How should a greenhouse be treated for spider mites on cucumbers? - briefly
Use a selective miticide such as «abamectin» together with predatory mites like Phytoseiulus persimilis, and maintain greenhouse humidity below 60 % to suppress reproduction. Perform weekly inspections and remove heavily infested leaves promptly.
How should a greenhouse be treated for spider mites on cucumbers? - in detail
Effective management of spider mites in cucumber production within a greenhouse requires an integrated approach that combines monitoring, cultural practices, biological agents, and selective chemicals.
Regular scouting is essential. Inspect the undersides of leaves at least twice weekly, using a hand lens to detect early signs such as stippling, webbing, or moving mites. Record population levels and map hot spots to guide interventions.
Cultural measures reduce mite establishment. Maintain humidity above 60 % whenever feasible, as dry conditions favor mite reproduction. Space plants to improve air circulation and reduce leaf microclimates conducive to infestation. Remove heavily infested foliage promptly and sanitize pruning tools between cuts.
Biological control agents provide sustainable suppression. Release predatory mites (e.g., Phytoseiulus persimilis, Neoseiulus californicus) at rates of 10–20 predators per square meter when mite counts exceed the economic threshold. Ensure compatibility by avoiding broad‑spectrum acaricides that could harm the predators. Supplement with entomopathogenic fungi such as Beauveria bassiana, applied as a foliar spray according to label recommendations.
Selective chemical options serve as a last resort. Employ miticides with low toxicity to beneficial organisms, such as abamectin or spirodiclofen, rotating modes of action to prevent resistance. Apply at the lowest effective concentration, covering both leaf surfaces, and observe the pre‑harvest interval stipulated on the product label.
Preventive steps reinforce long‑term protection. Rotate crops or introduce non‑host plants in adjacent benches to interrupt mite life cycles. Install fine mesh screens on ventilation openings to limit entry of airborne mites. Conduct sanitation of the greenhouse structure, removing plant debris that can harbor overwintering populations.
By integrating vigilant monitoring, optimized environmental conditions, targeted biological releases, and judicious use of selective miticides, cucumber growers can maintain spider mite populations below damaging levels while preserving the ecological balance within the greenhouse.