Influence of Nitrogenous Fertilizer Control on Direct Seeding Rice Yield and Quality

Abstract The rice stink bug, Oebalus pugnax (F.), is the most important pest of headed rice, Oryza sativa L., in the United States. Numerous studies have attempted to quantify the impact of O. pugnax feeding on rice yield and grain quality, but these studies have often produced conflicting results. Across mid-south U.S. rice, thresholds based on sweep net sampling are used to determine the need for insecticide applications, but few studies have related sweep net captures to rice quality parameters. Field trials were conducted in Louisiana in 2015 and 2016 that used different rates of insecticides to establish rice plots with mean O. pugnax infestations ranging from 0.8 to 24.6 insects per 10 sweeps. Insecticide applications improved panicle weight and head yields as well as decreased percentage peck. A series of linear regressions examined relationships between O. pugnax captures and rice yield and quality parameters, including panicle weight, head yield (% whole kernels), and peck (discolored grains). Mean O. pugnax sweep net captures across all sampling dates in both years were significantly and negatively correlated to panicle weight and head yield and positively correlated to percentage peck. Peck was negatively correlated with head yield. Results from sampling at different maturity stages indicate sweep net captures at grain fill and soft dough stages had the greatest influence on rice yield and quality parameters, respectively. Further research into impacts of milling quality reductions on farm revenue and the influence of cumulative infestations over grain development is needed to improve economic thresholds for O. pugnax in rice.

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Evaluation of direct seeding and transplanting in sugar beet for water productivity, yield and quality under different irrigation regimes and planting densities

Agricultural Water Management ◽

10.1016/j.agwat.2020.106230 ◽

2020 ◽

Vol 238 ◽

pp. 106230

Author(s):

Maryam Khozaei ◽

Ali Akbar Kamgar Haghighi ◽

Shahrokh Zand Parsa ◽

Ali Reza Sepaskhah ◽

Fatemeh Razzaghi ◽

...

Keyword(s):

Sugar Beet ◽

Water Productivity ◽

Direct Seeding ◽

Yield And Quality ◽

Irrigation Regimes

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Puddling, Direct Seeding, Mechanical Transplanting for Rice: Effect on Soil Characteristics and Productivity of Rice

10.21203/rs.3.rs-811574/v1 ◽

2021 ◽

Author(s):

Evans Asenso ◽

Zhimin Wang ◽

Jiuhao Li ◽

Lian Hu

Keyword(s):

Rice Yield ◽

Soil Nutrient ◽

Normal Growth ◽

Soil Condition ◽

Soil Improvement ◽

Soil Characteristics ◽

Direct Seeding ◽

Long Term Effects ◽

Germinated Seeds ◽

Moldboard Plow

Abstract Why puddling? It is an important operation to minimize soil nutrient leaching and thereby increasing the availability of plant nutrients and achieving reduced soil condition. Good puddle field conditions are needed to create favorable environment for normal growth of rice plants. However, long-term effects of puddling could lead to forms of large clods in fine textured soils; resulting in negative effect on the soil characteristics, preventing seed-soil contacts and leading to decline in rice yield. This study was conducted in 2 years with treatment including; puddling the land twice with moldboard plow and pre-germinated seeds were hill-seeded with direct seeding machine (PD), puddling the land twice with rotary tiller and pre-germinated seeds were hill-seeded with direct seeding machine (RD), puddling the land twice with moldboard plow and 15-day-old seedlings were hill-transplanted with transplant machine (PT), and puddling the land twice with rotary tiller and 15-day-old seedlings were hill-transplanted with transplant machine (RT) to assess the effect of puddling, direct seeding, and mechanical transplanting on soil characteristics and rice yield. Results revealed significant improvement in the bulk density and increase in SOC, N, P and K in PD. The maximum microbial population was found in PD. Rice yield showed a higher productivity increase of 7.44 t∙ha-2 and 3.91 t∙ha-2 in 2017, and 7.85 t∙ha-2 and 3.94 t∙ha-2 in 2018 respectively for 1H and 2H (1H: 1st harvest, and 2H: 2nd harvest) in PD. Overall, PD was found to be the most suitable puddling and rice establishment approach under paddy fields for soil improvement and increasing rice yield.

