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ThesisItem Open Access Studies on the pathogenicity and physiology of Cornespora cassiicola (Berk & Curt.) Wei.(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1970) George, P V; KAU; Paily, P VThesisItem Open Access Studies on the production of toxic metabolites by Trichoconis padwickii ganguly in culture filtrate(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1969) Jayachandran Nair, K; KAU; Sam Raj, JThesisItem Open Access Effects of collar mot and ring-barking on the Rhizosphere microflora and certain chemical constituents of sword bean plants(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1968) Kanakambaran, P N; KAU; Sam Raj, JThesisItem Open Access Air spora over rice crop with special reference to Piricularia oryzae Cav.(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1967) Maheswari Amma, S; KAU; Sam Raj, JThesisItem Open Access Mosaic disease of Dolichos bifforus L., transmission , host range and effect of the virus on the host(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1967) Sukumara Dev, V P; KAU; Sam Raj, JThesisItem Open Access Studies on certain chemical constituents of banana leaves in relation to incidence of leaf spot diseases. A note on the fungi occurring on banana(Division of Plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1966) Chandrasekharan Nair, M K; KAU; Sam Raj, JThesisItem Open Access Studies on the helminthosporium Disease of rice detection of mycelium of the fungus in different tissues of the seed obervations on a saltant of Helminthosporium oryzae.(Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1965) Krishnan Kutty Nair, M R; KAU; Sam Raj, JThesisItem Open Access Varietal screening of banana against anthracnose disease(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1984) Srinagesh, K L; KAU; Jose, P CLaboratory and field studies of the varietal screening of banana against anthracnose disease were conducted at the college of Horticulture. Vellanikkara and at Banana Research Station, Kannara respectively during 1981-1983. In the field the infection started at the distal end of the banana fruit and in course of time the infected fruit became blackened, shriveled and mummified. After Harvest, the symptoms appeared as small brown spots which enlarged quickly and coalesced forming larger patches. The affected areas were covered with orange to salmon pink coloured conidial masses. The detailed morphological studies of the fungus proved that the anthraemose disease of banana is caused by colletrichum cloeosporioides cooko and massee, the imperfect stage of glomerella cinoulata spauld and shrenk. Twenty five varieties of banana fruit were screened in vitro at different stages of development against anthracnose disease. The varieties showed different degrees of susceptibility at various developmental stages of the fruit. The pooled analysis of the data showed that the variety nendra padaththi followed by palayankodan, jurmani kunthali, boodida bontha bathes, peyan, kanchikela, pisang mas and kapok were found to be highly resistant. The varieties Zanzibar, adakka kunnan, klue teparod, chinia, nendran, venneettu mannan, koduppilla kunnan, hybrid sawai, poocha kunnan, red banana and boodles altafort were found to be resistant to the disease. The variety robusta was found to be susceptible. The varieties njalipoovan, pisang lilin, dwarf Cavendish, matti and gros Michel were found to be highly susceptible. The major chemical constituents of banana fruit viz. reducing sugars, total sugars starch, crude fibre, crude protein and tannin at different developmental stages of twenty five varieties were analysed. The reducing sugars and total sugar were found to increase steadily from immediately after female phase to ripened stage in all the varieties. The starch and crude fibre contents, though increased steadily upto full maturity. Declined sharply at the ripening stage. The crude protein and tannin contents were maximum at immediately after female phase but steadily decreased and were minimum at ripening phase. There was a significant positive correlation between reducing sugars, total sugars and per cent disease intensity at three fourth maturity. High sugars were responsible for susceptibility to the disease. A significant negative correlation was obtained between crude protein and per cent disease intensity at half maturity. A significant negative correlation was also obtained between tannin and per cent disease intensity at one fourth and half maturity stages. High crude protein and high tannin contents were responsible for resistance to the disease.ThesisItem Open Access Studies on the phyllosticta leaf spot of ginger(Department of Plant Pathology, College of Horticulture, Vellanikkara, 1981) Premanathan, T; KAU; Peethambaran, C KLaboratory and field experiments of “The studies on the Phyllosticta leaf spot of ginger” were conducted at the College of Horticulture Campus, Vellanikkara during 1979-1981. The first visible symptom of the disease was observed as chlorotic specks. Fructification was more during the later stages of crop growth. The detailed study on the plant and environmental factors influencing the disease development in the field revealed that the average number of leaves per plant has a significant positive correlation with the disease intensity. Koch’s postulate and morphological studies proved that the pathogen causing the disease is Phyllosticta zingiberi Ramakr. Uninjured leaves and first three leaves, even after injury, failed to exhibit the symptoms on inoculation. Conidia germinated by putting forth single or double germtubes. Sucrose solution (1,000 ppm) supported faster and maximum spore germination and the bipolar germination noted was maximum in this solution. The fungus entered the leaf by direct penetration of epidermal cells without appressoria formation. The pycnidiospores and mycelia of the pathogen were found to survive even after seven months in soil under different depths and moisture conditions. The type Maran was found to be the least susceptible followed by Karakkal and Bajpai, whereas type Vengara was the most susceptible one. Out of the 12 fungicides tried, one per cent Bordeaux mixture and 2,000 ppm Bayer 5072 gave cent per cent inhibition of the fungal growth in both solid and liquid media. Antracol 2,000 ppm and panolil above 500 ppm in solid medium; bavistin 2,000 ppm and cuman above 500 ppm in liquid medium gave cent per cent inhibition of fungal growth. In the field trial cuman, was found to be the most effective fungicide in controlling the disease, followed by Bordeaux mixture and panolil. Maximum rhizome yield was noticed in cuman treated plots followed by Bordeaux mixture.
