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P.V. Vara Prasad is a University Distinguished Professor, R.O. Kruse Endowed Professor in Agriculture, and Director of the Sustainable Intensification Innovation Lab at Kansas State University. He obtained his BS and MS degrees from Andhra Pradesh Agricultural University (India), and PhD from University of Reading (United Kingdom). His research focuses on understanding responses of crops to changing environments; developing best management strategies to improve and protect yields; and improving livelihoods of people and providing food and nutritional security to smallholder farmers. He is passionate about research, education, and outreach activities; and building human and institutional capacity around the world. He has active programs in multiple countries in Asia and Africa. He has published >280 peer-reviewed journal articles and book chapters. He has trained >150 students and research scholars from 25 countries. He gave >100 invited talks in 40 countries. He received >120 million US dollars (about $80 million as principal investigator) in grant funding and donations. He is an elected fellow of American Society of Agronomy; Crop Science Society of America; and American Association for the Advancement of Science.
The quantity and quality of forage and fodder crops is the major drawback of the livestock sector in the country. There is a need to bridge the gap between the supply and demand of fodder through the adoption of specific sustainable fodder production strategies. The field experiments were conducted during kharif (rainy, June–October), rabi (post-rainy, October–February), and summer (March–May) seasons of 2018–19 and 2019–20 to identify a sustainable fodder cropping system module in randomized complete block design with fifteen fodder cropping systems in three replications. The main objective of this research was to identify the most productive cereal–legume cropping system, both in terms of quantity and quality of biomass, to reduce the gap between supply and demand of quality livestock feed around the year. Among cropping systems, Bajra–Napier hybrid intercropped with lucerne, cowpea, and sesbania recorded significantly higher green fodder (163.6, 155.2, and 144.0 t/ha/year, respectively) and dry matter yields (32.1, 30.8, and 31.3 t/ha/year, respectively). Similarly, the same perennial systems also recorded higher quality yield and ash content. However, higher crude protein content was noticed in monocrop legumes, with the highest in sesbania (22.32%), while higher ether extractable fat was found in monocrop sesbania (3.78%). The monocrop oats recorded higher non-fiber carbohydrates (36.90%) while a monocrop of pearl millet recorded higher total carbohydrates (80.75%), however they were on par with other monocrop cereal cropping systems. Cultivation of legumes as a monocrop, and their inclusion as an intercrop with cereals resulted in lower fiber fractions and improved crude protein in intercropping systems. Furthermore, this improved the dry matter intake and digestibility of fodder. With higher sustainable yield index values and land-use efficiency, perennial intercropping systems were also found to be sustainable. Thus, cultivation of the Bajra–Napier hybrid with either lucerne, cowpea, or sesbania as an intercrop will help livestock farmers to achieve higher productivity in terms of quantity and quality, and forms a viable option for overcoming livestock feed scarcity.
Konapura Nagaraja Manoj; Bommalapura Gundanaik Shekara; Shankarappa Sridhara; Prakash Kumar Jha; P. V. Vara Prasad. Biomass Quantity and Quality from Different Year-Round Cereal–Legume Cropping Systems as Forage or Fodder for Livestock. Sustainability 2021, 13, 9414 .
AMA StyleKonapura Nagaraja Manoj, Bommalapura Gundanaik Shekara, Shankarappa Sridhara, Prakash Kumar Jha, P. V. Vara Prasad. Biomass Quantity and Quality from Different Year-Round Cereal–Legume Cropping Systems as Forage or Fodder for Livestock. Sustainability. 2021; 13 (16):9414.
Chicago/Turabian StyleKonapura Nagaraja Manoj; Bommalapura Gundanaik Shekara; Shankarappa Sridhara; Prakash Kumar Jha; P. V. Vara Prasad. 2021. "Biomass Quantity and Quality from Different Year-Round Cereal–Legume Cropping Systems as Forage or Fodder for Livestock." Sustainability 13, no. 16: 9414.
Agricultural expansion and urban development without proper soil erosion control measures have become major environmental problems in Cambodia. Due to a high population growth rate and increased economic activities, land use and land cover (LULC) changes will cause environmental disturbances, particularly soil erosion. This research aimed to estimate total amounts of soil loss using the Revised Universal Soil Loss Equation (RUSLE) model within a Geographic Information System (GIS) environment. LULC maps of Japan International Cooperation Agency (JICA) 2002 and Mekong River Commission (MRC) 2015 were used to evaluate the impact of LULC on soil erosion loss in Stung Sangkae catchment. LULC dynamics for the study periods in Stung Sangkae catchment showed that the catchment experienced a rapid conversion of forests to paddy rice fields and other croplands. The results indicated that the average soil loss from the catchment was 3.1 and 7.6 t/ha/y for the 2002 and 2015 periods, respectively. The estimated total soil loss in the 2002 and 2015 periods was 1.9 million t/y and 4.5 million t/y, respectively. The soil erosion was accelerated by steep slopes combined with the high velocity and erosivity of stormwater runoff. The spatial distribution of soil loss showed that the highest value (14.3 to 62.9 t/ha/y) was recorded in the central, southwestern and upland parts of the catchment. It is recommended that priority should be given to erosion hot spot areas, and appropriate soil and water conservation practices should be adopted to restore degraded lands.
Nareth Nut; Machito Mihara; Jaehak Jeong; Bunthan Ngo; Gilbert Sigua; P.V. Vara Prasad; Manny R. Reyes. Land Use and Land Cover Changes and Its Impact on Soil Erosion in Stung Sangkae Catchment of Cambodia. Sustainability 2021, 13, 9276 .
AMA StyleNareth Nut, Machito Mihara, Jaehak Jeong, Bunthan Ngo, Gilbert Sigua, P.V. Vara Prasad, Manny R. Reyes. Land Use and Land Cover Changes and Its Impact on Soil Erosion in Stung Sangkae Catchment of Cambodia. Sustainability. 2021; 13 (16):9276.
Chicago/Turabian StyleNareth Nut; Machito Mihara; Jaehak Jeong; Bunthan Ngo; Gilbert Sigua; P.V. Vara Prasad; Manny R. Reyes. 2021. "Land Use and Land Cover Changes and Its Impact on Soil Erosion in Stung Sangkae Catchment of Cambodia." Sustainability 13, no. 16: 9276.
