Document Type : Original Research Article
Authors
1
Medicinal and Aromatic Plants Research Department, Horticulture Research Institute, ARC, Egypt.
2
Ornamental Plants and Landscape Gardening Res. Dept., Hort. Res. Inst., ARC, Egypt
3
Piercing–Sucking Insect Research Department, Plant Protection Research Institute, ARC, Egypt.
Abstract
The present work was conducted at the Experimental Farm of EL-Quassasin Horticultural Research Station, Ismailia Governorate, Egypt, during the two winter consecutive seasons of 2016/2017 and 2017/2018. The aim was, to investigate the effect of different nitrogen fertilization rates (control, 50, 75 and 100% of recommended N rate), amino acids type (control, L-tryptophan, phenylalanine and L-tryptophan + phenylalanine) as a foliar spray at 150 mg/l for each one and their interactions on growth and production of coriander andpiercing–sucking pests infestation. The obtained results indicated that, nitrogen fertilization rate at 300 kg ammonium sulfate/feddan (recommended rate) significantly increased growth parameters (plant height, number of branches/plant and fresh and dry herb weights/plant), root system (fresh and dry weights of roots/plant and root length), yield components (number of umbels/plant and number of florets/umbel/plant, fruit yield/plant and /feddan), volatile oil productivity (volatile oil percentage, volatile oil yield/plant and /feddan) and chemical constituents (N, P, K and total carbohydrates percentages) compared to control. Moreover, the highest values of the above mentioned characters were registered by foliar spray of L-tryptophan + phenylalanine with significant differences between the other rates under study. Generally, the better growth characters and root system, higher yield components and volatile oil production, chemical constituents of fruits could be obtained by spraying L-tryptophan + phenylalanine at 150 mg/l on fertilized coriander plants with nitrogen at the recommended rate, followed by the combined treatment of nitrogen fertilization as 75% plus L-tryptophan + phenylalanine. In the same trend, highly significant differences (≤ 0.05) between the mean numbers of the piercing–sucking pests; i.e., Hyadaphis coriandri (Das), Bemisia tabaci (Genn.), Thrips tabaci (Lind.), Tetranychus urticea Koch., and their associated natural enemies i.e., Coccinella spp, Chrisoprella carnea (Steph.), aphids parasitoids and predacious mite which were resulted as the variation in nitrogen fertilization rates, and foliar spray of amino acids types. Also, the simple correlation calculation revealed significant coefficients for the relation between each of the surveyed pests and their associated natural enemies correlated with growth parameters (plant height and number of branches/plant) and seed yield/plant.
Keywords
Main Subjects
)
View on SCiNiTO