مجله چغندر قند
سال سی و چهارم شماره 1 (بهار و تابستان 1397)

In semi-arid regions e.g. Iran, water is the major limiting factor for the growth and yield of sugar beet. Development of cultivars with flexible growth period, dependent on the environmental condition, is one of the methods to reduce water usage for sugar beet cultivation. The present study was performed in Sugar Beet Research Station of Motahhari, Karaj, Iran as a split factorial based on a randomized complete blocks design with four replications in two years (2015-16). Main plots were devoted to sowing date (mid-April and late-June), and sub-plots to the factorial combinations of three harvest dates (12 October, 1 November, and 21 November) and six genotypes including promising hybrids (7112*261)*5RR-87-HF.33 and 261*276.P.77.SP.19 and commercial cultivars Pars, Jolgeh, Paya and IR7. Potential root yield (RY) and sugar yield (SY) was reduced by 3.5-3.8% per week owing to delay in sowing. The significance of sowing date × genotype interaction (P<0.05) highlights diverse response of various genotypes to the shortening of the growth period. Superior genotypes for delayed planting were identified based on the combination of two components of the least response to delayed sowing as well as achieving the highest yield under delayed sowing condition in terms of SY as Paya, IR7, and Pars. Although the direct effect of harvest date on RY, SY, and sugar content (SC) was not significant due to the significant interaction of year × harvest date, however in general, it increased RY, SY, and SC by 21, 38, and 1.72 %, respectively via delaying the harvest date from 12 October to 1 November 1 in 2015. Therefore, the harvest date of 1 November was the most suitable time for sugar beets harvest in Karaj region. Non-significant interaction between sowing and harvest date for various studied traits indicated that the impacts of delay in sowing cannot be offset by delay in harvest. Overall, results showed that by each single day advancement in sowing (between mid-April and late-June) RY and SY increased by 400 and 50 kg ha-1, respectively and for each day delay in harvest (between 12 October and 1 November) RY and SY were increased by 370 and 100 kg ha-1, respectively.

Considering the effect of climate change on climatic parameters such as temperature and rainfall as well as interaction of these parameters on plant physiology characteristics especially growing degree days (GDD) and capability of biomass production index (CBPI), the suitable location for crop cultivation can be determined by examining these indices. This study was performed to evaluate the effects of climate change scenarios B1 and A2 on determination of the appropriate location for autumn-sown sugar beet in South Khorasan province via the climatic parameters prediction using LARS-WG software under general circulation model HadCM3 and AHP weighting method based on climate parameters, plant physiology, hydrogeology, and topography, in ARC GIS 9.3 software during cultivation period of 2016-2017. Results showed that in general in both scenarios the majority of areas of the province are inappropriate for autumn-sown sugar beet cultivation so that based on the A2 and B1 scenarios, 72.81and 71.13% of the total area of the province are not suitable for cultivation, respectively and only 24.41, 2.69 and 0.08% of the province area based on the A2 scenario and also 25.36, 3.45 and 0.05% based on B1 the scenario were determined as medium, suitable, and very suitable in terms of cultivation. Also results of the final map showed that A2 and B1 scenarios in the near future (2011-2030), approximately have the same accuracy for locating the suitable area for sugar beet cultivation.

One of the main causes of drought occurrence in Urmia Lake in recent years was climate change and the development of crops with high water requirements including sugar beet. Water accounting is able to identify water saving opportunities by providing a clear picture of the amount of water used on the field. To this end, the water accounting and performance indicators based on the research results of the sugar beet fields in Miandoab region were extracted using the Aqua Crop model, and the accounting system was implemented based on low irrigation and irrigation duration in the framework of water accounting under field scale. According to the results, the contribution of precipitation from the net inflow in full irrigation with a seven-day rotation was about 8%, and with increased irrigation duration and imply of more low irrigation it amounted to 14%. An assessment of the drainage ratio from the gross inflow current showed that it was close to one in low irrigation interval and nearly all input water into the field was consumed (drained) and no opportunity was made to save water. Also, increase in irrigation duration resulted in an increase in the rate of evacuation of the total water consumption, which is considered as one of the objectives of water management in the field and improves the rate of evacuation process. Investigating the water use productivity indices showed that irrigation improved indices, but reduced the water use efficiency since in low irrigation, the rate of evaporation, which is a non-process loss, was significantly increased. Therefore, success in adopting a low irrigation strategy to save water involves the use of other management practices on the field such as the mulch and drip irrigation application which can control the evaporation.