Cultivars with efficient root systems play a major role in enhancing resource use efficiency, particularly water absorption, and thus in drought tolerance. In this study, a diverse wheat association panel of 136 wheat accessions including mini core subset was genotyped using Axiom 35k Breeders’ Array to identify genomic regions associated with seedling stage root architecture and shoot traits using multi-locus genome-wide association studies (ML-GWAS). The association panel revealed a wide variation of 1.5- to 50-fold and were grouped into six clusters based on 15 traits. Six different ML-GWAS models revealed 456 significant quantitative trait nucleotides (QTNs) for various traits with phenotypic variance in the range of 0.12–38.60%. Of these, 87 QTNs were repeatedly detected by two or more models and were considered reliable genomic regions for the respective traits. Among these QTNs, eleven were associated with average diameter and nine each for second order lateral root number (SOLRN), root volume (RV) and root length density (RLD). A total of eleven genomic regions were pleiotropic and each controlled two or three traits. Some important candidate genes such as Formin homology 1, Ubiquitin-like domain superfamily and ATP-dependent 6-phosphofructokinase were identified from the associated genomic regions. The genomic regions/genes identified in this study could potentially be targeted for improving root traits and drought tolerance in wheat.
Thippeswamy Danakumara; Jyoti Kumari; Amit Singh; Subodh Sinha; Anjan Pradhan; Shivani Sharma; Shailendra Jha; Ruchi Bansal; Sundeep Kumar; Girish Jha; Mahesh Yadav; P.V. Prasad. Genetic Dissection of Seedling Root System Architectural Traits in a Diverse Panel of Hexaploid Wheat through Multi-Locus Genome-Wide Association Mapping for Improving Drought Tolerance. International Journal of Molecular Sciences 2021, 22, 7188 .
AMA StyleThippeswamy Danakumara, Jyoti Kumari, Amit Singh, Subodh Sinha, Anjan Pradhan, Shivani Sharma, Shailendra Jha, Ruchi Bansal, Sundeep Kumar, Girish Jha, Mahesh Yadav, P.V. Prasad. Genetic Dissection of Seedling Root System Architectural Traits in a Diverse Panel of Hexaploid Wheat through Multi-Locus Genome-Wide Association Mapping for Improving Drought Tolerance. International Journal of Molecular Sciences. 2021; 22 (13):7188.
Chicago/Turabian StyleThippeswamy Danakumara; Jyoti Kumari; Amit Singh; Subodh Sinha; Anjan Pradhan; Shivani Sharma; Shailendra Jha; Ruchi Bansal; Sundeep Kumar; Girish Jha; Mahesh Yadav; P.V. Prasad. 2021. "Genetic Dissection of Seedling Root System Architectural Traits in a Diverse Panel of Hexaploid Wheat through Multi-Locus Genome-Wide Association Mapping for Improving Drought Tolerance." International Journal of Molecular Sciences 22, no. 13: 7188.
The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) (SCA), has become a major pest of grain sorghum since its appearance in the USA. Several grain sorghum parental lines are moderately resistant to the SCA. However, the molecular and genetic mechanisms underlying this resistance are poorly understood, which has constrained breeding for improved resistance. RNA-Seq was used to conduct transcriptomics analysis on a moderately resistant genotype (TAM428) and a susceptible genotype (Tx2737) to elucidate the molecular mechanisms underlying resistance. Differential expression analysis revealed differences in transcriptomic profile between the two genotypes at multiple time points after infestation by SCA. Six gene clusters had differential expression during SCA infestation. Gene ontology enrichment and cluster analysis of genes differentially expressed after SCA infestation revealed consistent upregulation of genes controlling protein and lipid binding, cellular catabolic processes, transcription initiation, and autophagy in the resistant genotype. Genes regulating responses to external stimuli and stress, cell communication, and transferase activities, were all upregulated in later stages of infestation. On the other hand, expression of genes controlling cell cycle and nuclear division were reduced after SCA infestation in the resistant genotype. These results indicate that different classes of genes, including stress response genes and transcription factors, are responsible for countering the physiological effects of SCA infestation in resistant sorghum plants.
Desalegn Serba; Xiaoxi Meng; James Schnable; Elfadil Bashir; J. Michaud; P. Vara Prasad; Ramasamy Perumal. Comparative Transcriptome Analysis Reveals Genetic Mechanisms of Sugarcane Aphid Resistance in Grain Sorghum. International Journal of Molecular Sciences 2021, 22, 7129 .
AMA StyleDesalegn Serba, Xiaoxi Meng, James Schnable, Elfadil Bashir, J. Michaud, P. Vara Prasad, Ramasamy Perumal. Comparative Transcriptome Analysis Reveals Genetic Mechanisms of Sugarcane Aphid Resistance in Grain Sorghum. International Journal of Molecular Sciences. 2021; 22 (13):7129.
Chicago/Turabian StyleDesalegn Serba; Xiaoxi Meng; James Schnable; Elfadil Bashir; J. Michaud; P. Vara Prasad; Ramasamy Perumal. 2021. "Comparative Transcriptome Analysis Reveals Genetic Mechanisms of Sugarcane Aphid Resistance in Grain Sorghum." International Journal of Molecular Sciences 22, no. 13: 7129.
Background COVID-19 transmission rates in South Asia initially were under control when governments implemented health policies aimed at controlling the pandemic such as quarantines, travel bans, and border, business, and school closures. Governments have since relaxed public health restrictions, which resulted in significant outbreaks, shifting the global epicenter of COVID-19 to India. Ongoing systematic public health surveillance of the COVID-19 pandemic is needed to inform disease prevention policy to re-establish control over the pandemic within South Asia. Objective This study aimed to inform public health leaders about the state of the COVID-19 pandemic, how South Asia displays differences within and among countries and other global regions, and where immediate action is needed to control the outbreaks. Methods We extracted COVID-19 data spanning 62 days from public health registries and calculated traditional and enhanced surveillance metrics. We use an empirical difference equation to measure the daily number of cases in South Asia as a function of the prior number of cases, the level of testing, and weekly shifts in variables with a dynamic panel model that was estimated using the generalized method of moments approach by implementing the Arellano–Bond estimator in R. Results Traditional surveillance metrics indicate that South Asian countries have an alarming outbreak, with India leading the region with 310,310 new daily cases in accordance with the 7-day moving average. Enhanced surveillance indicates that while Pakistan and Bangladesh still have a high daily number of new COVID-19 cases (n=4819 and n=3878, respectively), their speed of new infections declined from April 12-25, 2021, from 2.28 to 2.18 and 3.15 to 2.35 daily new infections per 100,000 population, respectively, which suggests that their outbreaks are decreasing and that these countries are headed in the right direction. In contrast, India’s speed of new infections per 100,000 population increased by 52% during the same period from 14.79 to 22.49 new cases per day per 100,000 population, which constitutes an increased outbreak. Conclusions Relaxation of public health restrictions and the spread of novel variants fueled the second wave of the COVID-19 pandemic in South Asia. Public health surveillance indicates that shifts in policy and the spread of new variants correlate with a drastic expansion in the pandemic, requiring immediate action to mitigate the spread of COVID-19. Surveillance is needed to inform leaders whether policies help control the pandemic.
