“STUDIES ON EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW (Oidium mangiferae berthet) IN MANGO”
| dc.contributor.advisor | SHARMA, I.M. | |
| dc.contributor.author | KAUR, LOVEPREET | |
| dc.date.accessioned | 2016-11-28T13:09:19Z | |
| dc.date.available | 2016-11-28T13:09:19Z | |
| dc.date.issued | 2015 | |
| dc.description.abstract | ABSTRACT Powdery mildew of mango, incited by the fungus Pseudoidium anacardii (formerly known as Oidium mangiferae Berthet), is one of the most common, widespread and serious disease throughout the world and causes significant yield losses up to 90 per cent. It is one of the major limiting factors in its cultivation affecting both yield and fruit quality in Himachal Pradesh. Present investigation was undertaken with the objectives to record the prevalence of the disease, study the role of abiotic environmental factors in disease development and to devise suitable disease management practices. Powdery mildew was found to occur in moderate to severe form in different major mango growing areas of Solon, Sirmour, Una and Kangra districts of Himachal Pradesh. The per cent disease index (PDI) varied between 58.52 to 80.14 and 60.23 to 79.62 during the year 2014 and 2015, respectively. The characteristic symptoms appear as white superficial powdery growth on the inflorescence, which turn brown and shed flower leaving behind the bare rachis. Microscopic examination of diseased samples showed barrel to ellipsoid – ovoid, single celled conidia produced in chains of two to four and mycelium was superficial, hyaline and septate. Pathogenicity test revealed the development of typical symptoms after 197 and 260 hrs of incubation on leaves and pedicel, respectively. Disease appeared in the last week of February or first week of March and multiplied at a faster speed between 15 March to 19 April during both the years (2014 and 2015) of observations. Thereafter, it progressed at a slow rate and ceased to develop in the last week of May. Correlation coefficient between mean temperature (0.937) and sunshine hours (0.939) was positive whereas it was negative (-0.564) with RH. Out of 41 cultivars, cv. Totapari showed moderately resistant reaction with the lowest apparent infection rate (0.02 per unit per day) and AUDPC (1.16), whereas rest of the cultivars exhibited moderately susceptible to highly susceptible reaction. In vitro evaluation of fifteen fungicides showed azoxystroblin + difenoconazole, azoxystroblin and tebuconazole were the most effective and inhibited the conidial germination up to an extent of 100, 98.75 and 97.89 per cent, respectively. In the field evaluation, out of nine in vitro effective fungicides, azoxystroblin + difenoconazole (0.04%), tebuconazole (0.05%), azoxystroblin (0.05%) and hexaconazole (0.05%) were the most effective (97.65-99.72PDC) in order in controlling the disease. However, hexaconazole was highly cost effective (CBR=1:56.03). Among the five spray schedules, spray of azoxystroblin + difenoconazole (0.04%) with the first appearance of disease, hexaconazole (0.05%) at fruit set and tebuconazole (0.05%) at pea to marble fruit size stage was most effective (99.97 PDC) and economic (CBR 1:31.3). Two consecutive sprays of dipotassium hydrogen orthophosphate (0.075%) first in January followed by another after 28 days were most effective (99.46 PDC). Further, three sprays of Bacillus subtilis (0.8%) staring with the emergence of panicles followed by another two sprays at an interval of 15 days was found to be the most effective (97.56 PDC) followed by Ampelomyces quisqualis (93.63 PDC). | en_US |
| dc.identifier.other | 48329 | |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/87840 | |
| dc.language.iso | en | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.these.type | M.Sc | |
| dc.title | “STUDIES ON EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW (Oidium mangiferae berthet) IN MANGO” | en_US |
| dc.type | Thesis | en_US |
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