A five year field trial evaluated 71 oilseed sunflower, Helianthus annuus L., accessions, 32 breeding lines, and 25 interspecific crosses for resistance to infestation by naturally occurring populations of the banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), in North Dakota. Germplasm with resistance to attack by the banded sunflower moth and sub sequent larval feeding damage in the seeds was identified. PI 251902 had less than 10% feeding damage per head in all five years of testing and less than 6% in three of the five years. PI 372259 and PI 170401 exhibited 12% or less seed damage in three years of evaluation and PI 253776 had only 3% damage in two of the three years and was the least damaged in 2004. Four other accessions (PI 170385, PI 291403, PI 494859, and PI 505651) revealed resistance in three of five years. A number of the interspecific crosses which were retested based on earlier results showed reduced seed damage in 2003, but subsequently exhibited much greater damage the following year due to higher populations of banded sunflower moth. Hybrid 894 was earlier used by others as a suscepti ble check; however, in the current investigation, this hybrid consistently had the lowest average seed damage from C. hospes feeding among the germplasm evaluated. Results from this investigation indicate that there is potential for developing resistant genotypes with reduced feeding injury that will help sun flower producers reduce yield loss due to the banded sunflower moth. In addi tion, plant resistance can effectively be combined with delayed planting to decrease densities of C. hospes, thus reducing crop losses without disrupting the control of the larvae by parasitoids.

Biofuels from wood, wastes and various agricultural crops are currently quite expensive. Seed oil plants, instead, represent a relevant renewable natu ral resource for biodiesel to be used as engine fuel. In consequence, new genetic modified varieties (GMV) have been obtained by biotechnological meth ods, which offer a wide range of special oils for bio-energetic purposes. How ever, growing sunflower GMVs for biodiesel production could create a potential risk due to pollen flow from transgenic to non-transgenic varieties when grown in the same geographic areas. Presently, pollen flow analysis by DNA-based tools is expensive and time consuming, and new, cheap and rapid methods are needed. The goal of this research was to estimate pollen flow in sunflower by using a “composite” line, with a monogenic dominant marker (TT) for a high phenotypic expression of blue leaf nervure, as pollinator, and an inbred line and a cytoplasmic male sterile line (cms) as recipient plants. The obtained results suggest that cytoplasmic male sterility could be used for the analysis of sunflower pollen flow.

An experiment was conducted at Rimski Šančevi Experiment Field of Institute of Field and Vegetable Crops in Novi Sad during 2000- 2005. The soil in the experimental plot was calcareous chernozem on loess terrace. Using the yield response factor (ky), the study investigated how sunflower yield and eva potranspiration were affected by deficit of available soil water during the grow ing season. The experiment consisted of an irrigated treatment (T1), in which irrigation was used when soil moisture levels dropped to 60-65% of FC (field capacity), and a nonirrigated control treatment (T0). The sunflower hybrid used in the study was NS-H-111. On average, no significant differences in yield level were observed between T1 (3.79 t ha-1) and T0 (3.75 t ha-1) treatments. Seasonal evapotranspiration (ETm) obtained in T1 treatment was in the 402-479 mm range. The yield response factor (ky) was obtained as 0.20 for total growing season and 0.27, 0.31 and 0.48 for vegetative, flowering and yield formation period, respectively. Period from flowering to maturity was the most sensitive towards water defi ciency.

Accessions from different Helianthus species, cultivated sunflower forms and interspecific hybrid forms and lines were included in this investigation. It was established that broomrape resistance was transferred from 11 perennial Helianthus species to interspecific hybrids developed on the basis of new sun flower lines. Some of the new lines possessed other desirable agronomical characters, which could be successfully transferred to new sunflower hybrid cultivars. Differences were observed in the origin of broomrapes found in dif ferent locations of northern Bulgaria. Diverse origin of some of the obtained sunflower forms was confirmed using the RAPD analysis.

Broomrape (Orobanche cumana Wallr.) is a parasitic plant, feeding on sunflower roots. In recent years some new, more aggressive broomrape races have been found in different parts of the world (Spain, Turkey, Romania, etc.). Soon afterwards they occurred in Russia and we started a special breeding program to control the parasites. A line (VK 623) resistant to race F was previ ously found among the lines from the VNIIMK breeding program. Several new prospective sunflower inbred lines with resistance to both broomrape races, E and F, were developed in a short time. Now they are being converted to cms lines. However, the recessive character of their resistance creates some difficul ties in commercial sunflower hybrid breeding, so, to obtain new donors of resistance, the cultivated sunflower was crossed with H. tuberosus (used as pollinator).