Sarah B Welch; Dinushi Amanda Kulasekere; P V Vara Prasad; Charles B Moss; Robert Leo Murphy; Chad J Achenbach; Michael G Ison; Danielle Resnick; Lauren Singh; Janine White; Tariq Z Issa; Kasen Culler; Michael J Boctor; Maryann Mason; James Francis Oehmke; Joshua Marco Mitchell Faber; Lori Ann Post. The Interplay Between Policy and COVID-19 Outbreaks in South Asia: Longitudinal Trend Analysis of Surveillance Data. JMIR Public Health and Surveillance 2021, 7, e24251 .
AMA StyleSarah B Welch, Dinushi Amanda Kulasekere, P V Vara Prasad, Charles B Moss, Robert Leo Murphy, Chad J Achenbach, Michael G Ison, Danielle Resnick, Lauren Singh, Janine White, Tariq Z Issa, Kasen Culler, Michael J Boctor, Maryann Mason, James Francis Oehmke, Joshua Marco Mitchell Faber, Lori Ann Post. The Interplay Between Policy and COVID-19 Outbreaks in South Asia: Longitudinal Trend Analysis of Surveillance Data. JMIR Public Health and Surveillance. 2021; 7 (6):e24251.
Chicago/Turabian StyleSarah B Welch; Dinushi Amanda Kulasekere; P V Vara Prasad; Charles B Moss; Robert Leo Murphy; Chad J Achenbach; Michael G Ison; Danielle Resnick; Lauren Singh; Janine White; Tariq Z Issa; Kasen Culler; Michael J Boctor; Maryann Mason; James Francis Oehmke; Joshua Marco Mitchell Faber; Lori Ann Post. 2021. "The Interplay Between Policy and COVID-19 Outbreaks in South Asia: Longitudinal Trend Analysis of Surveillance Data." JMIR Public Health and Surveillance 7, no. 6: e24251.
This study was conducted at the Dangishta watershed in the Ethiopian highlands to evaluate irrigation potential from surface and groundwater sources under different farming and water application systems. Daily streamflow and the groundwater table were monitored from 2015 to 2017. Shallow groundwater recharge was estimated using the water table fluctuation method. Automated baseflow separation techniques were used to determine the amount of runoff and baseflow from the total streamflow records. The potential of groundwater and runoff to sustain dry season irrigation (i.e., low flow) was evaluated considering two tillage systems (i.e., conservation agriculture, CA; and conventional tillage, CT), and water application (i.e., drip and overhead) systems for major irrigated crops (i.e., onion, garlic, cabbage, and pepper) grown in the Dangishta watershed. We found that the annual groundwater recharge varied from 320 to 358 mm during the study period, which was about 17% to 22% of the annual rainfall. The annual surface runoff depth ranged from 192 to 268 mm from 2015 to 2017. The results reveal that the maximum seasonal irrigable land from groundwater recharge was observed under CA with drip irrigation (i.e., 2251 and 2992 ha from groundwater recharge and surface runoff, respectively). By comparison, in the CT practice with overhead irrigation, the lowest seasonal irrigable land was observed (i.e., 1746 and 2121 ha from groundwater and surface runoff, respectively). From the low flow analysis, about 199 and 173 ha of one season’s irrigable land could be irrigated using the CA and CT systems, respectively, both with drip irrigation. Similarly, two-season overhead irrigation potential from low flow under CA and CT was found to be about 87 and 76 ha, respectively. The dry season irrigable land using low flow could be increased from 9% to 16% using the CA system for the various vegetables, whereas drip irrigation could increase the irrigable land potential by 56% compared to overhead irrigation. The combined use of groundwater recharge and runoff could sustain up to 94% of the dry season low flow irrigation through the combination of the CA system and drip irrigation. Decision makers must consider the introduction of feasible and affordable technologies to make use of groundwater and direct runoff, to maximize the potential of dry season production through efficient and appropriate CA and water management practices.
Abdu Yimam; Tewodros Assefa; Feleke Sishu; Seifu Tilahun; Manuel Reyes; P.V. Prasad. Estimating Surface and Groundwater Irrigation Potential under Different Conservation Agricultural Practices and Irrigation Systems in the Ethiopian Highlands. Water 2021, 13, 1645 .
AMA StyleAbdu Yimam, Tewodros Assefa, Feleke Sishu, Seifu Tilahun, Manuel Reyes, P.V. Prasad. Estimating Surface and Groundwater Irrigation Potential under Different Conservation Agricultural Practices and Irrigation Systems in the Ethiopian Highlands. Water. 2021; 13 (12):1645.
Chicago/Turabian StyleAbdu Yimam; Tewodros Assefa; Feleke Sishu; Seifu Tilahun; Manuel Reyes; P.V. Prasad. 2021. "Estimating Surface and Groundwater Irrigation Potential under Different Conservation Agricultural Practices and Irrigation Systems in the Ethiopian Highlands." Water 13, no. 12: 1645.
Long-term selection in maize (Zea mays L.) favored single-stalked phenotypes limiting vegetative growth. However, reduced plant densities create conducive environments to the expression of vegetative branches, called tillers. Tiller expression has motivated discussions about its yield impact in variable environments, but tiller research is lacking for modern corn genotypes. The objectives of this study were to i) quantify the relative importance of management, environment, and interactions on the yield impact of tiller expression for two modern genotypes; ii) understand impacts of observed tiller density, plant density, and their interaction on yield; and iii) identify key environmental determinants of yield response to tiller density in modern genotypes. In 10 environmentally diverse site-years across Kansas, USA, tiller presence and removal were evaluated in two commercial corn hybrids (P0657AM and P0805AM) across three target plant density levels (25000, 42000, and 60000 plants ha−1). Yields were increased or unaffected by greater plant densities and tiller presence within site-years. Environments varied in yield responsiveness to tiller density, but fine-tuning plant density was needed to maximize yields. Sites with yields most responsive to tiller density were characterized by good soil properties and photothermal quotient (PTQ) values (e.g. soils with high organic matter and climates with greater solar radiation and cooler temperatures). Favorable growing conditions can be exploited by plasticity traits such as tillering in unpredictable environments with annually variable optimum plant densities while limiting potential yield loss and producer risk due to disproportionate plant density. This article is protected by copyright. All rights reserved
Rachel Lynn Veenstra; Carlos Messina; Dan Berning; Lucas A. Haag; Paul Carter; Trevor Hefley; P.V. Vara Prasad; Ignacio Antonio Ciampitti. Effect of tillers on corn yield: Exploring trait plasticity potential in unpredictable environments. Crop Science 2021, 1 .
