scholarly journals Lower Nitrogen Availability Enhances Resistance to Whiteflies in Tomato

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1096
Author(s):  
Sreedevi Ramachandran ◽  
Sylvie Renault ◽  
John Markham ◽  
Jaime Verdugo ◽  
Marta Albornoz ◽  
...  
Keyword(s):  
Large Scale ◽  
Nitrogen Availability ◽  
Crop Yields ◽  
Fruit Production ◽  
N Availability ◽  
Significant Drop ◽  
Tomato Production ◽  
Trade Off ◽  
Pest Infestation ◽  
Root:Shoot Ratios

Soil nitrogen (N) supplementation via fertilizers may increase crop yields substantially. However, by increasing tissue N content, added N can make plants more attractive to herbivores, effectively reducing their resistance to herbivores (ability to avoid herbivore damage). In turn, greater pest infestation may cause more severe reductions in fruit production than a moderate N scarcity. In this study, we tested whether lower N supplementation results in greater resistance to whiteflies and lower fruit production in four tomato varieties. We assessed the effects of N availability on tolerance to herbivores (degree to which fitness is affected by damage) and tested for the long-hypothesized trade-off between resistance and tolerance. Plants grown at half of an agronomically recommended amount of N had greater resistance without a significant drop in fruit production. Tomato varieties differed in resistance and tolerance to whiteflies, and showed a clear trade-off between these modes of defense. Root:shoot ratios were greater at lower N, but had no clear relation to tolerance. We estimated that the economic benefit of decreasing N addition almost fully compensates for losses due to lower tomato production. Additionally, lower fertilization rates would contribute to reduce environmental costs of large-scale use of agrochemicals.

Allocation and morphological responses to resource manipulations are unlikely to mitigate shade intolerance in Houstonia montana, a rare southern Appalachian herb

2007 ◽  
Vol 85 (10) ◽  
pp. 976-985 ◽  
Author(s):  
Amy C. Euliss ◽  
Melany C. Fisk ◽  
S. Coleman McCleneghan ◽  
Howard S. Neufeld
Keyword(s):  
Nitrogen Availability ◽  
Carbon Allocation ◽  
Plant Biomass ◽  
Specific Root Length ◽  
Mycorrhizal Colonization ◽  
N Availability ◽  
Low Light ◽  
Southern Appalachian ◽  
Aboveground Growth ◽  
Root:Shoot Ratios

High light requirements limit the distribution of several rare plant species endemic to the southern Appalachian region. We studied the influence of light and nitrogen availability on carbon allocation and morphology in one of these species, Houstonia montana Small. Insights into growth and nutrition of H. montana are needed for predicting how it will respond to ongoing changes in its environment associated with atmospheric nitrogen deposition and resulting from succession and (or) management of grassy-bald habitats in which it occurs. We hypothesized that low light constrains belowground allocation, and that elevated N availability reduces limitations to aboveground growth at low light. We tested growth and mycorrhizal colonization of H. montana in response to interactions of light and N availability in a greenhouse experiment. Shade reduced plant biomass, root:shoot ratios, and mycorrhizal colonization, and increased specific leaf area (area/mass). Elevated N reduced root:shoot ratios and mycorrhizal colonization. Under low light, N addition increased specific root length (length/mass) and foliar chlorophyll. We found support for the hypotheses that low light and high N reduce belowground allocation in H. montana. However, we did not find that high N significantly alleviates limitation to plant growth in the shade, despite changes in allocation, morphology, and chemistry that were consistent with more efficient use of C for aboveground growth. Thus, variation in the soil N availability is unlikely to have a marked effect on the ability of H. montana to tolerate shade in its native habitat.

scholarly journals Nitrogen Availability and Fruiting Influence Nitrogen Cycling in Strawberry

1997 ◽  
Vol 122 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Douglas D. Archbold ◽  
Charles T. MacKown
Keyword(s):  
Nitrogen Availability ◽  
Fruit Production ◽  
N Cycling ◽  
N Availability ◽  
Storage Site ◽  
N Accumulation ◽  
N Content ◽  
Total N ◽  
Vegetative Tissues ◽  
N Pool

