I - --ii

Tropics (ICRISAT) and ICARDA to combine their respective chickpea programs.
ICRISAT posted a chickpea breeder to ICARDA in the 1977/78 season
to identify some promising sources of resistance to ascochyta blight in the
germplasm collection. Although not all lines identified that season maintained
their resistance under greater disease pressure the following season, several lines
did hold up and have been used widely in the breeding program since then.
In the following season, approximately 400 lines were tested during winter,
and some of them both in winter and spring. The results confirmed that wintersown
chickpeas are capable of producing over 3000 kg/ha and can successfully
grow even with as little as 250 mm of rainfall, compared to about 350 mm
normally required for the spring-sown crop.
Since that time, special attention has been focused on the development of
disease screening techniques, identification and wide-spread evaluation of
sources of resistance, incorporation of resistance into a range of genetic backgrounds
and studies on the nature' f inheritance of resistance. Epidemiological
studies on ascochyta blight have been conducted, and research on the use of
fungicides, particularly as a seed dressing, is under way. Agronomy trials are
aimed at identifying optimum cultural practices for the winter crop and include
research on inoculation with effective strains of Rhizobia. Aspects of plant
physiology, pest problems, weed control, economics and the role of winter chickpeas
in crop rotations are all now being investigated at ICARDA.
Resistance to Ascochyta Blight
As indicated earlier, the major hazard faced by winter chickpeas is ascochyta
blight. A severe epidemic of this disease can totally destroy the crop. Even in
spring-planted chickpeas, ascochyta blight is regarded as one of the main disease
problems throughout most of the Mediterranean region, including Spain (Cubero
1975), West Asia (Hanounik 1979) and North Africa (Djerbi et al. 1979). It can
be especially severe if late rains are received.
Winter chickpeas are thus only possible if adequate control of the disease can
be achieved. Although fungicides have been effective in some trials, in others the
level of control has been inadequate. In the 1978/79 season severe damage
occurred on one field at Tal Hadya in spite of fungicide (Diathane M45) application
on 12 separate occasions during the season. Thus the only reliable method of
disease control available to date is the use of resistant cultivars.
The relationship between disease resistance and yield was evaluated for 70
lines in the 1979/80 season at Tel Hadya (Table 1). The resistant lines had a
mean yield of over 2000 kg/ha, which was over twice the mean yield of the
susceptible lines. The highly susceptible lines failed to produce any seed at all.
By 1980 over 9000 germplasm accessions and segregating populations had
been screened at ICARDA. Twenty-two kabuli and 32 desi germplasm acces­
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