Poplar psyllid, Camaratoscena hoberlandti Vondracek, is considered as an important sucking pest of poplar in Iran. Feeding of adults and nymphal instars of the pest induces galls on poplar leaves, In this study that was carried out during 2001, its density on 13 native and exotic black poplar (Populus nigra) clones was evaluated in a randomized complete block design with 3 replications. From 9 stands planted in the middle of each plot, 4 were randomly chosen, then a branch with 130 cm length was selected in each geographical direction and number of galls on it was counted. The statistical data were analyzed by SAS8 software. A significant difference in infection rate was found between clones as well as geographical directions, Mean comparison with Duncken's test showed that Populus nigra 42/51 clone with the highest mean has a high density of the pest, while P.n. 62/149, P.n. 56/72, P.n. 63/135, P.n. 62/191, P.n. 62/127, P.n, 62/154 and P.n. 56/75 clones with no infection can be considered as resistant clones. In the geographical directions, the highest gall density was observed in eastern direction of the trees. Mean number of galls in eastern direction of the trees statistically different from those of western, northern and southern tree directions.

Antixenosis is defined as a resistance mechanism affecting pest establishment on their host plants. In this study, antixenosis mechanism were evaluated in twelve poplar clones belonging to four species namely, Populus alba, P. nigra, P. deltoides and P. x. euramericana against poplar woolly aphid Phloeomyzus passerinii Sign. Poplar cuts of each clone, placed in plastic jars containing water, were rest in growth chamber. The length and diameters of poplar cuts were 20 and 1-1.5 centimeter, respectively. A single cut of every poplar clones along with an aphid - infested cut were wrapped together with an elastic string. The bunch was then placed in controlled conditions of 60-70% RH, 20-22 Celsius and 16: 8 L: D photoperiods. After two days, the infested cut was taken away from the bunch, and aphid numbers were counted on each single cut. The cuts were placed together for second time, and the numbers of aphids were recorded on a two-day interval basis. Subsequently, the experiment was carried out with 18 replications. Statistical analysis revealed a significant difference (P<0.01) in aphid numbers among the clones. Number of aphids settled on Populus alba 58/57 (0.31 aphid/cut) was significantly less than the other clones. Consequently, a conclusion can be reached that this clone might be an immune poplar against the pest. Other than Populus alba 58/57,a number of clones including: Populus nigra 62/149; Populus nigra 62/72; Populus x euramericana 214; Populus deltoides 72/51 and Populus nigra 62/140 exhibited significantly low aphids density (2.54-4.91 aphid/cut). Therefore, it could be concluded that these clones contained a high level of antixenosis resistance. In contrast, aphid number recorded on P. nigra 56/72 (25.98 aphid/cut) was higher than the others, showing the most susceptible clone to P. passerinii establishment.

In this paper, enzymatic saccharification of poplar wood has been studied. Poplar wood samples were subjected to chemical processing (acidic delignification and swelling by ammonium hydroxide) under selected operational conditions. By removal of lignin along with recovery of cellulose both at the level of 80% solid residues were obtained that were, then, used as the substrate for enzymatic hydrolysis using a mixture of the following two enzymes, cellulose and cellobiase. Increase in the swellingcapacity of the cellulose substrate along with decrease of the polymerization degree of lignocellulosicmaterials facilitates the action of celluloses enzymes. Considering selected operational conditions in the enzymatic saccharification of the wood residues, glucose was produced at the level of 30 g/l. The experimental results were fitted to the hyperbolic empirical model. There was a close relationship between the experimental and the calculated results in some of the enzymatic treatments.

