IRANIAN JOURNAL OF HORTICULTURAL SCIENCE AND TECHNOLOGY
Year:2007 | Volume:8 | Issue:2|Papers Count:9

To investigate the effects of superabsorbent polymer on water requirement and growth and development of chrysanthemum (Dendranthema × grandiflorum Kitam.) a split plot experiment in a completely randomized design were carried out in Isfahan Parks Organization. In this experiment, six quantities of Superab-A200 superabsorbent polymer (0, 0.2, 0.4, 0.6, 0.8, 1% w/w) and four irrigation intervals (2, 3, 4, 5 days) were investigated. Use of polymer had positive and significant effects in dry stress conditions on flower number, flower diameter, flower fresh and dry weight, leaf number, leaf area, leaf fresh and dry weights, stem number, plant height, root fresh and dry weights, root/shoot ratio and leaf area ratio. The treatment of 0.8% polymer in 2-day irrigation interval produced the highest mean in all traits except root/shoot ratio. Polymer treatments of 0.6-1% in a 4-day interval were not significant when compared with or without polymer treatment in a 2-day interval.

In this study, the effects of different levels of NK fertilizers on the flower yield and essential oil content of Rosa damascena Mill. was studied. The experiment was conducted as a split plot design with sub plots in strips based on randomized complete block design (RCBD) with three replications at the experimental field of Agricultural Education Center, Karaj, Iran during 2002-2005. Horizontal and vertical factors were nitrogen (0, 30, 60, 90 and 120 kg ha-1) and potassium (0, 30 and 60 kg ha-1). Fiftheen stocks of R. damascena from Barzok were planted in each replication. Leaf area index, leaf nitrogen and potassium content, flower diameter, flower number fresh weight per flower and essential oil content (w/w %) were measured. Analysis of variance and mean comparisons were conducted for all traits using SNK method. The results showed significant differences at level of 1%, among treatments for leaf area index, leaf potassium content and flower yield components. The highest flower number and fresh weight were obtained by application of equal amounts of N an K fertilizer (60 kg ha-1), while, the application of 30 kg ha-1 of each fertilizer was the best combination to get the maximum of essential oil content. 

Susceptibility of stored ‘Satsuma’ mandarin fruit to chilling injury limits its fresh marketability. In this study, the effect of various heat treatments (Hot water washing and dipping) on chilling tolerance and other physiological attributes of ‘Satsuma’ mandarin were investigated. All treatments that applied in this study suppressed chilling injury development more or less in mandarin fruits but none of them could prevent it completely. The major reduction of chilling injury incidence and severity was found for fruits that previously drenched in 50°C for 30 seconds or immersed in that for 2 min. The higher hot water temperatures more than 50°C not only couldn’t reduce chilling injury development but also increased peel heat damage. We could not detect significant differences of heat treated and untreated fruits for juice acidity and sugar content during storage. Amount of ethanol and acetaldehyde emitted to juice headspace and ethylene production and respiration rate of fruits increased after 4 weeks storage in parallel to chilling injury appearance. Afterwards, their values decreased gradually with increasing chilling damage. Treatmens that reduced chilling injury developments successfully suppressed ethylene production and respiration.

Apricot is known as an early blooming and sensitive to chilling species. Rate of cold resistance of some commercial apricot cultivars namely Nassiri, ‘Ghermez Shahrood’, ‘Dorosht Malaier’, ‘Ghorban Maraghe’ and ‘Canino’ were investigated in east  Azarbaijan, which is one of the important apricot production region in Iran. Flower samples were treated under four different cold treatment levels (+2, 0, -2, -4°C). Sensitivity of stamen, petal, stigma, style and ovary to temperature treatments were morphologically evaluated. In all of the cultivars with progress of phenological stages and reducing temperature, damage percentage increased. Among the studied cultivars, ‘Dorosht Malaier’ had the lowest and ‘Ghorban Maraghe’ had the highest damage percentage in low temperature. ‘Nassiri’, ‘Ghermez Shahrood’ and ‘Canino’ were palced between the mentioned cultivars. Rate of proline after cold treatment was evaluated as well. The results showed that there is no correlation between increase in proline and cold resistance in above mentioned cultivars.

In these research the pollen morphology by using scanning electron microscopy and determination of optimum media for pollen germination have been studied. Study on pollen of  ‘KS6’, ‘KS7’, ‘KS8’, ‘KS9’, ‘KS10’, ‘KS11’, ‘KS12’, ‘KS13’, ‘KS14’ genotypes by SEM showed that all the pollen grains were tricolporate with striped ornamentation on their surface. The polar axis was between 29.46 – 58.20 mm and equatorial axis was between 16.70 – 46.60 mm lengths.  In order to determine the best medium for pollen germination, the pollen of three genotypes (KS7 , KS10 , KS11) cultured in medium prepared with sucrose (%15, %25), boric acid (0, 10, 40, 100 mg   l-1). and calcium nitrate (0 , 200 , 300 mg l-1) The results showed that the best pollen germination was in a medium with %15 sucrose, 0 mg l-1 boric acid and 300 mg l-1 calcium nitrate.

In this investigation, proliferation of shoots from mature trees nodal segments of two guava cultivars namely ‘Local 1’ from white–fleshed types and ‘Local 2’ from red-fleshed types was attempted. After surface disinfestation, the explants were cultured on Murashige and Skoog medium (MS) with 0.00, 0.25 , 0.50, 0.75, 1.00, 1.25, 1.50, 2.00 mg l-1 BA and 0.00 and 0.25 mg l–1 NAA and their combinations as well as on Woody Plant Medium (WPM) with 0, 0.5, 1, 1.5 and 2 mg l-1 BA. Generally, with addition of BA in culture medium the average shoot number was increased. The best shoot proliferation (4.4 shoots per explant) was obtained in ‘Local 1’ with 1.25 mg l-1 BA and adding 0.25 mg l-1 NAA in the medium significantly increased the average shoot number per explant (6 shoots per explant). In ‘Local 2’ the best shoot proliferation (3.4 shoots per explant) was obtained with 1.5 mg l-1 BA and in contrast to ‘Local 1’ adding 0.25 mgl-1 NAA in the medium decreased the number of shoot per explant. In comparison, MS medium was superior to WPM medium.