Papaya Ring Spot Virus (PRSV) as Influenced by the Length of Feeding Time of Aphids (Aphis gossypii)

Arce D Bellere,Leilidyn Y Zurbano

doi:10.17485/ijst/2019/v12i32/144496

Abstract

Background/Objectives: Aphids are known to be great vectors of Papaya Ring Spot Virus and its efficiency in disease transmission was observed based on the length of its feeding time on the healthy papaya plant. Methods/Statistical Analysis: The study was conducted at Bolo Sur, Sipocot, Camarines Sur and Red Lady Variety of Papaya was used as test crop. The study was composed of four treatments: T1 – control (without inoculants), T2 – the PRSV was inoculated for 30 seconds, T3 – 60 seconds and T4 – 90 seconds. The treatments were replicated three times and each replicate was inoculated with 10 aphids as vector. Appearance of symptoms, plant height and number of leaves were assessed for a period of 21 days for each of the treatments. Findings: Results showed that there are no significant differences on plant height among the treatments. However, significant differences on leaf number were observed where the healthy papaya plant had the most number of leaf, however, the length of feeding time of aphids did not had any significant result among the rest of the treatments. Furthermore, Symptoms of PRSV were observed 12 days after inoculation despite the varied feeding time of aphids. Application: Knowledge on the efficacy of PRSV transmission of aphids would be useful in assessing the crops to be grown with papaya and in formulating better fertilization and disease management. Keywords: Aphis gosypii, Carica Papaya, Disease Transmission, Non-persistent Manner, Papaya Ring Spot Virus

Highlights

Papaya (Carica papaya L.), an important fruit crop of Philippines and is extensively cultivated
Further test proved that no significant differences on the plant height increment were observed using varied treatments (Table 1)
With the significant result found in the study, it can be established that using aphids as vectors, Papaya Ring Spot Virus (PRSV) could be transmitted in a non-persistent manner for the transfer of virus occurs in only a short period of time

Summary

Introduction

Papaya (Carica papaya L.), an important fruit crop of Philippines and is extensively cultivated. Intended for the domestic market, papaya is predominantly grown by small-scale peasant producers with very little application of inputs. The average yield is low at only about 14 metric tons per hectare as compared to 70 to 90 metric tons per hectare under commercial/plantation scale production. Even yields of the newly developed high-yielding papaya varieties have remained low due to the growing incidence of the Papaya Ring Spot Virus (PRSV). PRSV was first detected in 1982 in the Southern Tagalog and Bicol Regions where it caused substantial damage to papaya orchards. The virus is believed to be widespread in Luzon and Visayas and is increasing in Mindanao where papayas for export are grown by multinational companies. PRV spread like a wildfire with 60 to 100% incidence and an estimated yield loss of about Php 6,309,000.001

Methods

Results

Conclusion