Questions related to Weed Ecology
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?
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?.
Native seed mixes have been used by several Federal agencies in the Western USA for 75 years, mostly sown after fires. For example, one agency, the BLM, is currently spending $25 million a year to do fire-restoration seeding projects.
However, the USGS David Pilliod report in 2017 reviewed 102 native seeding projects that were sown in the Great Basin, and found 70 of them had failed.
As another example, I am currently fixing a native seed mix failure here in San Mateo County, where two years ago a 100-pound mix costing $8,000 was sown with five species of native grasses and 20 different wildflowers. Those 25 species fought each other with allelochemicals to the death, so today, only two of them survived-- one grass and one wildflower. That is a 92% failure of that mix.
My question is--Today, when the Western agencies doing native seeding projects, instead of using any more seed mixes, are individual species being sown in mosaics, to keep the different species from fighting each other with allelochemicals?
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!!!
Due to continuous application of same herbicide, a minor weed becomes a major weed. This is called weed shift in response to weed control. In what way, we can measure the weed shift frequency?
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.
Increase in the number of species (especially broad-leaved weeds) was observed during in situ microbial (CDM) decomposition of rice stubble both in winter (sandy clay loam to clay loam) and rainy (sandy loam) seasons was observed at 60 to 90 days after treatment. Reviewing the literature, faster seed germination of Arabidopsis thaliana and Acacia Senegal seeds treated with Bacillus licheniformis was earlier reported. Azospirillum brasiliense Az39 promoted seed germination through phytohormone synthesis had been reported and in case of Euonymus americanus L. seeds, cellulase activity of cellulolytic ruminal bacterium Clostridium cellobioparum was implicated for the degradation of the testa of the seed, allowing imbibition and germination. Is there any relevant reports for effect of crop residue incorporation on germination of weeds?
Anyone has experience with Cuscuta spp invasion in natural landscape, grass and range-land?
Poisson for grazing animals?
Identification tips/key for species?
Thank you in advance
Tetracera indica is one of the weed in rubber plantation that has the potential of allelophatic substances. How to identify the allelophatic substances from this weed....
One of my objectives is to: Quantify and compare the seed rain of fleshy-fruited, bird-dispersed seeds under trees in weeded and non-weeded area.
Am planning to use random number table to randomly distribute seed traps under trees in both areas.
- Is there a better alternative to what am about to do.
- Is it necessary have the same size of the plot in both weeded and non-weeded area. (because I got mix answers where some said it's not necessary and some said it's necessary)
The place where am doing research the area of non-weeded is very small compared to weeded area (by how much I don't know). I would like to know how I can distribute seed traps in both areas for comparison.
For example if I have 30 seed traps how many should be in non-weeded and weeded areas.
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.
I am looking at the foraging behaviour of bell miners within areas with lantana intact, lantana sprayed and native understorey. This species is thought to relocate from an area after lantana removal and I think it will stay in an area regardless of the understorey plant species if the food source is still there.
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
There are a lot of weed species in the tropics that act as host plants of pest. Currently we have found four non-cultivated plant species that act as reservoirs of stink bugs, but we need to identify these plants in genus and specie.
Weed seedbank study is important. No matter how many times a crop field is weeded, newer weeds emerge. Why is this the case? How do we manage this problem?
We are working on a graminea grass which is an open pollination species.we would like to know if this species exists biomass "Heterosis", which may be interesting to improve the yiled of biomass of this forage crop.
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?
Mechanical methods have problems of leaving behind weeds especially within inter rows and chemical methods have issues of environmental pollution, side effects on consumers, and the vital one to consider weeds over time may develop resistance to chemicals.
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?
I want to grow the seeds of field bindweed (Convolvulus arvensis) in a laboratory. So I would like to provide the desired temperature seed germination.