One of the directions in sunflower breeding is the selection for resistance to broomrape. The population of broomrape has been stable in Serbia for a long period of time, but the racial composition has changed in recent years, with race E being predominant in the regions of north Bačka and Banat. Culti vated sunflower is genetically narrow and deficient in many desirable genes. Its genetic variability can be increased by the use of wild sunflower species and interspecific hybridization. The resistance to broomrape in 15 new experimental hybrids was tested on locations in Serbia (Pačir) during three years (2006, 2007 and 2008) and in Romania (Baragan, Braila) during 2008. These hybrids were produced by crossing female inbred lines (Ha-26PR-A, PH-BC2-92-A and Ha-98-A) suscepti ble to broomrape race E and new Rf inbred lines (RHA-D-2, RHA-D-5, RHA-D 6, RHA-D-7, RHA-D-8), developed from interspecific populations originating from H. deserticola and resistant to race E. All examined hybrids were resist ant to broomrape in both locations. Since broomrape race F is present in the location in Romania, it is expected that the new Rf inbred lines - male compo nents of the examined hybrids, possess the resistance gene for race F also.

Epiphytotic occurrence of broomrape was observed in Serbia for the first time in 1951, then again at the beginning of the 1990s which continues up to date. It is hypothesized that the new race was introduced by confectionery sun flower seed. Sunflower is threatened in the north of the region of Bačka. The main foci of hazard are sunflower fields on the route Subotica - Bačka Topola, with a tendency of spreading toward Senta and Čantavir, while the second direction is toward Čonoplja and Aleksa Šantić, and then to the south. Less intensive attack has also been noticed in Banat around Padej, Itebej and Vršac. It is significant to underline that broomrape has appeared in new localities Sve tozar Miletić, Mol, Novi Bečej and Zmajevo in which it had not been registered previously. In 2008, infected areas were found in Bor County (two sunflower plots) near the state border with Romania and Bulgaria. The analysis of the parasitic population showed that broomrape in Serbia belongs to race E of the parasite. Continual monitoring of the broomrape pop ulation is important due to changes in race composition and evolution of new, more virulent races. The most reliable method for control of the parasite is cul tivation of resistant sunflower hybrids including IMI resistant hybrids.

After a long period (about 30 years) without broomrape problems in sun flower fields, intensive infestations were observed in some parts districts of Northern Caucasus. Virulence of the pathogen populations from some regions of Northern Caucasus was compared with those of race F from Spain and a mixture of races F, G, H from the European part of Turkey. It was shown that the broomrape populations from Northern Caucasus have heterogeneous structure. The populations Svetlogradskaya, collected in 2005, and Moro zovskaya, collected in 2006, were most virulent. The first has the virulence comparable to one from Turkey and it is a mixture of nonvirulent and virulent races for the studied sunflower genotypes. Race F predominates in the mixture and has a there is an admixture (although insignificant) of more virulent indi viduals. The population Privolnenskaya from 2003 collection, is a mixture of different races also, but it is less virulent, containing race E and some insignif icant admixture of more virulent individuals (most likely race F).

The pathogenic composition of broomrape populations in Eastern Europe, Turkey and Spain has changed over the years, slowly at first and then rapidly. In Romania, there are three important areas infested with broomrape (Orobanche cumana Wallr.). These areas differ in infestation degree and pres ence of different virulence groups. A new, highly virulent population of broom rape attacked sunflower in Romania in 2006. Many commercial hybrids belonging to different companies or to research institutes lost their resistance to the parasite in a heavily infested area near the Black Sea. The sunflower dif ferentials set for the different races of the parasite have permited to identify a new, highly virulent population of broomrape in this area. The parasite infesta tion degree on the hybrids resistant to the old races has showed that this pop ulation is very aggressive. Several genotypes fully resistant to this new broomrape population have been identified in the sunflower germplasm collec tion of Fundulea institute. These genotypes (lines) can be used as sources of resistance genes as well as for obtaining resistant hybrids.

Broomrape (Orobanche spp) is one of the most dangerous plant parasites in Romania. of weedy of Orobanche cumana Wallr. broomrape populations have been identified in sunflower fields. The parasite is significantly dissemi nated, especially in the south and south-eastern parts of the country. The reac tion of some sunflower cultivars to O. cumana was studied under inoculation and natural contamination conditions. Under the inoculation conditions cre ated at Research Development Institute for Plant Protection in Bucharest, the hybrids HS 1900, Turbo, Justin and Favorit showed absolute resistance. Under natural contamination conditions, at SC Sport Agra srl, Amzacea Dobrogea, best result were showen by Rigasol, Flores, Albani Florena, Sunay, Favorit, Festiv and Turbo. The herbicides Treflan 48 EC and Assert 250 EC were most efficient (>80 %) in controling Orabanche cumana infestation, compared with other herbicides whose efficiency did not exceed 50%.

