Breeding improved rice cultivars for temperate regions: a case study

1994 ◽  
Vol 34 (7) ◽  
pp. 897 ◽  
Author(s):  
KS McKenzie ◽  
CW Johnson ◽  
ST Tseng ◽  
JJ Oster ◽  
DM Brandon
Keyword(s):  
Grain Quality ◽  
Management Practices ◽  
Breeding Program ◽  
Yield Potential ◽  
Cool Temperature ◽  
Rice Breeding ◽  
Rice Cultivars ◽  
Seedling Vigour ◽  
Selection For ◽  
Rice Water

An accelerated rice-breeding program was initiated in 1969 at the California Rice Experiment Station. The program is broad in scope, developing cultivars in all US market classes (long, medium, and short grains) and special purpose types (waxy and aromatics). This grower-funded rice-breeding program has released 27 new cultivars as well as improved germplasm lines. Statewide paddy rice yields have risen from 6.2 to 9.3 t/ha since 1978. The incorporation of semi-dwarfing genes, earlier maturity, and increased yield potential have contributed significantly to increases in grain yield. High experimental yields (>I1 t/ha) are routine and achieving increased increments of yield will become more difficult. After the initial shift to semi-dwarf cultivars, increasing efforts were directed toward improving adaptation to environmental stresses and grain quality. Screening and selection for cold tolerance in the form of seedling vigour for water seeding and resistance to cool temperature induced sterility at the reproductive stage are integral parts of the rice-breeding program. Progress is being made on incorporation into California rice cultivars of resistance to stem rot (Sclerotiurn oryzae Cattaneo) and aggregate sheath spot [Rhizoctonia oryzae-sativae (Swada) Mordue] from wild species and tolerance to rice water weevil (Lissorhoptus oryzophilus Kuschel). New restrictions and regulations of agronomic management practices may negatively impact rice production, creating problems in stand establishment, soil fertility, and weed, disease, and insect control. Breeding efforts to help minimise the adverse effect of these restrictions on yield and quality will increase in the future. Increased emphasis is being placed on improving milling yield and cooking and processing characteristics, and new laboratory methods are being explored to aid in evaluation and selection for grain quality.

scholarly journals The Genetic and Economic Impact of the University of Arkansas's Rice Breeding Program: 1983-2007

2011 ◽  
Vol 43 (1) ◽  
pp. 131-142 ◽  
Author(s):  
L. Lanier Nalley ◽  
Karen A. Moldenhauer ◽  
Nate Lyman
Keyword(s):  
Economic Benefits ◽  
Breeding Program ◽  
Test Plot ◽  
Rice Breeding ◽  
Rice Cultivars ◽  
Potential Yield ◽  
Rice Varieties ◽  
Yield Increase ◽  
Program Test ◽  
The University

This study estimates the proportion of rice yield increase in University of Arkansas Division of Agriculture's (UofA) released rice cultivars that are attributable to genetic improvements through the University's breeding program. Test plot data from eight UofA experiment stations were used to quantify the yield increases and potential yield growth decreases over time. In addition to quantifying the yield and yield variance evolution at the UofA, this study also calculates the economic benefits of the UofA rice breeding program. Results indicated that by releasing modern rice cultivars, the UofA rice breeding program increased average producer yield by 0.68 bu/ac annually. During the last decade, 1997-2007, the average annual economic benefits were 34.3 million (2007) dollars. When accounting for the spillover of UofA rice varieties to neighboring states the average annual economic benefit of the breeding program increases to 46.7 million (2007) dollars.

Yield improvement and adaptation of wheat to water-limited environments in Australia—a case study

2014 ◽  
Vol 65 (7) ◽  
pp. 676 ◽  
Author(s):  
R. A. Richards ◽  
J. R. Hunt ◽  
J. A. Kirkegaard ◽  
J. B. Passioura
Keyword(s):  
Disease Resistance ◽  
Grain Yield ◽  
Grain Quality ◽  
Management Practices ◽  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Grain Legumes ◽  
Yield Potential ◽  
Nutrient Use ◽  
Rainfed Wheat