AMA StyleRachel Lynn Veenstra, Carlos Messina, Dan Berning, Lucas A. Haag, Paul Carter, Trevor Hefley, P.V. Vara Prasad, Ignacio Antonio Ciampitti. Effect of tillers on corn yield: Exploring trait plasticity potential in unpredictable environments. Crop Science. 2021; ():1.
Chicago/Turabian StyleRachel Lynn Veenstra; Carlos Messina; Dan Berning; Lucas A. Haag; Paul Carter; Trevor Hefley; P.V. Vara Prasad; Ignacio Antonio Ciampitti. 2021. "Effect of tillers on corn yield: Exploring trait plasticity potential in unpredictable environments." Crop Science , no. : 1.
Gradually increasing temperatures at global and local scales are causing heat stress for cool and summer-season food legumes, such as lentil (Lens culinaris Medik.), which is highly susceptible to heat stress, especially during its reproductive stages of development. Hence, suitable strategies are needed to develop heat tolerance in this legume. In the present study, we tested the effectiveness of heat priming (HPr; 6 h at 35 °C) the lentil seeds and a foliar treatment of γ-aminobutyric acid (GABA; 1 mM; applied twice at different times), singly or in combination (HPr+GABA), under heat stress (32/20 °C) in two heat-tolerant (HT; IG2507, IG3263) and two heat-sensitive (HS; IG2821, IG2849) genotypes to mitigate heat stress. The three treatments significantly reduced heat injury to leaves and flowers, particularly when applied in combination, including leaf damage assessed as membrane injury, cellular oxidizing ability, leaf water status, and stomatal conductance. The combined HPr+GABA treatment significantly improved the photosynthetic function, measured as photosynthetic efficiency, chlorophyll concentration, and sucrose synthesis; and significantly reduced the oxidative damage, which was associated with a marked up-regulation in the activities of enzymatic antioxidants. The combined treatment also facilitated the synthesis of osmolytes, such as proline and glycine betaine, by upregulating the expression of their biosynthesizing enzymes (pyrroline-5-carboxylate synthase; betaine aldehyde dehydrogenase) under heat stress. The HPr+GABA treatment caused a considerable enhancement in endogenous levels of GABA in leaves, more so in the two heat-sensitive genotypes. The reproductive function, measured as germination and viability of pollen grains, receptivity of stigma, and viability of ovules, was significantly improved with combined treatment, resulting in enhanced pod number (21–23% in HT and 35–38% in HS genotypes, compared to heat stress alone) and seed yield per plant (22–24% in HT and 37–40% in HS genotypes, in comparison to heat stress alone). The combined treatment (HPr+GABA) was more effective and pronounced in heat-sensitive than heat-tolerant genotypes for all the traits tested. This study offers a potential solution for tackling and protecting heat stress injury in lentil plants.
Anjali Bhardwaj; Kumari Sita; Akanksha Sehgal; Kalpna Bhandari; Shiv Kumar; P. Prasad; Uday Jha; Jitendra Kumar; Kadambot Siddique; Harsh Nayyar. Heat Priming of Lentil (Lens culinaris Medik.) Seeds and Foliar Treatment with γ-Aminobutyric Acid (GABA), Confers Protection to Reproductive Function and Yield Traits under High-Temperature Stress Environments. International Journal of Molecular Sciences 2021, 22, 5825 .
AMA StyleAnjali Bhardwaj, Kumari Sita, Akanksha Sehgal, Kalpna Bhandari, Shiv Kumar, P. Prasad, Uday Jha, Jitendra Kumar, Kadambot Siddique, Harsh Nayyar. Heat Priming of Lentil (Lens culinaris Medik.) Seeds and Foliar Treatment with γ-Aminobutyric Acid (GABA), Confers Protection to Reproductive Function and Yield Traits under High-Temperature Stress Environments. International Journal of Molecular Sciences. 2021; 22 (11):5825.
Chicago/Turabian StyleAnjali Bhardwaj; Kumari Sita; Akanksha Sehgal; Kalpna Bhandari; Shiv Kumar; P. Prasad; Uday Jha; Jitendra Kumar; Kadambot Siddique; Harsh Nayyar. 2021. "Heat Priming of Lentil (Lens culinaris Medik.) Seeds and Foliar Treatment with γ-Aminobutyric Acid (GABA), Confers Protection to Reproductive Function and Yield Traits under High-Temperature Stress Environments." International Journal of Molecular Sciences 22, no. 11: 5825.
Sorghum [Sorghum bicolor (L.) Moench] is highly sensitive to chilling temperatures (<15°C soil temperatures) during germination and early seedling establishment. Hence, the main objectives of this research were to (a) validate the potential level of chilling tolerance in selected sorghum genotypes, (b) determine effective concentrations of selected safeners for improving chilling tolerance and (c) determine if safener combinations further enhance chilling tolerance compared to individual safener treatments. Four experiments were conducted with five sorghum genotypes, four safeners (oxabetrinil, fluxofenim, naphthalic anhydride and benoxacor), nine safener concentrations (0–25 μM) and two temperatures. The chilling-tolerant genotypes recorded higher germination percentage (98% vs. 63%) and root (3.0 vs. 0.8 cm) and shoot lengths (0.7 vs. 0.1 cm) compared to sensitive genotypes under continuous 15℃. Each of the four safeners applied at the highest concentrations tested (20 and 25 μM) significantly enhanced seed germination and seedling growth at 15℃. The combination of four safeners was more effective in reducing chilling stress-induced injury compared to individual, two- or three-way combinations. Enhanced chilling tolerance may be extended to other cereal crops after optimizing the genetic background and effects of agro-climatic conditions on safener chemistry, concentration, and proper combination of seed-applied safeners.
Amaranatha R. Vennapusa; Yared Assefa; David Sebela; Impa Somayanda; Ramasamy Perumal; Dean E. Riechers; P. V. Vara Prasad; S. V. Krishna Jagadish. Safeners improve early‐stage chilling‐stress tolerance in sorghum. Journal of Agronomy and Crop Science 2021, 1 .
AMA StyleAmaranatha R. Vennapusa, Yared Assefa, David Sebela, Impa Somayanda, Ramasamy Perumal, Dean E. Riechers, P. V. Vara Prasad, S. V. Krishna Jagadish. Safeners improve early‐stage chilling‐stress tolerance in sorghum. Journal of Agronomy and Crop Science. 2021; ():1.
Chicago/Turabian StyleAmaranatha R. Vennapusa; Yared Assefa; David Sebela; Impa Somayanda; Ramasamy Perumal; Dean E. Riechers; P. V. Vara Prasad; S. V. Krishna Jagadish. 2021. "Safeners improve early‐stage chilling‐stress tolerance in sorghum." Journal of Agronomy and Crop Science , no. : 1.
