Testing potting mixes with addition of dried blood, blood and bone and bentonite.

H. Kahl and A. Krug

School of Horticulture, Christchurch Polytechnic Institute of Technology, P.O. Box 540, Christchurch, New Zealand.

DOI: https://doi.org/10.37855/jah.2005.v07i02.37

Key words: bentonite, blood, bones, cabbages, growing media, lettuces, plant development, seed germination, slow release fertilizers, tomatoes, weight
Abstract: An experiment was conducted to study the effect of dried blood or blood and bone and bentonite, as a slow release fertilizer, on germination rate of lettuce, tomato, and white and red cabbages, plant yield and the attraction of sciarid flies (Sciaridae) and whiteflies (Trialeurodes vaporariorum). The potting mixes comprised: standard mix (60 litres compost + 20 litres sand + 20 litres composted bark + 300 g gypsum + 200 g kelp powder) + 250 g dried blood, 250 g blood and bone, 125 g bentonite (a); standard mix + 250 dried blood, 250 g blood and bone (b); standard mix + 125 g bentonite (c); and standard mix (d). The germination rate for lettuce and tomato was similar for the mixes with and without blood and bone. The germination of red and white cabbages was strongly affected by the presence of blood and bone. Only 13 seeds out of 80 germinated in the samples with blood and bone compared with a total number of 80 germinated seeds out of 80 in the samples without blood and bone. In the mixes with bentonite, 113



Journal of Applied Horticulture