Aphanomyces damping-off caused by Aphanomyces cochlioides Drechsler is one of the major diseases affecting sugar beet production worldwide. Growers rely mainly on hymexazol seed treatment to prevent infection by A. cochlioides at early stages of sugar beet growth. In vitro sensitivity of A. cochlioides isolates from Minnesota, North Dakota and Texas to pyraclostrobin, prothioconazole, tetraconazole, and hymexazol was determined using radial mycelial growth inhibition assay. The mean effective concentrations that reduced radial growth by 50% (EC 50 ) values were 0.52, 0.78, 2.39, and 3.48 µg ml -1 for hymexazol, pyraclostrobin, prothioconazole, and tetraconazole, respectively. Hymexazol and pyraclostrobin had lower EC 50 values compared to prothioconazole and tetraconazol under in vitro conditions. In vivo fungicide efficacy was evaluated in the greenhouse using an in-furrow application method. Aphanomyces cochlioides zoospore suspension was used as inoculum on seed and 2-week-old plants to compare the relative effects of fungicide treatments on disease severity. Hymexazol was most effective at reducing Aphanomyces damping-off compared to the other fungicides at both stages under in vivo conditions. Pyraclostrobin, prothioconazole, and tetraconazole provided more effective disease reduction to the 2-week old inoculated plants compared to those inoculated at seed stage. fungicide rotation partners for hymexazol that will effectively control A . cochlioides .
Experiments evaluated sugarbeet tolerance, herbicide efficacy on common lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.) and waterhemp (Amaranthus tuberculatus (moq.) J.D. Sauer), and rotational crop safety to ethofumesate (2-Ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranol methanesulfonate) in 2017, 2018, and 2019. Ethofumesate applied at 2.24 or 4.48 kg ha-1 at the sugarbeet two-true leaf stage reduced sugarbeet stature and recoverable sucrose in field experiments. Ethofumesate at 1.12 kg ha-1 plus glyphosate at 1.26 kg ha-1 applied preemergence (PRE) or early postemergence (EPOST) to 1.3-cm weeds provided broad spectrum control with the least sugarbeet stature reduction in field and greenhouse experiments. Corn (Zea mays L.), dry bean (Phaseolus vulgaris L.), soybean (Glycine max L.), and wheat (Triticum aestivum L.) stand density, stature reduction, flowering date, grain yield, test weight, and grain moisture were not affected by 4.48 kg ha-1 ethofumesate applied at calendar dates representing 9-, 10-, and 11-month intervals between sugarbeet and rotational crops.
Using marker assisted selection, a germplasm with a high frequency of resistance to sugar beet cyst nematode and rhizomania has been selected out of a single plant cross developed to verify the resistance to sugar beet cyst nematode conditioned by the HsBvm-1 gene.Seventeen F3 families from a mapping cross, homozygous for markers linked to the Rz1 gene (conferring resistance to Beet necrotic yellow vein virus) and the HsBvm-1 gene (conferring resistance to Heterodera schachtii), have been increased and released as an F 5 population.This population also has the potential to contain the Pm gene for resistance to powdery mildew but was not screened for this.Nine F3 families were chosen at random and greenhouse testing was completed to verify the usefulness of the HsBvm-1 gene marker in a pre-breeding program.Eight of Jan. -June 2020 FC242 (PI 687276) 1 the 9 families performed as predicted by the marker.One family chosen as segregating for the marker showed the phenotype of a susceptible population.Further experiments showed a distorted segregation ratio in this F3 family.HsBvm-1, the SNP marker linked to the HsBvm-1 gene is useful in a pre-breeding program and allows an increased efficiency in selecting a population of enhanced frequency of the HsBvm-1 gene before the line is taken for field testing.
Establishing an adequate plant population is one of the first challenges of sugar beet production.Reduced sugar beet emergence results in a decision between a lower than desired plant population or replanting the field.The objective of this study was to determine the plant population that warrants replanting a field to maximize extractable sugar ha -1 .The study was conducted in three environments during the 2016 and 2017 growing seasons.Two planting dates and six plant populations were utilized in each environment.The two planting dates were separated by 19 or 20 days to simulate a replant situation.Sugar beets in each planting date were hand thinned to six populations of 44,000, 58,700, 73,400, 88,100, 102,800, and 117,400 plants ha -1 .Planting date and plant population did not significantly affect sugar concentration.However, planting date and plant population influenced yield and extractable sugar ha -1 .Extractable sugar yield was maximized with the first planting date and populations of 102,800 and 117,400 plants ha -1 .A population of 58,700 plants ha -1 in the first planting date had similar extractable sugar yield to the second planting date populations of 88,100, 102,800, and 117,400 plants ha -1 .Sugar beet populations above 58,700 plants ha -1 should not be replanted based on the results from this study.
