Green-tech

Gene editing can sound like the stuff of sci-fi nightmares. Given the ability to selectively snip into the human genome, will we yield to the temptation to try to generate perfect little versions of ourselves? If we can dip into the genetic code, selectively editing for the traits we do or do not value, is that a Frankenstein scenario in the making? Probably not. “While scientists are focusing on an array of applications in the areas of health, agriculture and environment, fi ghting disease and improving health in humans is a top priority for many,” said Dr. Catherine Bliss, assistant professor in the University of California, San Francisco, Department of Social and Behavioral Sciences. As the name suggests, gene editing is the process whereby scientists “cut and paste strands of DNA — actually inserting, removing and replacing them — to modify an organism’s genetic code,” Bliss said. In a 2015 summit, scientists from around the globe agreed to channel their eff orts toward fighting di

The vi deo from MIT’s SelfAssembly Lab is not astonishing at fi rst glance. A string of plasticlooking material about a foot long is immersed in water. In seconds, the object seizes up, contracts and reshapes itself into a new confi guration. It may not look like much, but the implications are profound. The technology here is known generically as 4-D printing, or self-assembly. Unlike 3-D printing, which has become increasingly common, 4-D printing incorporates the added dimension of time, producing objects that possess the ability to evolve their properties under changing conditions. Researchers say it is akin to taking a simple fl at cloth and programming it to curve itself into complex threedimensional shapes. The transformation might be triggered by water, or by heat, light or electrical current. While it isn’t commercially available, lab tests have shown it is at least technically feasible. The process requires specialized materials, many of which are currently being investigated.

One nanometer is one-billionth of a meter. How small is that? Well, a sheet of paper is about 100,000 nanometers thick. It can be hard to conceptualize on that scale, and yet engineering is happening there. The United States National Nanotechnology Initiative cites examples, including nanotechnology-enabled catalysts that improve the combustion of methane to decrease greenhouse gas emissions, and nanosensors to detect things like moisture levels and diseases in food crops. Such sensors could help firefi \ghters and soldiers by detecting toxins in the air. Using sophisticated tools such as the scanning tunneling microscope and the atomic force microscope, nanotech scientists are making inroads on a number of fronts. In health care, for instance, nanoparticles can seek out tumors and deliver drugs. They can push the boundaries of DNA sequencing and perhaps enable tissue regeneration or advanced wound treatment. In one recent article published on Phys. Org, a science news service, scien

There are two main types of apple – dessert varieties which are eaten fresh and culinary or ‘cooking’ apples which are generally large in size and very sharp if eaten raw and need to be cooked before eating (usually with the addition of sugar). A few varieties are dual-purpose – they can be used either for cooking, or eaten raw after a period of storage to allow the apples to sweeten. There are also varieties grown specifically for cider-making. Some varieties of apple are ready for harvest as early as late July, but most will be ready for picking in September or October. For the benefit of the school calendar, we have selected varieties which will be ready for harvesting at the start of the school year in September. Most of the varieties listed below have good or partial resistance to scab or mildew, which are common disease problems in apple (see later section on ‘pests and diseases’) and are relatively easy to grow. Training Apple Trees. There are many different ways i

Fruit trees need water at the right time, but it can be confusing knowing when, and how much to give them. What most fruit growers don’t know is that if you want to grow good fruit, one of the most important times for your fruit trees to have enough water is spring. If the soil is too dry at that critical time, your fruit will be small that season, no matter how much water you give the trees later on. That’s because during flowering, when the fruit is fertilised, it goes through rapid cell division, and if it doesn’t get enough water at that time, cell division is limited. That’s going to limit the size of the fruit later in the season, even if the tree gets plenty of water. There’s no fixed rule about how much water a fruit tree needs, but it’s not too hard to work out. It depends on several things: • The age of the tree • The amount of fruit it has on it • Your soil type • The temperature • How windy it is There are some simple ways to check soil moisture in your garden. O

Getting the pruning right can make the difference between whether or you not your trees bear fruit, and is one of things we answer most questions about! Apricots and cherries are often pruned in summer, but other fruit trees such as peaches, nectarines, plums, apples, and pears are usually pruned when the trees are dormant, in winter. On the farm we prune about 5,000 trees each year, including cherries, apricots, peaches, nectarines, plums, apples and pears. Pruning can be extremely confusing – every book (or expert) seems to tell you a different thing! That’s why we base all our teaching on an understanding of the basic principles, because once you understand how a tree is likely to respond to a pruning cut, it makes it much easier to make pruning decisions. There’s no ‘right’ or ‘wrong’ with pruning – there’s just understanding the basics, getting to know your trees, and the wisdom that comes with experience and pratice. Got a monster tree in the backyard? Occasionally a

