I - --ii

120
nature. Ascochyta propagules on chickpea refuse will begin to lose viability as
the debris begins to decompose. Certain practices, such as plowing, will speed up
the decomposition of chickpea refuse. Crop rotation may also be effective in
reducing the inoculum of other seed- or soil-borne chickpea pathogens.
Field Sanitation
It has been reported that A. rabieiis able to multiply on the chickpea refuse that
is left in the field after harvest (Lukashevich 1958; Luthra et al. 1935; Zachos et
al. 1963) thereby providing a potential source of fungal inoculum which may
initiate new centers of infection from rain-splashed conidia. Therefore, any
chickpea refuse that remains in te field after harvest should be destroyed by
burning or burying. Deep plowinf, will ho-sten the decomposition of infested straw
and remove it as a source of fungal inoculurn.
Chemical Seed Treatment
Chickpea seeds introduced into an ascochyta blight free area should be treated
with an effective fungicide L.: a precaution against inadvertently introducing the
pathogen on infected seed. This is particularly important where the orig.n of the
seed is uncertain. Treatment of chickpea seed with some of the newer systemic
fungicides offers great promise in controlling surface and deep-seated infection
by A. rabiei.
The incidence of ascochyta blight in chickpea seedlings in Iran was reduced by
more than 80% and emergence increased by
over 45% when inoculated seeds
were treated with benomyl (Benlate) or thiabendazole (Mertect) (Kaiser 1973b).
Reddy (!980) reported the eradication of A. rabieiin naturally infected chickpea
seeds with the systemic fungicide tridemorph (Calixin M) used singly or in
combination with benomyl.
Field Inspection
Ascochyta blight can be present in chickpea plantings in low levels which makes
detection of the pathogen difficult. It is, therefore, essential that seed fields be
inspected carefully at periodic intervals up to the time of harvest by qualified,
trained personnel.
These inspections will also be useful in identifying the presence and potenlial
importance of other seed-, soil- and vector-borne diseases. Field inspections
should be coordinated with laboratory tests designed to detect A. rabieiand other
seed-borne pathogens on chickpea seeds.
Conclusions
If the above practices are followed, it should be possible to prevent the introduction
of ascochyta blight into disease-free areas or significantly reduce or eradi­