Despite the many agronomic benefits of conservation tillage, little is known regarding the effects of reduced tillage on the pest complex in sugar beet.We examined the effects of two types of tillage (strip till versus conventional) and different irrigation rates on yield as well as densities of insect pests, weeds, and a soil-borne plant pathogen in sugar beet.Yields were similar between tillage treatments for two of the three years, but were greater for conventional tillage during one year in which a wet spring may have slowed seedling development in strip-tilled plots.The low irrigation treatment exhibited lower yields in one of three years, regardless of tillage treatment.Eggs of beet leafminer flies were more abundant in conventional tillage on three of eight observation dates, but larval densities did not differ by tillage treatment.Bean aphid incidences generally were positively related to irrigation rate.Total weed counts within beet rows did not Journal of Sugar Beet ResearchVol. 56 Nos. 3 & 4 differ by tillage or irrigation, but between-row counts were greater for the high irrigation treatment during two years.Area under the disease progress curve for Rhizoctonia crown and root rot was higher in conventional tillage during one year.The results presented here show that strip-till sugar beet can be produced with yields comparable to conventional tillage without compromising pest management programs.
Nitrogen (N) management for sugarbeet is challenging due to the variable effects of weather on soil N transformations and N losses, and may be particularly difficult on soils subject to N leaching.A field study was conducted to determine if extending the in-season N application termination date beyond the conventional cutoff date of 10 weeks after planting would improve sucrose yield.Three in-season N application timing treatments were evaluated, each consisting of three fertigation events totaling 84 kg N ha -1 in addition to a preplant application of 67 kg N ha -1 .Treatments were 28 kg N ha -1 applied: (1) every 7-8 days from June 15 to June 30 (10 weeks after planting); (2) every 14-16 days from June 15 to July 15; and (3) every 28 to 32 days from June 15 to August 15.Treatments did not affect yield components, except in 2009 when terminating N application on August 15 reduced root sucrose concentration by 6.0 g kg -1 .Compared to the conventional June 30 cutoff, gross economic return was negligible for the July 15 cutoff and was consistently negative (-$146 ha -1 ) for the August 15 cutoff showing no advantage to extending the N application period beyond June 30.
The yield of sugar beet (Beta vulgaris L.) has almost doubled from 1993 to 2018 in the U.S. There is interest in understanding how increased root yield potential in sugar beet production systems has influenced the in-season nutrient uptake patterns in the plants. In 2014, a study was conducted to evaluate amounts and rates of dry matter, macro(N, P, K, Ca, Mg, S, and Na) and micro-nutrients (Fe, Mn, Zn, Cu, and B) accumulated by a single herbicide-resistant sugar beet variety (BTS 21RR25) on an irrigated Portneuf silt loam soil of southern Idaho. Nitrogen, P, and K fertilizers were applied at agronomic rates based on soil test values. Whole plants were destructively sampled at 16-d intervals from 9 June (germination) to 30 September 2014 (at harvest), separated into tops and roots, and analyzed for dry matter amount and nutrient concentrations to estimate amounts and rates of nutrient accumulation. Mean root yield was 67.5 tonne ha-1. Mean total accumulation at harvest was approximately 50.2 Mg ha-1, 268, 69, 529, 200, 122, 109, 28, 13, 1.85, 0.64, 0.16, and 0.68 kg ha-1 for dry matter, N, P, K, Na, Ca, Mg, S, Fe, Mn, Zn, Cu, and B, respectively. Dry matter, P, Cu, Mg, Mn, 54 Journal of Sugar Beet Research Vol. 56 Nos. 3 & 4
Average sugarbeet yield has increased from 38.8 to 82.9 Mg ha -1 since 1971.• Previous recommended nitrogen (N) rate of 146 kg N ha -1 did not consider current yield potential.• Fertilizer-N response increased in Red River Valley (RRV) but declined in southern MN.• Sugarbeet after corn requires 100 kg N ha -1 more than after spring wheat.• Fall-N application requires an extra 16 kg N ha -1 compared to spring to optimize sugar yield.