Continuous exploitation of soil results in organic matter and nutrient elements loss, and excessive chemical fertilizer application. For sugar beet, due to its higher nutritional demands, application of organic fertilizer is more important. Solitary or integrated application of green manures is a step towards reducing chemical fertilizer application. In this study, two species of green pea and Lathyrus sativus L. were planted as green manure and their dry matter accumulation and characteristics such as nitrogen and carbon content besides their effects on soil properties were evaluated compared with control. Then, effects of solitary or integrated applications of the abovementioned legumes with reduced levels of nitrogen fertilizer (80 and 160 kg ha-1 from urea source) versus 240 kg ha-1 urea as common rate and no fertilizer application as control, in total 8 treatments, were evaluated on sugar beet during 2012-14. Results showed that green manures had significant differences in terms of produced biomass, nitrogen and carbon. They changed nitrogen, carbon and carbon to nitrogen ratio of the soil in 50 days after application. Green manures showed optimum effects on weed density and biomass reduction. The highest root yield (47 t ha-1) and biomass (56.8 t ha-1) were achieved in green pea manure plus160 kg N ha-1 which was higher than chemical fertilizer (41.2 t ha-1). The highest sugar content (20.3%) was obtained under low N application in integrated green pea treatments. The highest rate of extraction coefficient of sugar was obtained in integrated green pea treatments and solitary application of green manure (about 18%), while the lowest extraction coefficient of sugar (16%) was obtained in nitrogen fertilizer treatment as well as integrated application of Lathyrus sativus + N. The highest white sugar yield (8 t ha-1) was obtained in green pea plus 160 Kg ha-1 N which showed 20% increase compared with control. In other integrated treatments, in spite of 1/3 to 2/3 reduction in N application compared with control, white sugar yield had no significant reduction. The lowest impurities rate including amino-nitrogen, K, and Na, and the lowest molasses sugar were obtained in green manure treatments or integrated application with low N levels. In conclusion, green manure application reduced chemical fertilizers usage while maintained yield, quality and product safety.

The aim of this study was to optimize the in vitro condition for sugar beet cultivation, its possible contamination with Heterodera schachtii, and also to identify susceptible and resistant cultivars to cyst nematode in a sterile plant culture medium. Seeds of a susceptible cultivar named Jolgeh and three resistant cultivars namely Pauletta, Sanetta and Nemakil were cultured on water-agar medium and then transferred to modified Knop medium after germination. Two weeks after germination, roots of each seedling were inoculated with 200 H. schachtii second-stage juveniles (J2s), and after one, two, four, and eight days after inoculation, roots were stained with Fuchsin acid and J2s number were counted. Number of J2s on 16 and 20 days after inoculation were counted as well. Results showed the highest rate of J2 penetration on 4th day and also significant difference between susceptible and resistant cultivars in terms of J2 number. Twenty days after inoculation, an average of 7.17 J2 were found on the roots of Jolgeh, 2.5 on Paulta, one on Sanetta cultivar and 1.2 on Nemakil. According to the results, the method applied in this study can be used as an easy and accurate method to evaluate sugar beet cultivar resistance to cyst nematode.

