Greenhouse Production of Vegetable Crops Grown with a Closed-Loop Fertigation System in a Pesticide-Free Environment

Abstract

The primary arthropod pests associated with greenhouse vegetable production in Florida are: broadmites, spider mites, thrips, aphids, and whiteflies. The primary disease is powdery mildew. The objective of this research was to identify pesticide-free control measures of the most common arthropod pests of the Florida greenhouse vegetable industry and to recycle water and nutrients, safely without disease pressure. Broadmites and spider mites are controlled with the predatory mite N. californicus if released prior to or at transplanting. Aphids and whiteflies are controlled with the parasitic wasps Aphidius colemani and Eretmoserus sp. or Encarsia sp., respectively, which can be released and/or reared on banker plants. Thrips populations can be reduced with generalist predators such as Orius sp., but more recently a predatory mite, Amblyseius swirskii has been reported to be effective. Disease resistant cultivars are preferred, however, cultural controls such as isolation from disease pressure, anti-condensation coverings, fans and aeration and bio-friendly fungicides are necessary. Regular scouting and correct identification of pests is key to pest management and implementing biological control. Plants were fertigated in a hydroponic system using pine bark or perlite medium in nursery pots. Drainage water was collected, sanitized, adjusted for EC and pH when necessary, then recycled to the plants. A sustainable, pesticide-free environment is not only safer for the plants and produce being grown, but also, employee safety and efficiency can be increased since re-entry periods that delay worker production are eliminated.