Effect of soil solarization on the growth of onion (Aliium cepa L.) and onion blight disease

Abstract

Soil solarization, with the addition of soil amendments, was carried out for a period of six weeks. The maximum temperature of solarized plots was 9.2–11.3oC higher than that of non-solarized plots and the minimum temperatures in solarized plots were 7.5–12.1oC higher than non-solarized plots. Moisture was conserved most effectively (10.05 percent) in the solarized plots treated with FYM, followed by poultry manure (9.27 percent), whereas, the least amount of moisture was conserved in plots supporting none of the amendments (1.72 percent). At the end of solarization, maximum fungal colonies (26A—104) were detected in solarized plots amended with poultry manure, maximum actinomycete colonies (268A—103) and maximum bacterial count (416.00A—103), were obtained in solarized plots with none of the amendments. The maximum root and shoot length, and yield were recorded in the seedlings from the nursery treated with solarization and in which FYM had been added. The average number of leaves recorded was also highest for solarized plots treated with FYM and least in non-solarized untreated plots. There was a gradual increase in the foliar blight disease intensity in the crop obtained from solarized plots treated with different amendments, from 1st to 11th standard week. However, from 11th to 13th SW, there was a steep rise in intensity in case of all the amendments.