You may already have some established fruit trees in your garden, or you might be planning to plant some. Whatever your situation, there are ways you can keep improving your fruit tree garden so that it better meets your needs. To get started on your planning, ask yourself these basic questions: How much fruit do I want to grow? (How much fruit do you and your family eat each week.) Do I want to preserve any fruit to eat over winter? How much space do I have? What types of fruit do we like to eat? What other purpose (if any) does my fruit tree need to meet (eg shade, beauty, screening an unwanted view, providing extra income...)? By choosing the right varieties that ripen one after another. We pick fresh fruit from November right through until May, with a selection of new varieties (and types of fruit) ripening up most weeks. For example, one week we might be picking 2 types of you could be picking fruit from your own trees from spring thr

When it comes to keeping your fruit trees healthy, prevention is better than cure! Keeping your fruit trees strong with healthy soil, good pruning, enough nutrition and water, and managing the crop load, as we’ve already described, are the first steps to preventing pests and diseases. Healthy trees are much less likely to be attacked (just like healthy people are less likely to get every cough and cold that’s going around!). There’s also lots of strategies you can use to protect your fruit trees from pests and diseases (these are the tricks that professional organic orchardists use): • Pick up all fruit from the ground under your trees throughout the fruit season, as it can easily spread disease to healthy fruit. • Make sure enough light and air can circulate around your fruit trees with pruning and weed control. Monitor your tree for pests and treat them—only if necessary—before they cause too much damage to a tree. Very often, the appearance of a pest will be followed by

Kenya has over 40 varieties of avocado. Hass is the main export variety and Fuerte is preferred for processing. Other commercial varieties are Keitt, Reed, Booth 8, Simmonds, Pinkerton, Nabal, Puebla, Tonnage, Ettinger, Hayes, G6 and G7. Varieties used as rootstocks include Puebla, Fuerte, Duke, G6, and G7. Avocado performs best between 1500-2100m a.s.l. with 1000 mm of well-distributed rainfall. Avocado thrives in deep (about 1 m of topsoil), permeable and free draining soil with adequate moisture retention and a pH of 5.5-6.5. Mulches and manure should be added to soils low in organic matter. Waterlogged soils favour the development of Phytophthora root-rot (see diseases). It has very low tolerance to salinity. If the pH is above 6.5, Gypsum (CaSO4) may be used to lower it. When laying out the field, one should consider the type of soil and climatic conditions, tree type and size, irrigation, and farm machinery access. The initial cultivation should be deep to allow be

Women are strong drivers of agroecological change in farming and consumer communities. One example is the women’s movement for agrobiodiverse, pesticide-free crop production in India. In other places, women experiment with intercropping, vegetable box schemes and seed exchanges. What motivates them? And what role does agroecology play in improving the lives of women? There are 500 million small scale farm families around the world, and 70% of the agricultural work on these farms is done by women. According to FAO, women could increase their productivity by up to 30% if they had the same access as men to productive resources. We have long known that women hold important agriculture and food knowledge, and that they are a force pushing for agroecological changes that lead to resilient farming. Where men tend to focus more on economic gains, women’s ultimate concerns tend to food sovereignty and nutrition, social stability and peace, and the conservation of biodiversity and nat

In the eyes of many, farming is not considered a desirable career. However, a growing number of urban youth see things differently. After a ‘first life’ outside agriculture, and often with a university degree, they have decided to become farmers. We call them new peasants. And many of these young people choose agroecology as an alternative way to enter the food system, promoting both social and environmental sustainability. This is a new urban–rural link, and a growing counter force to the dominant trend of rural outmigration. In interviews, new peasants in France told us they find fulfillment in farming. But they also emphasised that farming is a risky business, and it takes several years to build a secure livelihood from it. New peasants have little prior agricultural knowledge, and certainly no ‘family land’ to inherit. They often have to learn how to farm without the support of their rural neighbours who consider them ‘outsiders’. Lack of land due to high prices and land grab

Protecting Birds During the 1990s, there was just one Spix’s macaw left in the wild and that one disappeared in 2000. Luckily, there is a captive population that should reach 170 by next year and there are plans for a reintroduction programme. Spix’s macaw is only found in Brazil and is confined to the socalled ‘caatinga’ biome in the north-east. Caatinga is a dry area dominated by small trees, bushes and cacti and forests with larger trees that form alongside rivers. The parrots require the large trees, especially the caraibas that can grow 25m high, for nest cavities. Though habitat loss was a factor in its disappearance, the main reason the species went extinct in the wild was the illegal pet trade. And while there is still a problem with people trying to collect wild birds, the area around Curaçá, where the caatinga habitat is found, is very different to what it was 30 or 40 years ago and it is much harder to do things without being noticed. For instance, when a Spix’

The Komodo Dragons Komodo dragons inspired legends of fire-breathing monsters and, as Mark Eveleigh discovered, the truth is almost as strange as the fiction. Even on a bright, sunny day there’s something ominous about the Komodo archipelago. It’s as if the islands are trying to live up to the legend of their dragons. Sailing east from Bali across the famous Wallace Line, you pass the jungleclad peaks of Sumbawa and the soaring cone of Sangeang volcano before entering a tangle of islands that seems to be cut off from the world by the treacherous currents notorious among sailors. Then the sun-burned, savannah hills of Komodo island rise on the horizon, appearing more African than lush Indonesian. They are stubbled with prehistoric-looking lontar palms. Locals on neighbouring Flores island tap these palms to make a sort of arak with the unlikely name of sophie. On Komodo, however, people don’t venture into the hills unless strictly necessary. “A big ora killed a goat here yest

