Weed management using low energy lasers, alone and in combination with low dose photosynthetic electron transport inhibitors
Lead Research Organisation:
Harper Adams University
Department Name: Agriculture and Environment
Abstract
Weeds are estimated to cause average yield losses of approximately 13% globally. However, in certain crops and in certain situations losses can be significantly higher (weeds have been reported to cause 66% loss in wheat yield and 99% loss in onion yield in the UK). Weeds also cause significant management difficulties requiring extra cultivations and also hinder harvests and contaminate harvested product. Management of weeds is vital if cropping systems are going to provide food security. However, weed management can be time- and energy- expensive and often relies heavily on chemical controls
that can lead to development of herbicide resistance and unwanted environmental effects. One solution to this would be to design and implement weed management systems utilising in-field detection, weed mapping and targeted weed management.
This research programme will develop a laser-based target weed management system. Use of low energy lasers alone and in the presence of targeted low doses of photosynthetic electron transport inhibitors will be developed for control of broadleaved and grass weeds. Lasers will be targeted at the growing points of weeds in order to disrupt these and inhibit
seedling growth leading to reduced weed competition and subsequent seedling death. The key parameters for laser treatment (required laser power, power density with diffusers, wavelength, laser duration and heat of treatment) will be optimised for each weed species being studied. Optimised parameters will then be used in field trials and in association with automated weed detection and laser-targeting systems. Laser-based weed management systems will be environmentally benign, low in energy usage, safe and effective. This will make them a very valuable component of sustainable crop production systems offering food security to the UK and original proforma document worldwide.
that can lead to development of herbicide resistance and unwanted environmental effects. One solution to this would be to design and implement weed management systems utilising in-field detection, weed mapping and targeted weed management.
This research programme will develop a laser-based target weed management system. Use of low energy lasers alone and in the presence of targeted low doses of photosynthetic electron transport inhibitors will be developed for control of broadleaved and grass weeds. Lasers will be targeted at the growing points of weeds in order to disrupt these and inhibit
seedling growth leading to reduced weed competition and subsequent seedling death. The key parameters for laser treatment (required laser power, power density with diffusers, wavelength, laser duration and heat of treatment) will be optimised for each weed species being studied. Optimised parameters will then be used in field trials and in association with automated weed detection and laser-targeting systems. Laser-based weed management systems will be environmentally benign, low in energy usage, safe and effective. This will make them a very valuable component of sustainable crop production systems offering food security to the UK and original proforma document worldwide.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M016773/1 | 01/10/2015 | 30/03/2020 | |||
| 1712232 | Studentship | BB/M016773/1 | 01/10/2015 | 30/03/2020 | Louise Wright |
| Description | It is still early days regarding some findings, but it would appear after conducting several trials with the 680nm LASER treatment on plants alone (not including herbicide treatment) does have an effect on certain photosynthetic parameters. However, in one case, this is not a detrimental effect as hoped for, but an enhancement of the photosynthetic rate. There have now been plants treated with the herbicide as well as the 680nm LASER energy. These herbicides also target PSII. At the moment, the LASER energy is 'getting lost' in the effects of the herbicide and not proving more detrimental to the plants' photosynthetic efficiency. This does need further investigation but these are the early findings. I think it would be prudent to investigate the use of a number of wavelengths of light instead of the inclusion of a herbicide. Findings discovered whilst writing up (02/03/2020) When analysing OJIP parameter data, 680nm LASER energy appears to enhance the electron transport capability in Sinapis arvensis at higher LASER doses (2000mA). It would appear that S.arvensis is utilising the extra energy in a positive way. The same can not be said for the other test weed species, Chenopodium album, which shows little deviation from the control at most 680nm LASER doses. The OJIP parameters show how absorbance and dissipation levels mimic each other and the other OJIP parameters are largely dependent on the relationship between these aforementioned parameters. However, which the addition of photosynthetic electron transport chain inhibitors, the action of the 680nm LASER is drowned out by the effects of the chemical action. With Nevada treatment, which does not inhibit photosynthesis, the 680nm LASER in conjunction with Nevada does yield some intriguing results which suggest the LASER works well in causing detriment to plants in conjunction with Nevada. However, the addition of Calaris and Sencorex Flow (PSII inhibitors) the plant aims to rectify the loss in electron transport by absorbing more light, including 680nm LASER light. This is shown in the OJIP parameter data. It is worth noting that, using light of different wavelengths, ie, 680 and 700nm (absorbance peak of PSI) could either inhibit or promote electron transport. It could be that supplying 700nm in addition to 680nm is a useful way of promoting the productivity of plants housed in controlled environments. However, as in this study, it was found that two plants are different so this approach should be tailored to plants needs and biochemical differences. |
