K. Raja Reddy

Mississippi State University

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Wei Gao

Colorado State University

Vijaya Gopal Kakani

University of Florida

Raju Bheemanahalli

Mississippi State University

Duli Zhao

Agricultural Research Service

Chathurika Wijewardana

Mississippi State University

Vangimalla R. Reddy

Agricultural Research Service

H. F. Hodges

Mississippi State University

W. H. Patrick

Institut de Recherche pour le Développement

James M. McKinion

Mississippi State University

V. R. Reddy

Professor Jayashankar Telangana State Agricultural University

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Mississippi State University

185

Agricultural Research Service

University of Florida

Acharya N. G. Ranga Agricultural University

United States Department of Agriculture

Texas A&M University

Sri Venkateswara University

Sri Venkateswara Veterinary University

Mississippi Delta Community College

Louisiana State University

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Interactive Effects of Ultraviolet-B Radiation and Temperature on Cotton Physiology, Growth, Development and Hyperspectral Reflectance¶

Photochemistry and Photobiology (2004)

K. Raja Reddy Vijaya Gopal Kakani Duli Zhao Sailaja Koti Wei Gao

Current conditions of 2–11 kJ m−2 day−1 of UV-B radiation and temperatures of >30°C during flowering in cotton cultivated regions are projected to increase in the future. A controlled environment study was conducted in sunlit growth chambers to determine the effects of UV-B radiation and temperature on physiology, growth, development and leaf hyperspectral reflectance of cotton. Plants were grown in the growth chambers at three day/night temperatures (24/16°C, 30/22°C and 36/28°C) and three levels of UV-B radiation (0, 7 and 14 kJ m−2 day−1) at each temperature from emergence to 79 days under optimum nutrient and water conditions. Increases in main stem node number and the node of first fruiting branch and decrease in duration to first flower bud (square) and flower were recorded with increase in temperature. Main effects of temperature and UV-B radiation were significant for net photosynthetic rates, stomatal conductance, total chlorophyll and carotenoid concentrations of uppermost, fully expanded leaves during squaring and flowering. A significant interaction between temperature and UV-B radiation was detected for total biomass and its components. The UV-B radiation of 7 kJ m−2 day−1 reduced boll yield by 68% and 97% at 30/22°C and 36/28°C, respectively, compared with yield at 0 kJ m−2 day−1 and 30/22°C. No bolls were produced in the three temperature treatments under 14 kJ m−2 day−1 UV-B radiation. The first-order interactions between temperature, UV-B radiation and leaf age were significant for leaf reflectance. This study suggests a growth- and process-related temperature dependence of sensitivity to UV-B radiation.

Ultraviolet B radiation

Sunlight

Photosynthetically active radiation

Stomatal Conductance

10.1562/2003-11-19-ra.1

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Citations (77)

Hyperspectral Reflectance and Machine Learning Approaches for the Detection of Drought and Root–Knot Nematode Infestation in Cotton

Remote Sensing (2022)

