Questions related to Weed Science
Any method or technique are there to maintain homogenous weed population (approx. equal proportion of weed flora, diversity and density) on entire experimental plots to check the exactly efficacy of weed control method/herbicides.
Is there any post emergence weedicide to control nutsedges (Cyperus rotundus) in cotton without using any shield or perventive nozel? Any weedicide which can kill nutsedge but doesnt harm cotton crop?
The herbicides are knowingly or unknowingly sprayed by the farmers in the field crops caused plant injury. This situation has to be recovered and the crops should be saved. What is the recommended antidote for the above herbicides. If anyone knows please tell me with references.
In Weed Science field experiment, we normally go for statistical transformation of data to bring it near to normal distribution.Most of the time, we go for Square root transformation [ sqrt(x+0.5)]. My question is:
- whether the choice of transformation remain same for all set of weed data i.e. sqrt (x+0.5)
- If not, under situation we are using the different statistical transformation.
- Is it possible we can use different statistical transformations at different stage of observation.
We are looking for feral hemp seeds to use in our ongoing experiments on invasion risk of hemp in Florida (https://programs.ifas.ufl.edu/hemp/). There seems to be a lot of 'wild' populations in the Midwest, U.S., leftover from the industry in 1940s.
Any suggestion for sourcing/ collecting these seeds?
It is hard to find information about this theme. I would use the information to have a better understanding of the ecology of this species. This will be framed into a study of resistance to herbicides. I really appreciate you help.
25 years ago while replanting a 100-mile gas pipeline north of Reno in BLM lands in a cheatgrass area, at http://www.ecoseeds.com/greatbasin.html discovered that the exotic animal grazing had lowered the soil nutrients and organic matter below the thresholds needed for the local native seedling survival, that you can see at http://www.ecoseeds.com/good.example.html
By finding the soil nutrient thresholds in the top 5 cm, from around the seedlings of the desired native, and then testing the project area soils, and then adding fertilizers and organic matter along with the seeds, was able to get a cheatgrass-free planting in only six months, that remained 100% cheatgrass free for at least five years.
So my conclusion is that cheatgrass, instead of an "invasive" plants, the cheatgrass is what I call a "default" weed, only growing in soil too poor for the local natives and indicating poor soil conditions.
THE QUESTION IS, has anyone else used fertilizers to permanently eradicate other populations of cheatgrass, or added fertilizers to bring the soil nutrient thresholds up, so that the desirable plants are favored, and they can out-compete with the poorer-soil adapted weeds?
Weeds, particularly the invasive ones, are believe to have numerous negative impact on native species, including species extinction. Are there studies that provide results to support these claims, including the species involved?.
I am doing an herbicide bioassay which involve me mixing herbicide into a pot full of soil. I need to calculate the amount of herbicide I need to add to the soil in the pot to reach 1ppm of herbicide in soil. Is there a guide I can follow to do this type of work? I have not been successful finding publications that do this type of work.
With due respect, I would hereby request the scientific brethren to provide me a formula with examples to calculate the "impact" or "degree of impact" of alien invasive plant species in the introduced ecosystem.
I, would, hereby like to re-state that I am in need of a formula. Although, I have found certain formulae, but the variables are not clearly defined.
For example, Parker et al. (1999) suggested I (overall Impact)= R (range) × A (abundance) × E (per capita impact). Now, how to calculate R & E, is not clear!
Again, Lockwood et al. (2007) states I = Ft × Fe × Fs × E; how to calculate Ft, Fe, Fs & E is not stated!
Ricciardi (2003) opines Impact = A × F (ecological function per capita effect) × C (composition of recepient community); but no clarity with respect to calcuation of F!
I am at a loss!!!
I am looking for information and protocol to study gene expression in crops under competitive conditions with weeds.
What to consider? and what would be a proper technique to do so?
Any article or tips is appreciated
I am unable to find a protocol for norflurazon detection in plant tissue. I have only encountered works concerning quantification of norflurazon in soil samples (Essington et al., Comun. soil. sci. plant. anal., 1995) or clear standards (Mueller et al. weed science, 1992). Does anyone now about publications concerning this topic?
I am planning to study the effect of under-sowing cover crops like clover in control of weeds in winter wheat and canola.
My typical climate to see the effects there, is Mediterranean one, preferably.
It is appreciated if anyone can share any data or experience.
I am looking for data on control of Malva sp. in rapeseed. I wonder if anyone has done study on competition between Malva sp and rapeseed/canola. We are dealing with problem of Malva sp. and broomrape in rapeseed. Any tip and information is appreciated.
Weed prevention is a weed management component that prevents weeds from moving in to a new environment. I believe it is different from preventative weed control that aim to prevent weeds from establishing when their propagules are present already. Considering that weed management is prevention, eradication and control, why is it that weed prevention is not emphasised in IWM?
I intend to do weed characterization in my station and help my students know how to identify as well as classify weeds in the field. The only one I have is limited. Thanks for your help.
