Micronutrients have an important role in growth and yield of plants. This investigatin was carried out to evaluate effect of foliar applications of three micronutrients (Fe, Mn and Zn) at different times (4-6 and 8-10 leaf stage) with three replication on sugar beet. Based on results obtained all of the micronutrients used increased sugar beet sugar yield. Highest root yield was obtained by using 9 % of micronutrients at 4-6 leaf stage, but other concentrations did not have any effect on sugar beet yield. All of the three micronutrient concentrations increased root yield significantly. Application of 6% concentration increased root yield by 15.6 %. Mn application did not have any effect on sugar yield.9 % concentration of Zn foliar application increased sugar yield by 16.4 %, and application of 6 and 9% of Fe increased sugar yield by 18.6 and 36 % respectively. Sugar percent did not changed by Mn application, but high concentrations of Fe and Zn at 8-10 leaf stage increased it. Highest increase in sugar percent obtained by using Fe 9 % foliar appliction. Because of economical importance of sugar and root yield, foliar application of 9 % of Fe and Zn at 8-10 leaf stage will be suitable.

Experiments were carried out in a completely randomized design with 3 replication factorial arrangement. Experimental treatments were including genotype factor (including 15 sea beet samples from Khuzestan, Elam, Kermanshah, Kurdistan and Azerbaiyjan provinces and two sensitive and susceptible cultivar of sugar beet) and salinity factors (concentration of 0, 50, 100 and 400 mM) and drought factors (5 levels of 0, 3, 6, 9 and 12 bar). Results showed that the effect of salinity and drought treatments on germination percentage, radicle, plumule length, radicle, and plumule weight traits were significant and in both experiments with increasing stress intensity germination percentage, radicle and plumule length, radicle and plumule weight traits decreased. In both experiments, the germination percentage trait was less and hypocotyl weight trait more affected by stresses than other traits. Alsoو in both experiments, radicle growth was less affected by stress than the plumule. Statistical estimations showed that there was a significant difference between investigated genotypes for germination percentage, radicle length, plumule length, radicle weight and plumule weight in both experiments. In salinity and drought stress conditions, at least 5 and 7 sea beet genotypes were identified from Elam, Kermanshah, Khuzestan and Azerbaiyjan provinces, which were better in terms of germination and early growth characteristics than sugar beet cultivars. Based on this, it can be concluded that sea beet has high diversity and resistance potential against salinity and drought stresses during germination and early growth stages, and can be used to produce more resistance sugar beet against salinity and drought stresses.

Germination of seed and establishment of seedling in sugar beet could be influenced by chemical inhibitors of seed coat, seed hardness and impermeability to water and oxygen as well as seed reserves. Uniform seeds of cv 9597 were studied using a completely randomized design with 4 replications. Samples of 100 seeds were washed by distilled water, diluted hydrochloric acid and diluted hydrochloric acid which was neutralized by sodium hydroxide at the end of washing treatment. Each of the above treatments was applied at 2, 4 and 6 hours. Samples were sterilized by diluted sodium hypochlorite solution. Germination percent and the rate of germination in germinator and sand medium were calculated. Results showed that the type of treatment for washing couldn’t influence the percent and the rate of sugar beet germination seed in the germinator. But the rate of germination in sand medium increased significantly through water treatment. In addition, the time of applied treatments influenced the percent and the rate of germination in germinator and sand medium significantly. Interaction effects between the type of treatments and the time of washing also influenced the percent of germination in germinator and the rate of germination in sand medium significantly. Such that, the 6 hours washing with distilled water increased the percent of germination in germinator 1.87 times and the rate of germination in sand medium 43% in comparison with control, non-washed seed treatment.

In the present study, natural active enemies of pests in sugar beet fields in some regions of Iran including Gonbad, Ramian, Agha Qala (Golestan province), Nahavand (Hamadan province), Fereydoun-Shahr, Borkhar, Golpayegan (Isfahan province), Shahrekord (Chaharmahal & Bakhtiari province), Naghadeh, Miandoab (West Azarbaijan province) were studied. A total of 45 species of natural enemies including 10 parasitoids and 35 predators of the order, Hymenoptera (Braconidae: seven species in six genera; Ichneumonidae: single species), Diptera (Tachinidae: two species in two genera; Asilidae: four species in four genera; Syrphidae: three species in three genera), Coleoptera (Carabidae: seven species in six genera; Coccinellidae: five species in four genera), Hemiptera (Anthocoridae: six species in two genera; Miridae: five species in three genera; Nabidae: two species in two genera; Reduviidae: two species in two genera), and Neuroptera (single species from the family Chrysopidae) were collected and identified in different parts of the country. Due to high diversity of natural enemies in sugar beet fields, the support of these beneficial insects is necessary in order to reduce the consumption of chemical pesticides, and the success of natural enemies effectiveness.

In order to study some of the physiological responses of sugar beet plant to salinity stress, A 4- replicate CRD greenhouse experiment was conducted with five salinity levels (o, 85, 171, 256 and 342 mM Nacl). Seeds were planted in greenhouse and plantlets irrigated by Hoagland nutrition solution. Total dry weight, Leaf area, total Leaf chlorophyll, proline in shoot and Na+, k+ in the leaves were measured at the final leaf growth stage. Results showed that with increasing salinity levels total Leaf chlorophyll, Leaf area and total dry weight decreased, while proline content in shoots and Na+in leaves significantly increased with increasing salinity levels.K+ content in leaves decreased with increasing salinity stress. Accumulation of Na+ in the leaves particularly at high salinity levels lead to nutrient deficiency, ionic toxicity and growth decrease.The high level of proline enhanced the plant to maintain osmotic adjustment when growing under low water potentials.