Disease Assessment:
The plants developed from each assigned treatment were sprayed with individual AA, HA and its
interactions three times with 15-day intervals beginning from 30-day after sowing using a hand atomizer till
dripping. Plants sprayed with tap water only served as check. The plants were rated for disease incidence (DI)
and disease severity (DS), the former as the presence or absence of disease (percentage of infected leaves on
the plant) and the latter as the severity percentage of disease damage.
The disease severity (DS) of chocolate spot disease was estimated at 55 and 75 days from sowing under
natural infection by using the scale of Bernier et al (1993) as follow:
1= No disease symptoms or very small specks (highly resistance).
3= few small discrete lesions (resistant).
5= some coalesced lesions with some defoliation (moderate resistant)
7= large coalesced sporulating lesions, 50% defoliation and some dead plant (susceptible)
9= Extensive lesions on leaves, stems and pods, severe defoliation, heavy sporulation, stem girdling,
blackening and death of more than 80% of plants (highly susceptible)
The disease severity of rust was recorded at 100 days from sowing according to the standard scale
suggested by Bernier et al., (1993) as follows:
1= No pustules or very small non sporulating flecks (highly resistant).
3= few scattered pustules covering less than 1% of leaf area, and few or no pustules on stem (resistant).
5= pustules common on leaves covering 1-4% of leaf area, little defoliation and some pustules on stem
(moderately resistant).
7= pustules very common on leaves covering 4-8% of leaf area, some defoliation and many pustules on stem
(Susceptible).
9= Extensive pustules on leaves, petioles and stems covering 8-10% of leaf area, many dead leaves and severe
defoliation (highly susceptible).