As the primary nutrient applied to and used by strawberry, N allocation and cycling within the plant may play an important role in determining plant vigor and productivity. Our objectives were to determine 1) how N availability and fruit production affect N and fertilizer N (FN) partitioning among and within the vegetative tissues of `Tribute' strawberry (Fragaria ×ananassa Duch.) and 2) if the root N pool is temporary storage N. Plants were fed 15N-depleted NH4NO3 (0.001 atom percent 15N) for the initial 8 weeks, then were grown for 12 weeks with or without NH4NO3 with a natural 15N abundance (0.366 atom percent 15N), and were maintained vegetative or allowed to fruit. The vegetative tissues were sampled at 6 and 12 weeks. Neither N availability or fruiting had consistent effects on dry mass (DM) across all tissues at 6 or 12 weeks. At 6 weeks, the total N content of all tissues except the roots were higher with continuous N than with no N. Nitrogen availability was the dominant treatment effect on all plants at 12 weeks; continuous N increased leaflet, petiole, and total vegetative DM and total N of all tissues. Insoluble reduced N (IRN) was the major N pool within all tissues at 6 and 12 weeks regardless of treatment. Fruiting inhibited root growth and N accumulation at 6 weeks but had little effect at 12 weeks. The roots were a strong dry matter and N sink from 6 to 12 weeks. The FN pools, from the 15N-depleted FN supplied during the initial 8 weeks, exhibited changes similar to those of total N in plants not receiving N, in contrast to plants receiving continuous N where total leaflet and petiole N content increased while FN content declined. Total FN per plant declined nearly 26% over 12 weeks; the decline was greater in plants receiving N continuously than in those not receiving N, but the magnitude of the decline was not affected by fruiting. Increasing atom percent 15N values, primarily in plants receiving continuous N after the initial 8 weeks of receiving 15N-depleted FN, indicated that N cycling occurred through all tissues and N pools, proportionally more in the soluble reduced N pool but quantitatively more in the IRN pool. The root N pool was not a “temporary” N storage site available for re-allocation to other tissues, although N cycling through it was evident. Rather, leaflet N was primarily remobilized to other tissues.

scholarly journals Statistical and machine learning models for optimizing energy in parallel applications

2019 ◽  
Vol 33 (6) ◽  
pp. 1079-1097 ◽  
Author(s):  
Mark Endrei ◽  
Chao Jin ◽  
Minh Ngoc Dinh ◽  
David Abramson ◽  
Heidi Poxon ◽  
...  
Keyword(s):  
Machine Learning ◽  
Energy Efficiency ◽  
High Performance ◽  
Large Scale ◽  
Energy Use ◽  
Parallel Applications ◽  
Learning Models ◽  
Trade Off ◽  
Time Required ◽  
Machine Learning Models

Rising power costs and constraints are driving a growing focus on the energy efficiency of high performance computing systems. The unique characteristics of a particular system and workload and their effect on performance and energy efficiency are typically difficult for application users to assess and to control. Settings for optimum performance and energy efficiency can also diverge, so we need to identify trade-off options that guide a suitable balance between energy use and performance. We present statistical and machine learning models that only require a small number of runs to make accurate Pareto-optimal trade-off predictions using parameters that users can control. We study model training and validation using several parallel kernels and more complex workloads, including Algebraic Multigrid (AMG), Large-scale Atomic Molecular Massively Parallel Simulator, and Livermore Unstructured Lagrangian Explicit Shock Hydrodynamics. We demonstrate that we can train the models using as few as 12 runs, with prediction error of less than 10%. Our AMG results identify trade-off options that provide up to 45% improvement in energy efficiency for around 10% performance loss. We reduce the sample measurement time required for AMG by 90%, from 13 h to 74 min.

scholarly journals High-Throughput Phenotyping Methods for Breeding Drought-Tolerant Crops