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Spatiotemporal expression profile of novel and known small RNAs throughout rice plant development focussing on seed tissues

BMC Genomics ◽

10.1186/s12864-021-08264-z ◽

2022 ◽

Vol 23 (1) ◽

Author(s):

Anikó Meijer ◽

Tim De Meyer ◽

Klaas Vandepoele ◽

Tina Kyndt

Keyword(s):

Plant Development ◽

Early Life ◽

Small Rnas ◽

Rice Plant ◽

Rice Yield ◽

Small Interfering Rnas ◽

Yield And Quality ◽

Spatiotemporal Expression ◽

Generative Phase ◽

Generation Sequencing

Abstract Background Small RNAs (sRNAs) regulate numerous plant processes directly related to yield, such as disease resistance and plant growth. To exploit this yield-regulating potential of sRNAs, the sRNA profile of one of the world’s most important staple crops – rice – was investigated throughout plant development using next-generation sequencing. Results Root and leaves were investigated at both the vegetative and generative phase, and early-life sRNA expression was characterized in the embryo and endosperm. This led to the identification of 49,505 novel sRNAs and 5581 tRNA-derived sRNAs (tsRNAs). In all tissues, 24 nt small interfering RNAs (siRNAs) were highly expressed and associated with euchromatic, but not heterochromatic transposable elements. Twenty-one nt siRNAs deriving from genic regions in the endosperm were exceptionally highly expressed, mimicking previously reported expression levels of 24 nt siRNAs in younger endosperm samples. In rice embryos, sRNA content was highly diverse while tsRNAs were underrepresented, possibly due to snoRNA activity. Publicly available mRNA expression and DNA methylation profiles were used to identify putative siRNA targets in embryo and endosperm. These include multiple genes related to the plant hormones gibberellic acid and ethylene, and to seed phytoalexin and iron content. Conclusions This work introduces multiple sRNAs as potential regulators of rice yield and quality, identifying them as possible targets for the continuous search to optimize rice production.

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Prediction of Rice Milling Yield and Quality Attributes during Storage Using Regression Analyses

Transactions of the ASABE ◽

10.13031/trans.13441 ◽

2019 ◽

Vol 62 (5) ◽

pp. 1259-1268

Author(s):

Soraya Shafiekhani ◽

Jung Ae Lee ◽

Griffiths G. Atungulu

Keyword(s):

Hybrid Rice ◽

Storage Temperature ◽

Rice Yield ◽

Storage Conditions ◽

Milled Rice ◽

Yield And Quality ◽

Head Rice ◽

Rough Rice ◽

Milling Yield

Abstract. Regression analyses were performed to determine the storage conditions that exhibited the best outcomes for long-grain, hybrid milled rice yield and quality. This study evaluated mold population on rough rice, milled rice discoloration, and head rice yield (HRY) after storage of rough rice in airtight conditions at moisture contents (MCs) of 12.5%, 16%, 19%, and 21% wet basis and temperatures of 10°C, 15°C, 20°C, 27°C, and 40°C at two-week intervals for 12 weeks. The experiment used a popular long-grain hybrid rice cultivar (XL745). Rice lots were procured from fields with and without conventional treatment of the field with fungicide for plant disease management. Field treatment and no field treatment were considered as a block, and a Mann-Whitney test was conducted to determine effect. The response surface method, an extension of second-order polynomial regression, was used to examine optimal treatment conditions. Mold population and milled rice discoloration from a combination of storage conditions were predicted using regression models. The first-order and second-order terms of temperature indicated a nonlinear relationship between temperature and ln(discoloration). The MC was positively associated with ln(discoloration), but the degree of impact may change with temperature because the interaction term was significant. From the model evaluation (R2 and lack-of-fit test), the discoloration level is expected to be 57% (49% to 66% confidence interval) under conditions of 20% MC, 40°C, and nine weeks of storage for samples procured from fungicide-treated rice fields. This discoloration change is substantial compared to the initial discoloration of 9%. At high temperature (40°C) and MC (21%), discoloration started immediately after two weeks of storage. Anaerobic storage conditions impeded mold growth, especially at high storage temperature (40°C). Low mold populations were observed in rice stored at low MC (16%). According to the regression model, the critical storage temperature that may lead to discoloration is between 27°C and 40°C. Pre-harvest fungicide treatment of rice in the field for disease control significantly improved the HRY but had no significant influence on mold population or discoloration. This study suggests a range of storage conditions to prevent losses in milling yield and quality of rice. In addition, the studied storage conditions mimicked the typical conditions for on-farm, in-bin drying and storage in the U.S. Mid-South, especially for the top layers of rice inside the bin, and therefore provide an important reference for growers and rice processors using in-bin structures to manage the quality of long-grain hybrid rice. Keywords: Discoloration, Head rice yield, Mold population, Regression analysis, Rice quality, Rice storage.

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