Archive for the ‘Agrochemicals’ Category

Who needs glyphosate when friendly weeds can fight for you?

August 6, 2018

http://www.sundaytimes.lk/180722/news/who-needs-glyphosate-when-friendly-weeds-can-fight-for-you-303543.html published on SundayTimes on 22.07.2018

The government last week lifted the ban on glyphosate, in deference to complaints that the tea and rubber industries find it difficult to control weeds without the popular weedkiller – but a project successfully proves that weeds among tea bushes can be controlled without chemicals.

Good plants that grow under tea to make a carpet that deters growth of bad weeds

“You do not need agro-chemicals to control weeds in tea plantations as you can ecologically control the plants that are harmful,” Giri Kadurugamuwa of Rainforest Alliance, which has successfully experimented with an ecological method to control weeds, said.

“We must first understand that not all plants that grow in the underlayer are harmful: only about 25 per cent of the plants are weeds that suppress the growth of the tea bush, resulting in a drop in harvest,” Mr. Kadurugamuwa said.

The other plants are “good”, some enriching nitrogen in the soil, others being edible or having medicinal value.

“So, by assisting these friendly herbs to dominate the undergrowth we can control the growth of bad weeds,” Mr. Kadurugamuwa explained.

Initially, noxious or troublesome weeds must be removed manually before the weeds flower. This process need to be repeated periodically in the initial stages.

After a few cycles, a thick mat of good weeds that have been allowed to grow under the tea bushes will prevent the bad weeds from regrowing.

Once this natural control of weeds is established, growers do not need to put in intensive labour to uproot bad weeds frequently, and the money spent previously on weedkiller is also saved, Mr. Kadurugamuwa said.

There are more benefits to this process, the agriculture expert points out. The plants in the undergrowth protect the soil and enrich biomass, adding compost to the tea bush soil. “Many of the good leguminous plants have a root system that can add atmospheric nitrogen to the soil. Nitrogen is a good fertiliser, so, now, the tea bush gets an additional supplement of fertiliser.

During first few months, the bad weeds has to be uprooted

“Besides, it is known that the roots of some friendly plants add ‘friendly chemicals’ that can, in fact, assist the growth of the tea bush.

“It is like we provided a natural ecosystem of ‘friends’ to live with the tea bush. One feels good to be among friends than be alone, and now the tea bushes will be growing happily,” Mr. Kadurugamuwa said jocularly. “But jokes apart, the productivity of the tea goes up under the new method without herbicides,” he said.

Tea planters usually follow a ‘clean floor policy’ where no plant is allowed underneath the tea bushes – but this exposes the soil to erosion when it rains heavily.

With the new methodology, however, the soil is covered with a carpet of friendly plants so the soil is conserved. Some of these friendly plants, such as goku kola and mukunuwenna, are popular foods for humans, and there are herbs such as undupiyaliya that are used as medicine, so these are added advantages to growers.

Weedkillers do not kill tea bushes but can weaken them: they are, to an extent, poisonous to the tea bush. Mr. Kadurugamuwa showed us a tea bush that had decayed sections of bark as a result of exposure to weedicide.

The methodology explained by the Rainforest Alliance was first experimented on about two years ago in a pilot project at the Hapugasthenna Plantations in Hatton. Mahendra Peiris, who conducted the research from inception, showed us his thriving tea plot now after several cycles of this method.

In doing so, Mr. Peiris also pointed out that popular weedkillers are not effective against some weeds so that in any case manual labour has to be employed for weeding. Thus the new method is also cost-effective, he said.

The project was also supported by Global Environment Facility (GEF) and the United Nations Environment Programme (UNEP)’s project for mainstream sustainable tea production in India, China, Vietnam and Sri Lanka.

A tea bush decayed due to the use of too much weedkiller

Armed with knowledge of the trial, the Rainforest Alliance, with the help of GEF funds, trained farmers to use the methods in their plots. They also established a training centre at an abandoned tea factory and made some of the farmers “trainers” in order to spread the message to the others.

During a previous field study visit, The Sunday Times met several farmers from the Ratnapura area who practise this method. According to a Tea Smallholder Development Authority (TSHDA) official, the Ratnapura range has the highest number of tea smallholders, about 100,000. Of these, about 5,000 are using this weed management system and gaining benefits.

