Journal of Ornamental Plants
Volume:11 Issue: 2, Spring 2021

Water resources have been decreasing in recent years due to global warming, thereby requiring more studies to determine the effect of limited water on plants. This study aimed to determine the effect of different irrigation levels on the flowering and growth characteristics of zinnia plant (Zinnia elegans). The research was carried out in the Plant Production Research Center of the Faculty of Agriculture at Çanakkale Onsekiz Mart University, Turkey. For the study, zinnia plants were grown in pots under field conditions and 4 different irrigation treatments were created where 100% (I-100 / control), 75% (I-75), 50% (I-50) and 25% (I-25) decreasing moisture was applied and the soil moisture was monitored by sensors. Data were subjected to variance and PCB-Biplot analyses. Results showed significant differences among irrigation treatments according to measured traits. At the end of the study, irrigation water amount and plant water consumption values were found to be 28.1-142.8 mm and 33.9-144.4 mm, respectively. Water stress was found to have a negative effect on the growth and agronomic characteristics of zinnia. However, it was observed that the quality of flowers is not affected even if plant growth is negatively affected by a 25% water shortage.

The flowers of wild Rosa iberica are investigated to find the chemical constituents of its aroma and essential oil. The measurements were carried out by GC-FID and GC-MS analysis. The aromatic compositions emitted from the flowers revealed 11 constituents, among which phenyl ethanol (38.82%), benzyl alcohol (28.48%), and geraniol (12.57%) were the most abundant. The essential oil investigation detected 13 compounds, the most abundant ones being anethole (45.56%) and phthalic acid (32.23%). The scent and essential oil detected de novo in the petals of R. iberica are beneficial as natural ingredients in seasonings, therapeutic compositions, and an aromatic plant in breeding strategies of ornamental shrubs and flowers.

Selenium (Se) is an essential microelement for humans and a beneficial element for plants. Recently, biofortification with Se has emerged as a key practice to increase plant quality. The aim of present study was to investigate the postharvest responses of Pelargonium peltatum L. to the application of Se in soil. The Se was used as sodium selenite (Na2SeO4) in soil application of 20, 40, and 60 µM L-1 distilled water. The results showed that flower weight, relative water content (RWC), anthocyanin, and vitamin C decreased over the storage time. Malondialdehyde (MAD) increased by progressing the time of storage. Total phenolic content (TPC) and total flavonoid content (TFC) were significantly enhanced at early days of storage and then decreased up to the end of storage on days 4 and 6. Se significantly improved flower weight, RWC, anthocyanin, vitamin C, TPC, and TFC entire the storage. Although, Se was effective in enhancing the quality of P. peltatum L., there was no significant difference between 40 and 60 µM Se in all traits. Therefore, this experiment suggests using 40 µM Se to alleviate adverse effects induced by postharvest time growth on productivity of P. peltatum L.

Bedding plants form an important part of the urban public space and private gardens. Drought stress management is considered as an important factor in nowadays landscape. Low water use landscaping is becoming common issue in arid regions, little information is available about regulated deficit irrigation tolerance and responses of many ornamental plants, especially annuals and herbaceous perennials. Calendula officinalis L. (Asteraceae), known as calendula or marigold, is an annual species widely used around the world as a medicinal plant. The main aim of this study was to evaluate drought stress response at two levels (100 and 50% FC) on 13 pots of marigold cultivars (Candyman Orange, Fiesta Gitana, Citrus Cocktail, Neon, Candyman Yellow, Fruit Twist, Sherbet Fizz, Oopsy Daisy, Pot Marigold, Greenheart Orange, Calendula Porcupine, Pink Surprise and Touch of the Red) with 4 replicates under greenhouse conditions. The morphological and biochemical traits were measured and analyzed at the end of the experiment. Water stress (50% FC) reduced most of the evaluated traits and increased proline content (p <0.01). Flower characteristics such as flower and diameter were also observed declined as the aim indexes preserved. Finally two premium selected cultivars Neon and Candyman were selected as the most resistant. It seems that water supply is the main factor affecting growth and flowering is annual bedding plants and the quality and quantity declines in drought noticeably. Evaluation of these traits along with resistance response will help to use them for more sustainable with low input landscapes in mind.

Excessive accumulation of azolla in the wetlands of Guilan is currently an environmental problem. To this aim, a study was conducted to investigate the effect of Azolla compost on the growth medium of Zinnia ornamental plant. The treatment was a sandy loam soil and Azolla compost was replaced with 10, 20, 30, 40 and 50% by volume. The research was performed based on a completely randomized design with three replications and 54 pots. The chemical properties of the substrate including electrical conductivity, acidity, nitrogen content and phosphorus and potassium levels were measured. Growth indices including fresh and dry weight of leaves, stems, roots and flowers, and leaf chlorophyll content were also measured. Nutrient concentrations of nitrogen, phosphorus and potassium in the leaves of zinnia plant were measured. The results showed that the highest growth rate was observed in 20 and 30 % treatments of Azolla compost and the lowest growth rate was observed in control treatments. Azolla compost increased the concentration of nitrogen, phosphorus and potassium in the leaves, which indicated an increase in the quality of plant nutrition. Higher amounts of compost (40 and 50%) reduced plant growth indices compared to 20 and 30% compost treatments, but in the same treatments, plant growth was significantly higher than the control. In general, it can be concluded that Azolla compost can be used as a suitable organic matter in zinnia medium.

The effects of Nano-zinc oxide (ZnO), salicylic acid (SA), and sodium nitroprusside (SNP) were studied on sweet violets under different irrigation water regimes in a factorial experiment. The factors were drought stress at three levels including irrigation at 85 (control), 65 (moderate stress) and 55 (severity stress) percent of field capacity (FC) soil water depletion and foliar application of ZnO, SA, SNP, and distilled water as a control. Means comparison showed that the best resutls was obtained from interaction 200 mg L-1 SA, with irrigation and 85 % FC,  the treatment that influenced most traits positively. Also, 300 mg L-1 SA and both SNP rates significantly outperformed the control and Nano-ZnO. The lowest stomatal conductance was related to the 200 µM SNP at 55% FC. The lowest malondialdehyde (MDA) content was observed in 200 mg L-1 SA and 85 % FC treatment. The highest relative water content (RWC) was associated with the application of 1500 mg L-1, Nano-ZnO at 85% FC. The control plants at 55% FC recorded the highest proline (46.62 μg g-1 FW). The highest peroxidase (POD) enzyme activity was related to the treatment of 1000 mg L-1 Nano-ZnO and the highest ascorbate peroxidase (APX) to the treatment of 1500 mg L-1 Nano-ZnO at 55% FC.