The study presents results of a three-year experiment of variability of different Dutch potato varieties in Serbia: Adora and Cleopatra (early), Innovator and Frisia (mediumearly) and Desiree and Kondor (medium-late). The research was conducted during 2008, 2009 and 2010, in three different soil and climatic locations: Zemun (100 m a.s.l.), Srbobran (86 m a.s.l.) and Guča (370 m a.s.l.). The four-repplicate field trials were set up using standard methodology according to the random block desing. The analysis of variance suggest that number of tubers per plant, number of market tubers per plant and total tuber yield were significantly fluctuating depending on genotype (G), year (Y) and the location (L). In addition to individual influences of different factors, their interactions were also pronounced (G x Y, G x L, Y x L, G x Y x L). In the three-year period average, the highest total yield was recorded in Zemun (35.80 t ha‫,)¹-‬ followed by Guča (29.32 t ha‫,)¹-‬ while the lowest average yield recorded was in Srbobran (27.38 t ha‫.)¹-‬ The highest average yield of tubers in the three-year period was recorded in the Cleopatra variety, followed by Adora variety, while the lowest average yield was recorded in the variety Frisia. Obtained results show that the highest yields over observed locations were recorded in early varieties that formed medium number of tubers per plant (Cleopatra and Adora) and medium late varieties (Desiree and Kondor) that expressed good resistance to high air temperatures and stress caused by drought.

Blackleg outbreaks were noticed on three fields (total c. 100 ha) during two consecutive years (2018, 2019) in one of the main potato growing areas in Serbia (Bačka region, Vojvodina). The percentage of infected plants reached 40-70% with 10.5% to 44.7% yield reductions. From the three fields out of 90 samples Pectobacterium carotovorum subsp. brasiliensis was most frequently identified and diagnosed as causal agent of potato blackleg in Serbia for the first time (29 isolates). Dickeya dianthicola was a less frequently causative bacterium, which was also noticed for the first time (nine isolates). A total of 38 isolates were characterized based on their phenotypic and genetic features, including a pathogenicity test on potato. The repetitive element Polymerase Chain Reaction (rep-PCR) using BOX, REP and ERIC primer pairs differentiated five genetic profiles among 38 tested isolates. Multilocus sequence analysis (MLSA) of four housekeeping genes, acnA, gapA, icdA and mdh, revealed the presence of three so far unknown P. c. subsp. brasiliensis multilocus genotypes and confirmed clustering into two main genetic clades as determined in other studies. MLSA also revealed the presence of a new genotype of D. dianthicola in Serbia.

Thirty-six strains of Xanthomonas campestris pv. campestris (Xcc) isolated from cabbage, kale and broccoli were identified according to their pathogenicity, phenotypic and genotypic characterization. Pathogenicity was confirmed by the injection method with a hypodermic syringe into the mesophilic tissue of cabbage leaves. All strains were Gramnegative, aerobic, catalase-positive, oxidase-negative, grew at 35°C, produced levan, H2S and indole, did not reduce nitrate, hydrolyzed Tween 80, starch, gelatin and esculin and did not show tolerance to 0.1 and 0.02% TTC. The strains produced acid from d-arabinose, arginine, dulcitol, galactose, d-glucose, maltose, mannose, sorbitol, sucrose and xylose. The genetic characterization was based on the sequence analyses of 16S rDNA and ERIC and BOX PCR. Strains of different pathovars were also used to compare PCR resulting patterns. BOX-PCR of the strains from kale and broccoli, obtained using (GTG)5 primer, yielded patterns with a high similarity level to pathovar reference strain Xcc. The strains from cabbage yielded BOX and ERIC product patterns, distinguishing them from the other tested strains and reference strains. 16S rDNA of the representative strains was closely related to Xcc strain ATCC 33913. ERIC PCR and BOX using (GTG)5 primer generated different Xcc patterns and were effective in distinguishing strains from different plant hosts. [Projekat Ministarstva nauke Republike Srbije, br. III43010 i br. III46007

The study presents results of a three-year experiment of variability of different potato varieties in Montenegro: early maturity varieties (Riviera), medium early (Almera, Aladin and Bounty) and medium late (Agria, Margarita, Kennebec and Desiree). The research was conducted during 2015, 2016 and 2017, in acid, brown soil and three different climatic locations: Nedakusi (556 m a.s.l.), Sutivan (680 m a.s.l.) and Orahovica (900 m a.s.l.). Field experiments were set up using standard methodology in random block design in three repetitions. The analysis of variance suggest that number of tubers per plant, mean tuber weight, yield of small tubers, marketable and total yields were significantly fluctuating depending on genotype (G), year (Y) and the location (L). In addition to individual influences of different factors, their interactions were also pronounced (G x Y, G x L, Y x L, G x Y x L). In the three-year period average, the highest total yield was recorded in Nedakusi (31.41 t ha-1), followed by Sutivan (21.35 t ha-1), while the lowest average yield (17.36 t ha-1) was recorded in Orahovica. As expected, on the three-year average, the highest percentage of dry matter was found in late varieties Agria - 25.46%, then Desiree - 25.33%, followed by Kennebec with 25.13%, while the lowest percentage of dry matter was found in medium early variety Almera - 20.82%. The highest average yield of tubers in the three-year period was recorded in the Aladin variety, followed by Agria and Desiree, while the lowest average yield was recorded in the variety Riviera. Obtained results show that the highest yields over observed locations were recorded in medium early varieties that formed high number of tubers per plant (Aladin) and medium late varieties (Desiree and Agria) give satisfactory and stable yields.

The objective of this study was to investigate the influence of seed coat colour on the seed quality of four red clover cultivars (germination, dormancy (hard seeds) REZIME Cilj istraživanja bio je da se ispita uticaj boje semena četiri sorte crvene deteline proizvedene u Srbiji tokom dve godine na njihov kvalitet (klijanje, dormantnost (tvrdo seme), mrtvo seme i početni porast klijanaca (vigor)). U ovom istraživanju su prvo vizuelno razdvojena semena po boji, a zatim su razdvojena digitalnim kolor separatorom na svetla, tamna i mešovita. Rezultati su pokazali da