Browsing by Author "Venkitesan, T S"

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Bio-ecology of the cyst nematode infecting banana
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1989) Job Sathyakumar Charles; Venkitesan, T S
Pathogenicity of the cyst nematode on banana cv. Nendran carried out revealed that the nematode can affect crop growth and yield at lowest initial inoculum of 100 cyst3 per plant. However, the threshold level of initial inoculum of 800 to 1,000 cysts per plant the growth, yield and quality of fruits were considerably reduced. An initial inoculum of 100 to 1,000 viable cysts per plant at planting time could reduce bunch weight by 20.5?£ to 56.6?4. The nematode Infection was observed to affect quality of fruits by increasing acidity and reducing total sugars. This nematode attacks the minute tertiary feeder roots and not observed to attack the fleshy roots and rhizome portions. The attacked feeder roots turn black in colour and detach easily. The final nematode population revealed that there was significant build up in the density of population. The increase ranged from 15*59 to 35.18 per gram root and from 1,168 to 3,188 in 100 gram soil. A significant negative correlation was found to exist with plant growth parameters, bunch characteristics and root weight with the initial inoculum levels of cyst nematode population.
Control of cashew stem borer (Plocaederus ferrugineus L.) by the DD. 136 nematode (Nevaplectana earpocapsae Weiser 1955)
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1989) Madhu, S; Venkitesan, T S
Control of root-knot nematode (Meloidogyne incognita Kofoid and White, Chitwood) infesting black pepper (Piper nigrum L.) by bacterial pathogens
(Department of Entomology, College of Horticulture, Vellanikkara, 1990) Sheela, M S; Venkitesan, T S
Crop loss caused by the root-knot and reniform nematodes in brinjal and control of the pests
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1986) Jiji, T; Venkitesan, T S
Two pot culture experiments were laid out i) to study the pathogenic effect of different inoculam levels of root-knot and reniform nematodes on brinjal, alone or in combination each at 100, 500 and 1000 nematodes/plant comprising 10 treatments and 10 replications and ii) to study the effect of four granular chemicals viz. carbofuran, aldicarb, phorate and quinalphos at the rate of 1.0 and 1.5 kg ai/ha against the above two nematodes alone or in combination, comprising of twentyfive treatments and five replications. The results brought forth the adverse effect induced by the highest inoculum levels of two nematodes either alone or in combination on plant growth characters of brinjal even after 45 days of inoculation. The reniform nematode seems to have more pathogenic effect than root-knot nematode at the same inoculum level. The results obtained from the second experiment indicated that carbofuran or aldicarb at the rate of 1.0 and 1.5 kg ai/ha were found to be the best treatments resulting in increase in plant growth characters and yield and in reducing the nematode population in roots and soil. Phorate and quinalphos were found least effective in promoting growth of plants and in reducing nematode infestations. However the application of phorate or quinalphos at the rate of 1.5 kg ai/ha was found to have equal effect as that of carbofuran or aldicarb up to 15 days of their application.
Methods of application of DBCP (1, 2-dibromo-3-Chloropropane) for the control of plant parasitic nematodes
(Kerala Agricultural University, 1980) Venkitesan, T S; Seshadri, A R
Six methods of application of DBCP were evaluated with reference to the diffusion and penetration of the material into soil and the knock-down of plant parasitic nematode population in field and polythene column experiments. Under field conditions application of DBCP along with irrigation water gave maximum crop response and best kill in the 0-30 cm layer, but in deeper layers, injection followed by irrigation has given higher percentage kill. The Onion test in the polythene column experiment indicated that DBCP was able to penetrate 30-45 cm deep, when applied along with irrigation water. Injections at 15 and 23 cm depths resulted in the restricted movement of DBCP within 0-30 and 15-45 cm depths, respectively. When injections were given at 23 cm depth followed by irrigation, an upward as well 3s downward movement of the nematicide seems to have occurred. The depth of application by spot injegtion with without irrigation seems to be a critical factor jn obtaining highest percentage kill of the plant parasitic nematode population.
New records of plant parasitic nematodes from Kerala
(Kerala Agricultural University, 1981) Venkitesan, T S; Charles, J S; Sheela, M S
Occurance of plant parasitic nematodes associated with different crops in Cannanore district, Kerala
(Kerala Agricultural University, 1972) Venkitesan, T S
On the growth and yield of west coast tall coconut in relation to depth of planting
(Kerala Agricultural University, Vellanikara, 1969) Venkitesan, T S; Varada Rajan Nair, P
Pathogenicity of reniform nematode (Rotylenchulus reniformis Linford and Oliveira, 1940) on ginger (Zingiber officinale rose)
(Department of Agricultural Entomology , College of Horticulture, Vellanikkara, 1989) Elizabeth John; Venkitesan, T S
Two pot culture experiments were laid out (i) to study the pathogenic effect of different inoculum levels of R. reniforms on ginger comprising of seven treatments and four replications and (ii) to studythe relative pathogenic effect of root -knot and reniform nematodes singly or in combinations on the same crop comprising of five treatments and four replications. The duration of study was 120 days The result reveals that ginger is a good host for reniform nematode R. reniformis and it can cause pathogenic effect at a considerable extend at higher inoculum levels, within a period of 120 days.
Plant parasitic nematodes associated with pineapple in Kerala
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 1981) Hamza Koya, C P; Venkitesan, T S
As a part of the studies on the occurrence of plant parasitic nematodes associated with pineapple in Kerala, a survey was carried out in different agro climatic regions of the Kerala State and it was found that R. reniformis occurred in more than 76 per cent of the locations sampled. Helicotylenchus spp. were recorded in about 50 per cent of the locations. The other plant parasitic nematodes detected in association with the crop included Meloidogyne spp., Creconemoides spp., Pratylenchus spp., Hoplolaimus and Hemicyclophora occurred in very low population densities. A new species of Helicotylenchus closely resembling H. digitatus ( Hussain and Siddique, 1964) but differing with respect to spear knob characters and location of excretory pore has been reported to be associated with the crop. The pot culture trial with M. incognita indicated that this nematode could not induce pathogenic effect on the cv kew even at the highest inoculum levels of 10,000 larvae per 7.5 kg soil during the period of 180 days.
Studies on the burrowing nematode radopholus similis (cobb,1893) thorne 1949 on pepper(Piper nigrum L.) and its role in slow wilt disease
(Department of plant pathology, University of agricultural sciences, Bangalore ., 1976) Venkitesan, T S; Setty, K G H