مجله علوم باغبانی ایران
سال چهل و دوم شماره 4 (زمستان 1390)

Almond is among some of the most important nut crops requiring improvement in many aspects of its production. To do that, the first step is an evaluation of the genetic diversity of the existing germplasm. Towards this end, 56 vigorous almond seedlings were evaluated with recording eight morphological characteristics (trunk diameter, height of main trunk, canopy density, canopy angle, branch number, average branch size, branch tip color and growth power) as based upon an almond descriptor, at the Horticultural Research Station, University of Tehran. Cluster analysis, at a distance of 9, divided the genotypes into four groups. There existed 13 genotypes in the first group, 10 in the second, five in the third, and finally another 28 genotypes located in the fourth group. The first group included most East and West Azerbaijan genotypes plus two genotypes, one from Karaj Horticultural Research Station and the other from Estahban. In the second group, all the genotypes belonged to Azerbaijan, except two which belonged to Kashmar and Estahban. The third group included three genotypes from the Research Station while two from Azerbaijan. There were genotypes from varying areas in the fourth group. High correlations were observed among the traits, most of them being significant, as based on the Coefficients of correlation. The highest correlation (0.74), a significant one, was observed between foliage density and branching traits, while the lowest (0.007) observed between growth vigor and foliage density.

Knowledge of environmental and ecological factors as well as growth and development pattern of fruit trees is an important task in orchard management and fruit industry. In addition, determination of growth pattern is an important aspect in the orchard management system. In this research, the total photosynthesis rate and growth pattern was measured in nine Asian pear cultivars. Experiment was arranged as split plot design in time based on randomized complete block design (RCBD) with 9 cultivars and 14 sampling time, in 5 replicates. According to results, significant differences (P≤0.01) were observed in the amount of total photosynthetic rate, among cultivars and sampling times. Among the studied cultivars, ‘KS13’ with 17.10 and ‘KS14’with 11.15 μmol CO2 m-2 s-1, had maximum and minimum of total photosynthesis rate, during 14 weeks measurement, respectively. The highest total photosynthesis rate (25.24 μmol CO2 m-2 s-1) was observed in the week 14th, whereas the lowest amount (7.37 μmol CO2 m-2 s-1) was obtained in the second week of measurements. According to the results, ‘KS13’ and ‘KS6’ cultivars showed highest total photosynthetic rate. Also, seasonal changes in cumulative vegetative (branches) and reproductive (fruit) growth were measured during the growing season. Results indicated the existence of a simple fruit sigmoid growth curve for all studied cultivars. However, duration of each cumulative fruit growth phase was different among the studied cultivars. The growth reduction phase was happened 62 days after full bloom (DAFB) in KS13, KS14 and KS12 cultivars and 72 DAFB in the KS6, KS7, KS8, KS9, KS10 and KS11 cultivars. Results indicated that KS7, KS10, KS11 and KS14 are early; KS6, KS9, KS13 are mid-season, and KS8 and KS12 are late-season maturing fruit cultivars. Fruit data revealed that these cultivars have good adaptation to Tehran environmental conditions with optimum crop yield as a result of optimum photosynthesis activity during the growing season. In conclusion, the obtained results on vegetative and reproductive growth can be used for better and improved management of Asian pear orchards grown under Tehran environmental conditions.

In order to alleviate chilling injury in pomegranate (Punica granatum) cv. Rabab due to cold storage, the fruits were dipped in 0.7, 1.4 and 2 mM of Salicylic Acid (SA) for 10 min. After 1, 2 and 3 months of storage at 2°C, the fruits were tested for Chilling Injury (CI) as well as some biochemical parameters. The results revealed that with increase in storage time, CI and Ion Leakage (IL) increased, but the increasing trend in treated fruits was slower than that in control. With increase in SA concentration and storage period, Phenylalanine Ammonia Lyase (PAL) activity increased. Antioxidant activity and ascorbic acid content in arils of control fruits were more excessively reduced than those in treated fruits during storage time. Total Soluble Solids (TSS) content and pH increased during storage, while Titratable Acidity (TA) decreased. Among the qualitative parameters, it was only TA that was affected by SA application. For an enhancing of chilling resistance and maintenance of fruit quality during storage, 1.4 mM SA application was found as the most recommendable treatment. The results finally emphasized the positive effect of SA on pomegranate chilling resistance during the fruit's cold storage.

