EFFECT OF SOME NITROGEN SOURCES AND POTASSIUM LEVELS ON YIELD, QUALITY AND NITRATE ACCUMULATION IN LETTUCE LEAVES | ||||
| Journal of Plant Production | ||||
| Article 22, Volume 27, Issue 5, May 2002, Page 3401-3411 PDF (385.93 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2002.254724 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| M. E. Abou El-Nasr, | ||||
| Vegt. Res. Dept., Hort. Res. Inst., Agric. Res. Center, Giza, Egypt. | ||||
| Abstract | ||||
| To study the influence of nitrogen sources and potassium levels on growth, yield and chemical constituents of lettuce plants, cv. Balady, two experiments were conducted at Experimental Farm of Barramoon, Dakahlia Governorate during the winter seasons of 1999/2000 and 2000/2001. twelve treatments representing all possible combinations of three N sources (Urea, ammonium nitrate and ammonium sulphate) and four K doses (0, 20, 40 and 60 kg K2O / fed.) were used in split plots design with four replicates. The obtained results can be summarized as follows:- Vegetative growth and yield: 1. Effect of N-sources: Urea followed by ammonium nitrate were significantly increased growth and yield parameters (plant height, No. of outer and inner leaves, fresh and dry weight of outer and inner leaves, fresh weight / plant and total yield, ton/fed.) with no considerable differences among them in most cases. Ammonium sulphate was of the significant least effect. 2. Effect of K levels: Increasing K-levels from 0 up to 60 kg K2O/fed. considerably increased all the studied growth and yield parameters, 60 kg K2O level was the most superior one. 3. Effect of interaction: Interaction significantly affected growth and yield of lettuce plant, NH4NO3 x 60 kg K2O/fed followed by urea x 60 kg K2O/fed were the most superior treatments in their effect with no significant differences among them in most cases. K level (0 K2O/fed) x all N-sources used were the treatments of the significant least effect. Chemical constituents 1. Effect of N-sources: Both urea and ammonium nitrate were significantly improved N, P and K content of lettuce plant relative to ammonium sulphate with no considerable differences among them in most cases in the two seasons of study. On the other hand, urea was of the least NO3 content in their plant leaves. Ammonium nitrate was of the significant highest NO3 content in both seasons. 2. Effect of K-levels: N, P and K content considerably increased along with increasing the supplied K from 0 up to 60 Kg K2O/fed. NO3 accumulation was increased with increasing K from 0 to 40 kg K2O/fed, then decreased at 60 kg level. 3. Effect of interaction: K 0 level with all N-sources were the treatments of the lowest N, P, K and NO3 content relative to other treatments. NO3NH4 and urea x 60 kg K2O/fed were the treatment of the highest N, P and K, meanwhile, urea x 60 Kg K2O was of low NO3 content. Finally, it could be concluded that ammonium nitrate and/or urea each with 60 kg K2O/fed were the best treatments for maximizing the growth and yield of lettuce plant. Urea with 60 kg K2O/fed was the treatment of best yield and low NO3 content of leaves. So, it concluded as best treatment on basis of yield and NO3 safety level for human nutrition. | ||||
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