scholarly journals Review of Horseradish Breeding for Improved Root Quality and Yield in Illinois, USA

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 175
Author(s):  
Stuart Alan Walters
Keyword(s):  
Plant Root ◽  
Low Fertility ◽  
Asexual Propagation ◽  
Breeding Technique ◽  
Specialty Crop ◽  
Sustained Success ◽  
High Yields ◽  
A Minor ◽  
Root Quality ◽  
Traditional Breeding

Horseradish cultivars are highly heterozygous clones and are maintained through asexual propagation, using root cuttings. For many years, horseradish was believed to be sterile and therefore impossible to improve by traditional sexual crosses. Prior to the 20th century, the only way to improve horseradish was to select and plant root cuttings from the most desirable plants. Moreover, the development of new improved horseradish cultivars has also been somewhat limited by the lack of viable seed resulting from low fertility of horseradish flowers. However, in Illinois, USA, a horseradish breeding program was initiated in the 1950s to develop additional cultivars to widen the genetic base of the few cultivars being grown at the time. In more recent years, the proven cross breeding technique has been primarily used to obtain new genotypes of horseradish, since it is more efficient in producing new improved cultivars, compared to the polycross method that had been previously used for decades to obtain new genetic combinations. Since horseradish is a minor specialty crop with very little available information regarding breeding procedures, this review was developed to provide a better understanding of pollination barriers and methods for fertility improvement, traditional breeding procedures and cultivar development, and traditional breeding achievements and limitations. The development of new horseradish cultivars is essential for the sustained success of the Illinois, USA industry since it provides growers with a continuous supply of new selections that have increased vigor, outstanding root quality, and high yields.

Plantio Direto na Cultura da Mandioca

UNICIÊNCIAS ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 02-09
Author(s):  
Eduardo Barreto Aguiar ◽  
Eloty Justina Dias Schleder ◽  
Vitor Hugo Dos Santos Brito ◽  
Flávio Augusto Faedo Aguena
Keyword(s):  
Soil Conservation ◽  
Production Systems ◽  
Sandy Soils ◽  
Low Fertility ◽  
No Tillage ◽  
No Till ◽  
Technological Level ◽  
High Yields ◽  
Cassava Crop

A cultura da mandioca ocupa uma área plantada no Brasil de 1,4 milhões de ha. É a quarta cultura em volume de produção sendo cultivada em sua maioria em solos arenosos e de baixa fertilidade por pequenos agricultores e agricultores familiares. Na região Centro-sul do Brasil é cultivada em grandes áreas com alto nível tecnológico, onde se obtém elevadas produtividades. Por ser cultivada em largos espaçamentos e recobrir mal o solo é altamente susceptível aos processos erosivos. Comparada aos cereais sua produtividade é superior, podendo atingir valores acima 35 t.ha-1, e por isso extrai grandes quantidades de nutrientes, principalmente K. O plantio direto é considerado um sistema conservacionista que reduz as perdas por erosão e aumenta os teores de matéria orgânica reduzindo também as perdas de nutrientes por lixiviação principalmente em solos arenosos. Nos últimos anos avanços foram feitos no que se refere ao plantio direto da mandioca, refletindo no crescente aumento das áreas sob este sistema. Entretanto os resultados de pesquisa não são conclusivos devido ao pequeno número de experimentos conduzidos, e pela ausência de experimentos de longa duração, que melhor avaliam os efeitos dos diferentes sistemas de produção. Tradicionalmente, os efeitos do plantio direto nos primeiros anos são indiretos, refletindo em produtividade nos sistemas já estabilizados após 2 ou 3 anos de implantação. Contudo boa parte dos resultados relatados são promissores, e demonstram elevado potencial para a melhoria da competitividade da cultura e a sustentabilidade destes agroecossistemas.   Palavras chave: sustentabilidade, sistemas de produção, conservação do solo.   Abstract Cassava crop is cultivated on 1.4 million ha. It is the fourth crop in terms of production amount, mostly cultivated on sandy and low-fertility soils by small farmers. In the Center-South region of Brazil it is grown in large areas with high technological level, where high yields are obtained. Because it is cultivated in large spaces and covers the soil poorly, it is highly susceptible to erosive processes. Compared to cereals, its productivity is higher, reaching values ​​above 35 t.ha-1. With this it extracts large amounts of nutrients, mainly K. No-tillage is considered a conservation system that reduces losses by erosion, increases the contents of organic matter and also reduces the losses of nutrients by leaching mainly in sandy soils. Many advances have been made towards the development of no-tillage of cassava, culminating in the growing increase in areas under this system. However, the research results are not conclusive due to the small number of experiments, and the absence of long-term experiments. Traditionally, the effects of no-till in the first years are indirect, reflecting on productivity in systems already stabilized after 2 or 3 years. However, part of the reported results is promising, and demonstrate high potential for improving the competitiveness of culture and the sustainability of agro-ecosystems.   Keywords: sustainability, production systems, soil conservation.