2021 ◽  
Vol 22 (15) ◽  
pp. 8266
Author(s):  
Minsu Kim ◽  
Chaewon Lee ◽  
Subin Hong ◽  
Song Lim Kim ◽  
Jeong-Ho Baek ◽  
...  
Keyword(s):  
Drought Stress ◽  
High Throughput ◽  
Large Scale ◽  
Crop Yields ◽  
Plant Traits ◽  
Rapid Development ◽  
Plant Responses ◽  
Phenotypic Data ◽  
Agricultural Technologies ◽  
High Throughput Phenotyping

Drought is a main factor limiting crop yields. Modern agricultural technologies such as irrigation systems, ground mulching, and rainwater storage can prevent drought, but these are only temporary solutions. Understanding the physiological, biochemical, and molecular reactions of plants to drought stress is therefore urgent. The recent rapid development of genomics tools has led to an increasing interest in phenomics, i.e., the study of phenotypic plant traits. Among phenomic strategies, high-throughput phenotyping (HTP) is attracting increasing attention as a way to address the bottlenecks of genomic and phenomic studies. HTP provides researchers a non-destructive and non-invasive method yet accurate in analyzing large-scale phenotypic data. This review describes plant responses to drought stress and introduces HTP methods that can detect changes in plant phenotypes in response to drought.

scholarly journals Inconclusive evidence of sexual reproduction of invasive Halophila stipulacea: a new field guide to encourage investigation of flower and fruit production throughout its invasive range

2020 ◽  
Vol 63 (6) ◽  
pp. 537-540
Author(s):  
Fee O.H. Smulders ◽  
Kelcie L. Chiquillo ◽  
Demian A. Willette ◽  
Paul H. Barber ◽  
Marjolijn J.A. Christianen
Keyword(s):  
Sexual Reproduction ◽  
Clonal Growth ◽  
Large Scale ◽  
Fruit Production ◽  
Morphological Evidence ◽  
Invasive Range ◽  
Reproductive Structures ◽  
Halophila Stipulacea ◽  
The Caribbean ◽  
Low Rate

AbstractThe dioecious seagrass species Halophila stipulacea reproduces mainly through fast clonal growth, underlying its invasive behavior. Here, we provide morphological evidence to show that the first findings of fruits in the Caribbean were misidentified. Consequently, H. stipulacea reproduction is likely still only asexual in the Caribbean. Therefore, we introduce an identification key of H. stipulacea reproductive structures to encourage careful identification and quantification throughout its invasive range. Until large-scale seed production in invaded habitats is reported, the apparent low rate of sexual reproduction needs to be considered in current studies investigating the invasion capacity of this species.

scholarly journals Effects of Cover Crops, Compost, and Vermicompost on Strawberry Yields and Nitrogen Availability in North Carolina

2016 ◽  
Vol 26 (5) ◽  
pp. 604-613 ◽  
Author(s):  
John E. Beck ◽  
Michelle S. Schroeder-Moreno ◽  
Gina E. Fernandez ◽  
Julie M. Grossman ◽  
Nancy G. Creamer
Keyword(s):  
North Carolina ◽  
Pearl Millet ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Yields ◽  
Pennisetum Glaucum ◽  
Organic Production ◽  
Organic N ◽  
N Availability ◽  
Soil N

Summer cover crop rotations, compost, and vermicompost additions can be important strategies for transition to organic production that can provide various benefits to crop yields, nitrogen (N) availability, and overall soil health, yet are underused in strawberry (Fragaria ×ananassa) production in North Carolina. This study was aimed at evaluating six summer cover crop treatments including pearl millet (Pennisetum glaucum), soybean (Glycine max), cowpea (Vigna unguiculata), pearl millet/soybean combination, pearl millet/cowpea combination, and a no cover crop control, with and without vermicompost additions for their effects on strawberry growth, yields, nutrient uptake, weeds, and soil inorganic nitrate-nitrogen and ammonium-nitrogen in a 2-year field experiment. Compost was additionally applied before seeding cover crops and preplant N fertilizer was reduced by 67% to account for organic N additions. Although all cover crops (with compost) increased soil N levels during strawberry growth compared with the no cover crop treatment, cover crops did not impact strawberry yields in the first year of the study. In the 2nd year, pearl millet cover crop treatments reduced total and marketable strawberry yields, and soybean treatments reduced marketable strawberry yields when compared with the no cover crop treatment, whereas vermicompost additions increased strawberry biomass and yields. Results from this study suggest that vermicompost additions can be important sustainable soil management strategies for transitional and certified organic strawberry production. Summer cover crops integrated with composts can provide considerable soil N, reducing fertilizer needs, but have variable responses on strawberry depending on the specific cover crop species or combination. Moreover, these practices are suitable for both organic and conventional strawberry growers and will benefit from longer-term studies that assess these practices individually and in combination and other benefits in addition to yields.

