Reducing the severity of bacterial soft rot of melon by applying calcium and boron mixtures

ABSTRACT

Applying borate + calcium nitrate + calcium sulfate in moderate concentrations [in vitro or in vivo] definitely attenuated the extracellular cell wall degrading enzymes produced by Erwinia carotovora var. Carotovora. The obvious decrease in the activities may be associated with the presence of both calcium and borate. The results indicated that the disease severity was reduced to the maximum value of 10% by using 5 x 104 M borate + 105 M calcium sulfate plus 10-5 M calcium nitrate. This effective mixture significantly increased radicle and hypocotyl lengths and decreased the fresh of the whole seedling, whereas the dry weights were insignificantly affected. The results indicated that the average pH remained close to alkalinity by the end of the incubation period. The resistance of melon seedling may be attributed to the presence of high levels of calcium which form calcium complex with pectic substances rendering the resistance to hydrolysis