مجله چغندر قند
سال بیست و دوم شماره 1 (بهار و تابستان 1385)

This study was carried out to determine the optimal irrigation intervals in sugar beet seed production fields and to evaluate the effects of irrigation at different growth stages of sugar beet seed bearing plants (Cv. SHIRIN) on seed qualitative and quantitative characteristics. The treatments were four irrigation intervals including a control (I1) (irrigation at three stages; planting, bolting and flowering) and irrigation after 50(I2), 70(I3) and 90(I4) mm evaporation from class A pan. The experiment was conducted in four replications in Ardabil Agricultural Research Station during 2002-2003. Total irrigation water volumes in I1, I2, I3 and I4 were 3332, 5121, 4419 and 3693 m3/ha in 2002 and 2940, 5397, 5280 and 3327 m3/ha in 2003 which were applied at 3, 7, 5 and 4 times in each year, respectively. During growth periods 510.3 and 471.7mm evaporation and 156 and 136 mm precipitation were recorded in 2002 and 2003, respectively. According to the results, decreasing of irrigation intervals or increasing of applied water were not effective on unprocessed, marketable (seeds with >3.5mm diameter) and standard (seeds with 3.5-4.5mm diameter) with kernel monogerm seed yield. The I2 irrigation treatment decreased the portion of seeds with the diameter of >4.5mm by 41.45%. The increasing of water application decreased chaffy seed portion (11.40%) and increased with kernel seeds significantly (56.20%) in comparison of control (by 11.40 and 56.20%, respectively). Higher precipitation (156 mm) in 2002 led to significant decrease of unkernel seed rate by 5.28% and increased viable seeds by 15.75%. However, the standard viable seed yield at 2003 (1407.79 kg/ha) was significantly higher than that in 2002 (958.47 kg/ha).

Effects of the last irrigation time on quantitative and qualitative traits were studied for two sugar beet cultivars with intermediate and long growth periods. This research was conducted in the field of Agricultural and Natural Resources Research Center of Khorasan at Mashhad in 1381. Six treatments of withholding irrigation were applied on the cultivars using a spilit plot design within a randomized complete block design with four replications. Irrigation treatments arranged in main plots were 60, 50, 40, 30, 20 and 10 days before harvest and varieties 7233 and PP22 were in sub plots. The results showed that irrigation treatments had significant effects on the root yield, sugar content, white sugar content, Na, K, molas sugar, net and gross sugar content, while cultivars effects (except K) and irrigation×cultivar interactions were not significant either for root yield or other traits. In this experiment, net sugar content increased with shorter irrigation period before harvest. However, Duncan's test showed that there were no significant difference between irrigation treatments from 40 to 10 days before harvest. It was found that the 20-days-irrigation prior harvest provieded maximum gross income and an economized water use.

For determination of irrigated sugar beet crop evaporation (ETc) and water consumption a field experiment was conducted for three years (1991 to 1993) in Kabotar-Abad Agricultural Experiment Station. The climate was semi-arid according to Gossen method with mean annual precipitation of 90 to 110 mm. The soil was Esfahan Series with a silty clay loam texture. The crop evapotranspiration was measured in standard condition (none limiting water and nutrient) using a 2-m long, 1-m wide and 1, 2 m height drain type lysimeter based on water balance method. Sugar beet was planted in a 1000 Square meter fetch area. The planting season was from mid-April to mid-May. The annual crop was irrigated before depletion of readily available soil moisture content in root zone. The crop evapotranspiration was 1026, 1123 and 1041 mm and the total class A pan evaporation was 1326, 1344 and 1380 mm for 1991, 1992 and 1993 growing seasons, respectively. The sugar beet roots were harvested in November. The mean root yield, white sugar content, and white sugar yield, were 49.9 Mg/ha, 15.1 percent and 6.37 Mg/ha, respectively. The water use efficiency for root yield and white sugar content were 5.01, and 0.49 kg per m3 water use, respectively.

Drip irrigation is the most efficient technique known for improving irrigation water management. A two-year study was conducted to determine the effects of drip and furrow irrigation methods on yield and quality of sugar beet in north of Khuzestan. In the first year, the experimental design was a completely randomized block design with three replications. Treatments were, three drip irrigation levels (50%, 75%, 100% and 125% volume of water requirement for sugar beet) and one furrow irrigation. In the second year four drip irrigation treatments (50%, 75%, or 100% volume of water requirement for sugar beet), and two row spacing treatments (90 and 120 cm) were conducted in a split-plot design with three replications. A furrow irrigation treatment (row space = 90 cm) was also included in each replication. The treatments were arranged in a split-plot design with three replications. The results of two years showed significant differences (at 5%) in yield of root and sugar among different levels of drip irrigation and furrow irrigation treatment. Water use efficiencies of root and sugar were also significantly different (at 1%) among the treatments. In contrast, there was no significant difference among treatments in qualitative traits of root. Higher yield of root and sugar were obtained in furrow irrigation treatment (83.5 and 9.34 t/ha respectively), while lower root and sugar yield (71.16 and 8.73 t/ha respectively) were produced in drip-irrigation treatment with 50% level. This treatment had also the maximum water use efficiencies of root and sugar (18.3 and 2.29 Kg* m-3 water respectively). Plants in the furrow irrigation treatment had minimum water use efficiencies of root and sugar (6.14 and 0.69 Kg* m-3 water respectively). In the second year of experiment the quantitative and qualitative traits did not affect by row spacing treatments.

