Green-tech

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