The improvement in grain yield of wheat throughout Australia through both breeding and management has been impressive. Averaged across all farms, there has been an approximate doubling of yield per unit area since ~1940. This has occurred across a broad range of environments with different rainfall patterns. Interestingly, the gain in the driest years (9 kg ha–1 year–1 or 0.81% year–1) has been proportionally greater than in the most favourable years (13.2 kg ha–1 year–1 or 0.61% per year) when expressed as yield relative to 2012. These data from all farms suggest that further yield progress is likely, and evidence is presented that improved management practices alone could double this rate of progress. The yield increases achieved have been without any known compromise in grain quality or disease resistance. As expected, improvements have come from both changed management and from better genetics, as well as from the synergy between them. Yield improvements due to changed management have been dramatic and are easiest to quantify, whereas those from breeding have been important but more subtle. The management practices responsible have largely been driven by advances in mechanisation that enable direct seeding, more timely and flexible sowing and nutrient management, and improved weed and pest control, many of which have been facilitated by improved crop sequences with grain legumes and oilseeds that improve water- and nutrient-use efficiency. Most of the yield improvements from breeding in Australia have come from conventional breeding approaches where selection is almost solely for grain yield (together with grain quality and disease resistance). Improvements have primarily been through increased harvest index (HI), although aboveground biomass has also been important. We discuss future opportunities to further increase Australian rainfed wheat yields. An important one is earlier planting, which increases resource capture. This will require knowledge of the genes regulating phenological development so that flowering still occurs at the optimum time; appropriate modifications to sowing arrangements and nutrient management will also be required. To improve yield potential, we propose a focus on physiological traits that increase biomass and HI and suggest that there may be more scope to improve biomass than HI. In addition, there are likely to be important opportunities to combine novel management practices with new breeding traits to capture the synergy possible from variety × management interactions. Finally, we comment on research aimed at adapting agriculture to climate change.

Effect of Cultural Management Practices on Grain Quality of Two Rice Cultivars

2009 ◽  
Vol 86 (4) ◽  
pp. 405-409 ◽  
Author(s):  
R. J. Bryant ◽  
M. Anders ◽  
A. M. McClung
Keyword(s):  
Grain Quality ◽  
Management Practices ◽  
Rice Cultivars ◽  
Cultural Management

scholarly journals Threshing force of paddy as affected by loading manner and grain position on the panicle

2011 ◽  
Vol 57 (No. 1) ◽  
pp. 8-12 ◽  
Author(s):  
M.R. Alizadeh ◽  
A. Allameh
Keyword(s):  
Breeding Program ◽  
Lower Portion ◽  
Rice Breeding ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Bending Force ◽  
Local Cultivars ◽  
Tension Loading

Threshing force, which is the force that separates a grain from the panicle, has a great importance in evaluating losses over design and application of harvesting and threshing machines. In addition, it is important to know the shattering habit of rice varieties in rice breeding program. In this study, the threshing force of two improved rice cultivars Dorfac and Kadous (long-grain), and three local cultivars of Hashemi, Alikazemi (long-grain), and Binam (medium-grain) was determined. The threshing force was measured at three portions of upper, middle, and lower of the panicle and three loading manners as tension, bending perpendicular to the front of the grain (type 1) and bending perpendicular to the side of the grain (type 2). The results revealed that cultivars, loading manners and the grain position on the panicle significantly (P < 0.01) affected the threshing force. The highest threshing force of 0.887 N was obtained from the lower portion of the panicle under tension loading; while the least threshing force of 0.267 N was determined for grains from the upper portions of the panicle under bending force of type 2. In the case of tension loading, the highest threshing force value pertained to long-grain cultivars.

scholarly journals Growth and yield of transplanted rice as affected by different cultivars and weed management practices

2016 ◽  
Vol 8 (3) ◽  
pp. 1462-1466
Author(s):  
Sunil Mandi ◽  
Eajaz Ahmad Dar ◽  
Ashim Datta ◽  
Ram Pratap Singh ◽  
Manoj Kumar Singh
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Growth And Yield ◽  
Yield Potential ◽  
Dry Matter Accumulation ◽  
Rice Cultivars ◽  
Straw Yield ◽  
Transplanted Rice ◽  
To Come ◽  
Hand Weeding

