EFFECT OF NITROGEN SOURCES AND LEVELS AND PRUNING DATE ON JASMINUM GRANDIFLORUM, L

Abstract

Two field experiments were carried out in the Experimental Farm of Kafr El-Sheikh, Faculty of Agriculture, Tanta University, during two successive seasons (1996/97 and 1997/98). The first experiment aimed to study the effect of different nitrogen sources and levels on the growth, flowering, concrete recovery, absolute oil yield and chemical composition of Jasmiman grandiflorum,L. Shrubs of six years old were fertilized with three nitrogen sources i.e, urea (46.5%N), ammonium sulphate (20.5%N) and ammonium nitrate (33.5%N) as six levels of each source (60, 80, 100, 120, 140 and 160 g.N/plant) were used, in addition to control (unfertilized plants). The nitrogenous fertilizers devoted to each plant were divided into four equal portions, beginning from March lOth, with 40 days interval. Besides there was applied 60 g/plant of calcium super phosphate (15.5% P205) in three equal doses beginning from March l't and 60 g/plant potassium sulphate, (48% K20) in three equal doses, beginning from April Ist with 45 days interval for each fertilizer.

As for the second experiment, it aimed to study the effect of pruning date on growth, flowering, concrete recovery, absolute oil yield and chemical composition of Jasminum grandiflorum. The plants of 5 years old were pruned on six different dates (November 25'", December

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December 25th, January I 01h, January 25th and February 1oth ). The

pruning was done by removing all the past season shoots dead and diseased branches at a height of 50 em above the ground level and all leaves in the plants were stripped off.

The following results couldbe obtained:

Experiment -1:

Effect of nitrogen sources: • Application of ammonium sulphate gave the tallest plants, followed by urea, then ammonium nitrate in the two seasons. • The significantly highest leaf area resulted from applying urea compared to either ammonium sulphate or ammonium nitrate in both seasons.