Abstract:
Botrytis grey mold (BGM) is the most important biological constraint for lentil crop in
Pakistan. During 2007-08 and 2008-09, 912 varieties/lines were evaluated under field
conditions. There was no line found to exhibit immunity against Botrytis grey mold. 452 and
236 varieties/lines exhibited moderately resistant response against Botrytis grey mold during
2007-08 and 2008-09, respectively. During 2007-08 and 2008-09, 652 and 863 varieties/lines
exhibited susceptible response to Botrytis grey mold. 166 varieties/lines exhibited highly
susceptible response to Botrytis grey mold during 2007-08, while 171 one exhibited highly
susceptible response to Botrytis grey mold during 2008-09. Maximum disease development
occurred at temperature 23-26 oC and 18-24 oC, relative humidity at 5 pm 36-54 %, rainfall
0-3 mm, wind speed 3-5 Km/h and sun shine 6-10 hours. The data of susceptible to highly
susceptible lines/ varieties and meteorological variables were subjected step wise regression
analysis based on two years data a model consisting of all environmental variables explained
98 % variability in disease development. When these were split by years; a three
environmental variable model consisting of sun shine hours, relative humidity % at 8 am,
relative humidity % at 5 pm explained 96 % variability in botrytis grey mold severity during
2008. However, during 2009, four environmental variables model consisting of wind speed
Km/h at 8 am, max temperature oC, relative humidity % at 5 pm and rain fall mm explained
99 % variability in botrytis grey mold severity. For the management of BGM, three
antagonists (Trichoderma harzianum, Aspergillus flavus and A. niger), three plant extract
(Azadirachta indica, Bougainvillea spectabilis and Eucalyptus terticornis) coupled with three
fungicides including Topsin-M, Cabriotop, and Antracol with different doses were used in
laboratory experiment to assess their effectiveness against the colony growth of Botrytis
cinerea. Out of these, Cabriotop, Trichoderma harzianum, Azadirachta indica were found
effective in inhibiting the mycelium growth of the fungus. These same treatments were also
found effective in greenhouse experiments. The most effective treatments were tested on two
varieties and one advanced line under field condition. Among these Cabrio top at 150 ppm
was most effective in controlling BGM on Masoor-85, Masoor-93 and line 00518. The
protective spray of these treatments was significantly effective compared to curative spray.