Reduction of Insect Damage in Radish with Floating Row Covers

Abstract

ABSTRACT Radish (Raphanus sativus L.) is a short season direct seeded crop with multiple seedlings starting as soon as the ground has thawed to ensure continuous supply. Floating row covers can be used to protect crops from low temperature to stimulate germination and to exclude insect pests. There is a need to optimize the use of floating row covers for early and mid-season radish production with floating row covers of different weave and weight. Two types of floating row covers (Agryl P10 and Agryl P17) and an uncovered treatment were compared in a randomized block design experiment with four replicates in the muck soil region of southwestern Quebec. The floating row covers completely excluded cabbage maggots (Delia radicum L.) and significantly reduced beetle (Phyllotreta spp.) damage by 60% compared to control plots. Both floating row covers increased daytime temperatures relative to the control, with Agryl P17 producing the warmest microclimate. Covering the seeded plots increased total emergence by 19% and decreased mean emergence time by 1.3 days but did not affect the uniformity of seed germination as expressed by the spread of emergence. For the three sowing dates, the floating row covers accelerated growth relative to the control, resulting in heavier leaf weight and larger root diameter at harvest. Radish plants covered with Agryl P17 in the late season showed a decrease in foliage health, which likely resulted from excessive heat. Plants covered with Agryl P17 and Agryl P10 were harvested respectively 10 days ± 4 days and 7 days ± 5 days earlier than the control.