Agriculture Reference
In-Depth Information
2008; Legreve and Duveiller, 2010). Partially resistant varieties have often
been proved to be a reliable option. This approach reduces the chances
of complete elimination of respective pathogen which may in otherwise
lead to - “boom and burst cycles”. However, such approaches principally
rely on the resistance genes. There is always threatening for domination
of newly emerged race Ug99 (
P. graminis
f. sp.
tritici
) even the stem rust
resistance gene
Sr31
has been effective for over 30 years. The breakdown
of the gene
Sr31
will definitely convey serious consequences where other
resistant cultivars are not available (Flood, 2010).
The number and virulence status of inoculum are influenced by the cli-
mate change or the survival of the pathogen is primarily taken care by the
surrounding environment. Therefore, severity of epidemics is regulated
by the primary inoculum (infection unit) under changing climate (Chaube
and Pundhir, 2005). Management of infection unit is the important key to
manage a phytopathosystem (Zadoks and Schein, 1979). Under a mono-
cyclic process the management of a single infection unit and population
of infection units are required. However, the polycyclic process could be
managed with management of basic infection rate developed from the in-
fection units repeatedly infect the host.
The chemicals being used in plant disease management are most ef-
climate may lead to malformed effect of the applied chemical. Schepers
(1996) advocates for precipitation in order to improve distribution of fun-
gicide, however, heavy rainfall deplete residue of fungicide on the crop
canopy (Neuhaus et al., 1974). Atmospheric changes manipulate the mi-
croflora community structure of rhizosphere and phyllosphere. Such ma-
nipulation is driven by the physical climate over biocontrol agents (Ayres
et al., 1996; Manning and Tiedemann, 1995). Elevated CO
2
interacts with
the nitrogen and other essential availabilities in soil to promote population
and kind of mycorrhizal fungi that improves root and plant health (Stad-
don and Fitter, 1998).
The biotic environment is pathogen limiting (Zadoks and Schein,
1979):
Mycosphaerella musicola
(causes sigatoka disease) can infect ba-
nana earlier than a phyllosphere microflora build up, that is, within one or
two days after the leaves become unfolded. The above discussed manage-
ment strategies (resistance gene(s), pathogen, chemicals and the environ-
ment) can improve the phytopathosystems addressing plant health even
