replacement irrigation is initiated. Te ETo
-based
locations allow NTEP to determine the minimum level of deficit irrigation appropriate for, and thus the water savings from, each entry. It was determined that 80, 60 and 40 percent ETo
again in 2018, except for the St. Paul, MN, site which would utilize 0, 25 and 75 percent ETo
to its northern location.
In 2017, only Approach 2 sites at Riverside, CA, and Las Cruces, NM, collected data. In 2018, all five sites collected data, with four locations (Riverside, Las Cruces, Fort Collins, CO, and Logan, UT) running irrigation at 40, 60 and 80 percent ETo
MN, using 0, 25 and 75 percent ETo
replacement and St. Paul, replacement. All
sites were adjusted for any rainfall received during the 120-day drought period. At Riverside, the 40 percent ETo
irrigation regime was very harsh on all entries, with
no entry delivering acceptable lawn turf quality ratings (6.0+) throughout the drought period, or even minimally acceptable turf quality ratings (5.0) 60 days into the drought period. Turf quality ratings averaged over the entire season at 40 percent ETo
replacement showed all
entries with a 5.0 score or higher. Te 60 percent ETo replacement regime did not show a single entry with
an acceptable mean turf quality rating (6.0) at the end of the season, including recovery time. Te 60 percent regimes did show some statistical significance among some Kentucky bluegrass entries, but not tall fescue. Te 80 percent ETo
regime, which is considered adequate replacement of ET lost for cool-season grasses, did show
replacement levels would be utilized replacement due
some entries with acceptable turf quality averages, but with no statistical difference among Kentucky bluegrass or tall fescue entries.
Te Las Cruces, NM, site, while being hot during summer, is not quite as harsh as Riverside (maybe due to some summer rains), which elevated some quality ratings to acceptable levels. Statistical significance was only noted between the top bluegrass entry (‘PST-K11-118’) and the lowest entry (‘Midnight’) at 40 percent ETo
. No statistical
significance was seen at the 60 percent level, while several entries performed statistically better at the least harsh level of 80 percent ETo
was not seen at the 40 percent and 60 percent ETo
. Statistical significance among tall fescue levels
but was noted at the 80 percent level. At the 80 percent ETo level, the top performing Kentucky bluegrasses were ‘NAI-
13-14’, ‘NAI-13-132’, ‘Blue Devil’ and ‘Midnight’; the top tall fescues were ‘Tor’, ‘MRSL TF15’, ‘DLFPS-321/3678’, ‘RS4’, ‘Tunderstruck’ and ‘Titanium LS’.
Greater statistical significance was noted, among all ET levels, at Logan, UT, however no Kentucky bluegrass performed at the acceptable lawn quality level for the season average, many falling below even the minimally acceptable quality score for low maintenance (5.0). Overall, tall fescues performed better with ‘Tunderstruck’, ‘DLFPS-321/3679’, ‘LTP-SYN-A3’ and ‘RS4’ in the top turf quality statistical group under the 40 percent ETo
replacement (turf quality
scores of 5.7, 5.5, 5.3 and 5.2 respectively). Less, but still some statistical significance was noted at the 60 percent ETo
.
regime with no statistical differences seen in tall fescue mean turf quality scores at 80 percent ETo
TPI Turf News September/October 2019 Rainout Shelters, such as this one, are being used in both the cool-season and warm-season water use trials.
15
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76
