On-farm assessment of effect of low temperature at seedling stage on early-season rice quality

Low temperature is a common production constraint in rice cultivation in temperate zones and high-elevation environments, with the potential to affect growth and development from germination to grain filling. There is a wide range of genotype-based differences in cold tolerance among rice varieties, these differences often reflecting growth conditions in the place of origin, as well as breeding history. However, improving low temperature tolerance of varieties has been difficult, due to a lack of clarity of the genetic basis to low temperature tolerance for different growth stages of the rice plant. Seeds or plants of 17 rice varieties of different origins were exposed to low temperature during germination (15°C), seedling, booting, and flowering stages (18.5°C), to assess their cold tolerance at different growth stages. Low temperature at the germination stage reduced both the percentage and speed of germination. Varieties from China (B55, Banjiemang, and Lijianghegu) and Hungary (HSC55) were more tolerant of low temperature than other varieties. Most of the varieties showed moderate levels of low temperature tolerance during the seedling stage, the exceptions being some varieties from Australia (Pelde, YRL39, and YRM64) and Africa (WAB160 and WAB38), which were susceptible to low temperature at the seedling stage. Low temperature at booting and flowering stages reduced plant growth and caused a significant decline in spikelet fertility. Some varieties from China (B55, Bangjiemang, Lijiangheigu), Japan (Jyoudeki), the USA (M103, M104), and Australia (Quest) were tolerant or moderately tolerant, while the remaining varieties were susceptible or moderately susceptible to low temperature at booting and flowering stages. Three varieties from China (B55, Lijianghegu, Banjiemang) and one from Hungary (HSC55) showed consistent tolerance to low temperature at all growth stages. These varieties are potentially important gene donors for breeding and genetic studies. The cold tolerance of the 17 rice varieties assessed at different growth stages was correlated. Screening for cold tolerance during early growth stages can therefore potentially be an effective way for assessing cold tolerance in breeding programs.

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Comprehensive evaluation of low-temperature tolerance in soybean cultivars of different eco-types at seedling stage in Shanxi Province

Chinese Journal of Plant Ecology ◽

10.3724/sp.j.1258.2014.00093 ◽

2014 ◽

Vol 38 (9) ◽

pp. 990-1000

Author(s):

GUO Shu-Jin ◽

◽

LI Wei-Yu ◽

MA Yan-Yun ◽

ZHAO Heng ◽

...

Keyword(s):

Low Temperature ◽

Comprehensive Evaluation ◽

Temperature Tolerance ◽

Seedling Stage ◽

Shanxi Province ◽

Soybean Cultivars ◽

Low Temperature Tolerance

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Soybean Yield Loss Potential Associated with Early-Season Weed Competition across 64 Site-Years

Weed Science ◽

10.1614/ws-d-12-00164.1 ◽

2013 ◽

Vol 61 (3) ◽

pp. 500-507 ◽

Cited By ~ 16

Author(s):

Nathanael D. Fickett ◽

Chris M. Boerboom ◽

David E. Stoltenberg

Keyword(s):

Yield Loss ◽

Average Density ◽

Yield Potential ◽

Weed Competition ◽

Growth Stages ◽

Average Height ◽

Weed Species ◽

Potential Yield ◽

Early Season ◽

On Farm

Glyphosate applied POST can provide a high level of efficacy on many weed species in soybean, but delayed application beyond optimal weed growth stages might fail to fully protect yield potential. Further, we do not have a good understanding of the extent to which delayed glyphosate application and its associated yield loss is occurring on-farm. Our goal was to characterize on-farm weed communities in glyphosate-resistant soybean just prior to glyphosate application and estimate potential yield loss associated with early-season soybean-weed competition. In field surveys conducted across 64 site-yr in southern Wisconsin in 2008 and 2009, common lambsquarters, velvetleaf, dandelion,Polygonumspp., andAmaranthusspp. were the five most abundant broadleaf weed species across site-years, present in 92, 69, 64, 42, and 50% of all fields, respectively, at average densities of 14, 5, 5, 14, and 10 plants m−2, respectively. Average height of these species was 21 cm or less at or near the time of glyphosate application. Grass and sedge species occurred in 95% of fields at an average density of 41 plants m−2and height of 21 cm. The mean and median values of total weed density across site-years were 101 and 41 plants m−2, with heights of 19 and 17 cm, respectively. Recommended height for treatment is 15 cm. Glyphosate application occurred on average at V3 to V4 soybean growth stage, which is later than V2 soybean typically targeted to protect yield. Average yield loss predicted by WeedSOFT® was 5% with a mean economic loss of $47 ha−1. Predicted yield loss was greater than 5% on one-fourth of the site-years, all of which were treated at V4 soybean or later. The maximum predicted yield loss was 27%. These results suggest that glyphosate was applied at weed height and soybean growth stages that were greater than optimal to protect yield in many fields across southern Wisconsin. A soil-residual herbicide applied PRE, or a more timely POST application of glyphosate would alleviate the majority of these losses.

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Effects of Controlled Ambient Aeration on Rice Quality During On-Farm Storage

Cereal Chemistry ◽

10.1094/cchem.2003.80.1.9 ◽

2003 ◽

Vol 80 (1) ◽

pp. 9-12 ◽

Cited By ~ 9

Author(s):

R. P. Ranalli ◽

T. A. Howell ◽

T. J. Siebenmorgen

Keyword(s):

Rice Quality ◽

On Farm

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Cover crop management effects on soybean and corn growth and nitrogen dynamics in an on-farm study

American Journal of Alternative Agriculture ◽

10.1017/s0889189300003891 ◽

1991 ◽

Vol 6 (2) ◽

pp. 71-82 ◽

Cited By ~ 32

Author(s):

D. L. Karlen ◽

J. W. Doran

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Root Zone ◽

Winter Rye ◽

Nitrogen Accumulation ◽

Fertilizer N ◽

Hairy Vetch ◽

Early Season ◽

On Farm ◽

Ridge Tillage

AbstractCombining cover crops and conservation tillage may result in more sustainable agricultural production practices. Objectives of this on-farm study were to quantify effects of cover crops on growth and nitrogen accumulation by soybean [Glycine max (L.) Merr,] and corn (Zea mays L.) on a Nicollet loam (fine-loamy, mixed, mesic Aquic Hapludoll) near Boone, Iowa, Our farmer-cooperator planted soybean in 1988 using ridge tillage into an undisturbed strip with a hairy vetch (Vicia villosa L. Roth) cover crop and into a strip where previous crop residue and a negligible amount of cover crop had been incorporated by autumn and spring disking. In each strip, we established four plots for soil and plant measurements. Our cooperator planted corn on the same strips in 1989 into a cover crop that consisted of both hairy vetch and winter rye (Secale cereale L.). We determined the source of N accumulated by the corn by applying 67 kg N/ha of 15N depleted NH4NO3 fertilizer. In the absence of cover crops, early season soil NO3-N levels in the top 30 cm were higher, and corn growth and N accumulation were more rapid. At harvest, the corn grain, stover, and cob together accounted for 36 and 39 percent of the 15N fertilizer for the ridge tillage and disked treatments, respectively. We suggest that lower net mineralization of organic matter or greater denitrification losses before planting reduced the availability of soil N, This created an early season Nstress in corn grown with cover crops that was not overcome by broadcast fertilizer N applied three weeks after planting. Our on-farm research study has helped focus continuing efforts to determine if non-recovered fertilizer N is being immobilized in microbial biomass, lost by denitrification, or leached below the plant root zone.

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