Smallholder agriculture is a major source of income and food for developing nations. With more frequent drought and increasing scarcity of arable land, more accurate land-use planning tools are needed to allocate land resources to support regional agricultural activity. To address this need, we created Land Capability Classification (LCC) system maps using data from two digital soil maps, which were compared with measurements from 1305 field sites in the Dosso region of Niger. Based on these, we developed 250 m gridded maps of LCC values across the region. Across the region, land is severely limited for agricultural use because of low available water-holding capacity (AWC) that limits dry season agricultural potential, especially without irrigation, and requires more frequent irrigation where supplemental water is available. If the AWC limitation is removed in the LCC algorithm (i.e., simulating the use of sufficient irrigation or a much higher and more evenly distributed rainfall), the dominant limitations become less severe and more spatially varied. Finally, we used additional soil fertility data from the field samples to illustrate the value of collecting contemporary data for dynamic soil properties that are critical for crop production, including soil organic carbon, phosphorus and nitrogen.
Tara Ippolito; Jeffrey Herrick; Ekwe Dossa; Maman Garba; Mamadou Ouattara; Upendra Singh; Zachary Stewart; P. Prasad; Idrissa Oumarou; Jason Neff. A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning. Land 2021, 10, 458 .
AMA StyleTara Ippolito, Jeffrey Herrick, Ekwe Dossa, Maman Garba, Mamadou Ouattara, Upendra Singh, Zachary Stewart, P. Prasad, Idrissa Oumarou, Jason Neff. A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning. Land. 2021; 10 (5):458.
Chicago/Turabian StyleTara Ippolito; Jeffrey Herrick; Ekwe Dossa; Maman Garba; Mamadou Ouattara; Upendra Singh; Zachary Stewart; P. Prasad; Idrissa Oumarou; Jason Neff. 2021. "A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning." Land 10, no. 5: 458.
A crop simulation model was calibrated to (i) identify optimal planting date and quantify the impacts of nitrogen fertilizer and planting date on barley yield, and (ii) evaluate the responses of barley yield to climate change factors at Adigudom area, northern Ethiopia. Response of barley to seven planting dates at 10-days increments from 20-Jun and nine fertilizer rates at 16 kg/ha increments from 0 kg N/ha under five different soil types were evaluated. There were three irrigation treatment levels: I0 (no irrigation application); I1 (deficit irrigation: 4 irrigations); and I2 (full irrigation). Response of barley to midcentury (2040–2069) climate data from three global climate models under higher emission scenario was evaluated. The model simulated the barley biomass, yield, days to flowering and maturity satisfactorily. The optimal planting window for coarse, medium and fine textured soils were July 1 to July 20, July 1 to July 30 and July 20 to August 10, respectively. The optimal N fertilizer for the respective soils was 64, 32 and 32 kg N/ha, respectively. The difference between the simulated rainfed yield under optimal N fertilizer and on farm yield was estimated to be 1.1 Mg/ha. About 0.6 ± 0.4 and 0.5 ± 0.2 Mg/ha of the yield losses were due to nitrogen deficit and inappropriate planting date, respectively. Average barley grain yield is expected to decrease by 6–11% during the midcentury. This study showed that timely planting and N management along with elevated CO2 could contribute to yield enhancement and minimize the risk associated with future climate change.
A. Araya; P.V.V. Prasad; P.H. Gowda; M. Djanaguiramana; Y. Gebretsadkan. Modeling the effects of crop management on food barley production under a midcentury changing climate in northern Ethiopia. Climate Risk Management 2021, 32, 100308 .
AMA StyleA. Araya, P.V.V. Prasad, P.H. Gowda, M. Djanaguiramana, Y. Gebretsadkan. Modeling the effects of crop management on food barley production under a midcentury changing climate in northern Ethiopia. Climate Risk Management. 2021; 32 ():100308.
Chicago/Turabian StyleA. Araya; P.V.V. Prasad; P.H. Gowda; M. Djanaguiramana; Y. Gebretsadkan. 2021. "Modeling the effects of crop management on food barley production under a midcentury changing climate in northern Ethiopia." Climate Risk Management 32, no. : 100308.
Despite the ability of sorghum [Sorghum bicolor (L.) Moench] to withstand harsh environmental conditions, it is susceptible to water‐deficit stress during grain filling. To identify post‐flowering drought tolerant sorghum genotypes, parents of nested association mapping populations were evaluated under controlled and water‐deficit conditions in greenhouse and field conditions. In both experiments, water‐deficit stress was imposed by withholding water during the grain‐filling period. In field experiments, rootzone soil moisture was measured weekly using a neutron probe to quantify the plant available water under well‐watered and water‐deficit conditions. Investigations were focused on determining the variability in the grain‐filling pattern across different positions within the panicles (intra‐panicle) of 11 different sorghum genotypes. Water‐deficit conditions characterized by low plant available water had a consistently negative association with grain number along different positions in the panicle. Our findings indicate that maintaining grain numbers per panicle under post‐flowering water deficit is more important than increasing individual grain weight. Among the tested genotypes, SC35 and SC1103 were most tolerant to water‐deficit conditions under greenhouse and field conditions, respectively. Currently available biparental populations, developed using these genotypes, provide an opportunity to enhance tolerance to post‐flowering water‐deficit stress in sorghum. This article is protected by copyright. All rights reserved
Regina Enninful Adotey; Andres Patrignani; Blake Bergkamp; Gerard Kluitenberg; P.V. Vara Prasad; S. V. Krishna Jagadish. Water‐deficit stress alters intra‐panicle grain number in sorghum. Crop Science 2021, 1 .
AMA StyleRegina Enninful Adotey, Andres Patrignani, Blake Bergkamp, Gerard Kluitenberg, P.V. Vara Prasad, S. V. Krishna Jagadish. Water‐deficit stress alters intra‐panicle grain number in sorghum. Crop Science. 2021; ():1.
Chicago/Turabian StyleRegina Enninful Adotey; Andres Patrignani; Blake Bergkamp; Gerard Kluitenberg; P.V. Vara Prasad; S. V. Krishna Jagadish. 2021. "Water‐deficit stress alters intra‐panicle grain number in sorghum." Crop Science , no. : 1.
