Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2004
Publication Date: 2/8/2005
Citation: Russo, V.M., Diaz-Perez, J.C. 2005. Kaolin-based particle film has no effect on physiological measurements, disease incidence or yield in peppers. HortScience. 40(1):98-101.
Interpretive Summary: Excessive temperatures, especially at night, can cause plants to abort flower and fruit formation and reduce yields of vegetables. A kaolin-based material, originally designed to control insect damage to plants, has been found to cool plants. This material was applied to pepper plants in Oklahoma and Georgia to determine if it could be used to protect against flower and fruit abortion and affect yield. The material did cool plants to some degree. Regardless of location, sequence of application, date of application in relation to planting date, or cultivar on which tested the material did not benefit yield. This material is not recommended for use on peppers to improve yield where there is little, or no, pressure from insects.
Technical Abstract: Heat stress can limit yield in pepper (Capsicum spp.), generally through flower and fruit abortion. A kaolin-based particle film, originally developed to protect fruit trees from insects, has been found to reduce temperatures in tissues of plants. The kaolin-based material was tested to determine if it could be used to improve yields of pepper. In Oklahoma, seedlings of a bell pepper, cv. Jupiter, and a non-pungent jalapeño, cv. Pace 103, were transplanted at three progressively warmer planting dates that would assure that inflorescences would be subject to high day and night temperatures and treated with the kaolin material. Applications were begun as the first flowers were set and continued through the settings of the first three flushes of flowers on a three-times a week schedule, or on an as needed basis, to determine if the material improved yield. In Georgia, two bell pepper cultivars were transplanted at one planting date and treated with the kaolin-based material. In addition to yield, physiological measurements and disease incidences were recorded in Georgia. In both locations treatment with water only served as controls. In Georgia, the kaolin-based material had no significant effect on net photosynthesis, stomatal conductance, leaf transpiration or leaf temperature, as measured at midday on clear days. In Oklahoma, planting bell pepper after 15 May is not recommended for this location in years with normal conditions during the growing season. Planting the non-pungent jalapeño after mid-June, under some conditions during the growing season, can reduce yields. The kaolin-based material did not affect yield of peppers at either location and is not recommended for use on peppers if the aim is to increase yields when there is little, or no, pressure from insects.