ORANGE; AN INDIGENOUS PLANT

                                     

  ORANGE; AN INDIGENOUS PLANT

               

        INTRODUCTION

^1.    Orange is a round fruit, consumed mainly in winter. Its fleshy and is formed by small bags full of juice. The orange is used for consumption as fresh and for the industry, mainly in juice, fresh oranges are low in calories and a source of fiber, potassium, vitamin C and folate. They help to prevent cancer and cardiovascular diseases. There is a great amount of varieties which can be distinguished by their shape, size and by their color: red or orange, by their flavor, since they are sweeter or more acidic, by the time of maturity, and for having seeds or being seedless

        Varieties

2.    Most of the oranges grown are, 'Washington Navel' and the 'Valencia'. Florida's commercial cultivars are mainly: (early) 'Hamlin'; (mid-season) 'Pineapple'; (late) 'Valencia'.

      Pollination
3.    If orange farmers select to grow an orange tree from seed, this tree will probably not be able to produce fruits in less than 10 years. Moreover,  his tree will be susceptible to diseases. Thus, nowadays orange trees are usually propagated by grafting. In that way, orange farmers benefit from a combination of two different plant tissues, the root stock and the scion. The root stock is a healthy mature tree (not necessarily orange tree, but definitely citrus) and the scion is a desired and highly productive orange variety. In this way, orange farmers can plant the grafted orange trees (that are often one or two years old) and harvest a fair production usually after 1-2 years. Grafted trees are more resilient than “natural” trees, as the root stocks have been selected according to their resistance in cold, heat and various (local and universal) diseases. Nowadays, citrus trees other than orange (for instance rough lemon) are often used as root stock for orange production. Bees are definitely the most important carriers of pollen in the pollination of citrus, while the wind and some other pollinating insects such as thrips have little importance. Although the orange blossoms are self-fertile and theoretically do not need bees to cross pollinate and set fruits, the pollination activity of honeybees has been found to significantly increase fruit set and production. 

Climatic conditions

Citrus will tolerate high temperatures provided the trees are well supplied with soil moisture. Trees are sensitive to frost, but this varies with variety, tree age and health. Orange trees prefer light to medium textured soils, with good drainage and free from stagnant water. Orange fruits do not grow well in the ground where there was before another citrus field and this is attributed to the ground’s accumulation, over time, of some toxic substances and/ or the presence of some particular pathogens (often Thielaviopsisbasicola and Tylenchulussemipenetrans). A suitable location for installing orange field is normally a downhill position, resulting in a flat surface, where the cold currents can escape freely.¹⁶ Soil erosion in such a location is mostly avoided by installing areas of grass retained at a low level between the planting rows of trees.¹⁷ In soils with high inclination, it is better to create terraces.¹⁸ Satisfactory production is achieved In soils with pH 5,5 (mildly acidic) to pH 6,5, but the tree can tolerate pH 4,5 to 8. Orange is a crop that is sensitive to salts.¹⁹ Thus, if the water contains a large amount of salts, the growth and productivity of the trees can be limited.

Harvesting

Manual picking:²⁰ This has been tradition for hundreds of years, oranges are typically picked from the orange tree by hand. ²¹ Workers lean ladders against the tree, or stand it up near the tree, and climb to the top to pick the oranges from the tree branches. ²² Once removed from the tree, oranges are placed into canvas pick sacks which typically worn over the torso of the body.    

 

Canopy shake:²³ The canopy shake method of mechanical harvesting for oranges refers to a self-propelled machine that shakes the oranges free from the orange tree^.24 The oranges fall from the tree and are collected into a catch cloth, which can be a tarp or other large piece of fabric.²⁵ The catch cloth is then dumped into a truck called a "goat" which then dumps the oranges into an empty semi-truck trailer. 

                                                                                                                                   

Tractor shaking:²⁶ Another method of mechanical orange harvesting is called tractor shake.²⁷ Unlike the canopy shake method, which uses a catch cloth to catch the falling oranges, the tractor shake method simply uses a tractor to shake the oranges free from the tree.²⁸ Once free, the oranges simply fall to the ground where workers pick them up and place them in a canvas pick sack.²⁹ This method is actually a combination of manual and mechanical picking.

Diseases

³⁰ When properly planted and cared for, orange trees don’t suffer a lot of disease or insect problems.³¹ Preventing frost damage is often the most pressing issue, depending on where you live, because orange trees can not tolerate temperatures much below 32 degrees, depending on the variety.

Psorosis Bark Scaling Virus Disease:³² This disease causes patches of scaling or peeling bark on the trunk and branches.³³ It is most common in older trees. Unfortunately, there is no cure.³⁴ Continue to care for the tree properly to maintain health. If the tree becomes girdled, it will die and should be removed.

Foot Rot Fungus:³⁵ Lesions and cankers around the base of the tree usually indicate foot rot fungus, especially if the lesions ooze sap.³⁶ This disease is not treatable. Remove and destroy infected trees.³⁷ To minimize the risk of foot rot fungus, plant trees in well-draining soil and avoid overwatering them.³⁸ Raised beds and berms are necessary if you have heavy clay soil.

