On the basis of cage house studies, the most effective botanical, antibiotic and fungicides were further tested alone as well as in combinations against the bacterial blight of clusterbean under field conditions at Agricultural Farm, RARI, Durgapura during
kharif season 2018 and 2019. The artificially inoculated seeds with bacterial suspension were used for the experimentation and foliar spray with bacterial suspension were applied twice in a day on 30 days old plants. The seed treatment with streptocycline @ 250 ppm was common for each treatment. The two foliar sprays of fungicides, antibiotics and botanicals were applied individually as well as in combinations first at three days after last inoculation and repeated after 15 days. The per cent disease severity was recorded before spray, seven days after first spray and seven days after second spray. The grain and fodder yield were recorded at harvest.
Two years pooled data presented in the Table 1 and 2 revealed that all the tested botanicals, antibiotics and fungicides were found significantly superior over untreated check in both reducing the disease and increasing the yield when tested individually as well as in combinations. The data revealed that there was no significant difference in per cent disease severity (PDS) among the treatments when recorded before the time of first spray because it was initiation of the disease. However, both the treatments of different spraying schedules showed significant effect on per cent disease severity over the check at seven days after first spray (Table 1 and Fig 1). The minimum per cent disease severity was recorded in treatment T4- two foliar sprays of streptocycline @ 250 ppm with 6.67, 8.00 and 7.33 followed by T5- first foliar spray copper oxychloride @ 0.3 per cent and second foliar spray streptocycline @ 250 ppm (9.33, 10.67 and 10.00 PDS) and T6- two foliar sprays of copper oxychloride @ 0.3 per cent (13.33, 14.67 and 14.00 PDS) during
Kharif season 2018, 2019 and pooled respectively. The disease severity was highest in T11- control (32.00, 40.00 and 36.00) at seven days after first spray during both the years and pooled respectively.
Similarly, the minimum per cent disease severity was also recorded with two foliar sprays of streptocycline @ 250 ppm when recorded at seven days after second spray with 10.67, 12.00 and 11.33 followed by first foliar spray with copper oxychloride @ 0.3 per cent and second with streptocycline @ 250 ppm (14.67, 16.00 and 15.33 PDS) and two foliar sprays of copper oxychloride (16.00, 17.33 and 16.67 PDS) during
Kharif season 2018, 2019 and pooled respectively. The treatment T5 was found at par in efficacy with treatment T4 (Table 1 and Fig 1).
The data presented in the Table 1, Fig 1 revealed that all the fungicides, antibiotics and botanicals were found significantly superior over untreated check in reducing the disease when tested individually as well as in combination. Two foliar sprays of streptocycline @ 250 ppm were found best with minimum (12.00, 13.33 and 12.67 PDS) and maximum 73.96 per cent disease reduction over the check followed by first foliar spray with copper oxychloride @ 0.3 per cent and second foliar spray with streptocycline @ 250 ppm (16.00, 17.33, 16.67 PDS and 65.74 PDROC) and two foliar sprays with copper oxychloride @ 0.3 per cent with 18.67, 20.00, 19.33 per cent disease severity with 60.28 per cent disease control over the check during
kharif 2018, 2019 and pooled respectively. The treatment T5- (1
st foliar spray with copper oxychloride @ 0.3 per cent and second foliar spray with streptocycline @ 250 ppm) was found at par in efficacy with treatment T4- (two foliar sprays with streptocycline @ 250 ppm at 15 days interval).
The data on grain and fodder yield of both
Kharif season 2018 and 2019 and pooled presented in Table 2 and Fig 2 revealed that the maximum grain and fodder yield (12.68 and 28.06 q/ha) were recorded in T4-(two foliar sprays with streptocycline @ 250 ppm) with 243.63 and 115.34 per cent increase in grain and fodder yield respectively over the control followed by T5-(
1st foliar spray copper oxychloride @ 0.3 per cent +2
nd foliar spray streptocycline @ 250 ppm) with 12.08 and 27.50 q/ha and T6-(two foliar sprays with copper oxychloride @ 0.3 per cent) with 11.51 and 26.11q/ha.
The maximum incremental cost benefit ratio of 1:16.88 was computed in the treatment T4-(two foliar sprays with streptocycline @ 250 ppm) followed by T5-(1
st foliar spray with copper oxychloride @ 0.3 per cent and second foliar spray with streptocycline @ 250 ppm) with 1:15.70, T6-(two foliar sprays with copper oxychloride @ 0.3 per cent) with 1:14.96 (Table 2).
The present studies indicated that the seed soaking with streptocycline @ 250 ppm for 90 minutes followed by two foliar sprays of streptocycline @ 250 ppm or 1
st foliar spray of copper oxychloride @ 0.3 per cent and 2
nd foliar spray of streptocycline @ 250 ppm at 15 days interval was found the most effective in reducing the per cent disease severity and increasing the grain and fodder yield in clusterbean.
Earlier the scientist
Gupta (1991),
Thammaiah and Khan (1995),
Yenjerappa et al., (2004), Kumar et al., (2009), Yenjerappa et al., (2011), Jambenal et al., (2011), Jagtap et al., (2012),
Lokesh et al., (2014),
Antre et al., (2016), Bala et al., (2017), Kumar and Jahangirdar (2017),
Kumhar et al., (2018), Prasad et al., (2018), Bagari et al., (2019) and
Madavi et al., (2020) also reported the spray combination of streptocycline (250 ppm) + copper oxychloride (2000 ppm) as the best practice in management of bacterial blight at 15 days interval and increase the yield.
