Focus on Floriculture Vol 8 #2
Tomatoes and petunias were grown in 3 different media and 4 different nitrogen treatments. The media included: greenhouse mix, greenhouse mix plus added lime, and Grower's choice (a peat-vermiculite mix). The nitrogen treatments included: nitrate nitrogen, ammonium nitrogen, high salts-ammonium, and Peter's Peatlite Special. The most growth took place with the greenhouse mix-N03 or Grower's Choice- Peter's treatments for tomatoes. The least growth, in any media, was in the high salt treatment. The high pH-NH4 or greenhouse mix-high salt treatments resulted in the most growth of petunias, whereas, plants in the Grower's Choice-N03 treatment had the least growth. With the NH4, su pression of Ca and Mg uptake were measured along with an increase in the P uptake (except in the high pH mix) when compared to NOy Similar^ effects were found in the plants treated with Peter's Peatlite Special.
Keywords: Ca and Mg high salt treatment High pH-NH4 Peter's Peatlite Special Greenhouse mix-N03