[Mower pick up studies] [DG R&D History] [Irrigation studies] |
Irrigation studies Earlier in 2007 we performed an independent study to evaluate the amounts of water to disperse ContecDG on closely mowed creeping bentgrass at 0.105 inches. ContecDG was applied through a shaker bottle and using the application shaker box (shown right). All plots were treated with the measured amount. Immediately, 9 inch round plugs were pulled from the plots for each treatment.
Following the first run (replication) we realized that the plugs must be rated as soon as possible because the breakdown of the particles continued even after they were removed from the irrigation area. Results and Conclusions: No fertilizer tip burn or
phytotoxic effects were observed with any treatment included in the study. The ContecDG broke down the most following three revolutions. Few significant differences existed between ContecDG 13-0-26, 18-9-18 and 17-0-17 in each of the three irrigation regimes. The results below are the averages of all replications for the three formulas of ContecDG. After one turn of the sprinkler heads, the average particulate coverage of the three formulas was reduced to 41% of the original coverage visibility. Following the second and third turns, the coverage fell to 30% and 20% respectively as shown in the graph below.
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This trial was conducted in Gladwyne, PA on April 30th, 2007 with three ContecDG formulas ( 17-0-17, 18-9-18 and 13-0-26). All treatments were applied to a dry canopy at a rate of 0.5 lbs. N/1000 sq. ft.. Although, we had a tried for a low wind day, wind gusts were in the 10-20 mile per hour range. Two inch soil temperature in the putting green was 67 degrees F (19.4 degrees C). The individual 7.8 sq. ft. plots were laid out on a 'A-1' creeping bentgrass nursery putting green mowed at 0.105 inches. This green receives little fertilizer input and is subjected to significant amounts of wear from golfers practicing. 
Following the removal of the plugs, they were carefully placed back in the utility cart and taken to an active green on the course and placed in the center of a square irrigation design. This irrigation system was installed in 1990 and has head to head coverage in a square design (see image to the left). The heads are Toro 690 series with a full circle turn and an irrigation rate of 0.02 inches per revolution.
Plugs were visually rated on a linear 0 to 100 scale where 0 = no particle visible in the turf canopy and 100 = entire canopy full of particles that are not broken down. Data were subjected to analysis of variances (ANOVA) using SAS Mixed Procedure and significantly different means were separated according to the Fishers least significant difference test.  |