Epidemiology and Management of Turmeric (Curcuma longa L.) Leaf Spot [Colletotrichum gloeosporioides (Penz. and Sacc.)]
KrishiKosh
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Title |
Epidemiology and Management of Turmeric (Curcuma longa L.) Leaf Spot [Colletotrichum gloeosporioides (Penz. and Sacc.)]
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Creator |
CHAWDA, SHEHULKUMAR K.
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Contributor |
SABALPARA, A.N.
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Subject |
dna, topping, vegetables, adp, physical control, humus, plant extracts, livestock
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Description |
Turmeric (Curcuma longa L.) is one of the most important spice crops. During the survey, occurrence of leaf spot disease in turmeric (cv. Sugandham and Local) was observed in serious proportion inflicting heavy losses in south Gujarat. Considering the seriousness of the disease, the present investigation was carried out on various aspects to generate scientific information on this important pathological problem and to develop suitable management strategies to prevent the crop losses. The pathogen involved to cause the leaf spot in the area was identified as Colletotrichum gloeosporioides earlier by Patel (2000) which was confirmed by microscopic observations, study of symptomatology of the disease, morphology and cultural characters of the pathogen. The pathogen found to be attacking upper leaves of crop. The disease manifested in the form of elliptic or oblong spots of variable size. In the initial stage, the spots were pin head dot like in appearance. These spots increased in size and coalesced to form large patches involving major portion of the leaf. The centre of the spots were grayish white with numerous black dots like acervuli on both the surfaces. Sometime acervuli could be seen on the midrib too. When the intensity of the disease was severe, most of the leaves became yellowish, dried up and the field presented a blighted appearance. The leaf spot was found in severe proportion in both the popular varieties viz., Sugandham and Local in Navsari, Dangs, Surat and Tapi districts of south Gujarat. Losses due to the leaf spot was estimated up to 31.70 per cent. Due to leaf spot of turmeric, losses were found in all the growth parameters and ultimately affected in reduction of rhizome weight (24.63%). However, curcumin content was recorded to be increasing in diseased plants as compared to healthy plants in different genotypes. Phenol content was also recorded to be increasing due to the disease. Genotypes resistant to leaf spot contained higher amount of phenol as compared to the susceptible one. Non-reducing, reducing and total sugar content was recorded to be lower in diseased leaves as compared to the healthy leaves in all the genotypes. Young crops (2 to 5 months) were mostly remained free from the infection of the leaf spot. The infection was started during August and attained its peak on completion of major rainfall i.e. after 37th MSW. During the major progress (37th to 40th MSW), average temperature remained around 28 0C and 80 per cent relative humidity with moderate rainfall. Correlation coefficient study between weather parameters and disease intensity indicated that all the parameters jointly played an important role in the development of disease. The multiple regression equation [Ŷ = 77.39 + 1.04 (X1) – 3.69 (X2) – 0.0000000007 (X3) + 17.32 (X4) + 17.89 (X5) - 35.16 (X6) - 0.014 (X7) – 1.51 (X8) where X1 = Maximum temperature, X2 = Minimum temperature, X3 = Average temperature, X4 = Morning relative humidity, X5 = Evening relative humidity, X6 = Average relative humidity, X7 = Rainfall, X8 = Rainy days] was developed for the forecasting (R=0.81). Effect of lateral spacing and fertigation rate on leaf spot revealed that the disease was not significantly affected by lateral spacing but it was significantly affected by different levels of fertigation during both the years. Minimum disease intensity was recorded with full RDF (22.00) followed by 80 per cent RDF fertigation (24.50). Turmeric sown on the raised bed with 3 rows and applied bio-compost @ 25 t/ha or bio-compost @ 12.5 t/ha + gypsum @ 2 t/ha proved better for the management of leaf spot in turmeric as well as for getting higher rhizome yield. Amongst, 22 genotypes of turmeric screened against leaf spot disease, the genotypes viz., NVST-1, NVST-4, NVST-39, NVST-40 and NVST-50 showed resistance reaction. Genotype NVST-2, NVST-5, NVST-34, NVST-36, NVST-38, NVST-41, NVST-42, NVST-43, NVST45, NVST-47, NVST-48 and NVST-49 showed moderately resistant reaction. The rest of the varieties/genotypes proved susceptible including Kesar and Sugandham. The extract of Parthenium (Parthenium hysterophorus L.), Garlic (Allium sativum L.) and Acacia (Acacia nilotica L.) showed the strong inhibition of the pathogen. Among different isolates of Psuedomonas spp. tested in pot condition, P. aeruginosa (PaWS) showed maximum control (72.30%) of leaf spot followed by P. aeruginosa (PaWP) and P. fluorescens (PfWN). Among all the tested fungicides, carbendazim (0.5 g/l) and propiconazole (1 ml/l) proved better for the management of the disease as well as for getting higher rhizome yield. |
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Date |
2016-04-19T15:36:06Z
2016-04-19T15:36:06Z 2011-09 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/65489
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Language |
en
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Format |
application/pdf
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Publisher |
Navsari Agricultural University, Navsari
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