مجله چغندر قند
سال سی و دوم شماره 1 (بهار و تابستان 1395)

One of the most effective ways to deal with drought stress and increase water use efficiency is the development of drought-tolerant varieties which display less reduction in yield per unit water reduction. Therefore, the breeding of diploid pollinators was considered as an essential measure for producing drought-tolerant hybrids. In this study, from 4 diploid pollinator populations, 45 half-sib families were developed and evaluated under drought stress condition and subsequently superior families with high root yield were selected. New families were produced and after final evaluation, 23 families with high performance were selected and crossed with a male sterile monogerm single cross as female parent and eventually 23 test-cross hybrids were produced. These hybrids together with Gadook cultivar and a drought-tolerant hybrid (IR7), as controls, were evaluated in a randomized complete block design with four replications in two experiments including normal irrigation and drought-stress condition at Torogh Research Station in Mashhad, Iran for two years, 2007-08. Normal irrigation was performed after 90 mm evaporation from class A evaporation pan but under stress condition, irrigation was performed based on soil moisture measurement at different soil depths (after soil moisture depletion reached to wilting point). Results showed significant difference among the families in terms of sugar yield in both experiments. Sugar yield was decreased from 15.20 t ha-1 in normal irrigation to 7.10 t ha-1 under drought stress condition. Under drought stress, the highest root yield (55.78 t ha-1) was obtained in test-cross hybrid 12 [(436*231)*SBSI-DR I-HSF-14-P.35)] which was placed in superior group with hybrids 7, 6, 14, 2, 5, 10 and 3. Furthermore, the highest sugar yield (7.93 t ha-1) was obtained in hybrid 7 [(436*231)*SBSI-DR I-HSF-14-P.7]. In order to select drought-tolerant hybrids, Stress Tolerance Index (STI), Stress Susceptibility Index (SSI) and Tolerance (TOL) indices were calculated based on sugar yield. According to the results, test-cross hybrids 7, 9, 12, 18 and 22 were identified as drought-tolerant hybrids but based on sugar yield results, hybrids 7 and 12 were selected as promising hybrids with 7.93 and 7.51 t ha-1 sugar yield, respectively.

Current study aimed at determining the most reliable drought tolerant criteria for identification of sugar beet genotypes. A split plot design based on randomized complete block design with three replications was applied at Motahari Research Station, Karaj, Iran in 2012. Two irrigation treatments including normal irrigation after 80-90 mm and irrigation after 270 mm evaporation (stress condition) from class A evaporation pan were allocated to main plots and 36 sugar beet genotypes to sub-plots. Stress susceptibility index (SSI), harmonic mean (Harm), tolerance (TOL), mean productivity (MP), yield stability (YSI), drought response (DRI), stress tolerance (STI), geometric mean productivity (GMP), yield index (YI), drought resistance (DI), modified stress tolerance (MSTI), stress non-stress production (SNPI), abiotic tolerance index (ATI), stress susceptibility percentage (SSPI), relative decrease in yield (RDY) indices were estimated. According to the abovementioned criteria, genotypes 3, 35, 32, 5, 34, 13, 26, and 36 with high yield under both normal and stress conditions were ranked in group A. Comparison of the 16 indices showed that GMP, Harm, MSTI (based on K2STI), SNPI, STI, YI and YS indices could identify the group A genotypes accurately. However, the results of correlation coefficient between drought tolerance indices and raw sugar yield under normal and stress conditions showed the indices SSPI, ATI, MP, TOL, GMP, STI, RDY, Harm, YI, SNPI and DI as superior criteria.

The sugar beet plant has a conical-shaped root and at harvest the tap-root breaks which remains in the soil. As a result, a significant amount of root yield and consequently sugar content is lost. Furthermore, the field soil remains in the root fissures and is carried with the root to sugar factory. In rhizomania and nematode-infested areas, the soil movement causes the disease wide spread. In this study, the full-sib families 27102 and 27131 developed from an F2 population were used as pollinator and the single cross 231*261 as maternal parent for producing hybrids with smooth and round-shaped roots. The hybrids were produced and evaluated in a randomized complete block design with four replications in Karaj and Moghan. Helix and Rasoul cultivars were used as controls. Based on biplot and cluster analyses of quantitative and qualitative characteristics, the hybrids were divided into five groups. Based on root morphological characteristics (smoothness, form and root uniformity) as well as qualitative and quantitative traits (root yield, sugar yield, sugar content, and purity), the hybrids (261*231)*27102-S1.25, (261*231)*27102-S1.44, and (261*231)*27131-S1.3 with 83.84, 80.68, and 71.28 t ha-1 root yield, respectively, were considered as promising hybrids.

