Nine subterranean clover cultivars and 11 white clover lines were evaluated for persistence and production, under a combination of rotational grazing or cutting, for 4 years on rolling pumice hill country. The most successful subterranean clover cultivarwas 'Tallarook' , whichfor 4 yearsproduced the most dry matter (DM) (average 700 kg DM/ha per year) and accumulated the largest soil seed reserve (1500 kg seed/ha), Soil moisture stress over the summer severely limited persistence and hence production of all white clovers (average 400 kg DM/ha per year). Persistence was not assured by larger roots associated with large-leaved lines. Hill country types (e.g., 'Whatawhata Early Flowering') with a high stolon densityand/or free seedingability were the best adapted to this environment

Examining and developing screening techniques to identify drought‐resistant lines at the seedling stage is an important step for plant breeders. Therefore, the objectives of this research trial were to determine if the use of polyethylene glycol (PEG‐6000) is an effective tool to screen for water stress during seed germination and to determine potential cultivar differences within each species tested. Bermudagrass [Cynodon dactylon (L.) Pers.] cultivars selected included ‘Hollywood’, ‘Northshore’, ‘Riviera’, and ‘Transcontinental’. Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] cultivars included ‘Jaguar 4G’, ‘Quest’, ‘Summer’, and ‘Sundial’ as well as four experimental cultivars. Water stress levels were developed using PEG‐6000. For bermudagrass, seed was subjected to 0 (control), −2.5, −5.0, −7.5, and −10.0 MPa, while tall fescue water‐stress treatments included 0 (control), −2.0, −4.0, −5.0, and −7.0 MPa. Bermudagrass and tall fescue relative final germination rate (FGR) and relative daily germination rate (DGR) decreased with increasing concentrations of PEG‐6000. Regression analysis indicated that Sundial (−6.51 MPa) and Summer (−6.09 MPa) tall fescue and Transcontinental (−4.74 MPa) and Hollywood (−4.62 MPa) bermudagrass had the highest PEG concentration to reduce relative FGR by 50%. Results suggest PEG‐6000 is an effective technique for screening turfgrass cultivars that require less water for seed germination. This study also identified cultivars that would have a competitive advantage during the establishment phase if water is a limiting factor.

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Gaeumannomyces graminis var. graminis (Sacc.) Arx & Oliver was described as a pathogen of bermudagrass decline [takeall root rot (TARR)]; however, recent studies have reported that multiple ectotrophic root-infecting (ERI) fungi are associated with root rot in ultradwarf hybrid bermudagrass (UDHB) [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] putting greens. This study surveyed UDHB roots from a healthy and a TARR-symptomatic green. Real-time polymerase chain reaction multiplex assays facilitated the rapid identification and quantification of four ERI fungi: G. graminis, G. nanograminis P.L Vines & M. Tom.-Pet., Magnaporthiopsis cynodontis P.L Vines & M. Tom.-Pet., and Candidacolonium cynodontis P.L Vines & M. Tom.-Pet. Gaeumannomyces nanograminis was identified more frequently than G. graminis in roots from the healthy green and had the greatest inoculum density in 2018. In contrast, G. graminis was identified in 80% more root samples than G. nanograminis in the TARR-symptomatic green in 2017, and the inoculum density of G. graminis was >2 M DNA copies per 2-μl DNA sample. Magnaporthiopsis cynodontis was the predominant fungus in both greens throughout the study; however, its inoculum density was the lowest among all four ERI fungi. Two or more ERI fungi were frequently identified as co-colonizing UDHB roots. This study showed that multiple ERI pathogens were widely distributed throughout the roots of two UDHB greens regardless of symptom expression and confirmed that ERI complexes co-colonize UDHB roots. This is the first study documenting the widespread occurrence and inoculum density levels of multiple ERI fungi colonizing UDHB roots.