مجله چغندر قند
سال هفدهم شماره 1 (بهار و تابستان 1380)

One of the biggest barriers for agricultural production in Iran is water deficit. However, certain optimum approaches for water application can solve this problem. Deficit irrigation technique is an approach that could have a better and economic use of water in agriculture. In this regard, a research with three factors including two irrigation intervals of 8 and 12 days, two nitrogen fertilizer levels based on soil analysis result and 2/3 use of it, and four levels of irrigation, 100, 80, 60, & 50 percent of crop water requirement, was performed on sugar beet during 1998-1999 in Mahidasht agricultural research station, Kermanshah province. The experimental design was a Factorial Split Plot with Randomized Complete Block arrangement and three replications, in which irrigation intervals represented the main plot and nitrogen fertilizer along with irrigation levels represented the sub plots. Furrow irrigation method was used and the amount of applied water was measured with a flowmeter. The combined analysis of data showed that the amount of water had a very significant effect on root yield, white and gross sugar yield. Root yields of 52.5 and 48.2 t/ha were obtained from 100 and 80 percent of crop water requirement, respectively. However, from the economic point of view, the 80 percent water requirement treatment had the highest net benefit. The irrigation intervals of 8 and 12 days had no significant effects on sugar beet yield components. Therefore, the 12 days irrigation interval was recommended. Finally, the nitrogen fertilizer treatment did not show any significant effect. There was no significant difference between the nitrogen fertilizer treatments.

To perform stability analysis and study G*E interaction, eight commercial sugar beet varieties were evaluated in eight major sugar beet producing areas of Karaj, Mashad, Miandoab, Esfahan, Shiraz, Kermanshah, Moghan and Hamadan in three years using a Randomized Complete Block Design with four replications. The evaluated varieties were BR1, 7233, PP.8, IC, 7233-P29, PP22, H5505 and 41RT. Having done the simple and combined analysis, the stability parameters such as environmental variation, environmental coefficient of variation, Wrick’s ecovalence, stability variance (Shukla), coefficient of linear regression, mean square of deviation from regression, linear coefficient of determination and intralocation variation for six traits including RY, SY, WSY, Yield, K/S and KNa/S were calculated and compared with each other. Results of the combined analysis showed a significant difference in genetic variation among varieties for all traits and between years and locations, too. G * E interaction for RY, SY, Yield, K/S and Kna/s and G *L interactions for WSY were significant. Results derived from stability analysis showed the utmost utility of the variety, IC, in comparison with other varieties, because of its absolute stability based on three important traits: RY, SY and WSY. Two parameters, Wrick’s equivalence and stability Variance of Shukla, were shown to be exactly the same to determine the stable variety. Environmental variation and environmental coefficient of variation, in spite of having similarities in most traits, was not completely the same. There was a high correlation between the mean square of determination from regression and linear coefficient of determination in all traits and it was expectable because they both show the fitness of regression line.

Seeds of nine sugar beet lines: five drought tolerant, two susceptible, and two medium tolerant were washed, sterilised, dried, and sown in water agar medium for germination test. Seedling growth characters such as cotyledon fresh weight (CFW), cotyledon dry weight (CDW), root fresh weight (RFW), root dry weight (RDW), and root length (RL) were determined after the end of 28 days period of experiment. Mannitol was used as osmotic stress inducing substance at 0.0, 0.2, and 0.3M concentrations using a factorial design with three replications and 20 seeds per treatment. Relative germination percentage was determined as the germination ratio in the two stresses levels to that of the control (0.0 M Mannitol). Similarly, relative growth of RL, RFW, and CFW were also determined for sugar beet seedlings. Significant differences were found between stress levels for all seedling characters. Great genetic variation was found among genotypes for the germination rate and seedling characters except for CDW and RDW. Under nonstress condition, relative germination % and relative growth % for tolerant genotypes were greater than those of susceptible genotypes at early growth stage of seedlings. Results showed that drought tolerance could be expressed even in the seedling stages of sugar beet plant and may be considered as a criterion for early screening of potentially drought tolerant genotypes.

Two different viruses were isolated from sugar beet growing areas in Karaj, which caused mosaic symptoms. Collected samples were classified in two different groups. The host range of the first group was confined to some species in Chenopodiaceae and Amaranthaceae families. The sap of infected plants reacted positively with Beet Mosaic Virus antisera in ouchterlony double-diffusion test. Electron microscopy of infected plant’s sap revealed filamentous particles measured roughly 720-740 nm long.Thermal inactivation point was 55oc for 10 min., dilution end point 10-3 and longevity in vitro was two days. This virus was transmitted by green peach aphid (Myzus persicae) in non-persistent manner with 53.3 efficiency.Isolats in the second group caused necrotic local lesion in Vigna unguiculata, vicia faba and Chenopodium amaranticolor and became systemic in cucurbitaceaous and solonaceaous hosts. The infected sap of this virus reacted positively with Cucumber Mosaic Virus (type-Strein) antiserum. Upon electron microscopy, the isometric particles of the virus were measured 30nm. in diameter. Thermal inactivation point of this virus was 60 oc for 10min, dilution end point 10-4 and longevity in vitro was one day under greenhouse conditions. This virus was transmitted by the green peach aphid in non-persistent manner with 11.7 percent efficiency.

This research was to find the effects of low temperature during seed maturity on vernalization and it’s relationship with Bolting and yield and quality of sugar beet in Dezful. In a 5 years period of time. Seeds from one multigerm bolting resistant variety were produced in Karadj, a temperate region, and Ardebil, a cold region, every year and evaluated in Dezful area for Bolting, root yield, sugar content, white sugar yield, sodium, potassium and nitrogen.Results showed that the average of Bolting percentage was 5.6% and 8.12% in Karadj and Ardebil, respectively and there was a significant difference in 5% level of probability. Average root yield was 62.9 and 60.67 t/ha in Karadj and Ardebil, respectively. There was no significant difference between them in 5% level of probability. There were significant differences between seed production years, sowing dates and sugar content. The average of sugar content was 14.75 % in Karadj and 14.5 % in Ardebil. White sugar yield was 7.77 in Karadj and 7.25 t/ha in Ardebil and there was a significant difference in 5% level of probability. Considering bolting rate, sugar yield, sugar content and white sugar yield, the seed produced in Karadj was better than that of Ardebil. Therefore, it may be stated that the rate of bolting and its quantitative and qualitative traits were affected by the environmental conditions in each area.