Saturday, 26 August 2017

The Danger of using Picloram in Environmentally Sensitive Areas



In 2013 I first began noticing what was very clearly herbicide damage and death being caused in particular to two species of tree being Grewia occidentalis and Trema orientalis. I took photos of the affected trees but could not establish the source of or the herbicide that had caused the damage.



Trema orientalis that has been damaged by a very small dose of the herbicide picloram 

More and more I began noticing trees that had been affected or had been killed by what was very clearly as the result of herbicide poisoning but again I could not establish what herbicide had caused the death of the trees and when the spraying had occurred, in some areas the last spraying had occurred a few years previously.

About a year after first observing the herbicide damage to trees and other plants I accidentally discovered the culprit herbicide. 

I had removed a narrow band of bark down to the cambium on three trees on my property and carefully applied a very narrow band of Kaput Gel containing Triclopyr and Picloram in a band of about 50 mm on the bottom half of the area where the bark had been removed. Within a few days I noticed that two trees growing within a few meters of one of the trees started to show signs of herbicide poisoning and within two weeks one of the small trees Hippobromus pauciflorus was completely dead, the second small tree affected was Obetia tenax which very nearly died but eventually after more than three years recovered. For up to three meters along the line of the main roots all dicotyledonous ground cover plants were affected. A wild grape Rhoicissus tomentosa growing about six meters from one of the other trees was also very badly affected clearly from herbicide leached from the tree that had been treated with Kaput gel, eventually over ninety percent of the very large vine died what is left at the time of writing being August 2017 has not completely recovered.

Obetia tenax two years after having been poisoned by picloram which leached from the roots of a tree that was treated some distance away
Once that I had noticed how very small doses of picloram had affected other plants growing nearby I investigated what herbicides had been sprayed in the areas where so much herbicide damage had occurred and discovered Plenum containing Picloram has been sprayed to control weeds in adjoining grassland. In most areas where Plenum containing Picloram had been sprayed 100% of Trema orientalis trees had died.


Trema orientalis that has been killed by a very small amount of the herbicide picloram note the two trees growing beneath it have not been affected
Since then I have kept a very close eye on where ever I have seen contractors spraying or applying herbicides. Time and again I have found that Herbicides containing Picloram have caused excessive amounts of damage and death to a number of species.

I have observed that the following trees as extremely sensitive to very low doses of picloram


Barringtonia racemosa

Brachyleana discolor

Celtis africanus

Croton  sylvaticus

Dombeya cymosum

Ficus lutea

Grewia occidentalis

Hippobromus pauciflorus commonly known as false horsewood

Obetia tenax

Scadoxus puniceus

Trema orientalis

Wild grape Rhoicissus tomentosa


 
Croton sylvaticus dying after picloram following heavy rains in an area that had been sprayed a year or two before

Research on the internet confirmed what I had recorded but also brought to light some alarming facts as to the danger of using Picloram in sensitive natural areas or near to them.

 As a result of my own observations as well as what information I have obtained from the internet and a number of experts that  I have discussed the danger of applying Picloram with I will certainly never spray with any Herbicide containing Picloram in any natural area neither would I recommend any one else to do so.

I would go as far as to say do not under any circumstances ever spray with any herbicide containing Picloram in environmentally sensitive areas for instance in conservation areas or any other area when no damage to indigenous vegetation may occur. Also do not use herbicide gels containing Picloram and if there is absolutely no alternative then do so with extreme caution and only on plants that cannot be controlled with other herbicides because as reported above picloram leaches from the roots from the roots of plants that have been treated with it killing or damaging desirable plants growing nearby.



Barringtonia racemosa protected tree has been killed by the uninformed and careless use of picloram at the uMdloti river lagoon by an NGO doing alien plant eradication
Damage that has been cause to Barringtonia racemosa a protected tree in South Africa at the uMdloti river lagoon by an NGO doing alien plant removal

This sort of damage to the natural environment and protected trees can be avoided

There is no need at all to use Picloram in natural areas because there are herbicides that are just as effective and are far safer to use so please do not use this nasty herbicide in these areas.


The following information in regards to picloram has been published on the internet.


Picloram is a systemic herbicide that belongs to the pyridine family of compounds, used for general woody plant control. It also controls a wide range of broad- leaved weeds excepting mustards (crucifers). Most grasses are resistant to picloram so it is used in grassland management programs

Picloram can be sprayed onto foliage, injected into plants, applied to cut surfaces, or placed at the base of the plant where it will leach to the roots. Once absorbed by the foliage, stem, or roots, picloram is transported throughout the plant.