An experiment was conducted to study the competitive ability of rice cultivars in different weed management practices in transplanted rice. Five cultivars viz. BPT-5204, Malviya 36, HUBR2-1, Swarna and Adamchini were tested for three weed management practices viz. Hand weeding, Bispyribac-sodium@25g ha-1 and Weedy check. Among the different cultivars tested, the Swarna proved to be the best selection in producing higher grain (4.6 t ha-1) and straw yield (5 t ha-1) as well as harvest index (44.4%) due to more no. of tillers hill-1, dry matter accumulation, no. of panicles hill-1, no. of grains/panicle and test weight (20.3 g). The grain and straw yield in Swarnawere 130 and 43% higher than the lowest yielding cultivar Adamchini respectively. The best weed control was achieved by hand weeding thrice at 25, 55 and 85 DAT. The grain yield was 58 and 27 % higher through hand weeding than that of weedy check and Bispyribac-sodium applied treatment, respectively. To examine the performance of different rice cultivars in terms of growth and yield potential, evaluation of these cultivars is necessary with different weed management practices. Therefore, release of best weed suppressive rice cultivars for the farmers is important for improving the productivity as well as reduced cost of production for feeding the ever growing population of the country in the year to come.

scholarly journals Farmers’ Preferences for Varietal Traits, Their Knowledge and Perceptions in Traditional Management of Drought Constraints in Rice Cropping in Benin: Implications for Rice Breeding

2020 ◽  
Vol 12 (11) ◽  
pp. 56
Author(s):  
Blandine Y. Fatondji ◽  
Hubert Adoukonou-Sagbadja ◽  
Ndanikou Sognigbe ◽  
Christophe Gandonou ◽  
Raymond S. Vodouhè
Keyword(s):  
Abiotic Stress ◽  
Grain Quality ◽  
Rice Variety ◽  
Sowing Date ◽  
Rice Production ◽  
Yield Potential ◽  
High Yield ◽  
Limiting Factor ◽  
Rice Cultivars ◽  
Good Taste

Rice (Oryza spp.) is one of the most important crops that significantly contribute to food security in Benin. In the current context of climate change, drought is known to be the main abiotic stress in crops and a major yield-limiting factor for agricultural production worldwide. To assess farmers’ knowledge, the preference traits of the rice cultivars in use, their perceptions and management of drought stress in rice production in Benin, an ethnobotanical investigation was conducted in 50 villages throughout the major zones. The results showed that High yield combined with good grain quality (including good taste, softness after cooking, less starch, white pericarp, long grain length and swelling when cooked), medium maturing and tolerance to drought and flood were the most desired traits motivating farmers for growing rice cultivars. Taste and high yield were the paramount traits of IR841, the most popular rice variety currently cropped in Benin followed by its fragrance. Drought constraints was reported as the most damaging abiotic stress across the villages surveyed with field lost estimated up to 100% at the flowering stage. Changing sowing date (80%), the use of irrigation systems (10%) and the cropping of early maturing cultivars (7%) were the most traditional strategies to reduce drought impacts. Needs for tolerant varieties were clearly expressed by farmers to mitigate drought effects on rice production in Benin. The results of this survey emphasize the need for rice breeders to focus more on improving grain quality in addition to high yield potential and tolerance to abiotic stresses mainly drought.

Farmer participatory variety selection conducted in high- and low-toposequence multi-location trials for improving rainfed lowland rice in Lao PDR

2014 ◽  
Vol 65 (7) ◽  
pp. 655 ◽  
Author(s):  
J. H. Mitchell ◽  
Sipaseuth ◽  
S. Fukai
Keyword(s):  
Grain Yield ◽  
Lao Pdr ◽  
Breeding Program ◽  
Lowland Rice ◽  
Yield Potential ◽  
Rice Breeding ◽  
Wet Season ◽  
Potential Yield ◽  
Variety Selection ◽  
Participatory Variety Selection

Lowland rice in Lao PDR is predominantly grown under drought-prone, rainfed conditions in the wet season. We utilised a farmer participatory variety selection (PVS) approach in combination with multi-location yield trials (MLTs) conducted in high- and low-toposequence positions to test advanced breeding lines with the aim of improving the efficiency of the rice-breeding program and encouraging rapid adoption of improved lines. Upper position fields were utilised to screen for traits for unfavourable environments, including drought resistance, while lower fields were used to target yield potential. Yield was, on average, 13% lower in upper than lower (2.85 t/ha) field positions, and varieties adapted to high-toposequence position were identified. Farmer preference was not associated well with grain yield performance, with a significant positive relationship (r = 0.34*, n = 23) identified only in the Vientiane (VTN) low-toposequence trial; rather, the famers tended to choose lines they believed were best adapted to their own farm. Although a significant relationship existed for both farmer preference (r = 0.42*, n = 23) and grain yield (r = 0.50*, n = 23) in high and low toposequences across all provinces in 2010, this relationship was not significant in VTN, where the high position was low-yielding (1.2 t/ha). By utilising farmer preference information in combination with traditional MLT data, only lines agronomically acceptable to farmers were progressed into a seed-multiplication system for country-wide, farmer yield testing. Thus, the PVS-MLT approach has provided efficient delivery of highly acceptable lines to farmers, which directly contributes to improved efficiency of the rice-breeding program.