Karunawathi, one small-scale tea grower in Kahawatte, Ratnapura, who owns an estate of one acre and 20 perches in extent, said her income had increased after turning to the new weed management system. Another grower, Sumanawathi, said now she harvests 500kg per acre whereas earlier it was only 400kg, so the new system has helped to increase yield.

The manager of another tea estate, Sanath Gamage, said his estate has become more environmentally friendly under the new system. Mr. Gamage maintains a log that shows hare, lizards, land monitors and birds frequent these areas more than they previously did.

Birds can be monitored to show signs of potential pests, said Mr. Kadurugamuwa. For example, if a group of babblers spend a deal of time feeding in one area, that could be a sign that this portion of ground has been infected by a pest. The birds while reducing the number of pests, also gives an early warning to the farmer.

The Rainforest Alliance project is not without its challenges. It is not always easy to turn farmers away from weedkillers. Manual labour is required to remove bad weeds, and this is challenging on slopes. Large plantations are reluctant to practise the method.

Experts point out, nevertheless, that tea bush productivity in Sri Lanka is in constant decline and that given this situation it is indeed wise to promote this alternative method of de-weeding tea, especially given its many benefits.

“Let’s all hope that growers will start adopting these kinds of environmentally friendly practices to break the dependency on agro-chemicals,” Mr. Kadurugamuwa said.

How researchers co-opted a remote village to save rare fish

July 27, 2014

An attempt by villagers and wildlife enthusiasts to save a rare fish from extinction is a rare ray of hope amid the gloom of the gradual loss of biodiversity.

Last week, ignoring blood-sucking leeches, dozens of volunteers got their hands dirty and pants wet on the muddy banks of the Galapitamada stream, known to be the only habitat of the critically endangered Bandula Barb. They cleaned the stream and planted ketala aquatic plants on the edges of the stream to enhance the breeding habitat and give much-needed protection for this small fish.

Bandula Barb (Pethia Bandula) is one of the rarest and most endangered fish in Sri Lanka as it can only be found in a 2.5km stretch of a small stream in the Kegalle district. Their present count is just over 1000, so the threat to their existence is enormous.The habitat rehabilitation work held last Sunday was organised by the International Union of Conservation of Nature (IUCN) with the assistance of the Toyota Environmental Fund. This two-year project began in 2013 in accordance with the Bandula Barb Recovery Plan drafted by the Sri Lanka Biodiversity Secretariat of Ministry of Environment in 2007, looking into empowering the villagers to conserve the fish as the area is totally outside any protected areas. Habitat enrichment and the introduction of the fish into other habitats are part of this Conservation Plan, being implemented under the guidance of Professor Devaka Weerakoon.

The data on the drastic decline of Bandula Barb emerged through research carried out by Hasula Wickremasinghe in 2003 as part of her MSc research. In 1991, the fish “catch rate” – a technique used to measure fish population – as 15-100 but in 2003 it sank to 0–5. This is an 80 per cent decline of the population. Ms. Wickremasinghe and Sampath Goonathilake, prepared the Bandula Barb recovery plan under the guidance of Prof. Weerakoon.

In May 2013, a total of 598 Bandula Barbs were found. This number increased to 1073 in December that year, raising hopes that the species can recover but more work has to be done to get the population stable, according to experts.

The volunteers of the Aquatic group of the Young Zoologists Association (YZA) were the leading force behind last Sunday’s activities. The team planted native trees along the stream bank together with the participation of the villagers. As the climate in the area is expected to be drier with repercussions of climate change, it is hoped these trees could provide a lifeline to the stream, keeping it from going dry.

This stream in which the Bandula Barb lives flows between paddy fields and rubber estates so the agro-chemicals used in the paddy fields have become the main threat to their survival.

“So the IUCN tried to convince the villagers of the importance of turning to organic farming. We linked them with an organization supporting organic paddy cultivation and we are happy that the paddy fields adjacent to the stream areas turned into organic cultivation areas where agro-chemicals are not used,” said Naalin Perera, IUCN Programme officer, Biodiversity, pointing to the lush paddy fields.