A weed survey found in cotton field will be carried out in the different cotton growing regions including plain and Hill districts. What are the accurate methodology to do the survey?
We are interested in natural/safer alternatives to atrazine, for control of pre- and post-emergence broadleaf weeds in large field-corn plots under irrigation.
Generally we test all the organic fractions in search of activity based compound (e.g. for pesticidal activity we generally prepare organic fractions for different plant parts and select the most active fraction for phytochemical analysis) but in attached paper there is a short-cut where single plant part is selected for fraction preparation based on activity shown by ethanol extract....is this method same acceptable?
I'm dealing with weed management practices through allelochemicals for which I've to perform germination bioassays with weed seeds. The problem is seeds of Avena fatua, Chenopodium album, Phlaris minor and Rumex dentatus are not showing germination even I purchased them twice. Any suggestion from experts?
I am doing a research on the above plant, which is a weed in our area. If anyone give some idea on its impact, ecological requirements and the factors that limit its growth and development, please.
Eleusine indica is currently reported as weed resistant to herbicide at several district in North Sumatera, Indonesia. Is there a new method for analyze weed resistant to herbicide.
A common weed in cassava farms in Northern Sierra Leone. The unknown plant is dominant in crop fields of Kambia and PortLoko Districts, in Northern Sierra Leone. It was discovered during a survey of cassava pests, diseases and weeds. Scientific identification is a problem, please help.
Anyone who used Parthenium hysteroporous (weed) extracts for the management of insects pests? please attach the publications etc
Invasive grasses can be controlled by seasonal application of herbicides, soil disturbance and thatch removal. These are all expensive to apply, using man-made machines, and it is difficult to access many areas of the landscape. It seems to me that goats could accomplish the needed thatch removal, soil disturbance and seasonal cover reduction if they were brought into the site a few times a year before the grasses go to seed, and they could access more of the landscape than humans with machines.
This weed is winter perennial herb appears in early spring. The stems are erect and unbranched with 25-50 cm height. Second photograph (DSC1251) shows whorled leaf arrangement on stem. It has also tubers which usually buried at a depth of 20 cm or greater (fig DSC-1154). Please see attached files for more information.
No information about it's flowers is available at this time.
The photos (except for tuber photograph) were taken on 4/27/ 2015 in the Northwest of Iran.
Nowadays, allelopathy is topic of interest for weed control. Scientists are isolating the natural phytotoxins/allelochemicals for weed control. How one can justify that isolated allelochemicals will inhibit the growth of weeds only and not of the crop?
I want to know that from which site or field should we select the susceptible weedlines so as to evaluate the resistance level in any weed species?
Most scales used only define the extremes, thus the no damage and the plant death characteristic. the intermediates are arbitrary based solely on the discretion of the technician. I am of the opinion that such an approach elevates chances of heteroscedasticicity of the data and makes it difficult to make comparisons for scientists across locations. Moreover, different symptoms are expected for chemicals with different MOA and this should be taken into account by the scoring system.
May interested parties comment on developing a crop specific, robust and versatile scoring system which can minimize the discrepancies likely to be brought about by the arbitrary system
Weed management aims at reducing weed densities to populations which do not inflict yield penalties, but not necessarily eradicating the weeds. However, most published work does not take account of the aspect ETLs and such literature is scarce for most crop-weed interactions. How then can 1 reach a sound conclusion without such information. Secondly, how can growers tell when weeding is due without knowledge of ETLs. What are the rates of occurrences of type I and type II errors in weed management in the absence of ETL data.
Cynanchum acutum is one of the most important invasive plants. To reducing its damage, we should prevent its developement in new areas. But how about an infected garden?
I was interested to study the weed communities in certain area and correlates with climate. What is better to collect climate data during the year of study or during the past several years and what the best number of years to be expressive?
I am looking for software that can be used to calculate leaf area for a plant without damaging the plant. The "destructive method and the graph sheet method" are tedious and time consuming. Does anyone have any experience with this?
Mimosa invisa, an invasive weed, has become a very serious problem in my location and I intend to find out how best to control it and at what time the control methods should be introduced. Your contributions will be of great help. Thank you so much.
Based on indigenous knowledge, the seed extract of Cassia tora has been used for its medicinal values to treat various health problems. However, I do not have idea whether this plant is being used commercially or not. What may be the potential commercial utilization of the plant in Indian sub-continent, more specially in Nepal and India?
I'm interested in studying the effect of invasive species on plant community diversity, what are the major impacts can be measured to estimate the effect of invasive species on plant community in certain habitat?
One colleague found an invasive plant species not recorded previously in Iran and is asking where to submit a short note. I know that for example in phytopathology there are quite a few options to submit a short disease note to record plant diseases from a new host. This also exists for insects but I have no idea about plants. Does somebody have any idea?
Some weeds such as "Cynodon dactylon" have the ability to grow in Siberia and in the hot deserts of Arabia. What is the mechanism of adaptation? Do these plants contain adaptation genes? Can these genes be transferred "transcript" to other plants?