Primary bud necrosis is a physiological disorder that adversely affects the performance and yield in the vineyards. The present study was conducted to determine the time and intensity of bud necrosis incidence as well as the related anatomical changes in the developing buds of grapevine cv. Askari. A factorial experiment in a randomized complete block design of 4 replications was carried out for the purpose. A first factor taken into account was comprised of two levels of fruit removal treatments (with and whithout fruit), while the second factor being comprised of 10 levels of sampling dates, starting from 40 to 130 Days After Bud break (DAB), with 10 days intervals. A digital microscope was used to determine the percentage of necrotic buds as well as the healthy ones. The results revealed that the effects of fruit removal and sampling date as well as their interactions were significant on percent bud death at a 1% level. Both fruiting and de-fruited vines, bore the lowest bud necrosis at 40 and 50 DAB while the highest percentage of bud necrosis occurred at 130 DAB. The outward appearances of a healthy and a necrotic bud seemed the same and the first symptom of the necrosis disorder commenced at the 60 DAB. Anatomical observations of bud tissue revealed the incidence of bud necrosis within the central bud as a brown spot appearing and gradually expanding. Compound bud, carrying the initial necrotic bud remains on the vine and does not fall off the shoots.

A study was conducted at the Research Station of Department of Horticultural Science (Tehran University, Karaj) to evaluate the effects of water stress on yield, growth and some physiological parameters in Iranian melon. The experiment was set out in a split plot design with three replicates. Treatments consisted of factorial arrangement of three Irrigation levels (starting irrigation at -50, -65 and -75 cbar) and two Iranian melon landraces (Zard Jalali and Suski Sabz). The results indicated that the drought levels exerted significant effects on leaf area, stem length, proline accumulation, fruit weight as well as yield. Water stress caused significant reduction in fruit weight and melon yield. The lowest leaf area (31533 mm2), stem length (258.56 cm), fruit weight (2898.1 gr) and yield (57.96 T/ha) as well as the most proline content (1.455 mg/g FW) were obtained for the case of the most sever water stress treatment (-75 cbar). Landrace did not significantly differences for the studied traits.

In order to investigate the effect of two mycorrhizal species (Glomus mosseae and G. intraradices) on different growth aspects of two pistachio cultivars (P. Vera cv. Badami-Riz Zarand, and P. Vera cv. Qazvini), a greenhouse experiment was conducted taking into account three factors of: mycorrhizae inoculation at three levels (no mycorrhizae application as control, G. mosseae, G. intraradices), drought stress at four levels (100% FC as control, 75% FC, 50% FC, and 25% FC) as well as two pistachio cultivars (P. Vera cv. Badami- Riz Zarand and P. Vera cv. Qazvini) in a completely randomized design of three replicates. The results indicated that three months past the commencement of the drought, such vegetative traits as stem height and diameter, leaf area, as well as dry weights of leaf, stem and root decreased with increase in drought intensity. Plant-water relation parameters including relative water content, and water use efficiency were severely lowered as a result of the drought inflicted. In response to drought stress, osmo-regulation reactions were activated in pistachio plants, leading to an increase in proline and soluble carbohydrate content in plant leaves. Application of mycorrhizae considerably improved the vegetative growth in pistachio plants where G. mosseae and G. intraradices applications promoted stem height by 100%, and 75% respectively, and in comparison with control. Plant-water relations in mycorrhizal treated plants were superior over non-mycorrhizal applied plants. Furthermore, the results indicated that proline and soluble carbohydrate accumulations were higher in leaf while lower in roots of mycorrhizal inoculated plants as compared with control.

