Fifty populations.of wild annual and perennial sunflower were collected from the northwestern region of the United States. Six different species were represented with 28 populations of annual H. annuus, three H. petiolaris ssp. petiolaris, four H. cusicki, two H. maximiliani, twelve H. nuttallii ssp. nuttallii, and one H. pumilus. The most significant contribution was the collection of H. cusickii and H. pumilus accessions, which have potential for drought tolerance. Future explorations are needed to preserve the natural diversity of wild sunflowers.

A pedigree map of sunflower (Helianthus annuus) was prepared which contains detailed information on North American sunflower materials, e.g., published in various issues of Crop Science. S catalogue provides futher information on the pedigree and important agronomic traits, like disease resistance, oil content and maturity of the released germplasm pools, germplasms, populations, lines and cultivars. For verification of the relationships shown in the pedigree map, the restorer lines RHA 278 and RHA 279, which were derived from an F5 sib-selection, were investigated by Southern analysis with 75 genomic probe/enzyme combinations. They differ in the Pl2-gene conferring resistance to downy mildew, caused by Plasopara halstedii (Farl.) Berl. et de Toni. However, no restriction fragment length polymorphism (RFLP) could be detected. This result confirms the supposed close relationship between the two lines.

The autogamy and self-incompatibility of four sunflower cultivars namely NK-262, NK-265, NK--281 and Sundak were investigated under six pollination treatments. The pollination treatments were natural self-pollination, manipulated self-pollination, assisted self-pollination, foreign pollination, cross-pollination.It appeared that sunflower cultivar NK-262 wasself-compatible. Whereas, theefficacy of these pollination treatments in NK-265, NK-281 and Sundak were affected due to the ratio of seedset and autogamy exhibited by these sunflower cultivars. However, Sundak was self-incompatible. Maximum seedset (96.25%) was recorded in sunflower cultivar NK-262 under open-pollination The minimum seed set of 12.14% resulted in Sundak when assisted self-pollination was adopted. Estimates for percent autogamy of NK-281 were higher (92.64%) under cross pollination. However, the autogamy for the other pollination treatments was minimum. There were significant differences among the sunflower cultivars for the percent modified autogamy. NK-262 and Sundak exhibited maximum and minimum modified autogamy of 101.45% and 28.70%, respectively.

In the previous studies we concentrated attention to "head inclination' as one of the progressive sunflower plant traits. This trait has been found to be conditioned by a large number of major genes. Hybridological analysis has revealed 12 genes forming four three-member groups; each of the gene triads regulates the head inclination by 15 and within the gene triad complete dominance exist. The aim of this study is investigation of other progressive traits such as petiole length, leaf position and reaction of these traits to stand structure, i.e., increased stand density,

The results of a biochemical and genetic research showed that there were significant differences in the examined biochemical parameters (enzyme activity and protein content), among the tested sunflower genotypes and their F1 hybrids. The inheritance of the examined characters was controlled by both additive and non-additive gene actions, as indicated by the results of variance analysis for general (GCA) and special combining ability (SCA). These results were in accordance with the results obtained for inheritance mode when the combinations were observed separately, where intermediate inheritance, full or partial dominance or heterosis occurred. The genotype SNRF-4 having the highest mean values of enzyme activity (NR, GS, GOGAT and GDH) and leaf protein content was also the best general combiner.It is, therefore, recommended to be a parent in hybridization for high protein content. There was a positive correlation between the enzyme activity (NR, GS, GOGAT and GDH) and leaf protein content.

Prior to a treatment with GAs, biochemical characteristics of seed were analyzed in the sterile plants which were subsequently pollinated with pollen of the same line.It was found that the 1000-seed weight was reduced in the treated plants, while the kernel quantity remained unchanged. The kernel oil content and the protein quantity changed in dependence of genotype and vegetation conditions. The fatty acid composition of oil was also changed.It was concluded that the biochemical characteristics of F1 hybrid seeds produced after the sterilization of female plants with GA3 are not satisfactory. Similar investigations will be conducted on the later generations.

Sclerotinia sclerotiorum (Lib.) de Bary is a facultative parasite to which the cultivated sunflower is highly sensitive. The fungus attacks the root, stem and leaves, head discs and seeds, causing root rot, stem rot and head rot forms, respectively. According to the survey, the root rot and head rot were the major forms in China.In Jilin Province, the root rot was more serious, in Nong An county (in 37 fields) the incidence was between 0 and 17.5% over 5 years, i.e., the average incidence was 5.13%, which was related to the amount of sclerotia in seeds and soils. For economic purpose of controling the diseases, forecasting is important. This paper reports the results of studing the root rot forcast and its application.