Developing birdsfoot trefoil (Lotus corniculatus L.) varieties for permanent pasture applications in low latitude regions of eastern Australia

2008 ◽  
Vol 48 (4) ◽  
pp. 488 ◽  
Author(s):  
J. F. Ayres ◽  
W. M. Kelman ◽  
S. G. Wiedemann ◽  
L. A. Lane ◽  
B. E. McCorkell
Keyword(s):  
Germination Rate ◽  
Summer Rainfall ◽  
Phenotypic Selection ◽  
Lotus Corniculatus ◽  
Yield Potential ◽  
Birdsfoot Trefoil ◽  
Phenotypic Variance ◽  
Seedling Vigour ◽  
Eastern Australia ◽  
Selection For

Birdsfoot trefoil (Lotus corniculatus L.) is a potentially important alternative legume for recharge landscapes in the high rainfall zone in eastern Australia. However, in the summer rainfall region in northern New South Wales (NSW) where birdsfoot trefoil has the greatest potential application, flowering and seed set are limited by short daylength. Consequently, existing birdsfoot trefoil cultivars do not set enough seed to develop a seedbank that sustains a productive persistent stand. A breeding program was undertaken to develop birdsfoot trefoil cultivars adapted to short photoperiod to increase the area sown to deep-rooted perennials in the grazing lands in eastern Australia. Three new birdsfoot trefoil experimental varieties, Phoenix, Venture and Matador, were developed through: (1) phenotypic selection within cv. Grasslands Goldie for flowering intensity and pod set, (2) phenotypic selection for these same traits in a broader sample of 49 world-sourced lines, and (3) selection for prostrate growth habit among progeny of pair-crosses between erect and prostrate accessions identified as productive in southern NSW. Following two cycles of selection for flowering prolificacy and pod set, the average number of umbels per stem in the Goldie-derived populations was five times greater than in the commercial Goldie population; this response to selection closely approximated the predicted response based on previous estimates of heritability and phenotypic variance for this trait. In comparison with Goldie, the Syn1 and Syn2 populations of the three experimental varieties consistently expressed earlier flowering maturity and higher seed yield potential in glasshouse and field trials in northern NSW. While germination rate and seedling vigour of the three experimental varieties was slightly less than Goldie, intensive selection pressure on reproductive traits did not compromise seasonal herbage production.

scholarly journals Influence of protein concentration on farinograph absorption, mixing requirements and mixing tolerance

2004 ◽  
Vol 84 (3) ◽  
pp. 765-772 ◽  
Author(s):  
D. B. Fowler ◽  
M. I. P. Kovacs
Keyword(s):  
Grain Yield ◽  
Water Absorption ◽  
Protein Concentration ◽  
Grain Quality ◽  
Management Practices ◽  
Negative Relationship ◽  
Yield Potential ◽  
Dry Land ◽  
Cultivar Selection ◽  
Wide Range

Accurate and precise measurements of grain quality traits are required throughout the wheat (Triticum aestivum L. Em. Thell.) production and marketing chain to ensure that quality standards are maintained. In the present study, spring and winter wheat genotypes representing a wide range of grain quality types and protein concentration (PC) were grown in dry land and irrigated nitrogen fertilizer trials in western Canada to determine the influence of flour PC and quality on farinograph water absorption, mixing requirements and mixing tolerance. As expected, there was a strong linear relationship between PC and water absorption. In contrast, PC had a large nonlinear influence on mixing requirements and tolerance measurements, which made it difficult to make meaningful comparisons among genotypes when flour PC was less than 12%. Consequently, because cultivar grain yield potential, environment, and fertilizer management decisions have a large and variable influence on PC, it is important that cultivar selection procedures and marketing programs based on farinograph measurements include grain quality comparisons made over a wide range of PC and preferably at similar PC. This allows for a more accurate assessment of cultivar genetic potential that is independent of the normally strong negative relationship between PC and grain yield potential. When combined with the ability to segregate grain on the basis of PC at the time of delivery, it also allows producers a greater opportunity to select cultivars and adopt management practices that maximize returns while maintaining effective quality control in grain handling systems. Key words: Wheat, grain quality, farinograph, protein concentration, N management, cultivar selection and marketing

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