Efficacy of Newer Fungicides against Leaf and Fruit Spot of Custard Apple Caused by Colletotrichum Gloeosporioides
Abstract
Custard apple (Annona squamosal L.) belong to family Annonaceae is one of the finest fruits gifted to India by tropical America. The crop is badly infected with leaf and fruit spot disease caused by C. gloeosporioides . Five systemic, five contact and five ready mixed fungicides were evaluated against C. gloeosporioides under in vitro by poison food technique. Among the systemic fungicides, carbendazim 50WP was recorded highest mean mycelial inhibition (88.50%) followed by tebuconazole 25EC (81.10%). Among the non-systemic fungicides, copper oxychloride 50WP found superior for mean mycelial inhibition (94.43%) of C. gloeosporioides followed by mancozeb 75WP (89.10 %). Carbendazim 12% + mancozeb 63% WPrecorded maximum mean mycelial growth inhibition (95.89%) which was at par with tebuconazole 50% + trifloxystrobin 25% WG (94.43%) in ready mixed fungicides.
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Introduction
Custard apple (Annona squamosa L.),is the most important fruit crop of the tropical and sub-tropical regions of the world it belonging to the family Annonaceae. It has hardy in nature and commercially grown on marginal land and hillocks with minimum inputs. Annona squamosa Linn. is a small, semi-deciduous tree, 3-7 min height, with a broad, open crown or irregularly spreading branches, widely available indifferent agro-climatic zones of India. This fruit is sometimes also considered as “poor man’srich food” in the arid zones of India and required dry climate with mild winter. In India, custard apple was cultivated over 47 million hectares with an annual production of 402 MT (Anon, 2022). The area under cultivation of custard apple is increased only due to high economic returns obtained from this crop and that too at very low input cost. Since last 13-15 years, the crop is found to be badly infected with blackening of fruitsi.e., dry fruit spot caused by Colletotrichum gloeosporioides. It is prevalent in almost all custard apple growing areas of country. Now a day it has become a severe melody to this crop. About 60-70 percent losses have been reported due to the disease (Somwanshi et al., 2021). Considering the severity of this disease and frequent occurrence in the fields, it has been felt necessity to develop effective management strategies. Thus, attempts have been made to evaluate the efficacy of newer fungicides against leaf and fruit spot disease.
Conclusion
Among systemic fungicides, carbendazim, followed by tebuconazole and difenoconazole, exhibited the highest mean mycelial growth inhibition. Among non-systemic fungicides, copper oxychloride was the most effective, exhibiting the highest mean mycelial growth inhibition against C. gloeosporioides. Carbendazim + mancozeb showed higher mean mycelial growth inhibition against C. gloeosporioides. TABLE 3 EFFICACY OF READY MIXED FUNGICIDES AGAINST C. GLOEOSPORIOIEDS IN VITRO Tr. Percent growth inhibition over control Concentration (ppm)
Treatments No. 500 1000 1500 2000 2500 Mean Tebuconazole50+ Trifloxystrobin 25 72.03 74.34 77.02 80.98 84.43 77.76 T1 WG (89.99)* 92.22 94.44 97.03 98.51 94.43 46.32 51.69 55.18 58.49 63.26 54.99 T2 Azoxystrobin11.5+ Mancozeb 30 WP 51.85 61.1 66.92 72.22 79.25 66.27 Carbendazim 12 WP + Mancozeb 63 75.62 77.02 79.67 80.89 84.43 79.53 T3 WP 93.33 94.44 96.29 96.88 98.51 95.89 46.75 55.47 57.07 66.27 78.06 60.72 T4 Metiram 55 + Pyraclostrobin 5 WG 52.59 67.4 69.99 83.33 95.18 73.69 Azoxystrobin18.2+ 66.27 68.35 69.62 68.8 70.97 68.8 T5 Difenoconazole11.4 SC 83.33 85.92 87.4 86.4 88.88 86.38 4.5 4.5 4.5 4.5 4.5 4.5 T6 Control 0 0 0 0 0 0 52.12 55.43 57.38 60.19 64.48 Mean-61.84 66.84 69.17 72.64 76.72 Treatmentx Treatment Concentration concentration S. Em.± 0.325 0.297 0.728 C.D. at 5% 0.921 0.84 2.05 C.V.% 2.18 *Figures in parentheses are original values and outside are arc-sine transformed values