The response of four hybrids and their lines to water stress was tested in conditions of water culture. Water stress was induced by PEG. Plant reaction to water stress was estimated at the basis of nitrate reductase activity, proline accumulation, transpiration intensity, and relative water content. According to the results obtained it may be concluded as follows. Nitrate reductase activity, free-proline concentration, transpiration intensity and relative water content significantly differed among the tested hybrids and lines. Water stress reduced nitrate reductase activity, transpiration intensity and relative water content, and increased free-proline concentration in all hybrids and lines, although not equally. The greatest change was observed in the concentration of free-proline which increased in all tested hybrids and lines approximately 14 times, while nitrate reductase activity was lower by approximately 50% than that in the control plants. Nitrate reductase activity and free-proline accumulation which suffered great modification in plants under water stress, may be considered as the two parameters which indicate sunflower resistance to drought. However, this should be examined in field conditions, as well. Dependence between the examined morphological parameters and the response of the hybrids to water stress was not discovered.

A mosaic disease of sunflower (Helianthus annuus L.) was reported by Venugopal Rao et al. (1987) and etiological agent was found to be cucumber mosaic virus. Three species of aphids, Aphis gossypi Glov.; Aphis craccivora Koch, and Rhopalosiphum maddis Fitch. were found to be vectors of the virus. Further investigations were carried out to find out the other possible vectors and on the relationship of causal virus with the aphid A.gossypii which was proved to be the most efficient vector and the results of these studies are being reported herein.

Botrytis stalk and head rot was observed on three sunflower inbred lines under greenhouse and field conditions at NARC, Islamabad. The disease was characterized by rotting of the stalk and head with profuse production of conidiophores and conidia on grey to dark brown lesions. Based on the morphological and cultural characteristics, the causal organism was identified as Botrytis cinerea Pers. ex. Fr., which appears to be a new record on sunflower from Pakistan. The incidence of stalk rot was 25 and 30 percent in inbred lines HA-89 and RHA-296, respectively and 30 percent in CMS HA-89 line for head rot under greenhouse while in traces under field conditions,

Of the four different methods used for comparative studies, the dry inspection method was found to be very cheap and not time consuming but its sensitivity was very poor in testing sunflower seed for health status. The agar plate method was found very expensive and time consuming with low sensitivity in routine testing. The anchor paper method yielded high number of fungi and was found more time saving and economic as compared with the agar method. Seed recovery percentage was very high on the seven hybrid/variety of sunflower tested by the blotter paper method and found more simple, time saving and economic in routine seed health testing of sunflower than the other three methods.

The possibility of intercropping peanut in sunflower was explored at Hyderabad in India to maximize the production of oilseeds and oil. Peanut density of 333,333 plants/ha was intercropped in equidistant, paired, or skipped rows of sunflower each at a plant population of 55,555; 66,666 and 74,074 plants/ha. Sunflower and peanut yields were reduced in different intercrop treatments. But, the total oilseed production showed substantial improvement. Peanut intercropping in paired or skipped rows of sunflower with 55,555 or 74,074 plants/ha maximized the total oilseed production and oil yield while maintaining significant superiority over the sole crops.

The experiment object were 154 sunflower hybrids developed by research institutes and international breeding companies and intended for growing in the agroecological conditions of Europe, the Americas, Australia, Asia, and Africa. The hybrids were tested for the following characters: seed yield, oil and protein concentration, 1000-seed mass, volume weight, husk percentage, and autogamous pollination. Statistical calculations included the cluster analysis with the Euclidean distance treated as a metric distance. The hybrids were uniformly distributed in all five clusters regarding seed yield, protein concentration, husk percentage, and autogamous pollination. Regarding oil concentration and volume weight, more than 98% of the tested hybrids were clustered in three distinct groups.

The problem of reasonable use of energy in modern production, particularly in agriculture, is still of vital importance. Just this circumstance makes us concider the technology of cultivation of sunflower from the point of view of effectiveness /recoupment/ of productive energy expeditures, accumulated in the harvested vield. In our view, this is a more stable index than the economic one, because of the flexibility of prices for material resources and the economic system typical for our days. A more exhaustive analysis has shown that there are real possibilities of reducing the energy expenditures for the technology of tillage. For instance, in the block of main preparation of soil-by 6.9%, fertilizers-by 7.2, pesticides-by 4.7% etc. Another considerable reserve for improvement of energy balance of production is the increase of energy accumulated volume owing to increase of sunflower yield.