مجله چغندر قند
سال سی و پنجم شماره 1 (بهار و تابستان 1398)

A quality decrease of sugar beet roots under silage condition may vary for susceptible and resistant to rhizomania cultivars. The aim of this study was to evaluate the quality of resistant to rhizomania sugar beet pollinators under silage condition in Karaj (non rhizomania infected area) in 2014 and in Zarghan(infected to rhizomania site), Fars, Iran in 2015-16. The experiment was conducted in split plot in time based on a randomized complete block design with three replications. Studied factors included 11 sugar beet line comprised of nine genotypes, on susceptible and one resistant cultivars and silage duration including three levels of 20, 40 and 60 days. Different traits such as root dry matter, sucrose, sodium, potassium, alpha amino nitrogen, brix, and extraction coefficient of sugar were measured before and after silage. Roots were scored in terms of rot occurrence after silage. Results showed that rot severity of the roots in Zarghan was higher than Karaj. In Zarghan, the root rot of the sugar beet genotypes 31924, 31927, 31929, 32003, 32814 were lower than other genotypes after 60 days silage. During the three-years experiment, the silage potential of the sugar beet genotype 32003 with 71.86% extraction coefficient of sugar was more than other genotypes which can be used as a genotype with better silage condition in sugar beet breeding programs.

Identifying new areas for autumn-sown sugar beet (Beta vulgaris L.) production which requires less water than spring ones, has made it possible to increase the area under cultivation of ​​this crop. The best and least expensive way to identify suitable growing areas is the use of Geographic Information System (GIS). In order to identify the suitable areas for autumn-sown sugar beet planting in Fars province, long-term climatic data of 19-years up to 2016 including temperature and precipitation from 13 synoptic meteorological stations in Fars province including Eghlid, Jahrom, Zarin Dasht, Farashband, Fasa, Firoozabad, Qir&Karzin, Kazeroon, Lar, Lamerd, Nurabad and Nayriz were collected. Then, the required information layers including the characteristics of cumulative heat units, spring hours, biomass and altitude were calculated with GIS. Slope and altitude layers were extracted from their digital model, and the zoning map of the above-mantioned layers and the final zoning map were drawn using the hierarchical method in ArcGIS system environment. Based on the results, central, eastern, western and to some extent southern areas including Firoozabad, Fasa, Nayriz, Jahrom, Farashband, Zarrin Dasht, Darab, and Qir&Karzin were identified as potential areas for autumn-sown sugar beet planting. Northwestern (Kazeroon), Southeast (Darab, Neyriz and Hajiabad) and Southern and Southwestern areas (Qir&Karzin, Lar, and Lamerd) received between 140-170 hours in terms of the number of effective cold hours and were considered as favorable areas for autumn-sown sugar beet planting. The northern and southern margin of Fars province were identified as unsuitable areas for sugar beet planting. According to the province's final zoning map, 13% of the land was highly suitable, 23% was suitable, 31% was medium, and 33% was unsuitable for autumn-sown sugar beet planting.

This aim of this study was to evaluate the possibility of improving the yield and qualitative traits of sugar beet using seed hydropriming and increasing plant density under late planting. Two Iranian sugar beet cultivars (Aria and Shokoofa) were used. First, the optimal hydropriming limit of the seeds of the desired cultivars was determined in the laboratory and then the seeds of each cultivar were primed as much as needed for cultivation in the field. Cultivation was carried out with a single-row manual machine and as high-density to obtain the desired plant density after thinning. The first irrigation (drip system) was carried out on 9 May of each year. The experiment was performed as split factorial in a randomized complete block design with four replications. Cultivars (Shokoofa and Aria) were devoted to the main plots and primed and non-primed seed in two levels and density in four levels (70, 85, 100 and 115 thousand plants per hectare) were assigned as sub-plots. After harvest on23 November of each year and calculation of the yield, root pulp was taken and qualitative traits were measured. Finally, after obtaining two-year data, combined analysis of variance was done. Results showed that Shookofa with 44 t ha-1 root yield was superior to Aria with no significant difference between two cultivars in terms of qualitative traits. Priming had also no significant effect on any quantitative and qualitative traits of sugar beet. The highest root yield (45 t ha-1), sugar yield (7.1 t ha-1), and white sugar yield (5.9 t ha-1) were obtained at 100000 plants per hectare density. Therefore, for late sugar beet cultivation, non-primed seed of Shookofa cultivar with final density of 100,000 plants per hectare can be recommended as the optimal density.

