*Directorate of Extension Education, Punjab Agricultural University, Ludhiana-141004
Department of Plant Pathology, Punjab Agricultural University, Ludhiana-141004
National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
Present investigations were conducted under controlled conditions at PAU, Ludhiana. Plant growth parameters like height, girth, number of main branches, chlorophyll content, number and weight of tubers were recorded. The average height of virus infected potato plant was 20.20 cm as compared to that of healthy potato plants (31.22 cm). The height of healthy plant ranged from 22.50 to 37.50 cm whereas in case of infected plant it was 10 to 25 cm. Infected plants produced only 50 per cent main branches in comparison to the healthy plants. The average number of main branches observed on the infected plants was three as compared to healthy plants where it was 5.90. In healthy plants, main branches varied from 5 to 7 and in infected plants these varied from 2–4. The average girth of the stem of diseased plant was 2.32 cm while that of healthy was 2.60 cm. The chlorophyll content in the leaves of healthy plants varied from 2.630 to 2.320 mg/g while in infected plants chlorophyll content varied from 1.389 to 1.923 mg/g. The chlorophyll content in the leaves of infected plants was reduced by 35.88 per cent. The maximum number of tubers observed in the healthy plants was 14 and minimum was 9, while in infected plants the tuber number varied from 3 to 6. The average number of tubers per plant produced by the infected plants was 4.4 as compared to healthy plants where it was 11.2. The total weight of tubers per plant obtained from the virus infected potato plants was also one third of healthy plants. Weight of tubers in healthy plants varied from 490 to 730 gm per plant and from 150 to 290 gm per plant in infected plants.