scholarly journals Effects of Host Plant Resistance and Fungicides on Severity of Cucumber Downy Mildew

HortScience ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Adam D. Call ◽  
Todd C. Wehner ◽  
Gerald J. Holmes ◽  
Peter S. Ojiambo
Keyword(s):  
Host Plant ◽  
Downy Mildew ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Maximum Yield ◽  
Plant Size ◽  
High Yield ◽  
High Yields ◽  
A Minor ◽  
Moderately Resistant

Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis (Berk. And Curt) Rostov is a major disease of cucumber (Cucumis sativus L.) (Palti and Cohen, 1980) globally. Chemical control of downy mildew is necessary to achieve high yields in the absence of adequate host plant resistance. Most of the currently grown cultivars have some resistance to downy mildew. Before the resurgence of the disease in 2004, host plant resistance was sufficient to control the disease without fungicide use, and downy mildew was only a minor problem on cucumber. There are currently no cultivars that show resistance at a level equal to that observed before 2004. However, differences in resistance exist among cultivars, ranging from moderately resistant to highly susceptible. In this study, we evaluated the disease severity and yield of four cucumber cultivars that differed in disease resistance and were treated with fungicide programs representing a range of efficacy levels. The experiment was a split plot design with six replications and four years. Disease was evaluated as chlorosis, necrosis, and reduction in plant size on a 0 to 9 scale. Cultigen had a large effect in all four years. Fungicide has a smaller effect on resistance component traits and a larger effect on yield traits. The effects of cultivar resistance and fungicides appear to be additive until a threshold where maximum yield is reached. Highly resistant cultigens such as PI 197088 required only the least effective fungicides to achieve highest yields, whereas moderately resistant cultigens required a more effective fungicide to reach a similar level of yield. Susceptible cultigens did not achieve high yield even with the most effective fungicide treatments. It is likely that, even as highly resistant cultivars are released, growers will need to continue a minimal fungicide program to achieve maximum yield.

scholarly journals Ring Expansions of Cyclopropanated Carbohydrates

2021 ◽  
Author(s):  
◽  
Rhys Antony Batchelor
Keyword(s):  
Total Synthesis ◽  
Single Molecule ◽  
Ring Expansion ◽  
Reaction Conditions ◽  
Ring Expansions ◽  
Naturally Occurring ◽  
Synthetic Chemist ◽  
High Yields ◽  
A Minor

<p>The combination of cyclopropanes and carbohydrates functionality within a single molecule gives the synthetic chemist an interesting combination of reactivity and chirality to expand further upon. However, until recently relatively little work has been done in this field. Following the report of methodology to convert cyclopropanated carbohydrates into oxepines in high yields, this investigation set out to improve the selectivity of the rearrangement and also investigate the further utility of the subsequent products. Focused investigation of the starting substrates and reaction conditions led to a minor adaptation of the previously successful methodology for the ring expansion of cyclopropanated glycals. This resulted in a substantial increase in the selectivity of the reaction to generate oxepine rings in good to excellent yields with a range of nucleophiles. One of the oxepines was subsequently chosen for elaboration into a range of synthons for further investigations. These yielded a variety of oxepanes in good yields with well defined stereo- and regioselective outcomes. In the course of these reactions several unexpected products were isolated. These were further investigated with labelling experiments and a mechanism for their formation was proposed. Finally the methodology was applied to the total synthesis of a naturally occurring oxepine containing compound. Despite the apparent simplicity of the target, the effort was ultimately unsuccessful.</p>

scholarly journals Increase in pea productivity associated with irrigation management

