Screening of alternative products for integrated pest management of cucurbit powdery mildew in Sweden

Mira Rur,Margareta Hökeberg,Birgitta Rämert,Laura Grenville-Briggs,Erland Liljeroth,Ramesh R Vetukuri

doi:10.1007/s10658-017-1258-x

Mira Rur, Margareta Hökeberg + Show 4 more

https://doi.org/10.1007/s10658-017-1258-x

Copy DOI

Abstract

Cucurbit powdery mildew (CPM) is one of the most important plant protection problems in Swedish cucumber production. CPM fungi have developed resistance to the commonly used fungicide (Imazalil) rendering its current use less effective. We therefore screened a selection of alternative products, evaluating their ability to control CPM in seven small-scale, semi-commercial, greenhouse experiments. Products were screened for their ability to suppress CPM on a susceptible cultivar, in 2013. In 2015, the best treatments were tested in different combinations, in different intervals on a susceptible and a partially resistant cultivar. The treatment that gave the best CPM control was Sakalia in combination with wetting agent Yuccah, (based on Reynoutria sachaliensis and Yucca schidigera respectively) applied at 7-day intervals. This treatment was highly efficient on both cucumber cultivars. Sakalia mixed with Yuccah applied at 14-day intervals had an almost equally controlling effect on CPM. The microbial pesticides, Polyversum (Pythium oligandrum) and AQ10 (Ampelomyces quiscalis) and the fungicide Imazalil, provided no to poor control of CPM compared to control treatments. Hortistar (Silicon) partially reduced CPM infections and was more efficient on the partially resistant cultivar. We conclude that Sakalia in combination with wetting agent Yuccah could efficiently control the disease even under the severe conditions caused by artificial inoculation. Further testing of this combination in commercial greenhouses will enable evaluation of the potential effects on yield and beneficial or pest insects. The knowledge gained from this study can be used to develop IPM tools for commercial production systems.

Highlights

Cucumber is the most widely grown greenhouse crop in Sweden
Polymerase chain reaction (PCR) methods allow for more precise differentiation (Chen et al 2008)
The aim of this study was to screen for effective alternative products against cucurbit powdery mildew (CPM) in greenhouses and evaluate their effect on CPM alone and in combination with the standard fungicide

Summary

Introduction

Cucumber is the most widely grown greenhouse crop in Sweden. In 2015, cucumber was cultivated on 67 ha of greenhouse space, resulting in a total yield of 28,000 t (Persson 2015a). One of the most important foliar diseases of greenhouse cucumber is cucurbit powdery mildew (CPM), which causes yield losses and crop quality reductions. The infection often results in a shortened growing season (Cerkauskas and Ferguson 2014; Nuñes-Palenius et al 2006; Sitterly 1978). The disease is considered to be the major cause of crop losses in cucumber worldwide (Lebeda et al 2010). Braun & Shishkoff (formerly Sphaerotheca fuliginea (Schlechend.:Fr) Pollacci) and Golovinomyces cichoracearum Erysiphe cichoracearum) (DC.) VP Heluta (Braun 1995). Polymerase chain reaction (PCR) methods allow for more precise differentiation (Chen et al 2008)

Objectives

Results

Conclusion