نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 . نویسنده مسئول، دانشجوی دکتری فیزیولوژی تولید و پس از برداشت گیاهان باغبانی، گروه علوم باغبانی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
2 گروه علوم باغبانی، دانشکده علوم زراعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Strawberry is a herbaceous perennial plant that is mainly propagated using daughter plants obtained from runners in the form of bare roots from December to February from the nursery or propagation center. Typically, runners with larger crown diameters produce a higher number of flowers and consequently have higher yields. Proper nutrition is one of the factors affecting crown diameter. Nutrition during the induction of flowering period is very important for improving flowering. High nitrogen levels during summer may increase crown formation and generally increase production. In this research, application of different amounts of nitrogen fertilizer on mother plants during spring and fall seasons was carried out to determine its effect on the quantitative and qualitative traits of the produced runners.
Materials and methods: The research was conducted under field conditions in soil beds. Camarosa cultivar plantlets were obtained from a reputable nursery and planted in March 2017 with 40 cm spacing between plants in two rows on ridges in Ghaemshahr. The experiment was carried out as a factorial based on a completely randomized block design with spring fertilization at three levels (0, 150 and 300 kg/ha nitrogen) and fall fertilization also at three levels (0, 50 and 100 kg/ha nitrogen) with three replications (each replication containing 4 plants). Spring fertilization (S) was applied in three splits during March to April (March 30 to April 26) every week and fall fertilization (F) was also applied from Early to late September (September 7th to September 28th) in 2017 on mother plants every week. Then in late November, daughter plantlets were separated and planted separately based on each treatment. After planting the seedlings, no fertilization was applied in order to determine the effect of fertilization of mother plants on the growth and yield of produced plantlets. Subsequently, the fruits were harvested from early May and transferred to the laboratory. Then morphological, biochemical traits of the fruits as well as photosynthetic traits of the plants were evaluated.
Results: The results showed that nitrogen consumption of 150 kg/ha in spring and 100 kg/ha in fall resulted in the maximum fruit length of 3.91 cm. The use of fall fertilizer of 100 kg/ha has resulted in the highest fruit weight of 15.24 gr. Although this value was not significantly different from other high levels of nitrogen. The use of fall and spring fertilizer decreased the soluble solids and anthocyanin, so that the highest amount of soluble solids (8.47) was observed during the application of fall fertilizer and the time of application of spring fertilizer in the amount of 150 kg/ha, at the rate of 9.66. The amount of anthocyanin was at the highest level from the control treatment to the simultaneous application of 150 kg/ha in spring and 50 kg/ha in fall, and after that it was similar to soluble solids with a decrease. Excessive consumption of nitrogen fertilizer disrupts the balance of beneficial fruit compounds and increases fruit nitrate content. Increased over-consumption of nitrogen fertilizer leads to disruption of fruit compound balance such as vitamin C, anthocyanin, and other secondary metabolites. Fall nitrogen application had a more significant effect on increasing photosynthetic parameters and chlorophyll fluorescence including net photosynthesis and maximum quantum yield of photosystem II.
Conclusion: Overall, the results showed that nitrogen fertilization has a very great impact on the production of strong plantlets. According to the obtained results, application of 100 kg/ha of nitrogen in fall can be recommended for production of healthy strawberry plantlets with high numbers.
کلیدواژه‌ها [English]
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