In order to study the possibility of control of Heterodera schachtii in sugarbeet fields through integration of rotation with non- host crops and resistant catch crops and their effects on quantitative and qualitative traits of sugarbeet, this study was started from 2002 for three years in Esfahan province. The experiments were carried out in a randomized complete block design with eight treatments that consists of applying non host field crops, resistant catch crops, fallow and sugar beet (control) in four replications in an infected field that sugar beet cultivated continuously in recent years in Semirom region. After harvesting of sugar beet in 2004, quantitative and qualitative traits of sugar beet in different treatments were determined. The results showed that mixture of corn and S. alba cv. Sirola treatment had the most effect on decreasing the percentage of final population of eggs and second stage juveniles in comparison with initial population (89.2% decrease) and also the highest yield of root yield(RY), sugar yield(SY) and white sugar yield (WSY) in 2004, belonging to this treatment (with 30, 5.69 and 5.09 Tons/ha) respectively and Sugar beet treatment (control) had the most increase percentage of final population and the final population of it reached, up to sevenfold of initial population and also the lowest yield of RY, SY and WSY in 2004 belonging to this treatment, with 12.81, 2.22 and 1.87 Tons/ha, respectively.

In order to study the effects of nitrogen and phosphorous application on yield and physiological parameters of sugar beet polygerm seed (cv. 7233), this study was conductedin 2000-2001 in Ardabil Agricultural Research Station (Alarough). The experiment was carried out with two factors including nitrogen in 4 levels (0 as control, 100, 200 and 300 Kg N/ha) and phosphorous in 3 levels (0 as control, 100 and 200 Kg P2O5/ha) in four replications in a complete randomized block design. Each plot consisted of 8 rows of 10 meters long with row space of 65 cm. The results did not show any significant effects of nitrogen and phosphorous application on raw and marketable seed yield, while increase in nitrogen application to 300 kg/ha had a significant effect on the yield of standard(3.5-4.5mm) seed with kernel and led to a significant decrease in seed yield to 833 kg/ha. Following the natural increase in early growth period, total dry matter began to exponentially increase after gotting 350-400 heat units, but lessened after reaching the maximum total dry weight(453-626 g/m2) in the range of 750-900 heat units which accompanied by leaf fall. On the other hand, nitrogen application increased the total dry weight of plants and accelerated reaching to the maximum TDW. Leaf area index slowly increased to gain 300 heat units thereafter it increased exponentially. The highest leaf area index (1.61-2.67) was achieved with gaining 600-700 heat units. The growth trend of plants was ascending from the early growth season until receiving 550-590 heat units (1.04-1.54 g/m2/gdd) and then, it was descending. Finally, nitrogen and phosphorous application led to an increase in leaf area and biomass duration.

This study investigates the effects of inputs on production risk of sugar beet farmers in Fars province. The study carried out in 1996. The needed data were collected by completing questionnaire from 120 farmers in Fars selected through a two-stage cluster sampling survey. The results showed that pesticide, animal fertilizer, seed and irrigation have significant effects on production changes; while labor, chemical fertilizer and machinery practices have not significant effects on production risk. Also, the results of deterministic component of production function indicated that all variables except manure have significant effects on production average of sugar beet. The amount of R2 in generalized stochastic production function, random term and deterministic production function were estimated 0.86, 0.46 and 0.89, respectively.

In this paper price and non- price factors affecting the area of sugar beet cultivation was been studied, using a logarithmic model and a cross sectional data on 195 producers of sugar beet in Khorasan province in 2003 producers were selected based on stratified random sampling method. Results of study showed that percent of sugar (an impostor), type of seed, yield of sugar beet in the last year and type of irrigation system has the most positive effect on cultivation practice of sugar beet. Also, distance of the fields from processing centers and age has the most negative effect on cultivation area of sugar beet. With regards to the results, suitable locality of processing unit, establishment of supporting cash for sugar beet, reviewing in extension packages with high effecting authority, distribution of improved polygerm seeds with high sugar production, suitable pricing based on percent of sugar and refuse were suggested in this study.