Though we often refer to Tegenaria and Eratigena as house spiders, for most of the year nowadays we are actually far more likely to come across these species in our gardens, garages and outbuildings. These are areas where we tend to be far less scrupulous in our cleaning and tidying – and where there is therefore much more potential prey. If spiders are left undisturbed, females can live for several years and may stay in the same web complex throughout this time, repairing the sheet and enlarging the funnel as necessary. So, if house spiders are more commonly seen in locations other than our houses for most of the year, why do we see so many of them in our bedrooms, bathrooms and living rooms in autumn? The reason, as with so many activities involving animals, is sex. During spider season, male spiders are on the lookout for females and it is their romantic wanderings that bring them into our homes. In common with many different animals, it is male spiders that are the disper

Amazing Spiders During t his time of year, when summer draws to an end and autumn begins to take hold, is wonderful for exploring nature. There are amazing colours in our parks and gardens, a bounty of hedgerow berries, spectacular starling murmurations and fabulous fungi. However, for a substantial number of people – including many wildlife enthusiasts – this is also the start of an eight-legged nightmare in our homes, because September is spider season! The first sign that the season has arrived might be a big, hairy arachnid in your bath in the morning, or one scuttling quickly across your living room carpet as you watch TV in the evening. From that first sighting many wary householders – even those who are not arachnophobic – start to approach darkened rooms with trepidation. Spider sightings continue, seemingly relentlessly, into midautumn. But then, as abruptly as it started, spider season comes to an end. So what’s going on? It was an irresistible challenge to a pair of scient

Do hydroelectric turbines harm fish? Small scale hydroelectricity projects have been springing up all over Britain in the past decade as a means of harnessing clean energy from local rivers. Eight years ago, the weir next to the ruined water mill at Howsham on my local river, the Yorkshire Derwent, became the first site in the country to house an Archimedean screw turbine. The screw lies in a trough half in, half out of the water and rotates rather slowly as gravity pulls the water down the drop. The technology is exceptionally fish-friendly far from helter-skeltering around the screw as some visitors imagine, the fish (and other waterborne objects) drop gently through the thread as it turns above them and emerge at the bottom, unscathed and arguably safer than they would be running the weir itself. The same can’t be said for devices with fastspinning blades, which require mesh screens to prevent fish from being drawn in, adding to set-up and maintenance costs as the screens consta

How many marine aliens come to UK shores? No one knows for certain. Many will perish on arrival, particularly those that hail from warmer waters. Just 10 per cent are likely to survive and only 10 per cent of those will become invasive. Many aliens arrive by natural means, driven by wind or ocean currents. But with the huge increase in global trade and human movement over the past century, opportunities to hitch a lift usually via hulls and ballast tanks have risen. Many invasive species in the UK come from other temperate habitats in Japan, Australia and the US. They include the carpet sea squirt Didemnum vexillum, which can smother the seabed for kilometres, and the slipper limpet Crepidula fornicata, which alters habitats over huge scales. Such newcomers are estimated to cost the economy £1.7 billion per year, but we export species, too. Our common shore crab is now prolific in Australia, South Africa and North America, and counts among the world’s 100 worst invasive specie

How long do chimpanzees live? The longest recorded lifespan for a chimpanzee in captivity is 62, though a less reliable record exists of a female living until 78. Lifespan in the wild is harder to gauge, but a recent study of 306 chimps at Ngogo in Uganda’s Kibale National Park showed the average life expectancy to be about 33 years.  This is nearly twice as old as has been found for other chimpanzee groups, and about the same as the average lifespan of human hunter-gatherers. But the Ngogo group is not a typical one. Unlike other groups studied, it inhabits a productive, healthy forest with low levels of human disturbance. In which case, it might be a more accurate reflection of natural lifespan. CHIMP PESTICIDE ALARM Chimpanzees and baboons in Uganda are being born with abnormalities, including limb deformities, cleft lips and reproductive problems, that are being caused by pesticides. Wildlife in the northern area of Kibale National Park in western Uganda survives close to

Perhaps an answer has come in the advent of “ clean cars ”. These can be defined as vehicles that are electrically propelled using either bat - teries or fuel cells that run on on-board hydrogen, and often a hybrid of the two. The idea of electrical cars has been mooted for years, but it is only now, with the proven effects of climate change, that enough is being done to make them a viable commercial prospect. Rise Of Electric Cars Indeed, change is already upon us. Monthly figures published by the Society of Motor Manufacturers and Traders suggest that electric car sales in the United Kingdom have risen significantly over the past few years. While only around 500 electric cars were registered per month during the first half of 2014, this has now risen to an average of 5 000 per month during 2018 1 ) . Yet their production is not straightforward and many challenges face both producers and consumers before they can be considered mainstream. The first target, as Mr Yasuji Shibata,