In order to introduce new poplar hybrid clones (“Mofid” and P. ´ albaeuphratica) for commercial wood production in different parts of Iran, ecological range of productivity of the hybrids have to be determined. Therefore, adaptability of the hybrid clones, "Mofid" and its reciprocal cross hybrid (P. ´ albaeuphratica), along with Populus alba L. and P. nigra, as local clones, were investigated. The experiment was conducted based on a randomized complete block design with three replications. Three hundred individual cuttings of the clones were planted in 100 square m experimental plots by spacing of 2 ´ 2 m. Analyses of variance was performed on quantitative and qualitative characters recorded during four years. Results indicated that there were highly significant differences between the clones at 0.01 level of probability. P. ´ albaeuphratica hybrid showed higher diameter at breast height (4.98 cm), trunk height (2.08 m) and total height (5.24 m) than others two clones. Low level of breast height diameter and total height were observed for P. nigra L. clone as a local poplar clone. Mofid was sensitive to winter and spring cold conditions (below -30oC), While P. ´ albaeuphratica showed a high level of cold tolerance to the mentioned temperature.

Poplars are fast-growing species that were planted pure in the past. Mixed plantations of poplar with nitrogen fixing species have been recommended recently to increase the soil fertility. In this study, Ameraican poplar (Populus deltoids) has been planted with Peanut (Arachic hypogaea). The research was carried out on the base of randomized complete block design with five treatments and three replications, including three treatments at poplar plantation spacing (4´3 m), (4´6 m), (4´9m) mixed with peanut and two other treatments included pure plantations of poplar and pure cultivation of peanuts, result showed carbon, nitrogen and pH showed significant differences, but phosphorus and potassium between treatments didn’t show significant difference. The results of comparing height and dbh, showed significant differences between treatments, incorporation of these two plants can help to increase nitrogen fixation in soil and increase growth of poplar; also it causes more stabilization of carbon that they are essential environmental topics at the recent years.

Adults and larvae of the poplar leaf beetle are among the most severe pests of poplar plantations. In order to study development and reproduction of Chrysomela populi under laboratory conditions (T = 25±1°C; R. H. = 70±10%; Photoperiod (L:D) 16:8 h) pairs of overwintering adults were separately confined in a plastic container provided by fresh leaves of Populus nigra. Longevity of females and males were 27.4 and 43.4 days, respectively.Total number of eggs/female, number of eggs/batch and oviposition rate (eggs/female/day) averaged 415.6, 40.7 and 23.9, respectively. Developmental times of egg, three larval stages and prepupa and pupa were 4.9, 3.4, 3.5, 5.2, 1.6 and 3.5 days, respectively. Stage specific mortality was as egg> 1st instar > 2nd instar > 3rd instar > pupa> prepupa. In a poplar plantation near Neyshabour (Northeast of Iran), over wintering adults appeared in early April, fed on fresh leaves, copulated and started to lay their eggs two weeks later. First instar larvae appeared in late April. After spending three larval stages, prepupa and pupa, newly moulted adults emerged in late May. They fed on poplar leaves for a few days then left the trees to start their long diapause period within litter and grasses until the next spring. Thus, C. populi has one generation a year in the studied region. Data from the field were subjected to the Popsys 1f software, using Kiritani-Nakasuji-Manly (KNM) model. Estimations of duration of different immature stages were: 4.32, 5.85, 4.15, 6.21 and 2.95 days for egg, three larval instars and pupa (induding prepupa), respectively. The survival rates for the respective stages were 0.44, 0.33, 0.45, 0.31 and 0.57. Estimations of the model were compared with the findings of laboratory and nursery.

Poplar leaf weevil Platymycterus marmoratus Fst. is one of the most important pests of poplar plantations in Guilan province. High density of adults were observed on different poplar clones and species in Safrabasteh research station in northern Iran. This study was carried out during 2000-200 I in Safrabasteh poplar nurseries. This assessment is a preliminary study to find out the resistance of poplar clones against this pest. The treatements of the experiment included: 9 clones of P.euramerican and P. delta ides species (Populus deltoides Marsh. And Populus x euramericana Dode) which previously had demonstrated better growth than the others as well as P. caspica Bornm as a native species. 1440 cuttings from ten treatments were planted in 3 replicates in randomized complete block design (RCBD). Based on the results obtained for Astaneh- Ashrafieh, poplar leaf weevil adults appeared since mid May till late September with the peak of population in late June to first of July. The statistical data analysis of variance on abundance of adults weevil in MSTATC software, showed a significant difference (P<0.0001) between poplar species and clones. P. e. costanzo and P. cas pica demonstrated the most and the least density weevil, respectively, using LSD test method.

