Effects of Engineered Nanoparticles at Various Growth Stages of Crop Plants

Over the past decade, the production and applications of metal-based and metal-oxide nanoparticles (MBNPs and MONPs, respectively) have increased significantly due to their enhanced physicochemical properties and biological activities when compared with their bulk parent materials. Once MBNPs and MONPs enter agricultural soil via direct or indirect pathways, they can interact with crop plants and thus pose a threat to both animal and human health through food chain pathways. Although many review articles on engineered nanoparticles have been published, few have focused on the interactions of MBNPs and MONPs with crop plants and their current applications. Therefore, we reviewed the sources and behaviors of MBNPs and MONPs in agricultural soil, physiological and biochemical effects of MBNPs and MONPs on plants, uptake, translocation of MBNPs and MONPs in crop plants, factors affecting the interaction between MBNPs and MONPs and plants, and the applications of MBNPs and MONPs. Lastly, we propose where the future research priorities should be focused to provide a better understanding of MBNPs and MONPs. This review will help to promote scientific research regarding MBNPs and MONPs and to understand the risks and benefits of their association with plants and will contribute to the advancement of nanotechnology.

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FOLIAR NUTRIENT UPTAKE IN CRANBERRY

HortScience ◽

10.21273/hortsci.25.9.1148a ◽

1990 ◽

Vol 25 (9) ◽

pp. 1148a-1148

Author(s):

J. R. Davenport

Keyword(s):

Nutrient Uptake ◽

Plant Uptake ◽

Leaf Surface ◽

Crop Plants ◽

Vaccinium Macrocarpon ◽

Growth Stages ◽

Lower Leaf Surface ◽

Foliar Nutrient ◽

The One ◽

Different Growth Stages

Foliar feeding of crop plants is an increasingly popular practice. The use of foliar nutrients relies on the ability of the plant to sorb nutrients through the leaves. Cranberries (Vaccinium macrocarpon Ait.) are known to have a waxy cuticle on the leaf surface which may impede nutrient uptake, leaving only the lower leaf surface for effective uptake. This study was undertaken to determine the extent of foliar nutrient uptake by cranberries using rubidium as a tracer. Rubidium was chosen for its similarity to potassium in plant uptake. In replicated plots, cranberries were sprayed with rubidium at the rate recommended for foliar potassium at three different growth stages and three different times of day. Washed and unwashed leaves were analyzed one day, one week, and one month after rubidium applications. Stem, soil, and root material was analyzed for rubidium at the one week and one month sample times. Results will be discussed with reference to uptake and movement of foliar applied nutrients in cranberries.

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Systemic Crop Signaling for Automatic Recognition of Transplanted Lettuce and Tomato under Different Levels of Sunlight for Early Season Weed Control

Challenges ◽

10.3390/challe11020023 ◽

2020 ◽

Vol 11 (2) ◽

pp. 23 ◽

Cited By ~ 3

Author(s):

Wen-Hao Su

Keyword(s):

Weed Control ◽

Vision System ◽

Early Growth ◽

Crop Plants ◽

Growth Stages ◽

Vegetable Crops ◽

Plant Signaling ◽

Labor Costs ◽

Fluorescent Properties ◽

Different Levels

Conventional cultivation works to control weeds between the rows, but it ignores the weeds in crop rows which are most competitive with crops. Many vegetable crops still require manual removal of intra-row weeds not otherwise controlled by herbicides or conventional cultivation. The increasing labor costs of weed control and the continued emergences of herbicide-resistant weeds are threatening grower ability to manage weeds and maintain profitability. Intra-row weeders are commercially available but work best in low weed populations. One strategy for rapid weed crop differentiation is to utilize a machine-detectable compound to mark a crop. This paper proposes a new systemic plant signaling technology that can create machine-readable crops to facilitate the automated removal of intra-row weeds in early growth stages. Rhodamine B (Rh–B) is an efficient systemic compound to label crop plants due to its membrane permeability and unique fluorescent properties. The project involves applying solutions of Rh–B at 60 ppm to the roots of lettuce and tomato plants prior to transplantation to evaluate Rh–B persistence in plants under different levels of sunlight. Lettuce and tomato seedlings with the systemic Rh–B should be reliably recognized during their early growth stages. An intelligent robot is expected to be developed to identify the locations of plants based on the systemic signal inside. Reduced light treatments should help to alleviate the photodegradation of Rh–B in plants. After being exposed to full sunlight for 27 days, the systemic Rh–B would be detectable in tomato branches and lettuce ribs, and these plants are tolerant to root treatments with this fluorescent compound. This paper describes the project background and plan as well as the anticipated contributions of the research to allow the machine vision system to reliably identify the crop plants, and thus showing technical feasibility for outdoor weed control.

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Effects of Cycocel on Crop Plants in Sierra Leone II. Cassava (Manihot Esculenta)

Experimental Agriculture ◽

10.1017/s0014479700007328 ◽

1976 ◽

Vol 12 (4) ◽

pp. 321-328 ◽

Cited By ~ 1

Author(s):

D. K. Das Gupta

Keyword(s):

Sierra Leone ◽

Manihot Esculenta ◽

Dry Matter ◽

Tuber Yield ◽

Foliar Spray ◽

Matter Content ◽

Crop Plants ◽

Growth Stages ◽

Dry Matter Content ◽

Final Harvest

SUMMARYThe response of cassava to CCC was investigated by applying concentrations of 0, 500, 1000, 1500 and 2000 ppm twice or four times as a foliar spray, which resulted in a significantly greater tuber yield than the control with most marked effects at the final harvest. CCC at 1500 ppm, applied four times at various growth stages, gave the best increase in tuber yield. Application of CCC tended to cause greater RGR and dry matter content (percentage) of tubers.

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Metabolic signalling and the partitioning of resources in plant storage organs

The Journal of Agricultural Science ◽

10.1017/s0021859699006978 ◽

1999 ◽

Vol 133 (3) ◽

pp. 243-249 ◽

Cited By ~ 3

Author(s):

NIGEL G. HALFORD

Keyword(s):

Dry Weight ◽

Wild Relatives ◽

Crop Plants ◽

Wild Plants ◽

Young Plant ◽

Carbon And Nitrogen ◽

Cultivated Potato ◽

Metabolic Signalling ◽

Storage Organs ◽

Plant Storage

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

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Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083874 ◽

1978 ◽

Vol 36 (2) ◽

pp. 600-601

Author(s):

Wiktor Djaczenko ◽

Carmen Calenda Cimmino

Keyword(s):

Nervous System ◽

Glial Cells ◽

Early Period ◽

Postembryonic Development ◽

Ruthenium Red ◽

The Body ◽

Tubifex Tubifex ◽

Growth Stages ◽

Cell Processes ◽

Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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Characterisation of multilayer materials using a position-sensitive atom probe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176253 ◽

1990 ◽

Vol 48 (4) ◽

pp. 624-625

Author(s):

RAD Mackenzie ◽

G D W Smith ◽

A. Cerezo ◽

J A Liddle ◽

CRM Grovenor ◽

...

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Spatial Information ◽

Chemical Vapour ◽

Atom Probe ◽

Organic Chemical ◽

Growth Stages ◽

Multiple Quantum ◽

Quartz Wool ◽

Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

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