The IUCN also organized a workshop on freshwater fish for the village youths. This included a field visit to Kithulgala to observe the freshwater fish and methods of observation as well as techniques of counting.

The village youths became involved in the counting of number of Bandula Pethia in the stream in a survey conducted in December last year. A total of 1073 fish were recorded, an encouraging result for the conservation team. Mr. Perera also commended the enthusiasm shown by the village youth on learning more details about the freshwater fish.

The IUCN team has also reintroduced a population of Bandula Pethia to an isolated area close to Galapitamada. A wall was built under the project to prevent Bandula Barb being washed into the nearby paddy fields during heavy rains. The IUCN hopes the the effort to save the Bandula Barb from extinction will be successful.

http://www.sundaytimes.lk/140727/news/how-researchers-co-opted-a-remote-village-to-save-rare-fish-108595.html 

Bandula Barb

The Bandula Barb was discovered in 1991 by Rohan Pethiyagoda. Communicating through email, the expert on fish reveals that he first saw the Bandula Barb in an aquarium at the home of Rodney Jonklaas around 1987. Mr. Jonklass named the fish Bandula Barb because these specimen were given by Ranjith Bandula, an ornamental fish collector.

Mr. Jonklass thought it was a subspecies of the fish we now know as Pethia reval, or that it was a hybrid between Pethia reval and Pethia nigrofasciatus, the so-called Bulath Hapaya. Both those species too, occur in the same Kelani River basin as the Bandula Barb.
However, Mr.Pethiyagoda realised that that this could be a new species and his research with Maurice Kottelat ended in recognising the fish as a valid new species to science. This was later confirmed in 2012 through DNA analysis done by Dr. Madhava Meegaskumbura at Peradeniya University.

Mr. Pethiyagoda said no one knew the reasons for this fish having such a narrow ecological niche. “It is certainly unusual given that there is apparently nothing to prevent the species from dispersing further down the stream,” he added.

‘At first, we were suspicious’

“We are proud to have Bandula Pethia in the village as the fish made our quiet hamlet a famous place. Lots of people and collectors visited our village after getting to know the importance of this fish, but we haven’t allowed anyone to steal the fish,” said Ranjith Amarasiri, a villager who works with the researchers. “Even our children are protective of the fish and don’t allow outsiders to take them out,” Ranjith said, sharing a story of how a village child protested when outsiders tried to take away a specimen of Bandula Barb.

It is the vigilance of the villagers that helped the Bandula Barb to survive through these difficult times where exploitation, invasive species and pollution threatens Sri Lanka’s freshwater fauna.

“When I first visited Gapapitamada in 1987/88 the local people had no idea this fish existed or that it was special,” said Rohan Pethiyagoda who described the fish scientifically.

“They were initially strangers and didn’t say anything to us,” said Sarath Weerakkody, a villager who initially helped to build the link between villagers and conservationists. “When they combed the stream and started to catch fish we grew suspicious. Some youth who became angry and even threw stones at these researchers. But they came and explained to us about the fish and we also began to realise the importance of the fish,” said Mr. Weerakkody.

The effort of the villagers of Elpitiya, Hapudoda and Rabbidigala to prevent the extinction of the Bandula Barb could be a unique conservation model to protect Sri Lanka’s biodiversity.

Down to earth in soil fertility with bio-fertilisers

October 7, 2013
Imported destructive agrochemicals make way for home grown solutions that are eco friendly and harmless – by Malaka Rodrigo 

The harmful impact of misuse and overuse of agrochemicals have been highlighted in articles published in the Sunday Times in the past few weeks. As an alternative, use of bio-fertilisers which is a method of directly applying living microorganisms such as bacteria and fungi to fertilise the soil is becoming popular among farmers, even though these too have to be used with care, point out experts.

Research activites pertaining to vermiwash being carried out at the IFS, Kandy

“Bio-fertilisers are a good nature-friendly way of enriching soil with nutrients by establishing natural nutrient cycles. However, as many foreign bio-fertiliser products are being introduced to farmers, without being tested, there is a risk of introducing harmful organisms too into the country,” warns Prof. Gamini Seneviratne of the Institute of Fundamental Studies (IFS), Kandy. “These harmful micro-organisms can be invasive, spreading fast and causing enough damage,” he added.