In drought stress condition, it is important to estimate the N and K requirement of sugar beet. A drought-tolerant sugar beet genotype, BP Karaj, was evaluated in split plot factorial design based on a randomized complete block design with four replications at Motahari Research Station, Karaj, Iran for three years. Main plots were allocated to irrigation treatments including normal irrigation (control), irrigation with early season drought stress imposition, and irrigation with drought stress imposition during the growing season. Subplots were allocated to four N levels including 0 (control), 50, 100, and 150 kg ha-1 and three N levels including 0 (control), 100, and 200 kg ha-1. The highest root yield (49.43 ha-1) and white sugar yield (5.94 t ha-1) in irrigated condition were obtained in control treatment. Root yield under drought stress imposed early season and during the growing season was 39.84 and 34.85 t ha-1, respectively, which showed 19 and 30% decrease compared with the control irrigation treatment, respectively. The effect of N and K interaction on root yield, sugar yield and white sugar yield was significant (p

This study was conducted in split plot design based on a randomized complete block design in Naghadeh region, Urmia, Iran in 2009-10. Two sowing patterns including A1) single row planting with 50 cm between-row spacing, and A2) two rows planting on the hill with 40 cm distance and 50 cm between-row spacing (40×50) were allocated to main plots and four furrow compactions including B1) control, B2) furrow compaction with one time rolling, B3) two times rolling and B4) three times rolling were allocated to subplots. Furrow compaction had no significant effect on root yield and sugar yield. Sowing pattern had significant effect (p

In this study, the efficiency of two seed coating methods including coating and pelleting and 12 bacteria levels including control, Azotobacter, Bacillus, Pseudomonas, Azospirillum, combination of two bacteria, and combination of all bacteria with 1-CFU ml 107 concentration was evaluated on germination, seedling growth, and bacterial survival on seed coat after 6 months in sugar beet cultivar Pars. The experiment was conducted in a factorial arrangement based on a randomized complete block design with four replications in 2015. Results showed significant effect of bacteria on seedling fresh weight, normal seedling percentage, and seed vigor; however, the two coating methods had no significant effect on the above-mentioned traits. Seed coating with Pseudomonas resulted in 160, 50, 128 and 90% increase in seedling fresh weigh, normal seedling percentage, and seed vigor compared with control. The effect of Pseudomonas and Azotobacter combination was also positive. Bacterial survival after 6 months was higher in pelleted seeds than coated seeds. The Bacillus, Pseudomonas, Azospirillum and Azotobacter population concentration on coated seeds were 25000, 15950, 0 and 14100 CFU, respectively.

In order to identify and determine weed population in sugar beet fields, 92 fields from five counties of Kermanshah province in Iran were selected and evaluated at two growing stages (early May and late September) in 2014. The weed population indices were calculated by counting the number of weeds separated on othe basis of genus and species. For all fields, the latitude, longitude and altitude were recorded using GPS device. Eighty-five weed species belonging to 31 families were identified in different sugar beet fields. The dominant broad-leaf weeds identified at the beginning of the growing season (first sampling stage) were lamb's quarters (Chenopodium album L.) and field bindweed (Convolvulus arvensis L.) with 189.22 and 124.09% dominance index, respectively, whereas at the second sampling (late September), the dominant broad-leaf weeds identified were lamb's quarters (Chenopodium album L.), pigweed (Amaranthus retroflexus L.) field bindweed (Convolvulus arvensis L.), and cocklebur (Xanthium strumarium) with 207.92, 194, 111.22, and 107.93% dominance index, respectively. Green foxtail (Setaria viridis L.) was the dominant narrow-leaf weed in both samplings at the beginning and end of the growing season with 79.73 and 176.35% dominance index, respectively.

The main objective of this study was to investigate the economic efficiency of investment in sugar beet breeding research in Iran. The required information including the value and cost of sugar beet production in 2010 and the budget allocated to the sugar beet breeding research were obtained from the Office of Statistics and Information Technology of Ministry of Jihad-e-Agriculture and Agricultural Research, Education and Extension Organization, respectively. After estimating a function in which the dependent variable was crop value, and the independent variables were conventional inputs (water, labor, seed, etc.) and research expenditure costs, the research rate of return was determined using average production, marginal production, and the rate of investment interest. According to the results, the amount of marginal production of sugar beet breeding research cost variable was 10.93 Rials. The range of variations in rate of return in sugar beet breeding research investment was 48.97% and 37.56% for times lags of 6 and 7.5 years, respectively. Finally, the rate of return of sugar beet breeding research investment in the median of the above-mentioned range was 42.52%. The finding confirms that any investment in sugar beet breeding research in Iran would be economic.