Production characteristics of standard (susceptible) sugar beet varieties and those tolerant of rhizomania on infected soils

Abstract

Rhizomania is a sugar beet disease caused by the Beet Necrotic Yellow Vein Virus (BNYVV). Its vector is the fungus Polymyxa betae. This highly destructive disease is present in all sugar-beet growing countries. In Yugoslavia, as in most such countries, rhizomania is the most important disease of sugar beet. The use of chemical measures to control it is very expensive and crop rotation and improved cultural practice are not effective enough, so only the development and introduction into production of varieties highly tolerant (resistant) of rhizomania can secure a profitable production of sugar beet on infected soils. The existence of several different types of the BNYVV (thus far, three have been reported: A, B and P) and different levels of infection intensity on affected fields requires that the production characteristics of newly developed tolerant varieties be tested in small-plot trials before their introduction into commercial production. During 2000, we tested at the Rimski Šančevi site six varieties tolerant to rhizomania (NS Hy 8R, Luna, Puma, Rama, Rita, and Formula) as well as three standard varieties (Nera, Magda, Alina), which were used as the susceptible standards. The measurement of root yields and analysis of root quality were carried out on three dates at 30-day intervals beginning on August 15. The variety, lifting date, and their interactions all had a significant effect on all characteristics under study. The hybrid NS Hy 8R and the variety Rama were several times better in all respects than the susceptible standard, which indicates that the trial plot was severely infected by the rhizomania virus. The highest level of tolerance was exhibited by the hybrid NS Hy 8R, which outperformed all the other tolerant varieties with regard to all the characteristics under investigation. The only exception was the variety Rama, which had a higher root yield than NS Hy 8R.

Rizomanija je oboljenje šećerne repe koje izaziva virus nekrotičnog žutila nerava repe, a vektor virusa je gljiva Polymyxa betae. Ovo veoma destruktivno oboljenje prisutno je u svim zemljama u kojima se gaji šećerna repa, a kod nas kao i u većini zemalja predstavlja najznačajnije oboljenje ove gajene vrste. Korišćenje hemijskih mera borbe u suzbijanju rizomanije veoma je skupo, a plodored i poboljšane agrotehničke mere nisu dovoljno efikasni, stoga jedino stvaranje i uvođenje u proizvodnju sorata visoko tolerantnih (rezistentnih) prema rizomaniji omogućava rentabilnu proizvodnju šećerne repe na zaraženom zemljištu. Postojanje različitih sojeva virusa (za sada se navode 3 soja: A, B i P) i različitog stepena zaraženosti zemljišta ovim virusima, nameće potrebu provere proizvodnih karakteristika novostvorenih tolerantnih sorata u mikroogledima pre njihovog uvođenja u proizvodnju. Tokom 2000. godine na lokalitetu Rimskih Šančeva ispitivano je 6 sorata tolerantnih prema rizomaniji (NS Hy 8R, Luna, Puma, Rama, Rita, Formula) i 3 standardne sorte (Nera, Magda, Alina) koje su poslužile kao osetljivi standard. Utvrđivanje prinosa korena i analiza kvaliteta korena obavljena je u tri roka počev od 15. avgusta u intervalima od po 30 dana. Značajan uticaj na sva ispitivana svojstva ispoljili su sorta, rok ubiranja kao i njihova interakcija. Hibrid NS Hy 8R i sorta Rama višestruko su u svim ispitivanim svojstvima nadmašili osetljivi standard, a to ukazuje na visok stepen zaraženosti ogledne parcele virusom rizomanije. Najveći stepen tolerantnosti ispoljio je hibrid NS Hy 8R koji je, izuzev sorte Rama u prinosu korena, u svim ispitivanim svojstvima značajno nadmašio sve tolerantne sorte.