Picloram kills susceptible plants by mimicking the plant growth hormone auxin (indole acetic acid), and when administered at effective doses, causes uncontrolled and disorganized plant growth that leads to plant death

Picloram is the most persistent member of its family of herbicides which does not bind strongly with soil particles and is not degraded rapidly in the environment, allowing it to be highly mobile and persistent. The half-life of picloram in soils can range from one month to several years.


As a result Picloram can move off-site through surface or subsurface runoff and has been found in the groundwater. Picloram may also “leak” out of the roots of treated plants, and be taken up by nearby, desirable species.


Concentrations in runoff reported by researchers are often adequate to prevent the growth of non-target terrestrial and aquatic plants, and therefore, picloram should not be applied near water.


Picloram is a dicot-selective, persistent herbicide used to control a variety of annual and perennial broadleaved herbs and woody species. It can persist in an active form in the soil from several months to years, and can also be released from the roots of treated plants into the soil, where other non-target species may take it up and be injured or killed (Hickman et al. 1989). The cut-stump treatment is typically used to control woody species. Picloram is metabolized slowly by microbes and can be degraded through photolysis when directly exposed to sunlight. The half-life of picloram in soils can vary from one month to three years depending on soil and climate conditions. Other methods of chemical degradation do not occur readily. Picloram does not bind strongly with soils and can be highly mobile, moving to soil depths of two meters and laterally to one km.


Soils

Picloram is not readily degraded in soils and can be persistent and mobile. Estimates of the persistence of potentially toxic concentrations vary from a few months to three years, depending on soil and environmental conditions (Scrifres et al. 1972; Fryer et al. 1979; Johnsen 1980; Norris et al. 1982; Neary et al. 1985; Smith et al. 1988; Bovey & Richardson 1991; Close et al.1998). In soils where picloram persists for long periods of time, it has high potential to move vertically and horizontally, which can lead to contamination of water sources and non-target (terrestrial and aquatic) sites. Smith et al. (1988) reported that one and two years after treating a site with 3.38 kg/ha of picloram, residues were found in the soils and groundwater of an untreated site one km away

Water

Because picloram is water-soluble and does not bind strongly to soil, it is capable of moving into local waterways through surface and subsurface runoff (Michael et al. 1989). The extent to which picloram enters a waterway depends largely on the type of soil, rates of application, rainfall received post-application, and distance from point of application to nearest water body or groundwater (Trichell et al. 1968; Baur et al. 1972; Mayeux et al. 1984). In general, the larger the buffer between treated sites and surface water bodies or groundwater, the smaller the potential for water contamination

Vegetation

In non-susceptible species such as grasses, picloram is metabolized rapidly, while in susceptible species, picloram can remain intact for extended periods (WSSA 1994). When applied to soil, picloram is readily absorbed by plant roots. When applied to foliage, the majority of picloram (70-90%) remains in the leaves and only a small percentage is conducted to stems and roots (Meikle et al. 1966; Cessna et al. 1989; Hickman et al. 1990). Unabsorbed picloram remaining on leaf surfaces may photo degrade in sunlight or be washed off with rainfall or irrigation.

Picloram absorbed by plants can be released into the soil by passive transport through the roots and then taken up by roots of other nearby plants (Hickman et al. 1990). Therefore, even selective application of picloram to specific target plants could potentially harm nearby desirable plants.



Picloram

Chemical name:               4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid

Chemical class/use:         chlorobenzoic acid herbicide


Picloram is sold in South Africa under the following brand names

Grazon

Tordon

Browser

Access

Scrubber

Picloram is found in various herbicide mixes in South Africa under the following names

Plenum - Active Ingredients: Picloram (80g/l), Fluroxypyr (80g/l)

GLADIATOR 160 ME – Active ingredients: Fluroxypyr 80 g/l, Picloram 80 g/l

There are probably other trade names of herbicides containing picloram so please check before you apply herbicides in sensitive areas.

References

Weed Control Methods Handbook, The Nature Conservancy, Tu et al. 


Extension Toxicology Network, A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Michigan State University, Oregon State University, and University of California at Davis.
  



Article written by Michael Hickman 20.08.2017





Wednesday, 22 February 2017

Some thoughts on constructing and maintaining a natural pool


Nymphaea nouchali
Please take note this is only a brief list of the most important aspects to consider and is not by any means comprehensive 

For a professional fee I will design, give advice and supervise the construction of a natural pool for you.