A study was undertaken in Koun Mom district of Ratanakiri province in Cambodia to analyze the perceptions of the current status and constraints to soybean production and identify solutions to improve production and the management practices. Primary data were collected by personal interviews at field level of 130 producers. Most respondents were in the medium age category, Grade 4 education, with an average land holding of 2.96 ha and annual income of KHR 6,195,548 Riels (about 1548 USD). In terms of economic and production constraints, the high cost of fertilizers, severe insect and disease infestation, were identified as most important. Association with independent characteristics and scientific orientation were not significant, but education, land holding, annual income, socioeconomic status, and risk preference were significantly associated with constraints to soybean production. Within the context of sustainable agricultural production practices, it is suggested to improve high-yielding genotypes, ensure timely availability of high-quality seeds, and identify appropriate crop management practices (planting dates, planting density, nutrient and water management practices) and find ways to efficiently and effectively disseminate information to farmers to enhance soybean production in the region. In addition, extension agents and other agencies should provide soybean farmers marketing information, establish viable links between farmers and relevant stakeholders and private sector to improve access to inputs and modern technologies while the local and state governments should establish rural markets with good market infrastructure to enable farmers have high returns from soybean production.
Raby Nget; Edna Aguilar; Pompe Cruz; Consorcia Reaño; Pearl Sanchez; Manuel Reyes; P. Prasad. Overview of Farmers’ Perceptions of Current Status and Constraints to Soybean Production in Ratanakiri Province of Cambodia. Sustainability 2021, 13, 4433 .
AMA StyleRaby Nget, Edna Aguilar, Pompe Cruz, Consorcia Reaño, Pearl Sanchez, Manuel Reyes, P. Prasad. Overview of Farmers’ Perceptions of Current Status and Constraints to Soybean Production in Ratanakiri Province of Cambodia. Sustainability. 2021; 13 (8):4433.
Chicago/Turabian StyleRaby Nget; Edna Aguilar; Pompe Cruz; Consorcia Reaño; Pearl Sanchez; Manuel Reyes; P. Prasad. 2021. "Overview of Farmers’ Perceptions of Current Status and Constraints to Soybean Production in Ratanakiri Province of Cambodia." Sustainability 13, no. 8: 4433.
Heat stress is one of the production constraints for tomato (Solanum lycopersicum L.) due to unfavorable, above optimum temperatures. This research was undertaken to evaluate growth and fruit yield of tomato genotypes under three contrasting growing conditions (i.e., optimal temperature in field-, high temperature in field- and high temperature in greenhouse conditions) to determine their relative heat tolerance. Eleven tomato genotypes, including two local check varieties, were evaluated, and data on growth and yield were measured and analyzed. The interactions between the genotypes and growing conditions for all yield traits were significant. In general, the performance of tomato under optimal temperature field conditions was better than under high temperature field- and greenhouse conditions. Genotypes CLN1621L, CLN2026D, CLN3212C, and KK1 had consistently greater fruit yield per plant in all growing conditions. Although the local genotype, Neang Tamm, had lower yield under optimal conditions, it performed moderately well under high temperature field- and high temperature greenhouse conditions, and yield decrease under high temperature condition was minimal. Genotype CLN1621L had stable fruit setting compared to other genotypes under high temperature conditions. Since fruit setting and yield are important traits for heat tolerance, genotypes CLN1621L and Neang Tamm are potential candidates for breeding programs focused on improved yield and heat stress tolerance.
Sophoanrith Ro; Leangsrun Chea; Sreymey Ngoun; Zachary Stewart; Siranet Roeurn; Penghieng Theam; Sathya Lim; Rathana Sor; Meas Kosal; Malean Roeun; Kim Dy; P. Prasad. Response of Tomato Genotypes under Different High Temperatures in Field and Greenhouse Conditions. Plants 2021, 10, 449 .
AMA StyleSophoanrith Ro, Leangsrun Chea, Sreymey Ngoun, Zachary Stewart, Siranet Roeurn, Penghieng Theam, Sathya Lim, Rathana Sor, Meas Kosal, Malean Roeun, Kim Dy, P. Prasad. Response of Tomato Genotypes under Different High Temperatures in Field and Greenhouse Conditions. Plants. 2021; 10 (3):449.
Chicago/Turabian StyleSophoanrith Ro; Leangsrun Chea; Sreymey Ngoun; Zachary Stewart; Siranet Roeurn; Penghieng Theam; Sathya Lim; Rathana Sor; Meas Kosal; Malean Roeun; Kim Dy; P. Prasad. 2021. "Response of Tomato Genotypes under Different High Temperatures in Field and Greenhouse Conditions." Plants 10, no. 3: 449.
The rapid emergence of COVID-19 could have direct and indirect impacts on food production systems and livelihoods of farmers. From the farming perspective, disruption of critical input availability, supply chains and labor, influence crop management. Disruptions to food systems can affect (a) planting area; and (b) crop yields. To quantify the impacts of COVID-19 on major cereal crop's production and their cascading impact on national economy and related policies. We used the calibrated crop simulation model (DSSAT suite) to project the impact of potential changes in planting area and grain yield of four major cereal crops (i.e., rice, maize, sorghum, and millet) in Senegal and Burkina Faso in terms of yield, total production, crop value and contribution to agricultural gross domestic product (GDP). Appropriate data (i.e., weather, soil, crop, and management practices) for the specific agroecological zones were used as an input in the model. The simulated yields for 2020 were then used to estimate crop production at country scale for the matrix of different scenarios of planting area and yield change (−15, −10, −5, 0, +5, +10%). Depending on the scenario, changes in total production of four cereals combined at country levels varied from 1.47 M tons to 2.47 M tons in Senegal and 4.51 M tons to 7.52 M tons in Burkina Faso. The economic value of all four cereals under different scenarios ranged from $771 Million (M) to $1292 M in Senegal and from $1251 M to $2098 M in Burkina Faso. These estimated total crop values under different scenarios were compared with total agricultural GDP of the country (in 2019 terms which was $3995 M in Senegal and $3957 M in Burkina Faso) to assess the economic impact of the pandemic on major cereal grain production. Based on the scenarios, the impact on total agricultural GDP can change −7% to +6% in Senegal and − 8% to +9% in Burkina Faso. Results obtained from this modeling exercise will be valuable to policymakers and end-to-end value chain practitioners to prepare and develop appropriate policies to cope or manage the impact of COVID-19 on food systems.
P.K. Jha; A. Araya; Z.P. Stewart; A. Faye; H. Traore; B.J. Middendorf; P.V.V. Prasad. Projecting potential impact of COVID-19 on major cereal crops in Senegal and Burkina Faso using crop simulation models. Agricultural Systems 2021, 190, 103107 -103107.
AMA StyleP.K. Jha, A. Araya, Z.P. Stewart, A. Faye, H. Traore, B.J. Middendorf, P.V.V. Prasad. Projecting potential impact of COVID-19 on major cereal crops in Senegal and Burkina Faso using crop simulation models. Agricultural Systems. 2021; 190 ():103107-103107.
