Volume 62, Issue 3
September 1965, pages 103-157
pp 103-110 September 1965
pp 111-116 September 1965
pp 117-129 September 1965
An account is given of the incidence of blast disease of rice in correlation with some meteorological factors. The results show that forecasting of blast outbreak in India can be attempted on the basis of minimum night temperature range of 20°–26°C. in association with a high relative humidity range of 90% and above lasting for a period of a week or more during any of the susceptible phases of crop growth,viz., seedling stage, post-transplanting, tillering stage and at neck-emergence.
pp 130-139 September 1965
The reduction in the contents of chlorophyll in virus diseased pigeon pea leaves was observed to be as high as 60·9 per cent. Carotene and xanthophyll contents of diseased leaves also showed a decrease. The activity of chlorophyllase was increased due to virus infection. The total carbohydrate contents of diseased leaves were reduced. The synthesis of sucrose in diseased leaves was at a lower rate than in the healthy. This reduction in the ability to synthesize sucrose indicated a derangement of photosynthetic activity in diseased plants. Evidences were obtained to show that the translocation of sugars was reduced and that the nature of sugars translocated was altered in the diseased plants.
pp 140-144 September 1965
pp 145-148 September 1965
pp 149-154 September 1965
1. The common organic acids inhibited leaf phosphatase activity, This effect is mostly due to the hydroxyl groups in them.
2. The less common organic acids, which have only carboxyl groups, did not show any marked inhibitory action on phosphatase activity.
3. The less common organic acids eluted the leaf phosphatase after adsorption on aluminacγ gel to a greater extent than the more common organic acids.
4. The second elution of the purified enzyme from the aluminacγ gel was not possible with the organic acids as it was adsorbed on the gel.
pp 155-157 September 1965
This paper deals with the chromosome numbers of 11 species and 17 varieties of IndianCymbopogon, 5 species are only diploid, two, diploid and tetraploid and three, hexaploid.