Fruit Science Report Washington Navel Oranges

Fruit Science Report
Washington Navel Oranges
Introduction
In as far as appearances are concerned, the Washington Navel orange happens to have a rounded shape and is small to medium in size. One of the many distinguishing features of this particular tree are the white flowers which are scented. The canopy of the tree also appears droopy. In mid winder, the tree supplies seedless oranges that are rather tasty – making this particular variety ideal as either a commercial venture or as a past-time activity in a home orchid setting. It is important to note that the flesh of the fruit is firm and has a distinguishing deep color. The taste of the fruit could also be described as tangy and distinctly sweet. The Washington Navel orange, according to Ramsey and Markell (1920) “originated at Bahia, Brazil, apparently as a bud variation from the Portuguese orange variety, Laranja Selecta” (22). As the authors further point out, it is the early Portuguese settlers and explorers who are believed to have introduced the said Portuguese orange variety to Brazil. It was, however, not until the 1870 that William O. Saunder received the Washington Navel orange from Australia for prompt propagation and distribution. This particular tree had been introduced to Australia 11 years earlier. The propagating of the tree and the subsequent distribution to two pilot states, i.e. Florida and California took place upon its receipt at the United States Department of Agriculture. At the time, Saunder was the U.S. Agriculture Department’s gardens superintendent. In the words of Ramsey and Markell (1920), some of the Washington Navel orange cuttings “were transplanted to Riverside, California in 1873 and started producing sweet, juicy, seedless fruit that had crisp texture and an easy to peel skin” (89).
The history of the Washington Navel orange would largely be incomplete without the mention of Eliza Tibbets. Tibbets was a recipient of the trees sent to California. Those sent to Florida failed to flourish. To a large extent, as it has been pointed out elsewhere in this text, the climate of California was ideal for the tree’s culture. In the words of Ferguson and Grafton-Cardwell (2014), “it is believed that Tibbets received and planted three trees in his dooryard, located near the present junction of Central and Palm Avenues, two of which survived and became sources of budwood a few years later” (113). In that regard, therefore, it is these trees in the dooryard that ended up feeding the navel-orange industry in California.
In essence, the Washington Navel orange comes from the Rutaceae family and the Citrus genus. On the other hand, in as far as species is concerned, the Washington Navel orange happens to be a Sinensis. The tree grows to a height of approximately 6 to 30 feet – but with the dwarf variety reaching a maximum height of only 8 feet. Commercially, Washington Navel oranges could be found in California, Florida, and Arizona states of the U.S. Outside of the U.S., the tree is found in relative abundance in Egypt and Brazil where it is also grown commercially. In California, the San Joaquin Valley regions happens to be the primary Washington Navel orange growing area. El-Boray, Mostafa, Salem, and Sawwah (2015) point out that although the tree happens to be a key income source among commercial growers in various locations across the world, yield happens to be quite erratic. In the words of the authors, Washington Navel orange “yield is erratic and usually low in many areas due to lack functional pollen, rarely produce viable ovules and in addition, it is weakly parthenocarpic” (El-Boray, Mostafa, Salem, and Sawwah, 2015, p. 1320).
Production
Production Quantity
It should be noted, from the onset, that subtropical climates happen to be optimal for the growth of Washington Navel orange trees. Although there are some significant variations in fruit production from tree to tree, from a general perspective, Washington Navel orange trees, according to Ferguson and Grafton-Cardwell (2014) “produce 10 to 15 pounds of fruit during their third year but can produce up to 150 pounds when they reach full maturity... early and mid-season varieties can produce up to 250 pounds of fruit at maturity” (112). In California, the quantity of Washington Navel orange trees grown is enormous. Indeed, as Boule (2017), observes, during the 2014-2015 season, the season was able to produce approximately 81 million cartons of Washington navels. California happens to be ideal for the growth of the Washington Navel orange due to its favorable climate – i.e. mild and dry. This is particularly the case given that freezing weather does not favor oranges and, thus, the State’s taste of sunshine is largely ideal. In essence, the Washington Navel orange performs best in sandy-soils that are fast-draining and deep. However, the tree has been known to do well in many kinds of fast-draining soils. The fruit-bearing period of the Washington Navel orange, according to Considine and Considine (2012) commences in December and proceeds well into the months of April and May. However, according to the authors, mid-January happens to be the period during which sweetness peaks.