Chicago/Turabian StyleP.K. Jha; A. Araya; Z.P. Stewart; A. Faye; H. Traore; B.J. Middendorf; P.V.V. Prasad. 2021. "Projecting potential impact of COVID-19 on major cereal crops in Senegal and Burkina Faso using crop simulation models." Agricultural Systems 190, no. : 103107-103107.
The global COVID-19 pandemic has produced a variety of unanticipated shocks to farming and socio-economic systems around the world. In case of Senegal, the country was already facing number of challenges at the inception of the pandemic, including high rates of poverty, prevalence of food insecurity, combined with other biophysical and socioeconomic challenges faced generally in Sub-Saharan Africa. To understand farmer perceptions of the potential impacts of COVID-19 on agricultural systems and social well-being of smallholder farmers in Senegal. Particular attention was given to potential vulnerabilities and resilience in the targeted farming systems. A survey was developed to better understand smallholder farmer perceptions regarding the anticipated impacts of COVID-19 on their agriculture practices and social well-being. The survey was administered (between June 5 and June 20) with smallholder farmers (n = 872) in 14 regions covering all agroecological zones. Variables of interest included perceptions of potential impact on farming systems, agricultural productivity, communities, economics, markets, labor, gendered division of labor, food security, and community well-being. Across the three farming systems examined (cropping, livestock, and horticulture) significant majorities expressed concerns related to access to inputs, ability to plant (cropping, horticulture), reduction of yields (cropping, horticulture), ability to feed livestock, ability to sell livestock, and the ability to hire labor (horticulture). The majority of respondents also expressed concern that COVID-19 would make it more difficult to get enough food on a regular basis for their household (82.5%); that the markets where they purchase food will either be closed or significantly disrupted (79.5%); that the price of food would increase (73.5%); and the market where they sell their produce/livestock will be either closed or significantly disrupted (73.2%). Anticipated impacts of COVID-19 on agriculture will be felt on both the biophysical aspects such as production and access to inputs and socioeconomic aspects such as access to labor, markets, or rapid shifts in demand. Results support the need to use farming systems approach to gather perceived and actual impacts of COVID-19 and warrants a more in-depth examination of agronomic and biophysical issues as well as the impact on the livelihoods and social well-being of families at community and household levels. Further examination will help identify the characteristics that strengthen smallholder farming systems resilience to adjust to anticipated and unanticipated shocks, such as COVID-19, to decrease the negative impacts and increase the rate of recovery.
B. Jan Middendorf; Aliou Faye; Gerad Middendorf; Zachary P. Stewart; Prakash K. Jha; P.V. Vara Prasad. Smallholder farmer perceptions about the impact of COVID-19 on agriculture and livelihoods in Senegal. Agricultural Systems 2021, 190, 103108 -103108.
AMA StyleB. Jan Middendorf, Aliou Faye, Gerad Middendorf, Zachary P. Stewart, Prakash K. Jha, P.V. Vara Prasad. Smallholder farmer perceptions about the impact of COVID-19 on agriculture and livelihoods in Senegal. Agricultural Systems. 2021; 190 ():103108-103108.
Chicago/Turabian StyleB. Jan Middendorf; Aliou Faye; Gerad Middendorf; Zachary P. Stewart; Prakash K. Jha; P.V. Vara Prasad. 2021. "Smallholder farmer perceptions about the impact of COVID-19 on agriculture and livelihoods in Senegal." Agricultural Systems 190, no. : 103108-103108.
Rapid increases in minimum night temperature than in maximum day temperature is predicted to continue, posing significant challenges to crop productivity. Rice and wheat are two major staples that are sensitive to high night temperature (HNT) stress. This review aims to (i) systematically compare the grain yield responses of rice and wheat exposed to HNT stress across scales, and (ii) understand physiological and biochemical responses that affect grain yield and quality. To achieve this, we combined a synthesis of current literature on HNT effects on rice and wheat with information from a series of independent experiments we conducted across scales, using a common set of genetic materials to avoid confounding our findings with differences in genetic background. In addition, we explored HNT induced alterations in physiological mechanisms including carbon balance, source‐sink metabolite changes, and reactive oxygen species. Impact of HNT on grain developmental dynamics focused on grain‐filling duration, post‐flowering senescence, changes in grain starch and protein composition, starch metabolism enzymes, and chalk formation in rice grains are summarized. Finally, we highlight the need for high‐throughput field‐based phenotyping facilities for improved assessment of large diversity panels and mapping populations to aid breeding for increased resilience to HNT in crops.
Somayanda M. Impa; Bheemanahalli Raju; Nathan T. Hein; Jaspreet Sandhu; P.V. Vara Prasad; Harkamal Walia; S.V. Krishna Jagadish. High night temperature effects on wheat and rice: Current status and way forward. Plant, Cell & Environment 2021, 44, 2049 -2065.
AMA StyleSomayanda M. Impa, Bheemanahalli Raju, Nathan T. Hein, Jaspreet Sandhu, P.V. Vara Prasad, Harkamal Walia, S.V. Krishna Jagadish. High night temperature effects on wheat and rice: Current status and way forward. Plant, Cell & Environment. 2021; 44 (7):2049-2065.
Chicago/Turabian StyleSomayanda M. Impa; Bheemanahalli Raju; Nathan T. Hein; Jaspreet Sandhu; P.V. Vara Prasad; Harkamal Walia; S.V. Krishna Jagadish. 2021. "High night temperature effects on wheat and rice: Current status and way forward." Plant, Cell & Environment 44, no. 7: 2049-2065.
Small-scale irrigation in Ethiopia is a key strategy to improve and sustain the food production system. Besides the use of surface water for irrigation, it is essential to unlock the groundwater potential. It is equally important to use soil management and water-saving systems to overcome the declining soil fertility and the temporal water scarcity in the region. In this study, the solar MajiPump was introduced to enable dry season crop production in Ethiopia using shallow groundwater sources. The capacity of the MajiPumps (MP400 and MP200) was tested for the discharge head and discharge using three types of solar panels (150 W and 200 W rigid, and 200 W flexible). Besides, drip irrigation and conservation agriculture (CA) farming systems were evaluated in terms of water productivity and crop yield in comparison to the farmers’ practice (overhead irrigation and tilled farming system). Results indicated that the maximum discharge head capacity of the MajiPumps was 18 m, 14 m, 10 m when using MP400 with 200 W rigid, MP400 with 200 W flexible, and MP200 with 150 W rigid solar panels, respectively. The corresponding MajiPump flow rates ranged from 7.8 L/min. to 24.6 L/min., 3 L/min. to 25 L/min., and 3.6 L/min. to 22.2 L/min., respectively. Compared to farmer’s practice, water productivity was significantly improved under the CA farming and the drip irrigation systems for both irrigated vegetables (garlic, onion, cabbage, potato) and rainfed maize production. The water productivity of garlic, cabbage, potato, and maize was increased by 256%, 43%, 53%, and 9%, respectively, under CA as compared to conventional tillage (CT) even under overhead irrigation. Thus, farmers can obtain a significant water-saving benefit from CA regardless of water application systems. However, water and crop productivity could be further improved in the combined use of MajiPump with CA and drip irrigation (i.e., 38% and 33% water productivity and 43% and 36% crop productivity improvements were observed for potato and onion, respectively). Similarly, compared to CT, the use of CA significantly increased garlic, cabbage, potato, and maize yield by 170%, 42%, 43%, and 15%, respectively under the MajiPump water-lifting system. Overall, the solar-powered drip irrigation and CA farming system were found to be efficient to expand small-scale irrigation and improve productivity and livelihoods of smallholder farmers in Ethiopia.
