To meet the increasing demand for sweet potatoes in Canada, Vineland has published best production practices to support the creation of a national slip propagation industry. The new guide is also available in French, click here.
Actuators, 2019, 8(4), 76
The article can be viewed here
Abstract: Galley, A., Knopf, G.K and M. Kashkoush. Soft robotic grippers often incorporate pneumatically-driven actuators that can elastically deform to grasp delicate, curved organic objects with minimal surface damage. The complexity of the actuator geometry and the nonlinear stress–strain behavior of the stretchable material during inflation make it difficult to predict actuator performance prior to prototype fabrication. In this work, a scalable modular elastic air-driven actuator made from polydimethylsiloxane (PDMS) is developed for a mechanically compliant robotic gripper that grasps individual horticultural plants and fungi during automated harvesting. The key geometric design parameters include the expandable surface area and wall thickness of the deformable structure used to make contact with the target object. The impact of these parameters on actuator displacement is initially explored through simulation using the Mooney–Rivlin model of hyperelastic materials. In addition, several actuator prototypes with varying expandable wall thicknesses are fabricated using a multistep soft-lithography molding process and are inserted in a closed ring assembly for experimental testing. The gripper performance is evaluated in terms of contact force, contact area with the target, and maximum payload before slippage. The viability of the gripper with PDMS actuators for horticultural harvesting applications is illustrated by gently grasping a variety of mushroom caps.
Theoretical and Applied Genetics, September 28, 2019
The article can be viewed here
Abstract: Rouet, C., Lee, E.A., Banks, T. et al. Black spot, caused by Diplocarpon rosae, is one of the most serious foliar diseases of landscape roses that reduces the marketability and weakens the plants against winter survival. Genetic resistance to black spot (BS) exists and race-specific resistance is a good target to implement marker-assisted selection. High-density single nucleotide polymorphism-based genetic maps were created for the female parent of a tetraploid cross between ‘CA60’ and ‘Singing in the Rain’ using genotyping-by-sequencing following a two-way pseudo-testcross strategy. The female linkage map was generated based on 227 individuals and included 31 linkage groups, 1055 markers, with a length of 1980 cM. Race-specific resistance to four D. rosae races (5, 7, 10, 14) was evaluated using a detached leaf assay. BS resistance was also evaluated under natural infection in the field. Resistance to races 5, 10 and 14 of D. rosae and field resistance co-located on chromosome 1. A unique sequence of 32 bp in exon 4 of the muRdr1A gene was identified in ‘CA60’ that co-segregates with D. rosae resistance. Two diagnostic markers, a presence/absence marker and an INDEL marker, specific to this sequence were designed and validated in the mapping population and a backcross population derived from ‘CA60.’ Resistance to D. rosae race 7 mapped to a different location on chromosome 1.
- Edible horticulture
- Ornamental horticulture
Journal of Sensory Studies, June 20, 2019, e12526.
The article is available here at a cost.
Abstract: Grygorczyk, A., Jenkins, A.E. and A.J. Bowen. Sensory and consumer testing of live rose bushes presents several unique logistical challenges due to product size and the need to present roses during a small window of opportunity when they are in full bloom, the timing of which differs from plant to plant. The current study determined whether online (close up photographs of rose blooms) and in‐person (live plants) liking tests produced comparable results and discusses the logistical considerations of in‐person testing. Three studies were conducted: two in‐person to compare two different study design strategies (n = 199, n = 206) and one online (n = 209). Photos of rose blooms evaluated online did not correlate with in‐person liking evaluations (R2 = .00003). The best approach for in‐person testing (completing testing in 1 week with only blooming roses versus spreading out testing over 3 weeks) depended on the project budget and whether a particular rose of interest needed to be in the sample set.