فهرست مطالب mohammad naghi padasht dahkaei

A new group of colored shades called photo-selective netting shades are being developed, which can the affect the quality and quantity of light received by the plants, and at the same time provide optimal protection for them. Therefore, in order to investigate the use of colored shades (red, green and yellow) on the morphological and physiological characteristics of marigold, violet, croton and aglaonema, two separate experiments were carried out in winter and spring at Lahijan Flower and Ornamental Plants Research Station. The evaluated morphological traits included: plant height, fresh and dry weight of shoot and physiological traits included chlorophyll, carotenoid, anthocyanin, flavonoid, antioxidant capacity and catalase and peroxidase enzymes. The results showed that the yellow shade increased the vegetative power of the plants. The interaction effects of shade and plant species showed that the highest plant height, chlorophyll content and carotenoid content the plant were related to yellow shade and violet treatment. The results showed that the highest amount of anthocyanin, carotenoid and catalase was obtained under the red shade and the highest amount of total chlorophyll was obtained under the red and yellow shades in croton and aglaonema. The results of this research showed that the use of colored shades compared to not using shades created more favorable growth conditions for plants. Also, the yellow and red shades were better for the growth of the tested plants than the green shades and no shade and had a more favorable effect on the growth of the plants.

This experiment was performed to investigate the effect of Azolla and rice straw mixed compost in peat substitution on Dieffenbachia amoena. Factorial experiment based on a completely randomized design with two factors of nutrient solution in 2 levels (1- without solution, 2- with 130 mg N L-1, 32 mg P L-1 and 117 mg K L-1) and 5 levels of Azolla and rice straw mixed compost (0, 15, 30, 45 and 60 %) was done in 3 replications, with 3 plants per treatment in greenhouse conditions. Azolla and rice straw mixed compost was replaced with peat in the control. Compost was prepared from a volumetric mixture of 50 % Azolla and 50 % rice straw. Azolla and rice straw mixed compost replaced peat in the control treatment. The control bed contained 10 % perlite: 30 % vermiculite: 60 % peat (volume percentage). Growth factors including height, diameter, number of leaves, chlorophyll index, fresh leaf weight, fresh stem weight, leaf dry weight, stem dry weight, leaf area, physical and chemical characteristics of growth medium and nutrients were measured. The results showed that the use of 45 % Azolla and rice straw mixed compost in replacement with peat (with formula 10 % perlite: 30 % vermiculite: 45 % Azolla and rice straw mixed compost: 15 % peat), in addition to improves the growth factors of Dieffenbachia amoena plant, reduces the consumption of peat by up to 75 %.

To investigate the effects of silicon on the growth characteristics and the reduction of the powdery mildew damage to Zinnia (Zinnia elegans Jacq. ʻMagellanʼ), an experiment was carried out as a factorial experiment in the form of a randomized complete block design with two factors including eight treatments and three replications. The first factor included silicon concentrations at four levels (0, 50, 100, 150 mg L-1 Si) and the second factor consisted of the Si application methods (foliar spray and medium drenching). Depending on the concentration and method of silicon supplied, several horticultural traits were improved as a result of Si supplementation. Silicon content of Si-treated plants (100 and 150 mg L-1 Si foliar spray) significantly increased as compared with untreated controls. Disease severity of powdery mildew was reduced by sodium silicate. The results of our study demonstrated that foliar spray treatments were more effective in managing disease than drenches treatments.