P. Ramamoorthy Sathishkumar Samiappan Martin J. Wubben John P. Brooks Amrit Shrestha

Upland cotton encounters biotic and abiotic stresses during the growing season, which significantly affects the genetic potential of stress tolerance and productivity. The root-knot nematode (RKN) (Meloidogyne incognita) is a soilborne roundworm affecting cotton production. The occurrence of abiotic stress (drought stress, DS) can alter the plant–disease (RKN) interactions by enhancing host plant sensitivity. Experiments were conducted for two years under greenhouse conditions to investigate the effect of RKN and DS and their combination using nematode-resistant (Rk-Rn-1) and nematode susceptible (M8) cotton genotypes. These genotypes were subjected to four treatments: control (100% irrigation with no nematodes), RKN (100% irrigation with nematodes), DS (50% irrigation with no nematodes), and DS + RKN (50% irrigation with nematodes). We measured treatments-induced changes in cotton (i) leaf reflectance between 350 and 2500 nm; and (ii) physiology and biomass-related traits for diagnosing plant health under combined biotic and abiotic stresses. We used a maximum likelihood classification model of hyperspectral data with different dimensionality reduction techniques to learn RKN and DS stressors on two cotton genotypes. The results indicate (i) the RKN stress can be detected at an early stage of 10 days after infestation; (ii) RKN, DS, and DS + RKN can be detected with an accuracy of over 98% using bands from 350–1000 nm and 350–2500 nm. The genotypes ‘Rk-Rn-1’and ‘M8’ showed differential responses to DS, RKN, and DS + RKN. With a few exceptions, all three stressors reduced the pigments, physiology, and biomass traits and the magnitude of reduction was higher in ‘M8’ than ‘Rk-Rn-1’. Observed impact of stressors on plant growth followed DS + RKN > DS > RKN. Similarly, leaf reflectance properties exhibited a significant difference between individual stress treatments indicating that the hyperspectral sensor data can be used to discriminate RKN-infected plants from drought-stressed plants. Thus, our study reveals that hyperspectral and physiological changes in response to RKN and DS could help diagnose plant health before visual symptoms.

Root-knot nematode

Biotic stress

10.3390/rs14164021

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Citations (9)

Harvest Frequency and Nitrogen Effects on Yield, Chemical Characteristics, and Nutrient Removal of Switchgrass

Agronomy Journal (2014)

Ramdeo Seepaul Bisoondat Macoon K. Raja Reddy William B. Evans

Harvest frequency (HF) and fertilizer effects on biomass production, nutrient removal, and ethanol yield must be understood to help guide management decisions in switchgrass ( Panicum virgatum L.) production. This 4‐yr study quantified yield and chemical composition responses of Alamo switchgrass to factorial combinations (4 × 2) of four HFs (harvesting one, two, three, or six times annually) and two N application rates (80 and 160 kg N ha −1 ) in a randomized complete block design experiment with three replications. In all years, yields decreased linearly with HF. In the one‐cut HF, yield increased from 8.8 in Year 1 to 14.7 Mg ha −1 in Year 3 and plateaued thereafter. For the two‐cut HF, yield was similar across years, averaging 10 Mg ha −1 , but for the three‐ and six‐cut HFs, yield increased from Year 1 to Year 2 and declined by Year 4. Nutrient concentration increased with HF, while nutrient removal responses fluctuated among elements. Acid detergent fiber, neutral detergent fiber, hemicellulose, cellulose, and lignin concentrations decreased with increasing HF, but there was no effect of N rate. In Years 1 and 2, theoretical ethanol production (TEP) was similar between the one‐ (3.7 kL ha −1 ) and two‐cut HFs (4.2 kL ha −1 ) but decreased as the HF increased to three (2.6–3.4 kL ha −1 ) and six cuts (1.4– 2.5 kL ha −1 ). In Years 3 and 4, TEP decreased linearly with increasing HF. Greater HF resulted in reduced feedstock yield, quality, ethanol yield, and production, but N application rate did not have any effect.

Panicum virgatum

Hemicellulose

Neutral Detergent Fiber

Panicum

10.2134/agronj14.0129

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Impacts of <i>S</i>-Metolachlor Application Timing on Sweetpotato Growth and Development

American Journal of Plant Sciences (2019)