2018 ◽  
Vol 36 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Osvaldir F Santos ◽  
Fernando F Cunha ◽  
Tiago L Taira ◽  
Epitácio J Souza ◽  
Aguinaldo JF Leal
Keyword(s):  
Block Design ◽  
Irrigation Management ◽  
Climatic Conditions ◽  
Low Fertility ◽  
Mato Grosso ◽  
Randomized Block Design ◽  
Green Pea ◽  
Great Genetic Diversity ◽  
High Yields ◽  
Mato Grosso Do Sul

ABSTRACT Proper irrigation management is crucial to obtain high yields of pea, since its cultivation is recommended in cold and dry seasons. Taking into account the great genetic diversity, we considered necessary to evaluate cultivars which best adapt to the intrinsic conditions of Cerrado Region, as it presents low fertility soil, long dry period in the winter, drought periods (veranicos) in rainy season, mainly in January and February (summer). Thus, the aim of this study was to evaluate adaptability of green-pea cultivars under different irrigation depths in Northeast Region of state of Mato Grosso do Sul. The experiment was installed in a split plot scheme, with four irrigation depths [50, 75, 100 and 125% of crop evapotranspiration (ETc)] and at subplots, four pea cultivars (Forró, Frevo, Pagode and Samba) in a randomized block design with three replications. Pod length, number and mass of grains per pod, number of pods per plant, plant length, productivity and efficiency of water use were evaluated. Excess water supply (water stress) or shortage (water deficit) can cause decrease in the productivity of pea crop for green grains, considering replacement of 114.81% of Etc, the most recommended for the crop. Cultivar Forró, showed the best productive performance in relation to other cultivars, in the climatic conditions of Southern Cerrado (Mato Grosso do Sul, Brazil).

Soil treatment, plant species and management effects on improved pastures on a solodic soil in the semi-arid subtropics. 2. Cattle liveweight gains

1985 ◽  
Vol 25 (2) ◽  
pp. 380 ◽  
Author(s):  
JS Russell
Keyword(s):  
Rainfall Variability ◽  
Treatment Plant ◽  
Late Summer ◽  
Early Summer ◽  
Animal Production ◽  
Low Fertility ◽  
Steady Increase ◽  
Pasture Management ◽  
Rhodes Grass ◽  
A Minor

Increased and sustained beef cattle liveweight gains were obtained during 1974-79 on improved pastures in an experiment on a solodic soil at Kogan in southern Queensland. Annual liveweight gains of almost 100 kg/ha and 160 kg/steer were obtained at a stocking rate of 0.62 steers/ha on Rhodes grass fertilized with nitrogen; Rhodes grass and medics; and Rhodes grass, medics and siratro. The latter two pastures received an initial application of hydrated lime and gypsum (HLG). Medics responded markedly to HLG and this resulted in a 54% increase in liveweight gain per hectare on the Rhodes grassmedic pasture. However, the capacity of Rhodes grass-legume pastures to sustain higher stocking rates was much less than Rhodes grass fertilized with nitrogen. Rate of liveweight gain varied seasonally. There was a marked depression in late autumn and early winter, a steady increase in spring, a minor depression in late spring and early summer, and a minor increase in late summer and early autumn. Comparison of animal production with a long term experiment at Narayen on a low-fertility soil showed similarities, except for the poor performance of siratro at Kogan in terms of productivity and persistence. The main differences in the soils (both Alfisols) were the presence of levels of exchangeable sodium exceeding 40% in the subsoil, and poorer physical properties of the Kogan soil. Although the experiment has shown potential for increased animal production from improved pastures in this environment, factors limiting sustained high production are high liveweight losses in the cool months, rainfall variability and pasture instability. Conservative pasture management is needed if improved species are to be retained in pastures on these soils.

scholarly journals Ring Expansions of Cyclopropanated Carbohydrates

2021 ◽  
Author(s):  
◽  
Rhys Antony Batchelor
Keyword(s):  
Total Synthesis ◽  
Single Molecule ◽  
Ring Expansion ◽  
Reaction Conditions ◽  
Ring Expansions ◽  
Naturally Occurring ◽  
Synthetic Chemist ◽  
High Yields ◽  
A Minor

