INDUSTRY ROOT MEDIA ANALYSIS RESULTS - USEFUL IN DETERMINING GREENHOUSE NUTRITION PROBLEMS AND EDUCATIONAL-OPPORTUNITIES

Two years of floriculture greenhouse industry root media analysis resu lts from the Purdue University Greenhouse Media Testing Laboratory wer e studied for nutritional trends. Root media analysis results were sta tistically analyzed over 72 categories by crop, time, and firm. Sixty- five percent of samples were submitted in the spring and fall, during the period of highest production of greenhouse crops. The largest numb er of samples were from: roses (21.5%), poinsettias (14.5%), and geran iums (8%). Of the samples received, 87% came from 32 firms. The mean p H level for all samples was 6.32, which is above the acceptable range for most crops of 5.8 to 6.0 for soilless root media. In addition, 63% of all samples were also above the acceptable pH range. There were al so a large percentage of samples that contained excessive levels of ma gnesium (Mg) [39.4%], potassium (K) [27.4%], and phosphorus (P) [27.4% ]. Our analysis suggests the need for growers to purchase pH and solub le salt meters to regularly monitor greenhouse root media pH and solub le salts during the production cycle. This analysis provides us with d ata useful in developing educational programs targeted at problem area s in greenhouse nutrition.