A New Method for Hybrid Bermuda Grass (Cynodon dactylon × C. transvaalensis Burtt.-Davy) Vegetative Propagation

Hybrid Bermuda grasses (Cynodon dactylon × C. transvaalensis Burtt.-Davy) represent one of the greatest contributions to the growing quality of turfgrass in the warm season and transition zone areas of the world. Hybrid Bermuda grass production relies on vegetative propagation from sod or sprigs. In the past, efforts have focused on improving the technique of stolonizing (or sprigging) for establishment in new areas. Such propagation requires bulk harvesting and planting of all rhizomes and stolons. We have developed a novel method of propagation and establishment from a single node harvested from greenhouse grown stolons. Despite a stolon fraction bearing a single node being suitable for effectively propagating a warm-season turfgrass, the technique has been held as economically impractical until now. Our method has been developed to obtain the multiplication of plant material in soilless conditions by harvesting single-node sprigs, propagation of plants from the single nodes, and transplant of single plants in the field. The investigation aimed to identify values for method set-up. Indeed, node and internode size variability with differential between maximum diameters is crucial for discrimination. For Patriot Bermuda grass stolons, nodes exhibited a maximum diameter of 2.43 ± 0.46 mm, while internodes had a maximum diameter of 1.54 ± 0.16 mm. Based on these findings, a 2 mm sieve was selected, achieving an optimal ratio between the node fraction and internode residues. The sieve yielded 87% of node fractions and only 1% of internodes from the initial mix, demonstrating its efficacy. Further results for the transplanting phase indicated that a double release resulted in an average success rate of 98.8%, with only 6.9% blank cells when using a single release. The average was 149 plants per tray over 160 cells, representing a 93.1% success rate. These results underscore the efficiency and acceptability of the overall propagation process in alignment with market references

Assessment of the Effects of Autonomous Mowers on Plant Biodiversity in Urban Lawns

Gaining information on the impact of lawn management with autonomous mowers on the floristic composition is crucial to improve their plant biodiversity. In this study, an autonomous mower with a reduced mowing frequency and a more sporadic mowing management system with a ride-on rotary mower were compared in terms of the effect on three dicotyledonous species (Phyla nodiflora, Lotus corniculatus and Sulla coronaria) transplanted onto stands of Bermuda and Manila grass. Regardless of the management system, P. nodiflora achieved the best results in terms of survival for both lawns (74.92 and 58.57% in Manila and Bermuda grass, respectively). In Bermuda grass, a higher percentage of surviving individuals was observed for the ordinary mower management system (42.59%), rather than with the autonomous mower (9.10%), while no differences emerged on Manila grass. On both Manila and Bermuda grass, a higher average percentage of coverage for single individual was observed for the ordinary mower management system (1.60 and 0.37%, respectively) compared to the autonomous mower system (0.55 and 0.08%, respectively). P. nodiflora had a higher percentage of individuals with flowers with the ordinary management system rather than with autonomous mower system both on Manila (60.73% and 33.90%, respectively) and Bermuda grass (48.66 and 3.32%, respectively). Despite a lower impact on the planted species being observed for the ordinary mower management system, encouraging results were obtained with the autonomous mower, for instance regarding the percentage of surviving individuals for P. nodiflora (33.95%) and L. corniculatus (22.08%) on Bermuda grass and the percentage of individuals with flowers for the same two species (33.90 and 13.59%, respectively) on Manila grass. Furthermore, the autonomous mower management system’s primary energy consumption over the year was lower compared to that of the ordinary system both on Manila (200.4 and 614.97 kWh ha−1 year−1, respectively) and Bermuda grass (177.82 and 510.99 kWh ha−1 year−1, respectively)

Tecniche di trasemina di ibrido di gramigna con cultivar di specie appartenenti al genere lolium.

Le macroterme sono specie da tappeto erboso sempre più utilizzate ma la perdita di colore nel periodo di dormienza invernale ne costituisce un limite. L’overseeding è una tecnica utilizzata per insediare una specie temporanea che conferisca colore e attività di vegetativa al tappeto in dormienza. Per questo impiego sono preferibili cultivar microterme in grado di germinare in autunno e regredire spontaneamente in primavera. Lo scopo della ricerca è stato valutare l’effettivo avanzamento tecnico di nuove linee genetiche di microterme in termini di velocità di insediamento, parametri qualitativi nel periodo di vegetazione e regressione primaverile. Ventinove nuove cultivar di microterme sono state sottoposte a test di germinabilità e tempo medio di germinazione in condizioni standard e a basse temperature, allo scopo di simulare le condizioni termiche reali di campo. Le stesse cultivar sono state successivamente inserite in una prova di campo, dove sono state valutate la velocità di insediamento, qualità del tappeto erboso temporaneo e l’attitudine a regredire in primavera. Dalle prove di laboratorio a bassa temperatura sono emerse una ridotta percentuale di germinazione ed una estensione dei tempi di germinazione. Dalle prove di campo sono emerse differenze tra i parametri qualitativi tra le diverse cultivar e una generale elevata persistenza della microterma dovuta condizioni ambientali favorevoli. Warm-season grasses are species that are increasingly being used, but the loss of colour during the winter dormancy poses a limitation. Overseeding is a technique used to establish a temporary species that adds colour and vegetative activity to the dormant grass. For this purpose, cool-season cultivars capable of germinating in autumn and transitioning spontaneously in spring are preferred. The aim of the research was to evaluate the actual performance improvement of new genetic lines of cool-season grasses in terms of establishment speed, qualitative parameters during the growth period, and spring transition. Twenty-nine new cool-season cultivars underwent germination tests and germination mean time under standard and low-temperature conditions, aiming to simulate real field environemental conditions. The same cultivars were then included in a field trial, where the establishment rate, quality of the temporary grass stand, and the ability to regress in spring were evaluated. The laboratory tests at low temperatures revealed a reduced germination percentage and extended germination times. The field trial showed differences in qualitative parameters among the different cultivars, while high persistence of cool-season grasses was observed mainly due to favourable environmental conditions

Breaking the Rules: Towards an Experimental Design Pedagogy

The Great Game is a laboratorial course that problematises the traditional design studio approach, seeking for reframed modes of knowledge transmission through interactions among a multiplicity of actors and establishing situatedness as design principle. The didactic experiment of the Great Game tries to answer two questions. The first asks whether it is possible to teach an effective way of designing without applying the binary logic of what one (the teacher, a theoretical authority, an ideology) decides wrong (students’ knowledge up to that point, a certain way of doing architecture, intentions), and what is decided to be right (new and updated skills, another way of designing, ethically acceptable goals). The second asks whether it is in the form and organisation of the design studio that we should intervene (and modify) if we want to produce a change in terms of approaches to design. Logic and structure of the Great Game are presented, as well as (graphical) reports on the experiences of two iterations of the course: on these contents is built a correspondence between the pedagogical objectives and the effectiveness of design in intercepting the multiplicity of instances that emerge in any specific place and situation. We conclude by showing how through playful experimentation of architectural education, the Great Game tries to incentivise a form of knowledge that derives from nonlinear actions of mutual interlocutions and reciprocal positioning, or rather, the product of multiple instances, detournements, and even errors