Open AccessDo NH4:NO3 ratio and harvest time affect celery (Apium graveolens) productivity and product quality?
Author(s) -
S. A. Saleh,
Guangmin Liu,
Mingchi Liu,
Wei Liu,
Hongju He,
Magdi T. Abdelhamid
Publication year - 2019
Publication title -
folia horticulturae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.473
H-Index - 9
eISSN - 2083-5965
pISSN - 0867-1761
DOI - 10.2478/fhort-2019-0027
Subject(s) - apium graveolens , chemistry , horticulture , nitrate , chlorophyll , botany , food science , biology , organic chemistry
Due to the remarkable health benefits of celery ( Apium graveolens ), its consumption has increased over time. A partial substitution of NO 3 − with NH 4 + is recommended to limit the accumulation of NO 3 − in leafy vegetables. Hence, a factorial experiment with two factors, consisting of six treatments as combinations of three NH 4 :NO 3 ratios (0:100, 20:80 and 40:60) in nutrient solutions and two harvesting times (in the morning and in the evening), was conducted on celery plants in a soilless culture system. The results showed that 100% NO 3 as a sole N source significantly increased plant height, leaf number, chlorophyll, fresh weight, N, K, Ca, Mg, Fe, Mn, Zn, protein, dietary fibre, soluble sugars, nitrate, vitamin C, α-carotene, β-carotene and lutein of celery plants compared to either 80 or 60% NO 3 . However, this increase was not significant compared to 20% NH 4 :80% NO 3 in terms of leaf number, fresh yield, N, Mg, Mn, protein, soluble sugars, vitamin C and α-carotene. Harvesting in the evening significantly increased K, Mg, Fe, soluble sugars, α-carotene and β-carotene, and lowered the nitrate level in celery plants. In conclusion, partial replacement of 20% NO 3 -N with 20% NH 4 -N and evening harvesting are recommended for a greater fresh yield, higher quality, and lower nitrate level.