<p>The combination of cyclopropanes and carbohydrates functionality within a single molecule gives the synthetic chemist an interesting combination of reactivity and chirality to expand further upon. However, until recently relatively little work has been done in this field. Following the report of methodology to convert cyclopropanated carbohydrates into oxepines in high yields, this investigation set out to improve the selectivity of the rearrangement and also investigate the further utility of the subsequent products. Focused investigation of the starting substrates and reaction conditions led to a minor adaptation of the previously successful methodology for the ring expansion of cyclopropanated glycals. This resulted in a substantial increase in the selectivity of the reaction to generate oxepine rings in good to excellent yields with a range of nucleophiles. One of the oxepines was subsequently chosen for elaboration into a range of synthons for further investigations. These yielded a variety of oxepanes in good yields with well defined stereo- and regioselective outcomes. In the course of these reactions several unexpected products were isolated. These were further investigated with labelling experiments and a mechanism for their formation was proposed. Finally the methodology was applied to the total synthesis of a naturally occurring oxepine containing compound. Despite the apparent simplicity of the target, the effort was ultimately unsuccessful.</p>

scholarly journals Determination of prospectivity, plasticity and adaptive potential of new cultivars of spring barley from the collection of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources

2019 ◽  
pp. 168-173
Author(s):  
L. I. Kartasheva ◽  
L. M. Bondareva ◽  
T. N. Radyukevich
Keyword(s):  
Genetic Resources ◽  
Spring Barley ◽  
Plant Genetic Resources ◽  
Low Fertility ◽  
Hordeum Vulgare L ◽  
The North ◽  
Increasing Demand ◽  
Adaptive Ability ◽  
High Yields ◽  
New Cultivars

In the north-western region, barley is the main forage crop. Annually increasing demand of agriculture in forages challenges to create highly adaptive cultivars which under the conditions of unstable moistening and low fertility of sod-podzolic soils are capable to give high yields with good quality of production, resistant to the most widespread abiotic and biotic stressors. The objective of our research was to create new genotypes of spring barley with high economic and valuable characteristics of productivity. The research task was to study new collection samples of spring barley Hordeum vulgare L. by productivity and the main elements of the crop structure and to determine the indices of ecological plasticity, prospectivity, ear grain content, resistance to lodging and to determine the share of the ear in the total length of the stem, which characterize the adaptive ability of a cultivar. The research material was 14 new cultivars of spring barley obtained from the Federal Research Center “N.I. Vavilov All-Russian Institute of Plant Genetic Resources”. The studies were conducted according to generally accepted methods. As a result of the work, the best cultivars for all studied characteristics were selected: Suzdalets (Russia), Chill (Germany), Zhana (France). These samples will be actively used in hybridization to create new genotypes of spring barley.

scholarly journals Foundation Sweetpotato Seed Program in Virginia

1994 ◽  
Vol 4 (3) ◽  
pp. 236-238
Author(s):  
S.B. Sterrett ◽  
C.P. Savage
Keyword(s):  
Consumer Demand ◽  
Crop Improvement ◽  
Processing Industry ◽  
The Past ◽  
Specialty Crop ◽  
Seed Distribution ◽  
Foundation Seed ◽  
Root Quality ◽  
Selection Of

A procedure is described for maintaining root quality in a foundation seed program that serves a primarily processing industry. Trueness-to-cultivar root type and color is maintained through hill selections within the prefoundation seed at harvest. Internal color is examined after sprout production, but prior to planting. Each root of the prefoundation seed is lifted and cut. If any sectorial chimeras are visible or the internal color is lighter than expected for that cultivar, all sprouts from that root are discarded. Otherwise, sprouts are planted to generate prefoundation seed. Prefoundation roots not selected by hill selection are given to designated growers for production of foundation seed. Contracts with growers for foundation seed and seed distribution are the responsibility of the Virginia Crop Improvement Assn. (P.O. Box 78, Mt. Holly, VA 22524). Hill selection of `Hayman', a white-skinned, white-fleshed cultivar, over the past 20 years has essentially eliminated strings and nonenlarged roots. Improved root shape and smoothness has resulted in increased regional consumer demand for this specialty crop.

scholarly journals Adaptación del frijol a suelos de baja fertilidad bajo presión de enfermedades foliares en Costa Rica.