Cercospora leaf spot is one of the most important and common leaf diseases of sugar beet which causes several damages. This study aimed to find indices to distinguish susceptible and tolerant to cercosporaleaf spot sugar beet cultivars. The experiment was conducted in a factorial design based on randomized complete block design under laboratory and greenhouse conditions. Treatments included 11 sugar beet genotypes and contamination and non-contamination to cercospara leaf spot disease treatments. Different traits such as main photosynthetic pigmants (cholorophyll a, b, total cholorophyll and pigment ratio), auxiliary pigments (carotenoids, flavonoids and anthocyanins) and antioxidant enzymes activity such as catalase, proxidase and polyphenol oxidase, and shoot and root dry weight were measured. Results of the main photosynthetic pigments evaluation showed that the disease reduced the chlorophyll a and b  and consequently total chlorophyll content. The amount of photosynthetic auxiliary pigments, except carotenoids, increased as the disease progressed in infected plants. Cercospora leaf spot increased the activity of catalase, peroxidase and polyphenol oxidase enzymes and decreased dry weight of shoot and increased root dry weight with control. Cultivar HI0063 was affected by the disease earlier than other cultivars, and had a higher dry weight loss than other cultivars; also plant weight in this cultivar was higher than other cultivars and higher level of chlorophyll a and flavonoids was seen. The level of antioxidant enzyme activity of HI0063 was higher than the tolerant cultivar. Yasmeneas cultivar as the most tolerant cultivar showed the diseases symptoms later compared with other cultivars with the lowest leaf dry wieght reduction.

The successful application of herbicides for selective and economic control of weeds without damage to both the environment and crop is one of the important achievements in modern agriculture. In order to predict the additive, synergistic and orthogonal effects of binary mixtures of desmedipham+ phenmedipham+ ethofumesate, chloridazon and clopyralid herbicides based on Additive Dose Model (ADM), two greenhouse experiments were conducted in completely randomized design with 105 treatments and three replications for Chenopodium album L. and Portulaca oleracea L. weeds in the greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran in 2013. Experimental treatments consisted of seven herbicides with five mixing ratios of 0:100, 25:75, 50: 50, 75:25, 100:0 and three control treatments for each of the herbicide ratio. Results showed that the binary mixture of herbicides has a strong dependence on various factors such as weed species so that each species showed different response with different morphological and physiological characteristics. Accordingly, the mixture of desmedipham+ phenmedipham+ ethofumesate and clopyralid based on ADM model was synergistic. Also desmedipham+ phenmedipham+ ethofumesate, and chloridazon herbicides mixture had synergistic effect on weed control based on ADM model. In contrast, chloridazon and clopyralid herbicides mixture had additive effect on Portulaca oleracea L. and synergistic effect on Chenopodium album L. control.

The best way to increase crop production is to improve efficiency and productivity. In this study, the technical efficiency and productivity growth of sugar beet production factors in major produced provinces were estimated using data envelopment analysis (DEA) method for the period of 2004-05 to 2014-15. Results showed that Semnan, Fras, Qazvin, Markazi, Chaharmahal and Bakhtiari had no technical efficiency and the most non-optimal input usage was related to pesticide with 166% inefficiency in Chaharmahal and Bakhtiari province. In the other words, pesticide usage can be reduced to more than half in this province. Productivity growth analysis showed a 7% decrease in growth in studied provinces and only Southern Khorasan and North Khorasan provinces had productivity growth of 4 and 6%, respectively. The correlation coefficient between productivity growth and its components showed a positive and significant (P<0.05) relationship between productivity growth and technological changes. According to the results, Southern Khorasan and North Khorasan provinces were in better position in terms of efficiency and productivity growth. Therefore, the study of management practices and the use of indigenous knowledge in these provinces can lead to the introduction of a model to improve the sugar beet production efficiency in the country.

Fodder beet (Beta vulgaris L.) is the focus of attention as forage crop in Syria. However, recommended agronomic practices for maximizing productivity are limited. The study was conducted on summer date (1st of September), during 2016/2017 season, to study the effect of organic and potassium fertilizer on the productivity traits of fodder beet. The experiment was carried out as split plot design based on randomized complete block design (RCBD) with three replicates. The organic treatments (control, manure, sea weed extracts) were assigned to the main plots, while potassium treatments (90, 120, and 160 pure unit of K2O/ha) were distributed randomly in the sub plots. The results of analysis of variance showed a significant (P≤0.05) effect of potassium treatment on root and shoot weight per plant, and root and shoot crude protein contents. The best treatment was K90 to get the highest productivity and quality traits. In terms of organic treatments, the sea weed extracts surpassed the other treatments significantly.