Broomrape is the major issue in sunflower production in Serbia. Since its first occurrence, the species Orobanche cumana Wallr. had been responsible for considerable yield loss in some areas. In Serbia broomrape is present in the Vojvodina Province. Distribution and virulence groups of parasite are con stantly monitored. Only two distinct broomrape populations currently exist in this part of country. Race B is dominant in the south of the Vojvodina Province and race E in the north. During 2008, sets of 8 commercial hybrids with differ ent broomrape resistance genes were sown in regions with sunflower produc tion. Hybrids were sown on 34 different locations. Presence of broomrape was confirmed on 6 sites. Occurrence of parasitic plants was not detected on culti vars resistant to race E. Sunflower fields in regions where broomrape was not previously detected, were surveyed. The survey revealed occurrence of broom rapes in new regions. Infested areas are located in Bor County near the state border with Romania and Bulgaria.

Broomrapes (Orobanche spp.) which belong to the family Oroban chaceae are obligate parasitic flowering plants. The main center of distribution is the Mediterranean basin, where large areas are heavily infested. Yield losses due to Orobanche range from 5 to 100% depending on the region and the crop. Orobanche species infesting crops in the eastern Mediterranean region of Turkey are: O. aegyptiaca, O. ramosa and O. crenata. O. aegyptiaca / O. ramosa were present in 27.72% of the tomato greenhouses and 80% of the tomato fields, O. crenata and O. aegyptiaca / O. ramosa were present in 57.89% of the faba bean fields and 75.51% of the lentil fields. Sunflower cultivation has gradually increased in the eastern Mediterra nean region since 2004. In 2005, sunflower acreage and production in the region were tripled compared with 2004. There has not been any record on broomrapes in sunflower fields in eastern Mediterranean region yet, but broomrapes are considered a possible threat for sunflower fields in this area. Orobanche cernua Loef. causes considerable damage in sunflower fields in other regions of Turkey where sunflower has been sown for years and it may spread from those regions to the eastern Mediterranean region. In addition, sunflower is also a host plant of Orobanche ramosa L. and Orobanche aegyptiaca Pers. which were already found in some crops in the eastern Mediterrean region. Since the magnitude of the broomrape problem increases each year in Turkey, a “National Broomrape Project” has been organized in collaboration of some govermental institues and universities in 2006. The Project includes extension activities too. Because growers are not carefull about dispersal of broomrape, they should be trained how to apply preventive measures as soon as possible.

Broomrape (O. cernua) is one of the most serious hindrances in sun flower production throughout Turkey and East Europe. Previous and recent studies have shown that imidazolinone (IMI) herbicides applied on Imida zolinone-resistant sunflowers effectively control O. cernua by rapid absorbtion, translocation and accumulation in the root-attached parasite. However, sus ceptibility level of susceptible sunflower cultivars to herbicides has been an obstacle in the application of these herbicides. Preliminary studies have been conducted with susceptible sunflower cultivars. Best results were obtained with a single foliar treatment with Imazamox (35 g/l) + imazapyr (15 g/l), 43.75+18.75 g/ha was applied on imidazolinone-resistant sunflower plants at 8-10 true leaf stage. The treatment caused serious damage to susceptible sun flower plants but no damage was observed on IMI resistant cultivars since they completely controlled O. cernua, resulting in a significant increase in sun flower seed yield over the non-treated control. In addition, the same treatment controlled key weeds that seriously affect sunflower production. Broomrape (O.cernua) and weeds have infested sunflowers and significantly reduced yield in the observed sunflower production area. But, use of IMI resistant and broomrape tolerant hybrids has effectively suppressed and decreased weed population and epidemics in recent years.

Broomrape (Orobanche cernua Loeffl.) is the most serious problem in sunflower production in Turkey, some East European countries and Spain. A research covering broomrape tests of sunflower hybrids in the trials based on National Sunflower Research Project was conducted in Trakya region, which holds 75% of the sunflower production in Turkey, in 2006, 2007 and 2008. Based on this project, in conditions of natural infestation, 306, 443 and 533 commercial and candidate hybrids, inbred lines, etc. were tested in 2006, 2007 and 2008, respectively. Of the tested materials, 12 in 2006, 56 in 2007 and 140 in 2008 were found to be resistant. During winter, broomrape tests continued in growth chambers and in pots, under conditions of artificial infes tation. Broomrape seeds were collected from a naturally infested area in Trakya region and used to determine the reaction of developed hybrids and lines to the collected races. In this part of the study, 1752, 816 and 1389 genetic material were tested in 2006, 2007 and 2008, respectively. The tests showed that 332, 94, and 404 materials in 2006, 2007 and 2008, respectively, were resistant to the new races of broomrape used in the study.