Dothistroma needle blight (DNB) is one of the most important diseases of pine. Although its notoriety stems from Southern Hemisphere epidemics in Pinus radiata plantations, the disease has increased in prevalence and severity in areas of the Northern Hemisphere, including Europe, during the last two decades. This increase has largely been attributed to expanded planting of susceptible hosts, anthropogenic dispersal of the causative pathogens and changes in climate conducive to disease development. The last comprehensive review of DNB was published in 2004, with updates on geographic distribution and host species in 2009. Importantly, the recognition that two species, Dothistroma septosporum and D. pini, cause DNB emerged only relatively recently in 2004. These two species are morphologically very similar, and DNA-based techniques are needed to distinguish between them. Consequently, many records of host species affected or geographic location of DNB prior to 2004 are inconclusive or even misleading. The objectives of this review were (i) to provide a new database in which detailed records of DNB from 62 countries are collated; (ii) to chart the current global distribution of D. septosporum and D. pini; (iii) to list all known host species and to consider their susceptibility globally; (iv) to collate Drenkhan et al. 410 |

In this paper, the occurrence, frequency, and character of stormy winds in clonal poplar plantations in Vojvodina Province were studied in the period from 2016-2021 years. 10 large gusts of stormy winds were recorded, which caused enormous damage to poplar plantations. Depending on the strength of the wind, the age of the plants, and the state of soil moisture, the damage was reflected in windbreaks, windbreaks, and wind bending of trees.

Populus × euramericana (Dode) Guinier clone (cl.) “I-214” is a fast-growing interspecific hybrid between Eastern cottonwood (P. deltoides Bartr. ex Marsh) and European black poplar (Populus nigra L.). Populus × euramericana was introduced into Serbia in the 1950s and has become one of the most widely grown poplar species. In September 2019, cankers were observed on stems and branches of P. × euramericana cl. “I-214” trees in a two-year-old poplar plantation in the province of Vojvodina, Serbia. The canker tissue was soft and watery, and a colorless fluid that smelled rotten flowed from the cracks in the bark, suggesting possible bacterial disease. After two weeks, diseased trees experienced crown die-back and oozing of foamy, odorous exudates and this study aimed to identify the causal agent of the disease. Canker margins and exudates were collected from 20 symptomatic trees. The associated bacterium was isolated and identified using biochemical characteristics, phylogenetic analyses based on 16S rRNA gene sequences, and multilocus sequence analyses (MLSA) based on partial sequencing of three housekeeping genes (gyrB, infB, and atpD). The pathogen was identified as Lonsdalea populi. Pathogenicity tests were conducted on rooted cuttings of P. × euramericana cl. “I-214” in an environmental test chamber and demonstrated that the isolated bacterial strain was able to reproduce symptoms of softened, water-soaked cankers and exudation. To the best of our knowledge, this is the first report of L. populi causing bacterial canker disease on P. × euramericana cl. “I-214” in Serbia and in southeastern Europe (SEE). It is also the first report of a bacterial disease on hybrid poplars, including P. × euramericana in this country and in SEE. If the disease spreads into new areas, selection for L. populi resistance may need to be integrated into future poplar breeding programs.

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Two rust fungi, Melampsora larici populina and Melampsora medusae are common in all poplar growing regions worlwide. M. larici populina is native to Eurasia, while M. medusae is endemic to eastern Unated States on Populus deltoides. Poplar leaf rust (Melampsora sp.) is widely spread disease in our country, and can cause significant growing problems. Race that prevails in our growing region is M. Larici populina. This work initiated the research of population composition, i.e. qualitative participation of Melampsora races in popoluation of black poplars hybrid progenies using molecular methods. When five SSR markers were used the results showed that M. larici populina was found in three tested clones, while only M. medusae was determined in clone I-214

Height growth characteristics of one-year-old pedunculate oaks were studied during three calendar years on comparative regeneration areas both with and without fungicide protection against oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.). Three fungicides were used for the chemical protection of one-year-old pedunculate oaks: Microthiol special, Stroby DF and Anvil. The experiments were located in different site and stand conditions, and the growing seasons in which pedunculate oak seedlings were established were characterized by different precipitation sums and higher air temperatures when compared to multiannual average. The study sample included 1126 plants, and their shoot lengths were measured at the end of the growing season. In the analyzed sample, the second growth stage was recorded on 92.3%-100% of the treated plants and on 69.5%-100% of the untreated plants, the third growth stage was recorded on 52.6%-87% of the treated plants and on 42.1%-82% of the untreated plants, and the fourth growth stage was observed on 0%-37% of the treated plants and on 1.1-29% of the untreated plants. In the analyzed sample, the mean heights of one-year-old pedun-culate oaks were greater on the areas with fungicide protection, but the differences in the percentages of polycyclic growth and the differences in average lengths of individual flushes were not always statistically significant, when compared to the areas without protection, especially after the first stage. The study shows that the dominant effect on the percentage of the second, the third and the fourth stages and on their mean lengths was exerted by site and stand conditions, and that the effects of fungicide protection should be analyzed taking into account the polycyclism of pedunculate oak, i.e. the characteristics of polycyclic growth, which are the resultant of all the effects. In the studied conditions, the fifth stage of growth was recorded in five plants.

The study describes the negative impacts of the most important biotic and abiotic factors on the production of planting material in the forest nursery "Bišina" - Šekovići (Bosnia and Herzegovina). Weather disasters (heavy rain, hail, frost) and zoobiotic caused the most harm to cultivated plants (birds, roe deer). Activities and processes for removing and reducing the damages are explained for each of the elements stated.

The higher heating value of wood and bark was determined for several poplar (Populus spp) clones. The study included the juvenile one year old plants of the following clones: P.×euramericana cl. ostia, P. nigra cl.53/86, P. deltoides cl. PE 19/66, P.×euramericana cl. I-214, P. deltoides cl. S6-7 and P.×euramericana cv. robusta. By using FVI which takes into account ash content, wood bulk density, and moisture content, it was determined that poplar wood can be a significant energy raw material, primarily thanks to its short rotation cycle and a very high wood volume increment. Significant differences were determined in the values of wood basic density which affect the higher heating value of the study poplar clones, and consequently the yield (weight) of biomass produced per unit area of dense plantations. This is reflected also on the estimated amount of energy that can be produced by the combustion of biomass of the whole one year old plants