Early planting, management of edges and non-crop habitats reduce potyvirus infection in maize

Abstract

Viruses are a limiting factor in maize production areas around the world. The knowledge of the interactions between agroecosystems and the virus-vector-host system is limited, but a landscape-scale approach could help fill this gap. In this study, we show how the use of multiple spatial scales, i.e. 200, 500 and 1000 m, is a novel methodology for explaining the incidence of two closely related potyviruses: maize dwarf mosaic virus and sugarcane mosaic virus. To determine the factors involved in virus incidence, we recorded the proportion of surrounding crops and non-crop habitats at the landscape scale and, at the field scale, we recorded the planting date, the maize field area, the crop rotation and the weed diversity in the edges. In addition, we estimated the numbers of aphids with sticky yellow traps. Virus incidence in maize and in alternative grass hosts was determined by DAS-ELISA. Generalised linear mixed models were fitted using the multimodel inference method. The results showed that the most predictive model for the incidence of both potyviruses was at a scale of 200 m, but for the aphid abundance, it was at a scale of 500 m. Maize dwarf mosaic virus incidence was most affected by field management, and sugarcane mosaic virus by landscape variables. The planting date and the weed diversity in the edges were the field variables with the highest positive effects on both potyviruses. Moreover, both viruses were positively related to the abundance of aphids, and maize dwarf mosaic virus was only related to the cover of Johnson grass in the edges. Non-crop habitats had negative effects on potyvirus incidence at all spatial scales, showing that biodiversity in the landscape decreases the incidence of viruses. Here, we show that the early planting, the management of edges and the presence of non-crop habitats are key factors.

Effects of diversifying the planting period of maize on herbivorous and their natural enemies

“…For example, F. occidentalis was approximately three times more prevalent in fields planted later than in early plantings at V8-V16, when plants were more susceptible to thrips feeding. This differential susceptibility of maize plants to herbivore insect activity at different growth stages has been particularly observed for vectors of maize potyviruses (Achon and Sobrepere, 2001; Clemente-Orta et al, 2020a) and maize rough dwarf disease (MRDV) (Achon et al, 2013, 2015; Clemente-Orta et al, 2020b). In the first case, aphids that are able to transmit maize potyviruses were not found to be influenced in their abundance by the planting period at any growth stage in the present study.…”

“…), Empoasca vitis , aphids, phytophagous Thripidae, Z. scutellaris , and L. striatellus showed negative relationships in both spring and summer. Moreover, it was found that early and late maize planting dates have important effects on the incidence of SCMV, MDMV (Clemente-Orta et al, 2020b), and MRDV (Clemente-Orta, et al, 2021).…”

Spatial–temporal distribution of Dalbulus maidis (Hemiptera: Cicadellidae) and factors affecting its abundance in Brazil corn

“…Other studies also concluded that high-diverse landscape have negative effect on pest incidence in cornfields. 35,36 According to Clemente-Orta et al, 35 the incidence of virus disease in a certain area are determined by the vector biology, behavior and characteristics of landscape. For example, the high incidence of a disease can follow three scenarios.…”

“…Third, a large number of both vectors and infected plants occurring simultaneously. 35 Therefore, the landscape has a great influence in the pest-host plantdisease dynamic. Although this research was performed in a regional scale, it has an important impact on D. maidis and the corn stunt complex management.…”

Planting period is the main factor for controlling maize rough dwarf disease

“…The high dispersal capacity of L. striatellus 39 and the propagative type of virus transmission likely allow the vector to retain the infection capacity for longer than non-propagative viruses can. In the case of www.nature.com/scientificreports/ non-propagative maize viruses such as maize dwarf mosaic virus (MDMV), the closeness of maize field edges also had a strong effect, measured on a spatial scale of 200 m in the maize fields sampled 40 . Moreover, in the early season, grasses could provide the resources needed by the vector for overwintering, while in the late season, grasses in the ground cover of irrigated orchards could remain greener than those at the edges and could be a suitable host for vector reproduction in this area, as remarked by Clemente-Orta et al 41 .…”