Numerous species of soil bacteria which grow on or around roots, stimulate plant growth. Some of these microorganisms such as Rhizobium bacteria fix atmospheric nitrogen into soil and Pseudomonas Bacteria makes Phosphorus soluble, so plants can easily absorb them. Strains of these beneficial soil micro-organisms cultured in laboratories, come into the market as a bottled liquid. These bio-fertilisers can be mixed with compost and used in organic farming or as a supplement for chemical fertilisers. This can reduce the use of chemical fertilizers by at least by 25%.

In Sri Lanka, already there are companies producing bio-fertilisers. However, companies that import bio-fertilisers need to be closely supervised, as they cannot guarantee that imported bio-fertilisers are harmless. Hence, there should be a mechanism to monitor the quality and safety of the imported bio-fertilisers, emphasizes Prof. Seneviratne.

The IFS researcher stresses that the country can benefit from bio-fertilisers, because they are low cost, renewable sources of plant nutrients which can reduce use of chemical fertilisers. Prof. Seneviratne also revealed that an IFS project conducted in collaboration with the Tea Research Institute (TRI) is on the verge of introducing a new, patented formula of bio-fertiliser known as “Biofilmed bio-fertilisers” (BFBF), which has been rigorously tested for more than eight years.

Trials with tea revealed that the new fertiliser can actually reduce use of chemical fertiliser by 50%. It is to be introduced for commercial development by the end of the year. Developing BFBFs for other crops is under way. There are bio-pesticides too, which use similar techniques, but Dr Anura Wijesekara of the Pesticide Registrar’s office confirmed that Sri Lanka does not import bio-pesticides.

‘Vermiwash’ is a solution that contains extracts of earthworm enriched soil. The ‘Green Revolution’ initiated in the 1960s had promoted agrochemicals usage which Sri Lanka embraced. But once convinced of the ill-effects of agrochemicals, agro experts are returning to nature’s way. Earthworms to return fertiliser to the soil

At school we are taught that earthworms are a part of soil biodiversity that help enrich soil fertility. But, to promote the green revolution, we continue to use agrochemicals which kill these friendly creatures. Realising the important services earthworms provide to the soil, agricultural experts have experimented in getting the services rendered by these earthworms, into a specific fertiliser.

“Vermiwash’ is a liquid extract from soil worked on by earthworms. This contains friendly microbes and enzymes that stimulate plant growth,” Dr Gamini Hitinayake of Peradeniya University said.

A microbiological study of vermiwash has revealed that it contains nitrogen-fixing bacteria too. It is therefore an effective way of getting the nutrients back into the soil.

It contains enzymes- secretions of earthworms, which would stimulate the growth and yield of crops, and even develop resistance in crops.

Pointing out that vermiwash was not difficult to make and could be used for home gardens, Dr. Hitinayake gave the following steps:

  • Make small holes at the bottom of a barrel or large container mounted on a little platform.
  • Introduce soil containing earthworms into the container.
  • Introduce drips of water from the top onto the earthworm-rich soil, while collecting the runoff water from the bottom.
  • Mix this with water and apply to the crops.

Published on SundayTimes on 29.09.2013 http://www.sundaytimes.lk/130929/news/down-to-earth-in-soil-fertility-with-bio-fertilisers-64260.html

Excessive use of agrochemicals pollutes groundwater in many places

September 27, 2013

Last month, the Sunday Times highlighted that Sri Lanka’s farmers were over-using agro-chemicals, and warned that it could ultimately penetrate into the groundwater. This has now been confirmed by a study conducted by the Water Resources Board (WRB).

WRB Director General R.S. Wijesekare revealed that chemical compounds such as Nitrates, Phosphates and heavy metals were found in excess in many places in the districts they surveyed. The survey covered Jaffna, Ampara, Puttalam, Anuradhapura, Matale and Gampaha districts. Excessive Nitrate compounds were in samples taken from Kalpitiya and Jaffna, while Phosphate was in abundance in samples taken in Ampara. In samples from Anuradhapura, heavy metals such as Arsenic were found in quantities exceeding standard levels, he confirmed.