| Exploitation Route | The enhancement of the photosynthetic rate caused by the 680nm LASER could possibly be used in glasshouse growing of plants to speed on photosynthesis and thus plant growth in a far more targeted approach. I think this is well worth further research. For example, it would be interesting to assess other factors which could be affected from the administration of 680nm energy at different doses. Such other factors include reactive oxygen species generation, nutrient requirements, oxygen requirements and growth rate. I think if one was looking to inhibit plant growth, more focus should be placed on disrupting the oxygen evolving complex and then subsequently disrupting PSII and PSI. At the moment with only using 680nm, plants are able to negate the desired detrimental effects or even use it to their benefit. |
| Sectors | Agriculture, Food and Drink,Creative Economy,Environment,Manufacturing, including Industrial Biotechology |
| Title | 680nm laser |
| Description | The Harper Adams University engineering department constructed a working 680nm light source. This is composed of parts from other countries and allows for cutting edge research focusing on the effect of the 680nm light on the workings of photosystem II. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2017 |
| Provided To Others? | No |
| Impact | I am not able to assess biochemical damage from this specific, 680nm only light source on plants. This, to my knowledge is not being trialed anywhere else. |
| Title | Buying of the PSI Fluorpen |
| Description | The PSI Fluorpen was bought in order to be able to gain an insight into the finer workings of photosynthesis and specifically photosystem II (PSII). |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2014 |
| Provided To Others? | Yes |
| Impact | With this technology, may rapid measurements can be taken which reveal information about the biochemistry of PSII. From this data, we can reliably assess the effects that 680nm LASER has on plants alone, and in combination with photosynthetic electron transport chain inhibiting herbicides. The assessment of parameters including ABS/RC, DIoRC, EToRC, TRoRC and FvFm highlight at which point in the PSII reaction centre such treatments have an effect. It is possible to see where the herbicide and LASER treatments are having an effect if any and thus fine tune treatments to inhibit weed growth. |
| URL | http://handheld.psi.cz/products/fluorpen-and-par-fluorpen/ |
| Description | Laser test at Manchester University |
| Organisation | University of Manchester |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | No technical contributions made towards Manchester University as such but an opening towards future collaborations and communications. |
| Collaborator Contribution | Tested a 680nm laser at Manchester University on weed species prior to purchase at Harper Adams University. The results from this allowed us to decide to get the 680nm laser at Harper. |
| Impact | Contributed to the purchase of the 680nm laser necessary for this PhD project, not in terms of funding but positive results from experimental tests. |
| Start Year | 2017 |
| Description | Syngenta |
| Organisation | Syngenta International AG |
| Department | Syngenta Crop Protection |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Syngenta are the collaborative partner in this PhD project. I have attended student colloquiums at Jealott's Hill but so far have not been asked to present any findings. |
| Collaborator Contribution | So far, very little, but as yet, these contributions are not needed as all research can be successfully completed at Harper Adams University. |
| Impact | No outcomes as yet |
| Start Year | 2015 |
| Title | 680nm light source |
| Description | This device, housed in a safety box, is able to emit light of a constant 6880nm for a desired length of time. The maximum power output is 1100mW but this was deemed high enough to affect photosystem II (PSII). PSII absorbs light at 680nm effectively. Therefore, too much light at this wavelength is hypothesised to cause biochemical stress and slow down growth. Weeds are the focus of this project, therefore, the aim is to use 680nm along with PSII inhibiting herbicides to slow weed growth. The 680nm is absolutely necessary for the completion of this project and has been engineered to meet the needs of this project. |
| Type Of Technology | Systems, Materials & Instrumental Engineering |
| Year Produced | 2017 |
| Impact | Able to gather data regarding biochemical stress inflicted upon weed species after exposure to 680nm light. |
| Title | FluorPen |
| Description | The FluorPen From photosystems Instruments (PSI) (Czech Republic) has been an invaluable tool in this PhD project. It is able to gather huge amounts of data quickly and highly accurately and gives a detailed insight into the finer workings of photosystem II. This kit was bought using the PhD project budget and was worth every penny. I am just highlighting this as it might be highly useful for other similar projects looking at plant productivity funded by UKRI. |
| Type Of Technology | Physical Model/Kit |
| Year Produced | 2017 |
| Impact | This kit is able to quantify changes in photosystem II (PSII) at specific points in the pathway including absorbance of light, trapping of light, dissipation, overall health of PSII and the amount of energy being funneled into the electron transport chain. These fall under the parameters of OJIP however, FluorPen is able to measure and store many other photosynthetic parameters. Using this kit, I have been able to assess subtle changes in PSII after herbicide and 680nm LASER treatment alone on in conjunction. |
| Description | Appeared on short TV documentary |
| Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Media (as a channel to the public) |
| Results and Impact | Gave a short TV interview focusing on the use of laser in weed control. Make it clear that is was not 'James Bond' but fundamental biochemistry and has future applications in wider agriculture and not just in the laboratory |
| Year(s) Of Engagement Activity | 2017 |
| Description | School visit (Wigan) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Schools |
| Results and Impact | Gave a short talk about recent findings and what life is like whilst completing a PhD |
| Year(s) Of Engagement Activity | 2016 |