Papaya Ring Spot Virus

Papaya Annular Spot Virus / Papaya Ring Spot Virus – PRSV.

Papaya annular spot virus is caused by a virus of the Potivirus family, this disease is widely distributed in papaya producing regions in many countries around the world, among which is Mexico. It is considered as one of the most expensive diseases for its control since it considerably reduces the quality of the fruit and the yield of the plant.

Symptom.

The symptoms that can be commonly observed are chlorotic spots (apparently deficiency) and leaf and vein crushing mainly on young leaves or on the bud of the plant.

In green fruit you can see small rings, from which the name of the disease derives, which can also occur in the stems of the plant.

Figure 1. Typical symptoms of PRSV at the top of the sheet.

Figure 2. Annular spots present in the fruits and stems of the papaya plant.

Figure 3. Annular spots present in the fruits and stems of the papaya plant.

The Papaya Annular Spot Virus spreads non-persistently and rapidly over 20 different aphid species, in addition to being transmitted mechanically between plants.

This virus has 2 infective variants, type “P” and type “W”, the infective variant “P” affects the cultivation of Papaya although it can affect cucurbits while type “W” only affects cucurbits, and is considered to date It is not transmitted through the seed.

PRSV control.

Establish planting with disease-free plants.
Establish plantations in areas with low potential or presence of the disease.
Place trap crops around the plantations in order to reduce introduction by viruliferous aphids.
Some microorganisms such as fungi and bacteria have shown virus reduction in affected orchards.
Application of resistance inductors such as: azibensolar-S-methyl at doses of 7.5 to 15 gr. per hectare from the third month, with intervals of 15 days and another block of applications with potassium silicate at a dose of 1.5 liters. as of the sixth month with an interval of 15 days, they can reduce the severity and number of plants with the presence of the virus.
Undoubtedly, the elimination of diseased plants in the initial stages will prevent the spread between the plants and is considered to be the main measure of control of this disease.

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