Impact of tillage and landscape position on nitrogen availability and yield of spring wheat in the Brown soil zone in southwestern Saskatchewan

1998 ◽  
Vol 78 (3) ◽  
pp. 563-572 ◽  
Author(s):  
V. Jowkin ◽  
J. J. Schoenau
Keyword(s):  
Spring Wheat ◽  
Nitrogen Availability ◽  
N Uptake ◽  
Wheat Crop ◽  
N Availability ◽  
Inorganic N ◽  
Brown Soil ◽  
Soil Zone ◽  
No Till ◽  
Crop N Uptake

Nitrogen availability to a spring wheat crop was examined in the cropping season in a side-by-side comparison of no-till (first year) and tillage fallow in an undulating farm field in the Brown soil zone in southwestern Saskatchewan. Thirty different sampling points along a grid in each tillage landscape were randomly selected, representing 10 each of shoulder, footslope and level landscape positions. Nitrogen availability was studied i) by profile inorganic N content ii) by crop N uptake and yield of spring wheat (Triticum aestivum L.) and iii) by 15N tracer technique and in situ burial of anion exchange resin membranes (AEM).Pre-seeding available moisture content of the surface soil samples was significantly higher under no-till compared with tillage fallow. However, no significant differences in pre-seeding profile total inorganic N, crop N uptake and yield were observed between the treatments. At the landform scale, shoulder positions of the respective tillage systems had lower profile inorganic N, crop N uptake and yield compared with other slope positions. Soil N supply power, as determined by 15N tracer and AEM techniques, was not significantly different between the tillage treatments, indicating that N availability is not likely to be greatly affected in initial years by switching to no-till fallow in these soils under normal moisture conditions. Key words: Summerfallow, landscape, nitrogen, wheat

Responses of a long greenhouse tomato crop to summer CO2 enrichment

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 1395-1400 ◽  
Author(s):  
X. Hao ◽  
Q. Wang ◽  
S. Khosla
Keyword(s):  
Tomato Fruit ◽  
Co2 Enrichment ◽  
High Temperature Stress ◽  
Fruit Production ◽  
High Light Intensity ◽  
Vegetable Production ◽  
Tomato Crop ◽  
Tomato Production ◽  
Production Area ◽  
Marketable Fruit

While CO2 enrichment generally benefits tomato fruit production in winter its effects on summer tomato production (under high air temperature and strong ventilation) are still not clear, especially when the crop has been subjected to long-term CO2 enrichment in winter. Therefore, a study was initiated in 2005 to determine the feasibility of summer CO2 enrichment in southwestern Ontario, a major greenhouse vegetable production area in North America with very hot summers. The long tomato crop (cv. Rapsodie) was planted into rockwool slabs in six greenhouse compartments in January. From January to the middle of June, the tomato plants in all six greenhouse compartments were subjected to the same standard CO2 enrichment practice. From the end of June to August, three CO2 treatments (two compartments for each treatment) were applied: Control (ambient/no enrichment), Enrich1 (800 µL L-1 when ventilation was less than 10% and 400 µL L-1 when less than 50%) and Enrich2 (1200 µL L-1 when ventilation was less than 10% and 500 µL L-1 when less than 50%). In all treatments, CO2 enrichment ceased when ventilation requirement was more than 50%. Leaf photosynthesis, as indicated by the CO2 response curve, partially acclimated to the CO2 enrichment. Marketable fruit yield was reduced by the summer CO2 enrichment. Leaf deformation [short, thick, curled and somewhat crisp, dark grey-green leaves, so-called short leaf syndrome (SLS)] was observed in the greenhouse compartments with summer CO2 enrichment. SLS developed under high light intensity and high CO2 concentration might have limited response of the tomato crop to summer CO2 enrichment. Further investigation on the cause and mechanism of SLS is needed to improve the response of greenhouse tomatoes to summer CO2 enrichment. Key words: Photosynthesis, Lycopersicon esculentum, high temperature stress, acclimation

scholarly journals Water and fertilizers use efficiency in two hydroponic systems for tomato production