Issah A. Abukari Mark W. Shankle K. Raja Reddy Stephen L. Meyers Wei Gao

S-metolachlor is used to control/suppress yellow nutsedge, annual grasses and several broadleaf weeds in sweetpotato. However, a decline in storage root quality is suspected when excessive rainfall occurs within 24-h after application. A greenhouse study was conducted to determine the effect of S-metolachlor application timing on sweetpotato growth and development. S-metolachlor treatments (0 and 1 kg·ha-1) were applied over-the-top at 0, 5 and ten days after transplanting (DAT) and a simulated rainfall treatment delivered 25 mm of rain, 51 mm·h-1 intensity, immediately after herbicide application. Plants were harvested at 5, 10, 15, 20 and 80 DAT. During the first four harvests, roots were scanned and analyzed with WinRHIZO-Pro image analysis system to estimate root number, length, volume, and surface area along with aboveground growth parameters. At the final harvest, plant growth and biomass components, and quality of storage roots were recorded. Plants treated with S-metolachlor on day 0 and 5 DAT were significantly less than those of 10 DAT and untreated control for all measured parameters for the initial 20 days of plant growth. Even though vine length, leaf number, stem biomass, and total storage roots were not different among the treatments at 80 DAT, all other plant components and total biomass production and leaf area development for plants treated at 0 and 5 DAT were significantly (P % and 16% for plants treated at 0 and 5 DAT, respectively, relative to the untreated check. These results indicate that delaying S-metolachlor application to 10 DAT will be less damaging to sweetpotato growth and development, particularly marketable storage roots and yield.

Metolachlor

Transplanting

10.4236/ajps.2019.105057

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Citations (1)

Assessing morphological characteristics of elite cotton lines from different breeding programmes for low temperature and drought tolerance

Journal of Agronomy and Crop Science (2018)

Bhupinder Singh E. Norvell Chathurika Wijewardana T. Wallace Daryl R. Chastain

Abstract Cotton breeders in the United States strive to develop region‐specific genotypes adapted to low temperatures and variable soil moistures during early‐season planting. Nine elite upland cotton germplasm ( Gossypium hirsutum L.) lines, representing public breeding programmes from nine states across the cotton belt, were evaluated for cold and drought stresses during seed germination and seedling growth stages. Lines were subjected to three treatments, such as low temperature well‐watered (22/14°C, WW), optimal temperature drought stress (30/22°C, DS) and optimal temperature well‐watered (30/22°C, WW; control), to examine genotypic variability for cold and drought tolerance. The treatment including drought stress was irrigated at 50% of the control. Shoot and root traits measured at 25 days after planting were significantly affected by drought and low temperature, where significant genetic variability among lines was observed for both shoot and root parameters. Response indices were developed to quantify variation in the degree of tolerance among the lines to low temperature and drought. Accordingly, OA‐33 was identified as the most low‐temperature‐tolerant line and Acala 1517‐99 as the most drought‐tolerant line. Identification of both cold‐ and drought‐tolerant genotypes suggests existing genotypic variability could provide breeders the opportunity to improve cultivar response to early‐season drought or cold conditions.

Germ plasm

Drought Tolerance

Genetic Variability

Growing season

Breeding program

Fiber crop

10.1111/jac.12276

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Citations (47)

Resilience of cotton cultivars to chilling stress during germination

Plant Physiology Reports (2023)

Surabhi Gupta Lekshmy V. Sankarapillai K. Raja Reddy Salliana R. Stetina Raju Bheemanahalli

Radicle

10.1007/s40502-023-00746-4

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Citations (2)

Quantifying soil moisture deficit effects on soybean yield and yield component distribution patterns

Irrigation Science (2018)

Chathurika Wijewardana K. Raja Reddy Firas Ahmed Alsajri J. Trenton Irby L. Jason Krutz

Moisture stress

10.1007/s00271-018-0580-1

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Citations (58)

Methane Production and Emissions from Four Reclaimed and Pristine Wetlands of Southeastern United States

Soil Science Society of America Journal (1994)