2006 ◽  
Vol 11 (2) ◽  
pp. 31
Author(s):  
Rodolfo Araya ◽  
Jorge A. Acosta
Keyword(s):  
Costa Rica ◽  
Low Fertility ◽  
Yield Potential ◽  
Annual Precipitation ◽  
High Yield ◽  
Rhizobium Tropici ◽  
Low Input Agriculture ◽  
Superior Genotypes ◽  
Genetic Pools ◽  
High Yields

The aim of this study was to identify bean genotypes with high yield potential when grown in soils of low fertility and under the pressure of foliar diseases. Diverse genotypes, known for its adaptation in soils of low fertility and/or resistance to other biotic and abiotic stresses were evaluated in the field during 1996 and 1997. In total, 562 genotypes, 251 bred and 311 landraces, were evaluated in two locations in Costa Rica: Fraijanes (1750 msnm; 15.3 °C; 3025 mm annual precipitation; 10º09’ North and 84°12’ West); and Alajuela (840 msnm, 23,1 °C; 1966 mm annual precipitation; 10°01’ North and 84° 16’ West). Plant stand was of 15 seeds per lineal m and plot size was variable due to seed availability; at planting inoculant of Rhizobium tropici was added directly onto the seed in the row (4 kg/ha). Bred line A 321, the control genotype UCR 55, A 483, G11640, G19696, G10843 and BAC50 displayed high yields in both locations. Genotypes that showed high yield in only one location were, in Alajuela: Guanajuato 132, Negro INIFAP, VAX 2 and MAR 3; in Fraijanes higher yielders were G13860, G92, MOC 112, Bayo Alteño, J 117; Negro 8025 and A 247. Outstanding landraces and bred lines from diverse geographical areas and genetic pools that displayed adaptation in soils of low fertility were identified in germplasm introduced from CIAT, México, Perú and Guatemala. It is emphasized the importance of evaluating native material and the exchange of germplasm among countries. Superior genotypes will be used for bean breeding in low input agriculture.

Hill slope effects on the vertical fluxes of photosynthetically fixed 14C in a grazed pasture

Soil Research ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 655 ◽  
Author(s):  
S. Saggar ◽  
A. D. Mackay ◽  
C. B. Hedley
Keyword(s):  
Plant Root ◽  
Low Fertility ◽  
Microbial Biomass C ◽  
High Fertility ◽  
Pulse Labelling ◽  
Soil System ◽  
Hill Country ◽  
Chase Period ◽  
Grazed Pasture ◽  
Below Ground

New Zealand hill-country farms consist of an amalgamation of land units in different slope and aspect categories, each with unique production potentials. Information on the influence these slope categories have on carbon (C) partitioning is imperative for more accurate and complete understanding of C inputs and fluxes through a grazed hill pasture ecosystem. The effects of 3 slope categories [representing 1–12°, 13–25°, and ≥26° microtopographical units corresponding to low (L), medium (M), and steep (S) slopes] on the vertical translocation of photosynthetically fixed C was studied by using a 14 C-CO2 pulse-labelling chamber technique. Pasture and soil samples were taken after 4-h, 7-day, and 35-day chase periods, to examine the fluxes of 14C in the pasture plant{root–soil system. Total C and 14C were determined in the pasture shoot, root, and soil components. Microbial biomass C and 14C contents in each soil were also determined using the chloroform fumigation{extraction technique. Pasture composition and growth varied with slope category. High fertility grasses (90%) were dominant on the L slope while low fertility grasses (≥60%) were dominant on the M and S slopes. Shoot growth over 35 days amounted to 4470, 2045, and 1308 kg/ha at the L, M, and S slopes, respectively. The standing root biomass did not differ signifficantly among the slopes. Allocation of the 14C-labelled assimilate below-ground was rapid, with 23–35% detected in the roots within 4 h of pulse-labelling. The above- and below-ground partitioning of 14C varied with the length of the chase period, and was strongly influenced by slope. Pasture plants allocated more C below-ground in the M and S slope categories. During the study period, 173 kg C/ha was assimilated daily at the L slope site, with 73 kg being respired, 50 kg remaining above-ground in the shoot, and 43 kg being partitioned into the root. In comparison, at the S slope, of the 56 kg/ha C assimilated daily, 22 kg was respired, 14 kg remained in the shoot, and 18 kg was partitioned into the root, and the daily input to the soil varied between 2 and 7 kg C/ha. By using annual growth measurements from adjacent areas, the amounts of C translocated annually to roots and soil at each slope category were also estimated from the 14C distribution of spring growth. At the L slope site, 9340 kg C/ha was respired, 6375 kg remained above-ground in the shoot, and 5510 kg was translocated to roots and 930 kg to soil. At the S slope site, 5710 kg C/ha was respired, 3490 kg remained in the shoot, and 4490 kg was translocated to the roots and 555 kg to soil.

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