This is a subject that has fascinated me for much of my life having had my first encounters with fish ponds at my grandparents’ home as far back as I can remember. I used to sit for hours at my grandmother fairly large fish pond fascinated by the wildlife that it attracted in particular the whistling frogs, Hyperolius marmoratus or Painted feed frog, as I now know them. I was also extremely fascinated by the dragon flies, back swimmers and pond skaters that grandmother fishpond attracted. I was not particularly interested in the bright orange gold fish that she kept in it. As a result of this interest I first started constructing small ponds as a school boy. While in Germany way back in time I got to know about the company re-natur in Germany that specialises in the construction and supply of materials for natural pools
Faszination Gartenteich written by Wolfram Franke.


Crinum paludosum
Design and functionality
Most of those who give into the temptation to construct of have a natural pond constructed for them are going to want a pond that is a peasant blend of good design and high functionality, in short it must look good at the same time serving its purpose of attracting the largest variety of wildlife into the garden as possible. This is easy to do if the designer knows his or her subject well and follows a few basic rules
There are things that are desirable to have and some that are necessary, what is desirable is not always necessary. If the pool looks like a dogs breakfast it will probably work but not as well as if it is well planned with open patches of water and all the plants in their own preferred places and it will certainly look a lot better if it is well planned

Size of pool
For a number of reasons the larger the pool the better, however ponds the size of an average bucket can work which can and will attract the odd insect of small frog. Generally the larger the pool the more stable it is the more wildlife it will attract and the easier it is to keep in ecological balance.

 Painted Reed FrogHyperolius marmoratus
Depth of the pool
To be most successful the pool must have both shallow and deep sections, most of the plants will only grow in relatively shallow water leaving the deeper sections to remain free of vegetation which is a desirable and necessary design factor
Shallow areas must be created for the planting of most of the aquatics that are desirable for planting in a natural pool

Movement of the water
It is desirable that there is some movement of the water but this is not necessary for the pond to be successful.
The provision of a small low volume pump that pumps daily during the hours of daylight is a most desirable addition to any pond, the pump could be powered by a solar panel. Directing the flow of water over a pebble or gravel stream or over a waterfall will introduce a considerable of extra oxygen into the water which is of particular benefit on hot humid days with little air movement.

Free access into and out of the pool
The design must allow creatures that fall into the pool in error to have a way to escape without being doomed to drowning

Safety of young children
The pool must be designed in a manner that it is not easy for small children to fall into it and drown. Where this is not possible or for additional safety a suitable fence that allows the unrestricted passage of desirable creatures to reach the pool must be erected

Nymphoides thunbergiana
Construction materials
I am not going to go into any detail on this aspect other than to mention a few materials that can be used.
Where the ground water level is high enough all that is required is to dig out a hole which will soon fill with water.
Natural clay can be used to create a natural pond liner
Various grades of plastic can be used
Concrete
Bricks and mortar
Fibre glass
These are the materials that are most often used to create ponds and pools

Construction methods
Again I will not go into detail on this aspect of pool construction as there are many methods depending on a number of factors.

Containers can be converted to small ponds
Just about any container that holds water can be made into a micro pond which attract wildlife such as frogs and dragon flies
If anyone needs more information please contact me.

A newly emerged dragonfly busy pumping up its wings
Water supply
Water to keep the pool filled can be obtained from the following sources
Mains water
Rain water capture from roofs
Water capture from air conditioners
Boreholes

Pumps and Filters
Neither pumps nor filters are essential however both can improve the conditions within the pool for a number of creatures.
The running times of pumps will be determined by both the design as well as the preference of the owner of the pool. Solar panels can be used to provide power for the pumps.
Bio filters planted with plants can be constructed that provide both filtration as well as desirable features to add interest to the design.
When using a filter do not forget to use a leaf trap.
Use only energy efficient pumps, most designed for use in Koi ponds are far more efficient than the majority of equivalent capacity pumps supplied for swimming pool use

Snoring Puddle
Phrynobatrachus natalensis 
Décor
Décor such as waterfalls, streams, rocks, branches can be added
Planting
Plant either directly into the soil provided or into planting containers.
Plastic crates lined with shade cloth hessian or even newspaper is ideal to plant aquatic plants into

Planting medium
Use low nutrient clay, sand or small natural river stones.

