EFFECT OF SOME SLOW AND FAST RELEASE NITROGEN FERTILIZERS AND PINCHING ON YIELD AND QUALITY OF RED ROOMY GRAPEVINES

Abstract

This experiment was conducted during 1998/1999 and 1999/2000 seasons on • one hundred and fourteen uniform and head trained Red Roomy grapevines in a private vineyard located at Seif-El-Sharkaya village, Mallawy district, Minia Governorate. The soil texture is clay loam. This study aimed to throw some light on the effect of three newly slow release N fertilizers namely sulphur-coated area, phosphorus-coated urea and urea-formaldehyde and compared with two conventional fast reiease N fertilizers namely ammonium nitrate and urea either singly or in combination with pinching on some growth aspects, leaf content ofN, P and K, berry set, yield as well as physical and chemical properties of Red Roomy grapes. The experiment involved the following thirty-eight treatments:- !- The first factor (A) included the subsequent nineteen treatments from the levels of the three slow release and the two fast release N fertilizers. a 1 : Sulphur-coated urea at 20 g N /vine. a2 : Sulphur-coated urea at 40 g N /vine. a3 : Sulphur-coated urea at 60 g N /vine. a4 : Sulphur-coated urea at 80 g N /vine. a5: Phosphorus-coated urea at 20 g N /vine. a6 : Phosphorus-coated urea at 40 g N /vine. a7 : Phosphorus-coated urea at 60 g N /vine. a8: Phosphorus-coated urea at 80 g N /vine. a9 : Urea-Formaldehyde at 20 g N /vine.