In order to study the effect of seed priming on and the growth of sugar beet seedling under stress condition, an experiment was conducted in the laboratory and greenhouse of the Department of Agronomy, Faculty of Agriculture, Urmia University in 2017. Experimental units were arranged in factorial based on completely randomized design with three replications. The first factor was four salinity levels (0 as control), 5, 10, and 15dS/m of sodium chloride and the second factor was priming treatments including magnetic water, salicylic acid, calcium chloride, and sodium chloride for 8 h and non-priming (control). The effect of salinity levels on all studied traits was significant (P < 0.01) except for the seedling germination. The effect of seed priming on all the studied traits was significant (P < 0.01). Furthermore the interaction of the two treatments on germination index and seedling length was significant (P < 0.01) as well as for shoot length (P < 0.05). Results showed that 15 dS/m salinity level reduced final germination percentage, radicle length, radicle dry weight, shoot dry weight, seedling weight, seedling vigor index, speed of emergence, uniformity of emergence, percent of seed emergence, and speed of emergence-coefficient by 8.89, 33.33, 51.35, 46.41, 44.44,25.23, 12.39, 13.05, and 49.05% and increased mean time to germination by 56.46% compared with control, while priming with NaCl significantly increased final germination percentage, radicle length, radicle dry weight, shoot dry weight, seedling weight, and seedling vigor index by 14.55, 9.95, 84.21, 27.77, 22.72, 58.94, 26.23, 17.32, 10.07 and 9.09% and reduced mean time to germination by 13.14%. The highest germination index, stem length, and seedling length and also the lowest mean time to germination were obtained at zero salinity level and priming with sodium chloride. In addition, priming with sodium chloride at other salinity levels was able to moderate the effect of salinity stress on these indices and was recognized as the best priming treatment.

In this study, the antagonistic activities of eleven isolates belonging to 10 species of Trichoderma fungi including Trichoderma harzianum, T. atroviride (two isolates), T. viride, T. orientalis, T. citrinoviride, T. asperellum, T. spirale, T. crassum, T. pseudokoningi and T. ceramicum against rhizoctonia solani AG2-2, the causal agent of sugar beet root rot, were evaluated in a completely randomized design with four replications. Results showed that all Trichoderma isolates reduced the growth of pathogen significantly and the highest antagonistic effects were observed in dual culturing test in T. harzianum Z1 isolate, which caused 76.57% inhibition of pathogen mycelial growth. In greenhouse experiments, the efficacy of four selected Trichoderma isolates on sugar beet root rot control in Shirin cultivar was evaluated. Results showed that T. harzianum Z1, T. atroviride Z2, and T. orientalis Z4 caused 71.1, 66.6, and 58.3% decrease in root rot severity, respectively. In field experiments (2013-14) conducted in Hamedan Agricultural and Natural Resources Research Center, the effect of selected Trichoderma isolates in comparison with fungal treatment (carboxin-thiram) and control treatment on the occurrence and severity of root rot was evaluated through artificial contamination by Rhizoctonia solani. Results showed that selected Trichoderma isolates were significantly different in terms of disease control and T. harzianum Z1 isolate caused 66.4% reduction in the incidence of infection and 56% reduction in root rot severity compared with control. Therefore, this isolate is considered as the most effective antagonist in decreasing of Rhizoctonia root rot disease of sugar beet root.

The turnip moth, Agrotis segetum is considered as one of the most important pests of sugar beet. The larvae of this pest feed on sugar beet crown from the second age onwards and cut off the root from the stem causing seedling dryness. This research was conducted during 2013-15 in West Azerbaijan and Lorestan provinces. The efficacy of Bt Semisolid bait was compared with an organophosphate pesticide, Dursban in West Azarbaijan and Lorestan provinces. Four treatments including Dursban (Chlorpyrifos) EC 40.8% 2 l/ha, Bt bait (5l Bt (Biolop) + 50l water + 100 kg wheat bran)/ha, Bt (Biolop) Spray (3 ml/l), Semisolid Bt bait (100 Kg/ha) were used on the turnip moth in sugar beet fields in a randomized complete block design with four replications, in two periods of 7 and 10 day after emergence. In the province of West Azerbaijan, results of combined analysis of variance showed that the treatment of premature Bt semisolid bait with 4.3% damage had thehighest rate of damage reduction and was significantly better than other treatments. In the Lorestan province, the efficacy of Semisolid Bt bait and Dursban was better than the other treatments.

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 the effect of various groundwater resource management policies on sugar beet cultivation area in Khorasan Razavi province, a positive mathematical programming model was used. The studied areas included Mashhad, Neyshabur, Sabzevar, Torbat-Jam and Torbat-e-Heidariyeh. Required information was obtained by completing the questionnaires as well as information banks and publications of Jihad-e-Agriculture Organization and Khorasan Razavi Districts Organization. The studied scenarios included increasing the price of water, reducing the discharge of water from wells, and increasing irrigation efficiency in the form of improving irrigation management, as well as developing new irrigation systems which were studied in the form of several sub-scenarios. Results showed that the policy of increasing the price of water not only leads to sharp decrease in the area under sugar beet cultivation but also reduces the farmers’ income. However, the policy of less water withdrawal from agricultural wells showed less reduction. The policy of increasing irrigation efficiency along with controlling the area under cultivation, in addition to preserving groundwater, increased the sugar beet cultivation area and farmers’ income.