نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 استادیار پژوهش، بخش تحقیقات منابع طبیعی، مرکز تحقیقات کشاورزی و منابع طبیعی استان هرمزگان، سازمان تحقیقات، آموزش و ترویج کشاورزی، بندرعباس، ایران.
2 استادیار، گروه مهندسی منابع طبیعی، دانشکده کشاورزی و منابع طبیعی دانشگاه هرمزگان، هرمزگان، بندرعباس، ایران
3 دانش آموخته کارشناسی ارشد مهندسی منابع طبیعی، مدیریت و کنترل بیابان، دانشگاه هرمزگان، بندرعباس، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: In order to reduce water consumption and producing suitable seedlings, we need have a perfect knowledge of grey mangrove habitat condition in two vegetative periods and their growth replies in the nursery. So, the aim of this study was to investigate the germination percentage and grey mangrove replies to the different levels of light, irrigation and contracted effects of them in two 3-month growth periods in the nursery.
Material and Methods: Propagules were collected from 30 healthy mother trees in the summer of 2022 and cultivated in five groups (3 pots in every group) of plastic pots in the coastal nursery (Factorial statistical design). We carried out irrigation regimes (2 times a day, once a day, every other day and every second day) and light treatments in five levels of 0%, 25%, 50%, 75% and 100% on propagules. In order to investigate vegetative replies of seedling to light and irrigation in the two 3-month periods (measurements), collar diameter, height and leaf number (after becoming bi-foliate), were measured using digital caliper and ruler. Growth amounts were calculated from the differences of collar diameter and height in two 3-month periods. Germination percentage was recorded at the initial growth and also leaf area of 6-month seedlings were measured in all treatments and were analyzed using GLM at the level of 95%.
Results: According to the results, germination percentage was higher in two times and daily irrigation as well as 50% and 75% light treatments than that of in the others (P≤0.05). In two times irrigation, leaf area with amount of 22.83 cm2 had a significant difference than the other treatments (P≥0.05). leaf area had the highest amounts in 50%, 0 and 75% light treatments (P≤0.05). All vegetative characteristics in the first 3- month and second 3-month measurement had a different reply to the light and irrigation significantly. Also, all the growth properties of seedling, except for leaf number, were higher in the first 3-month measurement that those of in the second 3-month measurement. In the second 3-month measurement, there were lower differences among treatments. According to the results, in the first 3-month measurement, diameter growth had the highest amount in the irrigation regime of two times a day (0.41 mm), once a day (0.36 mm) and light level of 50% (0.32 mm) while in the second 3-month measurement, diameter growth differences decreased in 50, 25 and 75% light treatment and were in the same groups. Also, in the first 3-month measurement, height growth had the highest amount in the twice a day irrigation treatment with the value of 4.75 cm decreased in the second 3-month measurement (2.41 cm) that was at the same group along with once-a-day irrigation regime (2.21 cm). Height growth in the first 3-monthe measurement had the highest amount at 50% light (4.48cm) and 75% (4.34 cm) light treatment changed in the second 3-month measurement. Unlike the other vegetative characteristics, leaf number was lower in the first 3-month than that of in the second 3-month.
Conclusion: According to the results, grey mangrove seedlings are more sensitive to the light and irrigation at the first 3-month growth and exhibit stronger replies to them. So, providing the suitable irrigation and shade is so important in the initial growth of grey mangrove seedling in the nursery. We must provide 50% light and twice a day irrigation at the first 3-month for grey mangrove seedling in order to grow suitable while we can increase light intensity and also irrigation cycle.
کلیدواژه‌ها [English]
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