Louis A. Schipper K. Raja Reddy

Abstract Wetlands are significant contributors to global CH 4 emission. We measured CH 4 emissions at two pristine wetlands [Okefenokee swamp and the Everglades (Water Conservation Area 2A)] and two reclaimed wetlands (Sunny Hill Farm and Apopka Marsh) in Southeastern USA, and we attempted to relate emissions to CH 4 production rates of the soil and the soil's biological and chemical properties. Methane emissions through cattail [ Typha sp.] and waterlily [ Nymphaea ordorata (L.)] ranged from 0.09 to 1.7 g CH 4 m −2 d −1 and exhibited high spatial and temporal variability. Diffusive flux of CH 4 was calculated using dissolved CH 4 profiles in the soil pore water and accounted for <5% of the plant‐mediated emissions. Potential CH 4 production rates were measured as a function of depth using soil samples obtained at 2‐cm increments. Methane production rates were the same order of magnitude at all sites (<1–70 ng CH 4 ‐C g −1 soil C d −1 ) and were highest in the surface soils (0–6 cm) at three of the wetland sites, indicating that the predominant source of C available to methanogens was in the surface soils. Methane production rates in the top 24 cm ranged from 0.3 to 1.1 g CH 4 m −2 d −1 and annual C losses due to anaerobic decomposition accounted for between 0.68 and 3.7% of the total C in the surface 24‐cm soil depth. Methane production was observed at sites with porewater SO 4 concentrations of up to 20 mg SO 4 ‐S L −1 , suggesting that methanogenesis occurred in the same soil layer as SO 4 reduction, possibly in microsites where SO 4 concentration was depleted.

Swamp

10.2136/sssaj1994.03615995005800040039x

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Citations (39)

Temperature and elevated CO2 alter soybean seed yield and quality, exhibiting transgenerational effects on seedling emergence and vigor

Frontiers in Plant Science (2024)

Naflath Thenveettil Raju Bheemanahalli Krishna N. Reddy Wei Gao K. Raja Reddy

Introduction Environmental conditions play a prime role in the growth and development of plant species, exerting a significant influence on their reproductive capacity. Soybean is sensitive to high temperatures during flowering and seed developmental stages. Little is known about the combined environmental effect of temperature and CO 2 on seed yield and quality and its future generation. Methods A study was conducted to examine the effect of temperature (22/14°C (low), 30/22°C (optimum), and 38/30°C (high)), and CO 2 (420 ppm (ambient; aCO 2 ) and 720 ppm (elevated; eCO 2 )) on seed yield, quality, and transgenerational seedling vigor traits of soybean cultivars (DS25-1 and DS31-243) using Soil-Plant-Atmospheric-Research facility. Results A significant temperature effect was recorded among yield and quality attributes. At high-temperature, the 100-seed weights of DS25-1 and DS31-243 declined by 40% and 24%, respectively, over the optimum temperature at aCO 2 . The harvest index of varieties reduced by 70% when exposed to high temperature under both aCO2 and eCO 2 , compared to the optimum temperature at aCO 2 . The seed oil (- 2%) and protein (8%) content altered when developed under high temperature under aCO 2 . Maximum sucrose (7.5%) and stachyose (3.8%) accumulation in seeds were observed when developed under low temperatures and eCO 2 . When the growing temperature increased from optimum to high, the seed oleic acids increased (63%), while linoleic and linolenic acids decreased (- 28% and - 43%, respectively). Significant temperature and CO 2 effects were observed in progenies with the highest maximum seedling emergence (80%), lesser time to 50% emergence (5.5 days), and higher seedling vigor from parents grown at low-temperature treatment under eCO 2 . Discussion Exposure of plants to 38/30°C was detrimental to soybean seed yield, and eCO 2 levels did not compensate for this yield loss. The high temperature during seed developmental stages altered the chemical composition of the seed, leading to an increased content of monounsaturated fatty acids. The findings suggest that parental stress can significantly impact the development of offspring, indicating that epigenetic regulation or memory repose may be at play.

Stachyose

Transgenerational epigenetics

10.3389/fpls.2024.1427086

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Citations (2)

First report of Groundnut Bud Necrosis Virus infecting Taro (Colocasia esculenta)

Australasian Plant Disease Notes (2011)

Y. Sivaprasad B.V. Bhaskara Reddy Kumar Chandan K. Raja Reddy D.V.R. Sai Gopal

Colocasia esculenta

10.1007/s13314-011-0011-0

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Citations (14)