In a field experiment, during three successive years of 2007, 2008 and 2009, the effects of planting pattern and high corm density on agronomic performance of saffron was investigated at the Research Station of Ferdowsi University of Mashhad. A complete randomized block design in a factorial arrangement of three replications being employed. Treatments consisted of three corm rates of planting (4, 8 and 12 t ha-1) along with three planting patterns (row, random and hill planting). Results revealed that during the three years of experimentation, corm rate of planting, and planting pattern significantly affected the number of flowers per unit area, fresh and dried flower weights as well as the fresh and dried stigma weights. A high corm rate of planting of 12 t ha-1 resulted in a highest number of flowers, fresh and dried flower weights as well as fresh and dried stigma yields. Row planting pattern resulted in a better performance than the others, as regards the number of flowers, fresh, and dried flower weights. The highest fresh and dry weights of stigma per unit area were obtained from the row planting pattern. The number of daughter corms increased significantly in the second year of experimentation for a corm planting rate of 12 t ha-1 (30.81% more as compared with 4 t ha-1 corm rate of planting), and for hill planting pattern (43.07% more as compared with row planting). Corm rate of planting did not significantly affect the fresh and dry weights of daughter corms per unit area during any of the three years, but with change in planting pattern from row to either hill or random planting, there was a decreasing trend in fresh and dry weights of daughter corms per unit area during the first year of experimentation. Interaction of row planting pattern and 12 t ha-1 of corm was rate of planting represented the best combination of treatments only in the first year affecting the number of flowers, fresh and dried flower weights as well as fresh and dried stigma weights per unit area. Also in the third year, number of daughter corms, fresh and dry weights of daughter corms were affected by interaction effects of corm rate of planting and planting pattern. In general, results revealed that increasing corm density from 4 to 12 t ha-1 in a row planting pattern, performed best among all the treatments.

In order to investigate the effects of Hinokitiol (0.1, 1, 5 and 10 Micromolar), Humic acid (100, 500. 1000 and 10000 ppm), Sucrose (2.5, 5, 7.5, and 10 percent), and Silver Thiosulphate (0.25, 0.5, 1 and 2 mM) treatments on longevity and some quality characteristics of cut yelloween lily flowers, an experiment was conducted in the form of a completely randomized design of two replications (time) in the Postharvest Laboratory of Mohaghegh Ardabili University. The results indicated that Silver Thiusulfate at o.25 to 1 mM increased the vase life of cut lily as compared with control and other treatments. Hinokitiol at 5-10 Mm decreased the vase life of the flower up to 2.4 days. The applied treatments, except for their higher concentrations, increased the uptake of in-vase solution, maintaining their relative fresh weight. Humic acid, a substitute with Cytokinin-like activity, markedly extended leaf longevity. In other words, a pulse treatment of the flower with 1000 ppm humic acid was found out as the most suitable treatment in preventing the flower from leaf yellowing under the general experimental conditions.

The use of such biostimulants as humic materials has recently become common in turf management operations. These products have been used to help the establishment of turfgrass and to enhance the turf stress tolerance capacity. This experiment was aimed at studying the effect of humic acid on some growth factors in turf grass. It was carried out in a factorial Randomized Complete Block Design (RCBD) of four replications and in controlled conditions. Turf seeds were sowed in polyethylene pots and following the establishment of the plants, they were monthly sprayed with Leonardite humic acid in concentrations of 0, 100, 400 and 1000 mg/L. Nine weeks past the start of treatments, such characteristics as height, fresh and dry weight, as well as the level of such elements as micro and macro nutrients were measured along with the visual quality of samples assayed. The results revealed that application of humic acid in concentrations of 100 and 400 mg/L were more effective than 1000 mg/L. The concentration of 100 mg/L positively affected the fresh and dry weight as well as the visual quality of the plants while the 400 mg/L concentration more profoundly affected K and Fe. The two concentrations of 400 and 1000 mg/L exerted a more serious effect on Zn content. None of these concentrations played any role on P content. An increase in humic acid concentration (1000 mg/L) caused a reduction in the height of the plants.

The effect of the organic, integrated and conventional methods of kiwifruit cv. 'Hayward' production on the fruit quality at its harvest time was investigated. Such traits as fruit size, firmness, Total Soluble Solids (TSS), Titratable Acidity (TA), total chlorophyll, total carotenoids, vitamin C, total phenol, flavonoid compounds (catechin, quercetin 3-glucoside and chlorogenic acid) as well as the antioxidant potential of the fruit were evaluated. The results revealed that total carotenoid, TA, TSS/TA in organically produced fruits and in comparison with the conventional and integrated treatments did not significantly differ. But the fruit firmness, TSS, total chlorophyll, ascorbic acid, total phenols, such a flavonoid type as quercetin 3-glucoside, total quercetin, chlorogenic acid, catechin as well as the antioxidant potential were higher in organically produced fruits. Total soluble solids and fruit length in the conventional and integrated management methods were significantly higher than those in the fruits organically produced. The fruits from organic treatments were somehow small and round. A negative correlation was observed between TSS and firmness, but a positive one between total flavonoid, antioxidant capacity as well as between chlorophyll and fruit firmness. Overall, the results indicated that the nutritional value and antioxidant compounds present in the fruits produced through organic farming methods stand at higher levels.