Tewodros T. Assefa; Temesgen F. Adametie; Abdu Y. Yimam; Sisay A. Belay; Yonas M. Degu; Solomon T. Hailemeskel; Seifu A. Tilahun; Manuel R. Reyes; P. V. Vara Prasad. Evaluating Irrigation and Farming Systems with Solar MajiPump in Ethiopia. Agronomy 2020, 11, 17 .
AMA StyleTewodros T. Assefa, Temesgen F. Adametie, Abdu Y. Yimam, Sisay A. Belay, Yonas M. Degu, Solomon T. Hailemeskel, Seifu A. Tilahun, Manuel R. Reyes, P. V. Vara Prasad. Evaluating Irrigation and Farming Systems with Solar MajiPump in Ethiopia. Agronomy. 2020; 11 (1):17.
Chicago/Turabian StyleTewodros T. Assefa; Temesgen F. Adametie; Abdu Y. Yimam; Sisay A. Belay; Yonas M. Degu; Solomon T. Hailemeskel; Seifu A. Tilahun; Manuel R. Reyes; P. V. Vara Prasad. 2020. "Evaluating Irrigation and Farming Systems with Solar MajiPump in Ethiopia." Agronomy 11, no. 1: 17.
A calibrated and validated Decision Support System for Agro-technology Transfer – Cropping System Model (DSSAT-CSM), CERES-Maize, was used to (1) evaluate maize (Zea mays L.) yield and water productivities (WP) under various irrigation frequencies (IRF) triggered by different plant available soil water (PASW) on three soil types, and (2) assess the optimum IRF and PASW triggers for maximum yield and water productivity on three different soils (with a depth of 1.2 m) in Finney County, Western Kansas. The treatments were four IRF (2, 4, 7, and 9 days), four PASW (5%, 25%, 50% and 75%) irrigation trigger and three soil types with a total of 48 combinations. The model was set to automatically apply 25 mm irrigation at selected day intervals when certain irrigation triggering PASW conditions were met. This study showed that maintaining higher PASW up to 75% or above might result in too many irrigations per season, which could be costly. IRF-9 showed substantially lowest yield under most PASW tested in this study. The highest yield was simulated at irrigation amount of 400–450 mm and ET of 650–800 mm depending on soil types. The highest irrigation water productivity (IWP, 30–33 kg/ha/mm) was simulated when triggered by 25% and 50% PASW for Ulysses silt loams. Overall, IRF-4 under 50% PASW threshold provided the maximum maize yield and WP for all soil types.
A. Araya; P.V.V. Prasad; P.H. Gowda; V. Sharda; C.W. Rice; I.A. Ciampitti. Evaluating optimal irrigation strategies for maize in Western Kansas. Agricultural Water Management 2020, 246, 106677 .
AMA StyleA. Araya, P.V.V. Prasad, P.H. Gowda, V. Sharda, C.W. Rice, I.A. Ciampitti. Evaluating optimal irrigation strategies for maize in Western Kansas. Agricultural Water Management. 2020; 246 ():106677.
Chicago/Turabian StyleA. Araya; P.V.V. Prasad; P.H. Gowda; V. Sharda; C.W. Rice; I.A. Ciampitti. 2020. "Evaluating optimal irrigation strategies for maize in Western Kansas." Agricultural Water Management 246, no. : 106677.
The reproductive phase of coconut is extremely sensitive to high temperature, manifesting as button (female flower) shedding and poor nut set. The progamic phase, which elapses from pollination to fertilization, is one of the most critical phases during the sexual reproduction processes in annuals and fruit trees and is extremely vulnerable to high temperature. Hence, we investigated the progamic phase of the tall coconut cultivar West Coast Tall (WCT) and the effect of high temperature on the phase under both in vivo and in vitro conditions. Coconut has a long pistil and its length was found to be 18.2 ± 4.9 mm in WCT. Pollen germination on stigma occurred one day after pollination and the pollen tube traversed through the pistil and reached micropyle of ovule four days after pollination at 29 °C. However, high temperature (Tmax > 33 °C), both under in vivo and in vitro conditions, significantly reduced pollen tube growth through the pistil, suggesting its inability to reach the ovule on time to effect fertilization. High temperature also advanced nectar secretion and stigma receptivity and the receptive stigma was dry without nectar, rendering it unappealing to insect pollinators. Thus, both poor pollination and the inability of pollen tube to reach the ovule on time to effect fertilization could be the cause of poor nut set in the coconut variety WCT under high temperature. However, it was encouraging to note that the pollen tube growth was less vulnerable to elevated temperature under high humidity, suggesting that climate change effect on coconut in coastal regions with high humidity might be less severe.
K. B. Hebbar; P. Neethu; P. Abhin Sukumar; M. Sujithra; Arya Santhosh; S. V. Ramesh; V. Niral; G. S. Hareesh; Paingamadathil Ommer Nameer; P. V. V. Prasad. Understanding Physiology and Impacts of High Temperature Stress on the Progamic Phase of Coconut (Cocos nucifera L.). Plants 2020, 9, 1651 .
AMA StyleK. B. Hebbar, P. Neethu, P. Abhin Sukumar, M. Sujithra, Arya Santhosh, S. V. Ramesh, V. Niral, G. S. Hareesh, Paingamadathil Ommer Nameer, P. V. V. Prasad. Understanding Physiology and Impacts of High Temperature Stress on the Progamic Phase of Coconut (Cocos nucifera L.). Plants. 2020; 9 (12):1651.
Chicago/Turabian StyleK. B. Hebbar; P. Neethu; P. Abhin Sukumar; M. Sujithra; Arya Santhosh; S. V. Ramesh; V. Niral; G. S. Hareesh; Paingamadathil Ommer Nameer; P. V. V. Prasad. 2020. "Understanding Physiology and Impacts of High Temperature Stress on the Progamic Phase of Coconut (Cocos nucifera L.)." Plants 9, no. 12: 1651.