بررسی تاثیر کودهای نیتروژنه بر جلب شته و خصوصیات کمی و کیفی گل داوودی

Chrysanthemum is one of the important cut flowers in the world and Iran. One of the most important pests of chrysanthemum(Dendranthema morifolium) is aphids and kitchen garden aphid Aphis gossypii Glover have the biggest dispersion in iran. In order to investigate relationship between plant nitrogen with aphids population and quantitative and qualitative characteristics of flower in chrysanthemum, the experiment was carried out in completely randomize block design with four replication and five nitrogen treatments 0, 100, 200, 300 and 400 kg/h as ammonium nitrate (AN) with five additional treatment including: 1) 200 kg/h N as ureafrom (38% N)( UF1), 2)100 kg/h N as ureafrom plus 100 kg/h N as AN (UF2),3) 100 kg/h N as ureafrom plus 100 kg/h N as AN (UF3), 4) 200 kg/h N as sulfuric cotated urea inner production (19% N) (SCU1 ) , 5) 200 kg/h N as imported sulfuric cotated urea(32%N)(SCU2). Ureaform, sulfuric cotated urea and quarter AN fertilizers were used befor plantind and remained AN top dressing in three steps (fifteen days interval after planting). Aphid population measured after each top dressing fertilizer. Results showed number aphid in leaf had significant correlation (r=64%) with plant nitrogen (P 0.01). The greatest increase number aphid in leaf at N300 amounting to 7.14 fold and the least at N400 3.42 fold incontrast with control (NO) were observed. The highest bud and flower diameter, dry and wet weight and flower qualitative number got by N400. The greatest flower number in plant, chlorophyl index and iron, zinc, copper and boron amount in plant was obtained by SCU2. Key words: Aphid, Aphis gossypii Glover, chrysanthemum, Dendranthema morifolium, nitrogen, ammonium nitrate, slow release fertilaizer, sulfuric cotated urea, ureaform.