moisture approaches the wilting point (Anselmi and Giorcelli, 1990). Poor aeration is also unfavourable for disease occurrence, as the growth of R. necatrix mycelia is retarded when the oxygen content of the air is less than 10% (Araki, 1967).…”

“…As a consequence, fungal distribution is often restricted to the topsoil (Abe and Kono, 1955; Makambila, 1976). Mycelial growth is strongly inhibited by light (Anselmi and Giorcelli, 1990; Makambila, 1976), and its development requires high levels of organic matter (Agarwala and Sharma, 1976; López and Fernández, 1966).…”