Best Practices in Planting and Cultivation
Ferguson and Grafton-Cardwell (2014) recommend planting the Washington Navel orange in an area that is sunny. The authors further point out that ideally, only those trees that have “a good skirt of branches near the soil line” should be selected for planting” (Ferguson and Grafton-Cardwell, 2014, p. 117) This essentially means that for all intents and purposes, trees whose trunks are long should be avoided. It is also recommended that at the time of planting, any of the tree’s fruits should be picked off. This essentially stimulates the tree to make new foliage as well as roots. The relevance of water and fertilizer cannot also be overstated at the onset. This effectively means that in addition to ensuring that the tree is thoroughly watered, citrus-tree fertilizer should be applied – albeit lightly. However, going forward, it is important to note that in late fall, the tree should not be fertilized. This is more so the case given that this would, as Ferguson and Grafton-Cardwell (2014) point out, essentially “promote new, tender foliage growth that could be subject to frost damage during the winter” (117). In seeking to maintain fruit quality, pruning is of great relevance. A sunny position and soil that is humus rich are also essential for the wellbeing of the tree.
As it has been pointed out elsewhere in this text, Washington Navel orange supplies fruit that is seedless. The seedless fruit is in this case as a consequence of blooms whose pollen is not viable. It therefore follows that other citrus trees cannot be pollinated by the flower because of this particular insufficiency. In that regard, therefore, left to its own devices, the Washington Navel orange cannot be able to partake in the propagation of navel orange trees. It is for this reason that, as Susser (1997) points out, various citrus tree varieties come in handy in the propagation of navels via grafting.
In as far as drought-tolerance is concerned, Considine and Considine (2012) observe that this happens to be a moderate draught tolerant plant. It should be noted that to a large extent, the Washington Navel Orange does relatively well in both zone 10 and zone 9 parts. This is more so the case given that as Considine and Considine (2012) point out, “the Washington Navel Orange is more cold-tolerant than some other varieties of orange trees, and it will survive temperatures as low as 28 degrees for short periods” (113).
Other Variations
Other variations of the Washington Navel orange are inclusive of the Robertson and Trovita (Considine and Considine, 2012). In essence, unlike the Washington Navel orange, the Trovita variation thrives best in desert and coastal areas. Also, its harvest commences later than that of the Washington Navel orange. This mutation of the Washington Navel orange also has a few seeds and is much smaller. On the other hand, when it comes to the Robertson variety, the fruit happens to ripen much earlier in comparison to that of the Washington Navel orange. The fruit quality also happens to be lower. Considine and Considine (2012) observe that this particular strain of the Washington Navel orange has a more rapid early growth – and hence “is resistant to the June drop” (34).
Diseases and Other Problems
The Washington Navel orange is exposed to a number of problems – from abiotic disorders to fungal diseases, insect problems, and plant diseases. It is important to note, from the onset, that in as far as plant diseases are concerned, there are quite a number of bacterial as well as viral infections that pose a risk to the Washington Navel orange. According to Ferguson and Grafton-Cardwell (2014), a particularly troublesome disease that affects the tree is known as the citrus stubborn disease (CSD). Apart from CSD, there are also other equally troublesome diseases which could affect the growth and productivity of the Washington Navel orange. These are inclusive of the phytophthora root rot, the brown rot, and the anthracnose. Next, it as far as insects are concerned, it is important to note that there are quite a number of insects that could occasion significant damage to Washington Navel orange trees. While some are disease carriers, others feed off the plant and cause stunted growth. Some of the insects known to wreak havoc on this front include, but they are not limited to, mealybugs, citrus leaf miners and cutworms, and California red scales (Ferguson and Grafton-Cardwell, 2014). Others are aphids and Asian citrus psyllid.
