Journal of Soil and Plant Interactions

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In order to improve the quantitative and qualitative traits of lisianthus (Eustoma grandiflorum “Mariachi Blue”) a factorial experiment ws performed as completely randomized design at three levels of vermicompost (0, 5 and 10% v/v) and humic acid (0, 2 and 4 kg/m³) with three replications, under the greenhouse conditions. Evaluated traits were number of Leaves, buds and branches, peduncle length and diameter, vase life, internodes length, shoot height, main stem diameter and fresh and dry matter weights of stem and roots. Results showed that vermicompost significantly affected peduncle length and diameter, number of leaves, height and dry matter of shoot and humic acid affected flower diameter, shoot dry matter, and dry and fresh weights of roots. Also, the interaction effect of vermicompost and humic acid had a significant effect (p<0.01) on traits such as internode length, peduncle length, number of leaves, main stem diameter, flower diameter, shoot dry and fresh weight and dry and fresh weight of roots. It seems that humic acid has an important role in nutrients absorption, yield parameters and quality of lisianthus. Considering the positive effects of 5% vermicompost and 2 kg/m³ humic acid treatments, in can be suggested to apply these organic fertilizers after transplanting stage of lisianthus.

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Optimum nutrition is one the most effective strategies in floriculture industry. In this regard, a factorial experiment designed based on CRD with three replications on New Guinea impatiens in greenhouse. Treatments were slow release fertilizer (12-11-18-2.7MgO-8S) at 5 levels (0, 1.5, 3, 4.5 and 6 kg/m³) and humic acid at three levels (0, 2 and 4 kg/m³), mixed with substrate. The F₁ seeds of New Guinea impatiens planted in plug trays consisting of 50% peat moss, 40% perlite and 10% rice husk (v/v) as medium. After 70 days, traits such as transplant height, number of leaves, shoot diameter, total fresh and dry weight of shoots and roots, chlorophyll content and leaf nutrient concentration was evaluated. Results showed that the highest transplant height (4.38 cm) was observed in applying 3 kg/m³ of slow-release fertilizer mixed with 4 kg/m³ of humic acid, the greatest stem diameter (3 mm) was observed in 4.5 kg/m³ of slow-release fertilizer treatment and the highest number of leaves (18.9) was observed in 3 kg/m³ of slow-release fertilizer treatment. It seems that slow-release fertilizer increased nutrient elements efficiency and decreased their leaching from the substrate and also, humic acid increased plant nutrient uptake during transplant production. According to the results of this research, it could be recommended to use 3-4.5 kg/m³ of slow- release fertilizer and 2-4 kg/m³ of humic acid in the substrate for transplant production of New Guinea impatiens.

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The present investigation was carried out to evaluate the impacts of different concentrations of N and Ca and N:Ca ratio in nutrient solution on growth indices, yield and tipburn of butterhead lettuce (Lactuca sativa var. Capitata) in floating system. The experiment was conducted as completely randomized design, with 8 treatments and 3 replications, in Research Greenhouse of Shahrekord University. Treatments (different concentrations of Ca and N (mg/L) in the nutrient solution) included T1 (N60 + Ca80), T2 (N80 + Ca80), T3 (N100 + Ca80), T4 (N120 + Ca80), T5 (N120 + Ca160), T6 (N160 + Ca160), T7 (N200 + Ca160) and T8 (N240 + Ca160). Results showed that there was no significant difference between treatments for number of leaves; but significant differences were observed in tipburn percent, leaf and root fresh weight, leaf and root dry weight, and stem length and diameter. The highest head weight, length and diameter of stem, and root and leaf dry weight were observed in T1 (N60 + Ca80), T2 (N80 + Ca80) and T3 (N100+ Ca80) treatments. The weight of head in different treatments varied from 218 to 326 g/plant. Increasing the N concentration to more than 100 mg/L decreased the yield. Higher yield was obtained in 80 mg/L Ca concentration as compared to 160 mg/L. The tipburn occurrence of the treatments varied from 10.5 to 42.5 percent. The lowest tipburn occurrence was observed in T2 and T6 (N:Ca=1) treatments; while it was highest in T1 and T5 (N:Ca=0.75) treatments. Leaf analysis showed that significant difference was observed among the treatments with respect to N and Ca content. The T2 treatment (N80 + Ca80) was the best due to its high yield and lower tipburn incidence

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To evaluate the effect of different culture media on growth indices of Pelargonium ×hortorum “Maverick Star” in plug culture, a greenhouse experiment was carried out based on a completely randomized design with seven treatments and four replications. The treatments were seven different substrates including peat moss (100%), cocopeat (100%), peat moss + cocopeat (60%+40%), peat moss + cocopeat (50%+50%), peat moss + cocopeat (40%+60%), peat moss + perlite (50%+50%) and cocopeat + perlite (50%+50%). At the end of the experiment, growth indices such as root volume, root fresh and dry weights, plant height, stem diameter, shoot fresh and dry weights, number of leaves, leaf area, leaf chlorophyll content and flowering time were evaluated. Results showed that most of the measured traits were significantly affected by the culture medium. The medium containing 100% peat moss had the best effect on the evaluated traits and the weakest results on most of the traits were observed in 100% cocopeat substrate. Results also showed that adding peat moss to other culture media made some positive changes in most of the measured traits.