Papaya Essay

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Papaya have become a favourite tropical fruit worldwide, being known for its sweet taste and aromatic undertones. It is fruit of the plant, Carica papaya which belongs to the family Caricaceae. Papaya ringspot virus (PRSV) is a pathogenic plant virus that’s grouped as ‘RNA viruses’ belonging to the the Potiviridae family and Potyvirus Genus PRSV is known to be rod-shaped and between 760–800 nm long. Studies have shown that PRSV could have originated as back as 2000 years ago , yet was only discovered in Hawaii in the late 1930s. The pathogen is grouped into two classifications , PRSV-Papaya(p) which infects both cucurbits and papaya and PRSV-Watermelon(w) which is limited only to cucurbits. The Disease Cycle Epidemiology PRSV-P can infect both Papaya and cucurbits such as watermelon and squash, while PRSV-W can only infect cucurbits. It was found that originally only type-W was present in Australia , while type P was discovered 20 years later. It is believed that PRSV-P originated as a result of mutations in PRSV-W. A Sequence analysis of both types showed that the coding sequence of the coat protein were very similar in both. (SCREENSHOT CITATION) Transmission Plant Viruses don’t produce any specialized structures for propagation or dispersal therefore most plant viruses cannot divide for long periods outside of a host. Transmission can occur via mechanical contact such as plant-to-plant interaction, human handling and through tools used during cultivation. Generally in the field the single most important method of transmission is by the Aphid vector. Aphids feed on plant sap of epidermal cells or phloem via their sucking mouthparts. Essentially when an aphid arrives on a plant, the stylets are inserted into the phloem f... ... middle of paper ... ... have more then one set in place to reduce wait time. Wash hands regularly, or wear gloves, again it slows down but its better then transmitting the disease. Roguing Removing the source of infection by eliminating any infected plants , this will reduce spread via plant-to-plant interaction, and vector interaction. However, this isin’t very practical , as symptoms may take up-to three weeks to appear an by then it would have spread. Netting In Taiwan, papaya plants were covered with netting in-order to ensure that aphids had limited access to the crop , therefore resulting in more healthy produce. This proved to be popular as it was effective against the aphids however the quantity of fruit remained high but the quality had degraded as a result of this limitations imposed by the net. The netting comes with consequences both financially and environmentally.

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