Reduction of substrate volume per plant by 1/3 without considerable yield decrease, would result in financial saving. Three substrata were used. rockwool, coconut fibres and expanded clay. The highest yield was obtained on rockwool, which is recommended as growing substrate.
In Croatia a three years preliminary research has already been conducted to explore the possibilities of sweet potato (Ipomoea batatas) cultivation and introduction into our growing areas. Positive effects on the yield were expected from the endomycorrhiza application according to the new growing technologies close to organic-biological production, as well as from mulching with differently colored polyethylene (PE) films. Arbuscular mycorrhizal (AM) fungus Glomus mossae was used as inoculants. A significant positive effect of mycorrhiza on the yield of sweet potato roots, as well as on the average root mass, however not on the number of roots per plant, was recorded. PE mulching had a significant effect on the yield and average root mass, as well. Interaction AM × PE film provided the significantly highest yield of thick toots per plant.
Modern watermelon production is almost based on the use of transplants. Watermelon transplants are grown mostly in plug trays of various sizes and cell volumes. The aim of this research was to determine the optimal plug size, cultivation period and influence of arbuscular mycorrhizal fungi on the quality of watermelon transplants. The research was conducted in a heated plastic greenhouseduring 2003 and 2004 . A three factorial trial was set up as a randomized complete-block design with three replications. There were three plug sizes - 100 ml cells (plug tray with 40 cells), 80 ml cells (plug tray with 60 cells) and 60 ml cells (plug tray with 84 cells). The second factor, mycorrhizae included the substrate with or without inoculation with the arbuscular mycorrhizal fungus Glomus mosseae. Cultivation time was 30 and 45 days in 2003, and 40 and 55 days in 2004. In both years the best developed watermelon transplants (highest stem, greatest number of leaves, largest stem diameter, highest plant and root mass) were the ones planted in 100 ml cells . Differences between transplants grown in 60 and 80 ml cells were shown not significant. In 2004, inoculated transplants were better in all attributes compared to uninoculated ones. In both years transplants grown for 45 and 55 days were larger and had more leaves per plant, larger stem diameter, and greater plant and root mass compared to those grown for 30 and 45 days.
ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Greenhouse 2010 and Soilless Cultivation AGRONOMIC TRAITS OF SOILLESS GROWN BELL PEPPER