Browsing by Author "Davis, T.A."

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    A ‘2^7Confounded design' for a manurial experiment on coconut
    (1969-04) Davis, T.A.
    A mioronutriont-manurial experiment on a factorial 2^7 confounded design was started in 1053 on a 8-hoctaro coconut plantation at the Central Coconut Research Station, Kayangu-lam, Kerala State as an attempt to control the Root (wilt) disease affecting the palms. The micro-nutrients tried were Boron, Copper, Manganese, Iron, Molybdenum, Zinc, as well as Magnesium. Data on the fruit-yield and other morphological characters were recorded on the 384 experimental palms from the inception of the experiment. The fruit-yield data alone upto and inclusive of 1000 were considered for the Analysis of Covariance and the results reported. After 1000, the micro-nutrients were administered directly into the palms in liquid form by a different method. Results of analysis have revealed that the healthy palms did not show any significant response to the application of any of the micro-nutrients. But palms in the early satge of the root (wilt) discard res ponded favourably to the treatment combination of Boron and Iron. However, when applied alone or in combination with Copper, Iron depressed the nut-yield in this category of palms significantly. Severely diseased palms responded very favourably with Magnesium and Molybdenum when applied individually.
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    Sap Transfusion, A New Devise For Virus Transmission Trials In Palms
    (1954) Nagaraj, A.N.; Menon, K.P.V.; Davis, T.A.
    The symptomatology of the Wilt disease of coconuts in India has been briefly discussed, a study of which points to the possibility of this being a virus disease. Preliminary attempts at grafting in coconut failed. As a substitute to grafting a new technique, i.e., sap transfusion has been adopted for virus transmission trials and the method has been described in detail. This method in effect simulates an organic union between a diseased root scion and a healthy root stock. Of the two possible ways of effecting transfusion or sap from a diseased to a healthy tree, the one wherein the sap pumped up by a severed diseased root is transfused into the system of a healthy tree is more practicable. However, this method is not utilisable for feeding infective extracts of aerial parts of infected coconut palms or other hosts. Therefore, feeding extracts through tips of roots induced in boxes for the sake of convenience was attempted. The absorption of extracts through uncut roots being slow and selective, these were fed through cut ends of mature roots of healthy palms.
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    Sap Transfusion, A New Devise For Virus Transmission Trials In Palms
    (1954) Nagaraj, A.N.; Davis, T.A.; Menon, K.P.V.
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    Studies on coconut pollen with reference to the leaf and root (wilt) diseases
    (1960) Thomas Varkey; Davis, T.A.
    The number, size, percentage germination etc. of the coconut pollen in relation to the root (wilt) disease were studied at the Central Coconut Research Station, Kayangulam, Kerala. The dry pollen of a healthy coconut palm is ellipsoidal measuring about 66.4 u. by 33.2u and when it gets soaked with water, it assumes a spherical shape measuring about 49.8 along the diameter. However, the pollen from diseased palms measure less. Dimunitive ones and pollen having irregular shape are at their maximum in the case of diseased, trees in the acute condition. Even where the tree produces only a few male flowers on account of its exhaustion due to disease, the flowers were observed to have numerous normal looking pollen grains capable of germination and presumably fertilisation. The percentage of dummy pollen is higher in diseased palms and there is a correlation between the percentage and the stage of infection. It was also seen that the dummy pollen was more in the case of root (wilt) diseased palms than in. the leaf diseased ones of the same stage of infection. It was also seen that the percentage of germination of the pollen dwindles as the tree gets aggravated with the diseases. In the case of very young palms (healthy ones), the percentage germination of pollen was found to be much lower than that of healthy adult palms.
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