The Effects of Insect Rearing Waste Compost on Helianthus annuus and Tithonia rotundifolia

Abstract

In recent years, there has been a greater demand for growing substrates for ornamental plants. However, as cost rises and quantities of these materials become more limited, alternative forms of growing media are now being sought. A study was conducted to test the efficacy of using insect rearing waste as an alternative growing media for plants. Common sunflower (Helianthus annuus L.) and Mexican sunflower (Tithonia rotundifolia (Mill) S.F. Blake) were grown in different ratios of insect colony waste compost (ICW) combined with cardboard (Cb) (ICW+Cb) and nursery mix (NM) mixtures. The purpose of this experiment was to determine whether insect colony waste (ICW) from fruit fly rearing would sustain plant growth. Selective characteristics of the potting substrates revealed that the ratio of 100:0 ICW+Cb:NM had a 7.6 pH, 0.86 dS m-1 EC (salinity), 0.46 g cm-3 bulk density, and 50.1 percent water holding capacity at saturation. For common sunflower, there was a significant difference between the 100:0 and 0:100 ICW+Cb:NM blends for plant height, with the 100:0 ICW+Cb:NM mixture having the greatest height. For the Mexican sunflower, the 100:0 ICW+Cb:NM produced significantly more leaves and had a greater stem diameter than some of the other mixtures of potting substrate. There was no indication that the insect colony waste combined with cardboard (ICW+Cb) would inhibit plant growth. ICW+Cb have the potential to be used as an alternative substrate for growing plants.