Sooty Canker:³⁹ Twigs and branches of trees infected with sooty canker develop peeling bark.⁴⁰ Underneath the bark, you’ll find a black fungus.⁴¹ The leaves may turn brown and wither and the twigs may die back.⁴² To control sooty canker, remove all infected branches.⁴³ Cut them back 12 inches behind the infected area and disinfect your tools between cuttings by dipping them in a solution of one part chlorine bleach to 10 parts water.

Sooty mold:⁴⁴ Trees affected by sooty mold have blackened spots on the leaves. Sooty mold is not really a disease, but a fungus that feeds on the honeydew left behind by aphids and leafhoppers.⁴⁵ Wash the spots off with a gentle soap and water solution.⁴⁶ In most cases, aphids and leafhoppers leave on their own, especially if your garden has plenty of predatory insects like ladybugs.⁴⁸ In severe infestations, though, you can try spraying the leaves with a steady stream of water or with an insecticidal soap or oil.

Tip or Marginal Leaf Burn:⁴⁹ Yellowing at the tips or edges of the leaves usually indicates excess salts in the soil, rather than a disease.⁵⁰ To alleviate this problem, flood the soil several times each year to help dilute and leach out the salts.

Citrus Greening:⁵¹ This bacterial disease is spread by the Asian citrus psylid and causes yellow mottling on the leaves.⁵² You might also notice that the midvein seems enlarged and pronounced.⁵³ There is no cure for this disease, although proper care can help the tree survive.

Cigar Leaf Curling:⁵⁴ Wilted, curled and brittle leaves usually indicate the tree isn’t getting enough water.⁵⁵ Install at least three drip irrigators under the tree.⁵⁶ Frequent water during dry weather so the soil is moistened to a depth of 2 feet beneath the surface.

 

Storage facility

⁵⁷ Oranges should always be stored in the refrigerator.⁵⁸ Since oranges start to decompose as soon as they’ve been picked, storing them in the fridge will slow down the process and keep them fresher, longer.

Nutritional value

 

⁵⁹ Oranges are highly beneficial for your body.⁶⁰ A medium, 2 1/2-inch orange offers lots of vitamins, minerals and fiber, all for a measly 60 calories.⁶¹ While orange juice is also full of nutrients, you'll miss out on fiber, so it is better to consume the whole fruit.⁶² Oranges are easy to tote around, since the thick skin protects them from bruising.⁶³ Toss one in your bag for a quick mid-morning snack, add orange wedges to a grilled chicken salad or find other ways to add more oranges to your diet.

Lower Cholesterol:⁶⁴ Oranges are full of soluble fiber, which is especially beneficial for lowering cholesterol levels.⁶⁵ Soluble fiber attracts water in your gut, forming a slow-moving gel.⁶⁶ As this gel substance travels through your intestinal tract, it picks up some of the excess cholesterol compounds and pushes them out through fecal waste. ⁶⁷ Your cholesterol levels will go down over time, decreasing your risk of suffering from heart disease.⁶⁸ You need 14 grams of total fiber for every 1,000 calories, explains the Colorado State University Extension website.⁶⁹ Having an 1,800-calorie-per-day diet means that you need 16 grams of total fiber.⁷⁰ A medium, 2 1/2-inch orange has approximately 3 grams of fiber, more than half of which is soluble fiber.

Optimal Heart Function:⁷¹ Oranges provide potassium, an electrolyte mineral responsible for normal heart function.⁷² Potassium works with other electrolytes, including calcium, magnesium and sodium, to carefully maintain fluid levels both in and around cells.⁷³ Steady fluid balance allows electricity to conduct through your system, making your heart beat.⁷⁴ When potassium levels get too low, you may develop an abnormal heart rhythm, known as an arrhythmia.⁷⁵ You need 4,700 milligrams of daily potassium, according to the Linus Pauling Institute. A medium, 2 1/2-inch orange offers nearly 240 milligrams of potassium.

Lower Risk of Disease:⁷⁶ Oranges, and other citrus fruits, are chock-full of vitamin C. One of the roles of vitamin C is to protect cells by neutralizing free radicals.⁷⁷ When free radicals build up in your body, they cling to healthy cells, causing permanent damage.⁷⁸ Free radicals cause chronic diseases, like cancer and heart disease. Getting adequate amount of daily vitamin C reduces your risk of developing these chronic conditions.⁷⁹ Women require 75 milligrams of daily vitamin C, while men need 90 milligrams, notes the Office of Dietary Supplements.⁸⁰ You'll get more than 50 milligrams from one medium, 2 1/2-inch orange.

Good Vision:⁸¹ Oranges are rich in vitamin A, which includes a group of compounds that protect your eyes.⁸² Carotenoid compounds of vitamin A, like lutein, beta carotene and zeaxanthin, can help prevent age-related macular degeneration, a condition that leads to blindness.⁸³ While there is not a specified amount of how much of each carotenoid you should get on a daily basis, vitamin A does have a specific recommendation.⁸⁴ Vitamin A allows your eyes to absorb light by keeping membranes surrounding your eyes healthy and also lessens your chances of having night blindness.⁸⁵ Men require 900 micrograms of daily vitamin A and women need 700 micrograms, the Office of Dietary Supplements explains. One medium, 2 1/2-inch orange has almost 15 micrograms of vitamin A in addition to high amounts of the other vitamin A-related carotenoids.

Reference

www.bing.com/images                                                           en.wikipedia.org/wiki/Orange_(fruit)                                                           https://healthyeating.sfgate.com/