The effects of full and limited irrigation sugarbeet production practices on soil water extraction and evapotranspiration water use efficiency were investigated in 2015, 2016, and 2017 near Kimberly, Idaho. Four irrigation regimes (fully irrigated (FIT), 75% FIT, 50% FIT and 25% FIT) were studied in 2015 and 2017 and three irrigation regimes (fully irrigated, 60% FIT, 30% FIT and rainfed) were studied 2016. Soil water was extracted from all layers of the 2.25 m soil profile and the pattern of extraction was impacted by irrigation regime. In general, net soil water depleted from the 2.25 m soil profile between emergence and harvest and seasonal average soil water extraction decreased with depth and irrigation amount. For all irrigation treatments and all study years, 70 to 90% of soil water extraction was from the 0 to 1.2 m soil profile and 4 to 10% of soil water extraction was from the 1.8 to 2.25 m soil profile. Water use efficiency increased under limited irrigation. Root yield water use efficiency was greatest for the 50% FIT, 60% FIT, and 75% FIT treatments in 2015, 2016, and 2017, respectively. Estimated recoverable sucrose water use efficiency was greatest for the 50% FIT, 60% FIT, and 50% FIT treatments in 2015, 2016, and 2017, respectively. Root yield water use efficiency was greater and estimated recoverable sugar water use efficiency was equal or greater than reported in other studies. Additional
A regulatory sequence from a serine proteinase inhibitor gene (BvSTIpro) that is induced by the sugar beet root maggot was fused to the β-glucuronidase (GUS) reporter gene to characterize its expression patterns in transgenic Nicotiana benthamiana plants.In 2-and 6-week old BvSTIpro-GUS transformed plants, GUS expression was observed throughout leaves and roots that was comparable to GUS staining detected in plants transformed with the positive control 35S-GUS gene construct.At 10-14 weeks, GUS expression in the leaves and roots was reduced as compared to the younger plants and the 35S-GUS control but was up-regulated by abiotic and biotic stress.At 6 to 24 hours after mechanical wounding, GUS expression increased throughout the wounded leaves and roots of 14-week old plants to constitutive levels observed with the 35S-GUS gene.Fall armyworm (Spodoptera frugiperda) feeding on BvSTIpro-GUS leaves and roots similarly induced GUS gene activity like those observed with the 35S-GUS control.We demonstrate that the BvSTI promoter induced gene expression in response to abiotic and biotic stresses.Fusion of the BvSTI promoter to resistance genes should provide expression at sites of pest and pathogen invasion to augment the capacity of the plant to defend itself.
The genetic basis of sugarbeet is very narrow.Moreover, it is recognized that introgression of genetic diversity into elite populations enhances long-term breeding progress.Beta vulgaris subsp.maritima, a wild relative of sugarbeet, is a source for increasing the genetic diversity within cultivated sugarbeet.Being closely related to sugarbeet, fertility problems among hybrid progeny are rare.B. v. subsp.maritima is distributed over a large geographic area and therefore exposed to a wide range of environmental conditions and disease organisms.This report describes eleven sugarbeet germplasm lines; F1044, F1045, F1046, F1047, F1048, F1049, F1050, F1051, F1052, F1053, and F1054; that were selected from crosses between a sugarbeet breeding line and eleven B. v. subsp.maritima accessions originating from France, Belgium, and Denmark.The sucrose concentration of the eleven germplasm lines ranged from 123 g kg-1 to 143 g kg-1 compared to 153 g kg-1 for an adapted hybrid.The 3-year average recoverable sucrose concentration of the lines was 85% of the recoverable sucrose concentration of the adapted hybrid.It is assumed that F1044 -F1054 will be used to introduce genetic diversity into elite breeding populations that have or are segregating for many of the traits desired for commercial production.
Sodium, potassium, and amino-nitrogen, referred to as impurities, are constituents of sugarbeet that impede sucrose extraction.Lines selected for low or high concentration of a single impurity component were crossed with a common female line to determine their impact on the sodium, potassium, amino-nitrogen, sucrose, recoverable sucrose, and invert sugar concentration and root yield in the resulting hybrids.The relatively low sodium and potassium concentration of hybrids with low-sodium and low-potassium pollinators, respectively, indicated that pollinators with relatively low sodium or potassium concentration can substantially reduce the sodium or potassium concentration of a hybrid.Roots of hybrids with pollinators selected for high amino-nitrogen concentration had higher amino-nitrogen concentrations than hybrids with their unselected parental populations as pollinators.However, the difference between the reduced amino-nitrogen concentration observed for hybrids with pollinators selected for low aminonitrogen concentration and the amino-nitrogen concentration of hybrids with the unselected parental population as a pollinator was not significant.In general, altering one of the impurity components resulted in only small changes in root yield, sucrose concentration, or loss-to-molasses.Selection for a combination of impurity components, sucrose concentration, and root yield traits and multi-environment evaluations will be required to improve the value and productivity of the crop.
Sugarbeet root maggot is a major insect pest of sugarbeet in many North American production areas.Chemical insecticides are the primary control.Host-plant resistance that ensured consistent control would provide an economically and environmentally favorable alternative to complete dependence on insecticides.A sugarbeet root maggot resistant line, F1024, selected from cultivated sugarbeet germplasm, was used to pollinate a susceptible cms line.The resulting hybrid was compared to a susceptible adapted hybrid in the presence and absence of root maggot.In a 3-year trial, there was a 1.5 Mg ha -1 difference in root yield between the adapted hybrid and the hybrid with the F1024 pollinator, in the absence of root maggot.In contrast, the average root yield of the susceptible adapted hybrid was 17.5 Mg ha -1 less than the root yield of the hybrid with the F1024 pollinator at a site with root maggot present.The reduction in damage utilizing host-plant resistance appears to be similar to the sugarbeet root maggot control obtained with insecticides.
