EFFECT OF DIFFERENT LEVELS OF NITROGEN FERTILIZER, LEAF REMOVAL AND A FUNGICIDE TREATMENTS ON BUNCH ROT DISEASE OF GRAPES

Document Type : Original Article

Authors

1 Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt.

2 Plant Pathology Department, Faculty of Agriculture, Cairo Univ. , Giza, Egypt

Abstract

Two field trials with 10 years old grapevines c. v. Red globe (seeded cultivar)
were conducted during 2003 and 2004 at Menia govemorate, Egypt. In these trials,
treatments consisted of N1 at 30 unit of Nitrogen (Amonium sulphate), N2 at 45 N
unit, N3 at 60 N unit, N4 at 75 N unit, N5 at 90 N unit and control (without adding N)
were applied to determinate the effect of different levels of Nitrogen on bunch rot
disease incidence and severity. An additional trial was to compare the leaf removal
treatment with non managed control. All piots were established in a split-plot design
with or without using fungicides. The above mentioned treatments were applied during
each growing season starting at full bloom till veraison stage (the beginning of
ripening) in order to control bunch rot disease. The obtained results showed that
incidence and severity of bunch rot disease were significantly reduced when the
treatment of nitrogen fertilizer 30 N unit was used while the high levels of nitrogen
fertilizer increased incidence and severity of the bunch rot.
Leaf removal also reduced disease incidence and severity in nonsprayed
control compared with the in tact nonsprayed control. The highest reduction in disease
incidence and severity was in the treatments with three sprays of fungicide Euparen M
at bloom, pre-close and veraison stages. Also, the produced fruit yield from treated
vines was significantly higher during the first and the second seasons in comparison
with that of untreated vines.

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