Journal of Agricultural Sciences (Sep 2021)
Effect on Yield and Some Quality Characteristics of Seed Harvest at Different Stages of Maturity in Nigella sativa L.
Abstract
Nigella sativa L. is a significant medicinal and aromatic plant due to the usage of both its seed and fixed oil. The aim of the study is to investigate the effects on seed yield, various yield components, fixed and essential oil content, and chemical composition (2018 year) of black cumin when harvesting the seed at four different stages of maturity. These stages were 25% (SH1), 50% (SH2), 75% (SH3) and 100% (SH4) browning of capsules. Two-year field experiments (2017 and 2018) were set up according to a randomized complete block design with triplicate, using a black cumin population obtained from the Burdur province under Isparta ecological conditions.Significant statistical differences were found among the harvest stages in regards to the seed yield, plant height and the thousand-seed weight, while no differences were found in the numbers of capsules and branches, essential oil and fixed oil contents in both experimental years. Seed yield and its components increased during the harvest stage up to SH3, while essential oil and fixed oil contents decreased insignificantly from SH1 to SH4 in both years. According to the combined years; plant height, the number of capsules, the number of branches, the 1000 seed weight, seed yields, essential oil and fixed oil contents varied between 38.3-42.5 cm, 6.03-6.85 capsule plant-1, 6.50-6.91 branches plant-1, 2.30-2.57 g, 307.3-542.3 kg ha-1, 0.087-0.101% and 31.14-32.69%, respectively. The main components of black cumin essential oil were characterized by cymol (25.01-26.90%), thymoquinone (2.39-4.41%), carvacrol (10.12-10.41%), junipene (5.33-6.66%), Δ-3-carene (5.55-8.71%), β-pinene (2.98-3.65), trans-sabinene hydrate (8.02-11.93%) and α-thujene (7.82-9.42%) according to harvest stages in the 2018 season. Considering the present results, SH3 stage was advised because of its higher seed yield. The contents of essential oil composition of black cumin varied according to harvest stages.
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