Some of the agrochemicals will be absorbed by plants, but most of it will collect on the soil or be washed away as runoff. Part of it leaches through to the groundwater. What goes in will come out, so not only the people in the immediate vicinity, but others in the area too could be affected by contamination.

Water samples from 30 Secretariat Divisions covering these districts have been collected periodically, under this study initiated in 2011. Mr Wijesekare said that the results have highlighted the need for some control of using agro chemicals. He said that WRB with other agencies such as the Agriculture department and farmers are planning to conduct a program in Puttalam to educate farmers to use the Agrochemicals responsibly while monitoring the ground water periodically to check for improvements of the quality. He also said the survey has been done on a Pilot scale and are trying to do the exercise covering the whole island.

Head of Sri Lanka programme of International Water Management Institute (IWMI), Dr Herath Manthreetilake has also stressed the importance of having such programmes at least in priority areas prone to groundwater pollution.

He also pointed out that periodic monitoring has to be continuous, to get a clear idea of pollution levels. Isolated incidents of chemical spills on depleted groundwater reserves due to drought, can increase the concentration of chemicals, so the results may not be entirely accurate – but data captured periodically on the groundwater condition can give a better picture. Dr Manthreetilake said that groundwater in most industrial countries such as Japan, are polluted beyond usage. Therefore, to avoid falling into the same trap, it is important to continue with a proper monitoring mechanism of groundwater sources.

Published on SundayTimes on 22.09.2013 http://www.sundaytimes.lk/130922/news/excessive-use-of-agrochemicals-pollutes-groundwater-in-many-places-63297.html 

Not only milk powder; mind about hidden poison in vegetables too..!!

August 26, 2013
Study shows farmers overuse pesticides; calls for speedy action and monitoring scheme Some cultivators grow pesticide-free vegetable for their consumption – by Malaka Rodrigo 

Reports of dicyandiamide (DCD) and whey protein allegedly found in milk powder have sparked widespread panic among consumers, but little do they know that vegetables they consume are equally if not more contaminated, according to a recent study on the use of agrochemicals by farmers.

The report based on an extensive survey in the upcountry says that although it has been advised that farmers should not use any chemicals 14 days prior to the harvesting of vegetables, some farmers do not follow this safety rule. Some 30% of upcountry farmers apply pesticides until 7-10 days before harvesting although some of them knew the harmful effects of agrochemicals, the report prepared by the Hector Kobbekaduwa Agrarian Research and Training Institute (HARTI) says.

Fit for human consumption? Vegetable plots in Nuwara Eliya

In a shocking revelation, the report also says that about a quarter of the famers surveyed maintain agrochemical-free vegetable plots for their own consumption.  This dual approach adopted by these farmers, the report says, raises the question whether they are knowingly poisoning the consumers.

The report emphasises the urgent need to monitor pesticide residues in vegetables in the market.  The report titled “HARTI Policy Brief on Minimising the Damages of Pesticides” is based on a field research conducted in the Badulla and Nuwara Eliya Districts among 240 randomly selected vegetable and potato farmers.

Only the main hill country crops potato, bean, leeks and cabbage were handpicked for the investigation by the HARTI researchers; but the outcome has been scary.  Drawing attention to recent findings that linked the excessive use of agrochemicals by paddy farmers to the mystery Chronic Kidney Disease in the North Central Province, the report notes that vegetable also could contain arsenic and other harmful residues of agrochemicals.

The research also highlights the ignorance of farmers who overuse or misuse agrochemicals. According to the survey, nearly half of the upcountry famers apply pesticide as a precautionary measure even before any appearance of symptoms of pests or disease.
“The upcountry’s misty wet environment makes vegetable plants prone to pest attacks and fungal diseases. Farmers take their own decisions as to what pesticide to use and how frequently it should be used. Usually they end up in spraying an overdose,” said M.M.M. Abeeyar who led the team of researchers and authored the report together with M.T. Padmajani and M.A.C.S. Bandara.
Farmers who spoke to the Sunday Times said pesticides had lost their strength and often the instructions given on the label of the bottle were not useful.