Introduction: The implementation of the forest restoration plan in the northern region of Iran has led to an increase in efforts to enhance wood production through the cultivation of poplar seedling. Particularly, poplar trees hold a significant position among wood producers due to their distinctive features. The key consideration revolves around identifying suitable and cost-effective lands for planting fast-growing species. Purpose of this study focuses on assessing the land suitability for poplar (Populus nigra L.), a prevalent forest species in the country, through a quantitative land evaluation method based on the FAO approach. Material and Methods: The research gathered and classified the edaphic and climatic requirements of poplar tree by utilizing various library resources, data from the soil laboratory of the Research Institute of Forests and Ranglands, and field survey (Soil Profiles). The climatic and soil characteristics were quantitatively classified into five categories: highly suitable (S1), moderately suitable (S2), low/critically suitable (S3), The Quantitative Classification of soil and climate properties was done in five classes: suitable (S1), moderate suitability (S2), low or critical suitability (S3), currently not suitable (N1) and permanent not suitable (N2). For validation, a quantitative assessment of land suitability for poplar cultivation was performed across six soil types, including Nowshahr forest brown, Nowshahr gray brown pedzolic rich in organic matter, Chamestan alluvial regosol, Chamestan Rendezina, Chalous  Pseudogley , and Karaj alluvial cambisol, using a parametric method (second root). Findings: Results indicate that spruce thrives in wet and semi-humid regions in a dry-type manner, with ideal conditions found in areas receiving 1500-1800 mm of rainfall. In drier, semi-arid zones, irrigation is essential for meeting water requirements. Optimal growth temperatures for spruce range from 11-16 degrees Celsius in moderate climates. Poplar flourishes in soils with a light to medium texture, granular or cubic structure, good to fast drainage, and low underground water levels with adequate calcium and magnesium cations. Conclusion: The study showed that the most suitable soils for poplars have a light to medium texture with a granular or crumb structure, with adequate drainage, the absence of high groundwater and the sufficient amount of calcium and magnesium cations in the soil. Soils with incomplete drainage and heavy texture do not provide suitable conditions for poplar plantations. In terms of quantitative evaluation, Mollic Udifluvents soils with medium texture had the highest score for poplar plantations.

The aim of the study was to investigate the effects of different species and clones of poplar on beneath soil properties and their differences in amount of nutrient elements in their litters. Soil (0-20 cm depth) and litter sampling was made under the randomized complete blocks design with three replicates and five treatments of 18 year old poplar species and clones, including four exotics; Populus euramericana triplo, Populus deltoides 69.55, Populus deltoides 63.51, Populus euramericana 45.51 and one native: Populus caspica (control) planted at 4x4 m. spacing. The measured soil and litter chemical properties consisted of: Organic carbon, total nitrogen, phosphorus and potassium. The measured poplar characteristics consisted of: total height, stem diameter at breast height (dbh) and crown diameter. Results showed that there were significant differences (r<0.05) between the poplar species and clones in respect to the soil and litter chemical properties, except potassium in soil. Furthermore, the highest and the lowest amount of nutrient elements in the litter belonged to P.d.63.51 and P. caspica, respectively and Populus deltoides 63.51 achieved the greatest stem and crown diameter and total height. It can be concluded that Populus deltoides 63.51 in addition to its proper growth, has a positive effects on soil nutrients due to its better litter quantity and quality production in comparison to the other species and clones.