 where it gets sunlight for prolonged hours, as this gives it a sunburn.
Here are the reasons which could result in the stalk or stem of the plant turning yellow, as well as the measures you can take to rescue it from this condition.
Water Problems: Yellowing bamboo stalk is caused commonly due to inadequate watering. Chemically polluted, toxic water or chemical fertilizers can also lead to yellow stalks. Therefore, make sure you use gentle fertilizer and bottled spring water.
Cold Weather: During winter, if you observe the stalk turning yellow, it is due to extremely low temperatures. For indoor gardening during winters, make sure you provide lukewarm water, and keep it in a warm place.
Mites: If you observe webbing, brown, sticky material on the leaves or stalk, it could be a sign pointing to mites. In such a case you can use a mild pesticide. Replace the plant if it shows no progress even after using the pesticide.
Fungus: This is a very common problem in cheaply produced lucky bamboo plants. This causes premature death of the plant, which means you should always buy it from high quality suppliers. If you experience yellowing of stalk due to a fungal infection, it is better to get rid of the plant.
Even after following the solutions, if the plant is not showing any progress, it is better to get rid of it. Sometimes, if your plant is over 4-6 years of age, then the stalk will turn yellow with age. That is, it is an indication that it is coming close to its natural death.
Arundo donax towers over the tallest man’s head. It’s thick, bamboo-like, and three-stories tall. It can withstand cold, and it can withstand drought. Give it water, and a little nitrogen, and it grows. Fast.
Killing it can be difficult. In California, where it was introduced in the 1800s, Arundo has gotten so out of control that in some places it seems to be the only plant growing on the riverbanks. It doesn’t have seeds, but it doesn’t need them: it has other methods of multiplying. A fierce rainstorm can tear up its shallow roots and spread them far downstream. There, they start growing all over again.
Mow it down, spray it with pesticides-it’s all futile. If any of the monstrous reeds are left upstream, they’ll grow back. Arundo doesn’t need to be near water to thrive, though. It grows pretty much anywhere. It grows in Oregon, Arizona, Texas, Missouri, Georgia, Florida, Maryland, Virginia-down the West Coast and across the broad swath of the southwest and southeast, up into the mid-Atlantic. Often it remains in small stands, growing tall, but staying in one place. But sometimes, it takes over and becomes an invasive species-an expensive problem for humans and a mortal threat for plants and animals.
Energy companies, however, are set to make Arundo one of the stars of the biofuels industry. They think they can control it. They’re willing to take the risk. But not everyone is so sure it’s worth it. If the companies fail-if Arundo does get out-it could have irreparable consequences.
In Mills River, North Carolina, up in the mountains and not far from Asheville, a small plot of Arundo has been growing since 2008, alongside switchgrass and another unusually tall plant called giant miscanthus. This patchwork of grasses was planted as part of a study on crops that could feed a next-generation biofuel plant. The qualities that make Arundo frightening to people who’ve dealt with it as an invasive-its size, sturdiness, and quick growth-make it attractive to the biofuel industry. Although it’s not the only biofuel crop North Carolina is looking to grow (or the only one that’s considered invasive elsewhere in the country), it does have the potential to yield the most biomass per acre-a key metric to making next-generation biofuels financially feasible.
“It’s the difference between having this industry work or not work,” says Matt Harrod, a director at Chemtex International. An Italian-owned polyester fiber, plastics, and design technology company, Chemtex has dipped into the biofuels market, and worked with liquefied natural gas, as well. Last year, in Crescentino, Italy, the company started up the world’s first commercial-scale plant to make ethanol from plants like Arundo instead of corn or sugar cane. The company’s also part of a joint venture that invested $200 million in developing a process to make this sort of cellulosic matter a cost-effective source for biofuel. Now, Chemtex wants to bring that same process to America, and has spent almost a million dollars lobbying the federal government over the past two years.
For years, the biofuel industry has been chasing the advantages of developing plants like Arundo as biofuel crops. And while there’s reams of research on different sources and strategies for creating cellulosic biofuel, the industry has had little success scaling that research up into a commercial enterprise. If “energy grasses” are proven a financially viable feedstock, the crops that feed ethanol plants could be grown on marginal land, with less chemical fertilizer than corn. The amount of land needed to meet the government’s renewable-fuel goals could shrink, too. But growing a crop like Arundo on an agricultural scale is the botanical equivalent of adopting a wolf. Most agricultural crops are like dogs: we’ve spent thousands of years domesticating them; we know, more or less, how they behave; we can control them. Like a tame wolf, Arundo might seem like it’s behaving well now, but there’s an inherent danger in having it around.
“We haven’t talked about doing something on this scale in this time period since the invention of agriculture,” says Jacob Barney, a professor of invasive-plant ecology at Virginia Tech University, who’s studied these grasses. Corn has been bred for 10,000 years to grow only where humans plant it. Arundo’s been bred for only a fraction of that time. “It’s a wild thing,” Barney says.
To the industry, ultimately, planting Arundo is about saving money. Higher yields per acre mean they have to spend less on land. Chemtex plans to contract with farmers to grow 18-19,000 acres of biofuel crops, according to Harrod, the Chemtex director. So far, he has about half of that accounted for, with switchgrass and biomass sorghum. Adding Arundo to the mix could help keep Chemtex’s costs down.
In southeastern North Carolina, the land that’s most likely to be converted to fields of energy grasses is currently growing bright green, knee-high Bermuda grass for cow forage. But one day soon, you could driving down the same country road by these same fields and all of a sudden start feeling a little like Rick Moranis in Honey I Shrunk the Kids, with fields of grass stretching far above your head.
It’s difficult to predict if a species will become invasive in any particular place. But once it does it’s almost impossible to stop its spread. California has spent tens of millions of dollars trying to get rid of Arundo, and across the country, invasive species cost the economy a total of $7.7 billion in eradication costs and lost agricultural productivity. Many of these plants were planted by well-intentioned people for good reasons.1 1. Kudzu, the most commonly cited scare story, was originally intended to provide shade and prevent soil erosion; it has taken over millions of acres of land. (There’s been some interest in using kudzu as a biofuel stock, as well.).
The little regulation that does exist is inconsistent. Maryland has six plants on its noxious-weed list. None of those plants are on Virginia’s list. California has listed Arundo as a noxious weed. So have Texas, Hawaii, and Tennessee. Fourteen states consider it invasive. Environmental groups pushed for North Carolina to add Arundo to the state’s noxious weed list, but earlier this year, the state’s Board of Agriculture denied their petition. The state government has long been promoting the biofuel industry; the board said that Arundo could be grown “responsibly,” as long as proper management practices were in place.
Right now, the federal government is paying scientists to figure out how make Arundo grow even bigger and faster while simultaneously paying other scientists to figure out how to eliminate it. Lambert’s lab is collaborating with the USDA’s Agricultural Research Service to find a biocontrol agent for Arundo-a bug or a fungus that naturally keeps it in check. In the long run, using biocontrol is cheaper than continuing to plow money into chopping Arundo down and spraying it with pesticides.
Like Arundo, though, these “agents” are wild things. “Once you release them, you can’t get them back,” says Lambert. If these scientists find the right insect and release it in California, there’s no guarantee it won’t make its way across the country, to fields where Arundo’s being grown as a biofuel, and decimate those crops. Scientists who do this work worry that the biofuel industry’s interest in Arundo will create political heft that weighs against their own work. Given the money Chemtex has already spent on lobbyists, it’s not an unjustified fear.
This is the story of every form of energy-new or old-that the country is pursuing right now. Fracking horizontal wells is riskier than