|
|
:
|
Among the factors influencing sugar beet production, the selection of a proper cultivar has an essential role to play. Presently, the three diseases of Rhizomania, Rhizoctonia root and crown rot, and sugar beet cyst nematode are the main challenges of spring sugar beet cultivation in Iran. It has been estimated that about 40 and 50 percent of sugar beet fields in Iran are affected by the two diseases of rhizomania + rhizoctonia and rhizomania + nematode, respectively. Since it is very difficult to fight these soil-borne diseases, the sowing of resistant cultivars in infected feilds can be a good solution for the viability of sugar beet cultivation. In main sugar beet-growing countries, pilot field trials are conducted to compare cultivars and their results are provided to farmers to decide on appropriate cultivars. The present study was conducted within the scope of the sugar factories in Kermanshah and Lorestan (12 cultivars resistant to rhizomania + rhizoctonia) and Hamedan (10 cultivars resistant to rhizomania + nematode) in 2021-2022. In each trial, six 30-m-long rows were randomly assigned to the cultivars with no replication. At the harvest time, 10 samples (each sample from an area of 5 m2) were harvested. After topping, the plants were counted and four samples were sent to Sugar Technology Laboratory to prepare pulp and analyze it chemically. The analysis of variance was performed on the field data and laboratory results. It was found that in the two trials of rhizomania + rhizoctonia, the infection to these two pathogens was at an acceptable level in Lorestan but at a negligible level in Kermanshah. In the trial of rhizomania + nematode, the farm infection level was significant. In the farms infected with rhizomania and rhizoctonia, the three cultivars of ‘Perfecta’, ‘Anaconda’, and ‘Gecko’ stably produced the highest root, sugar, and white sugar yields although ‘Cadmus’ was among the best cultivars in terms of sugar and white sugar yield whereas, in non-infected conditions (Kermanshah), ‘Rivolta’ exhibited the highest root, sugar, and white sugar yields. In the farms infected with rhizomania and cyst nematode, the three foreign cultivars of ‘Ghazira’, ‘BTS5950’, and ‘Drafter’, as well as the Iranian cultivar of ‘Shokoufa’, performed the best in yield. A comparison of the yield of newly improved domestic cultivars (‘Dena’, ‘Sina’, and ‘Tara’) with that of the control cultivars (‘Ekbatan’ and ‘Shokoufa’) showed the lack of any significant development in the newly improved domestic cultivars.
|