Nutrition
Nutrition is very important but be very, very careful not to over nitrify the water apply a little at a time and wait for results. Apply at the point of use if at all possible.

Agricultural grade fertiliser rolled up in a piece of news paper,
Agricultural grade slow release fertiliser rolled up in a piece of news paper,
Grow sticks

are the most suitable sources of nutrients for your natural pond.
One can add liquid fertiliser to the water but be extremely careful.

Running Frog
Kassina senegalensis
Maintenance
Control of duck weed Lemna species is most important because if left it can very rapidly get out of control. Control all fast growing species and those that move out of their allocated zone before they get out of hand and take over the pond.
Sludge may need to be removed from time to time. Bio filters will need cleaning from time to time, plants growing in bio-filters will need cutting back from time to time to remove nutrients from the system.

Control of Mosquitos
Mosquitos could become a temporary problem in a newly constructed natural pool but there is no need to panic whatsoever the problem will resolve it’s self as the pond matures and is colonised by insects that eat mosquito such as Dragonfly larvae, back swimmers of the family Notonectidae and pond skaters of the family Gerridae
Mosquitos can also be controlled by the introduction of suitable small carnivorous indigenous fish such as Barbus viviparus (bowstripe barb). If the mosquitos become a problem they can easily be controlled with Mosquito wise, which is a biopesticide containing the Bacillus thuringiensis subsp. israelensis

Selection of plants
Beware of fast growing fast multiplying plants in particular grasses and sedges because most become dominant taking over the entire pond in time making it a dogs breakfast.

Kniphofia pauciflora below is most worthwhile to plant in your pool because it is very attractive and is almost extinct in the wild

Kniphofia pauciflora
Chlorophytum bowkeri
Crinum paludosum
Cristella dentata
Cyperus dives
Cyperus sexangularis
Cyperus textilis
Eulophia angolensis
Gunnera perpensa
Ipomoea ficifolia
Kniphofia pauciflora
Kniphofia rooperi
Ludwigia stolonifera
Nesaea radicans
Nymphaea nouchali var. caerulea
Nymphoides thunbergiana
Persicaria attenuata
Persicaria serrulata
Phragmites australis
Potamogeton pusilis
Potamogeton schweinfurthii
Ranunculus multifidus
Schoenoplectus scirpoides
Typha capensis
Xyris capensis
Zantedeschia aethiopica

Dragon flies
A variety of colourful dragon flies will quickly make your new natural pool their home



Shrimps
The fresh water shrimp Caridina nilotica is a useful addition to the natural pool because it is a scavenger and algae eater which does very well and multiplies very rapidly in a pool that is free of large fish.

Frogs
Afrixalus fornasinii                            Greater Leaf-folding frog
Hyperolius marmoratus                      Painted Reed Frog
Hyperolius argus Argus                      Argus Reed Frog
Schismaderma carens                         Red Toad
Phrynobatrachus natalensis                Snoring Puddle Frog
Kassina senegalensis                          Running Frog


Greater leaf folding frog
Afrixalus fornasinnii 
Fish
Be extremely careful when deciding to introduce fish into your pond in particular if it is a very small pond as fish can do a lot of damage to the aquatic ecosystem in particular eating plants and or eating desirable insects such as dragonflies, water boatmen and pond skaters.
The introduction of suitable small carnivorous indigenous fish such as Barbus viviparus bowstripe barb

Bowstripe Barb
Barbus viviparus 

.For a professional fee I will design, give advice on and supervise the construction of a natural pool for you




Links to further information

Mosquito wise is a biopesticide containing the Bacillus thuringiensis subsp. israelensis




Indigenous Frogs
Afrixalus fornasinii Greater Leaf-folding Frog http://frogmap.adu.org.za/Species_text.php?sp=30

Hyperolius marmoratus Painted Reed Frog http://frogmap.adu.org.za/Species_text.php?sp=590


Phrynobatrachus natalensis Snoring Puddle Frog http://frogmap.adu.org.za/Species_text.php?sp=740

Insects
Water boatmen  Notonectidae https://en.wikipedia.org/wiki/Notonectidae

Pond skaters of the family Gerridae https://en.wikipedia.org/wiki/Gerridae

Plants

re-natur Germany https://www.re-natur.de/


Michael Hickman
Landscape Design and Rehabilitation Specialist

Tel: +27 82 061 2593

michael@ecoman.co.za

22.02.17


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