Abiotic and cultivar effects on the incidence of pest arthropods in 16 citrus scion varieties grafted on two rootstocks

Abstract

Interactions among pests could differ among types of citrus hosts. Also, the climate factors may affect the population fluctuation of these pests. Therefore, the aim of this study was to establish the potential vulnerability of citrus cultivars to pest pressure over time as an aid to pest management. During 48 months between 2017 and 2020, pest arthropods from the families Aphididae, Liviidae, Gracillariidae, Aleyrodidae, Diaspididae and the order Acari were sampled bi-weekly in a common orchard with 32 cultivars [(16 citrus scion varieties of three citrus types (9 oranges, 4 mandarins, and 3 limes-lemons) grafted onto two rootstocks (CPB 4475 and SxE)]. Percentage of presence of each arthropod taxon was determined by visually inspecting five leaf buds or five leaves or five fruits, or combination of those, in two of six randomly sampled trees, in each one of three 210 m 2 plots established for each cultivar, for a total of 192 trees in each sampling. Percentages of presence of each arthropod taxon on each tree among cultivars were compared and correlations between these percentages and the climatic factors temperature, relative humidity, and rainfall recorded on a daily basis, were calculated. Among the three citrus types, mandarins had the greatest presence of aphids; oranges had the greatest presence of whiteflies, leafminers and Diaphorina citri, and limes-lemons had the greatest presence of mites. Presence of mites, aphids, D. citri and leafminer were positively correlated to relative humidity. Among mandarin varieties aphids had higher percentage of presence on Oneco and Owari Satsuma and among orange varieties Pineapple had a higher presence of it than the other varieties in study. Leaf miner had higher presence on Orange Sweet variety grafted on SxE rootstock than on any other orange cultivar.

Aphid species found on citrus in Ogan Komering Ilir District, South Sumatra, Indonesia

“…The symptoms found are on young leaves and old leaves that are stiff and curled, then the flowers will wither and die. The presence of aphids is significant because they can attack various types of citruses [25]. The abundance of aphids population can be influenced by biotic and abiotic factors [26].…”