Third, fungal infections also deserve mention. Ferguson and Grafton-Cardwell (2014) point out that the key spreading agent of these infections happens to be spores whose primary mode of dispersion is rain and wind. Alternaria rot is one such fungal disease. According to the authors, this particular infection brings about or occasions premature color change of oranges. In the words of Ferguson and Grafton-Cardwell (2014), “infected fruit color prematurely and if they do not drop, later develop a deeper orange color than healthy fruit” (79). Lastly, there is also the issue of abiotic disorders. In basic terms, these could be conceptualized as concerns that are not triggered or brought about by living organisms. In that regard, therefore, these are often a consequence of a wide range of issues emanating from the environment, i.e. deficiencies in soil nutrients, flooding, sunburn, strong winds, extreme temperatures, etc. A good example of an abiotic disorder is the navel orange split. Geiger and Dunkan (2007) observe that this particular disorder is occasioned by the swift movement of plant sugars and water to the fruit – effectively affecting the ability of the said fruit to “produce enough rind to hold the substances... the excess fluids cause the skin to burst” (95). One effective strategy in seeking to reign in this abiotic disorder is the adoption of effective watering practices and ensuring that the fruit does not suffer sunburn.
Other factors Impacting Production
Apart from the age of the tree, as has been highlighted elsewhere in this text, there are various other factors that have an impact on Washington Navel orange tree production. These include, but they are not limited to, time of year and application of fertilizer. It is also important to note that there are various approaches that have been embraced in an attempt to improve the fruit quality as well as yield of the Washington Navel orange. One such approach, according to El-Boray, Mostafa, Salem, and Sawwah (2015) is the utilization of certain foliar applications of some natural biostimulants. In a study seeking to assess the impact of biostimulant treatment on the Washington Navel orange fruit quality and yield, the authors found out that “all biostimulants treatments increased fruit set, yield and fruit quality and decreased fruit drop as compared with control treatment (El-Boray, Mostafa, Salem, and Sawwah, 2015, p. 1320).
Conclusion
In the final analysis, it should be noted that this particular tree also happens to be ideal for the backyard orchid. This is more so the case given that it supplies oranges that are not only seedless, but also tasty. Today, the tree is largely considered to be of great significance to California’s citrus industry. Many find it delicious to eat. There are also others who like the fruit due to its lack of pesky seeds. The fact that it is relatively easy to grow also makes it an ideal plant for both commercial and domestic purposes. However, it should be noted that there is need to embrace evidence-based practices in the planting as well as cultivation of the Washington Navel Orange. This would help protect the tree from some of the problems affecting its growth and wellbeing – as has been highlighted elsewhere in this text. Given its rich history in California, it is highly likely that the Washington Navel Orange will continue to be an important part of the citrus industry in this very region.
References
Boule, D. (2017). A Brief History of the Navel Orange in California – From the Sacramento Bee. Retrieved from http://www.merlofarminggroup.com/brief-history-navel-orange-california-–-sacramento-bee
Considine, D.M. & Considine, G.D. (2012). Foods and Food Production Encyclopedia. New York, NY: VNR.
El-Boray, M.S., Mostafa, M., Salem, E. & Sawwah, O. (2015). Improving Yield and Fruit Quality of Washington Navel Orange Using Foliar Applications of Some Natural Biostimulants. J. Plant Production, 6(8), 1317-1332.
Ferguson, L. & Grafton-Cardwell, E.E. (2014). Citrus Production Manual. Richmond, CA: UCANR Publications.
Geiger, P. & Dunkan, S. (2007). Farmers' Almanac. Mason, OH: Almanac Publishing Company.
Ramsey, H.J. & Markell, E.L. (1920). The Handling and Precooling of Florida Lettuce and Celery. Washington, DC: Government Printing Office.
Susser, A. (1997). The Great Citrus Book. New York, NY: Ten Speed Press.