2020 ◽  
Vol 38 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Rodolfo De la Rosa-Rodríguez ◽  
Alfredo Lara-Herrera ◽  
Libia Iris Trejo-Téllez ◽  
Luz Evelia Padilla-Bernal ◽  
Luis Octavio Solis-Sánchez ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Open System ◽  
Closed System ◽  
Good Alternative ◽  
Fruit Production ◽  
Tomato Production ◽  
Hydroponic System ◽  
Production Water ◽  
Use Efficiency ◽  
Hydroponic Systems

ABSTRACT The amount of water and fertilizers used in the production of vegetables, specifically tomatoes, is high. This study was carried out to determine water and fertilizers use efficiency in closed and open hydroponic systems for tomato production under greenhouse conditions. Two treatments with eight replications were assessed; each replication consisted of 67 pots with two plants each. One treatment was a closed hydroponic system (with nutrient solution recirculation), and the other was an open hydroponic system (with non-recirculating nutrient solution). We quantified the amounts of water and fertilizers applied, as well as the losses (drained nutrient solution), in the two treatments during the entire cycle of tomato. In the nutrient solution (NS) we also measured electric conductivity (EC), pH, volume applied, and volume drained, and total weight of fruits (25 pickings). There were no significant differences between the two treatments on fruit production. Water use efficiency was 59.53 kg/fruit/m3 for the closed system and 46.03 kg/fruit/m3 in the open system. In comparison to the open system, the closed system produced 13.50 kg more fruit per cubic meter of water, while 10.31 grams less fertilizers per kilogram of fruit produced were only applied. Water and fertilizers use efficiency were higher in the closed system, by 22.68% and 22.69%, respectively. More efficiency was obtained in the closed system, regarding the open system. We concluded that the closed system is a good alternative to produce tomato and preserve the resources involved in the process (like water and fertilizers), thus reducing pollution.

scholarly journals Potential utilization of spent Agaricus bisporus mushroom substrate for seedling production and organic fertilizer in tomato cultivation

2019 ◽  
Vol 43 ◽  
Author(s):  
Carolina Figueiredo Collela ◽  
Lívia Martinez Abreu Soares Costa ◽  
Tatiana Silveira Junqueira de Moraes ◽  
Diego Cunha Zied ◽  
Danny Lee Rinker ◽  
...  
Keyword(s):  
Agaricus Bisporus ◽  
Organic Fertilizer ◽  
Tomato Fruit ◽  
Nutrient Content ◽  
Fruit Production ◽  
Production Cycle ◽  
Seedling Production ◽  
Tomato Production ◽  
Growth And Nutrition ◽  
Average Production

ABSTRACT The production of Agaricus bisporus results in significant residual material after cultivation. Due to its physical properties and nutrient content Spent Mushroom Substrate (SMS) has great potential for use in agriculture. Our study evaluated the feasibility of using SMS as an alternative substrate for the production of Paronset® hybrid tomato seedlings and as an organic fertilizer in its production. To conduct the fruit production experiment, the plots consisted of three types of fertilizers (SMS of A. bisporus, NPK and bovine manure) with four replications. The seedlings produced in the SMS presented higher rates of germination time and speeds, and stood out from the other substrates in the evaluation of seedling quality. In the tomato fruit production phase, the average production of the plants originating from the SMS was 20% higher than the seedlings from the commercial substrate. The plants cultivated with the SMS presented higher production than the plants cultivated with bovine manure incorporated the soil. According to our results, The SMS was as good as the commercial substrates tested. Therefore, the SMS can be recommended for the growth and nutrition of seedling production and denotes potential viability for use in the tomato production cycle in its different phases.

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