Cabbage farmer Chamly complained that his crop was being attacked by a pest these days, but the pesticide he used was not answering. “The instructions on the label asked us to mix 28 units. We even doubled this dose – but the problem still persists,” he complained.
Pesticides Registrar Anura Wijesekera said they were testing on the quality of pesticides at the point of import. He advised the farmers to stick to the dose mentioned on the label.

He said pesticides varied and some took time to act and this was probably why some farmers question their strength and overuse them. With the correct dosage, the pest problem could be effectively dealt with.  Dr. Wijesekera, however, noted that the quality of pesticides in the market should also be monitored.

Sarath Fernando, an official of the advocacy group, Movement for National Land and Agricultural Reform (MONLAR), said the dearth of agriculture officers to advise farmers had aggravated the problem.  “Farmers just get advice from pesticide dealers or decide on a pesticide by following their neighbours. Earlier, there were enough agricultural officers to instruct farmers,” he said.

Mr. Fernando said vegetable could be grown successfully and profitably without any use of agrochemicals.  The activist said agrochemicals killed both useful and harmful insects and the long term use would enable the pests to develop resistance to them.
Besides these direct harmful effects, agrochemicals also pollute waterways and groundwater sources.

The HARTI report recommends the setting up of pest clinics to advise farmers on the correct use of pesticides and alternatives methods.  Following the Sunday Times report last week, several experts welcomed the Agriculture Minister’s move to authorise state officials including those in the health sector and Grama Niladharis to take legal action against those resorting to the indiscriminate use of pesticides and those who encourage this practice.

They also say there should be a mechanism to monitor and stop the sale of vegetable with pesticide residues. Until such steps are taken, consumers are advised to wash vegetables properly to minimise the harm.  Pesticides are more harmful than DCD in milk powder, the experts say. They ask why the government is not taking prompt action in the same way it acted on the milk powder case.

Promote ‘Green Band’ pesticides 

The Government banned the sale of some pesticides a few months ago. But upcountry farmers say the other pesticides are not as effective as the banned products.

Pesticides are colour coded based on their hazard levels and Class I pesticides or “Red band” pesticides are banned in Sri Lanka. Although Class II and Class III pesticides are largely used in Sri Lanka, farmers are advised to use the Class IV or ‘Green Band’ pesticides which are considered ‘least harmful’.

Green Band pesticides are effective as other class of pesticides but they take more time to attack the pests and are expensive. Therefore, farmers usually go for pesticides that give instant results.

Will overuse of agrochemicals bring another ‘Silent Spring’?

The impact of agrochemicals to biodiversity has long been established.  Rachel Carson’s study – which came out as a famous book ‘Silent Spring’ in 1962 — showed how the use of DDT affected birds. She found out that the DDT that passed onto birds through the food chain made the shells of the eggs thin. Thus they broke prematurely due to the weight of the mother bird and this was identified as the cause for the decrease in the bird population.

But there can be lots of unknown impacts. The ‘National Red List 2012 on Conservation Status of the Fauna and Flora’ launched last year explains the possible impact of agrochemicals on animals and plants in Sri Lanka. The species associate in freshwater are the most vulnerable, according to the Red List.

It says the heavy use of agrochemicals has contributed to the population decline of at least two species of endemic fish, pethiya bandula and aplocheilus dayi (uda handaya) and several species of other fish. Even the washing to the pesticide tanks in waterways also affects these fish.

The excessive use of agrochemicals also poses a threat to the orchid populations, the Red List’s chapter on Orchids states. Pesticides’ impact on orchid pollinators in turn affects many other plant species. Amphibians, freshwater crabs, freshwater plants, dragonflies, reptiles, spiders, dung beetles are some of the other species that are affected by agrochemicals, according to the Red List.

Application of insecticides and weedicides should be carried out in a manner that would have the least effect, especially on pollinators such as bees – the Red List says. Measures such as application of insecticides prior to flowering and at a time of the day when bees are less active on flowers would minimize their exposure to such chemicals, it says.

All pesticides approved for release in Sri Lanka should be assessed for impact on non-target organisms and the environment in general, and the labelling of such products should include information on environmental safeguards, it recommends.

Published on SundayTimes on 25.08.2013 http://www.sundaytimes.lk/130825/news/hidden-poison-in-vegetable-agrochemicals-59490.html