Strawberry ( Fragaria × ananassa ) production practices followed by growers in the United States vary by region. Understanding the challenges, needs, and opportunities in each region is essential to guide research, policy, and marketing strategies for the strawberry industry across the country, and to enable the development of general and region-specific educational and production tools. This review divided the United States into eight distinct geographic regions and an indoor controlled or protected environment production system. Current production systems, markets, cultivars, trends, and future directions for each region are discussed. A common trend across all regions is the increasing use of protected culture strawberry production with both day-neutral and short-day cultivars for season extension to meet consumer demand for year-round availability. All regions experience challenges with pests and obtaining adequate harvest labor. Increasing consumer demand for berries, climate change-induced weather variability, high pesticide use, labor and immigration policies, and land availability impact regional production, thus facilitating the adoption of new technologies such as robotics and network communications to assist with strawberry harvesting in open-field production and production under controlled-environment agriculture and protected culture.

An unprecedented freeze occurred between 4 and 10 Apr. 2007, causing extensive crop loss across a large area of the United States. This event occurred late in the spring and temperatures were unusually low for an extended period. Low-temperature injury on small fruit plants was reported in 21 states. Missouri and Arkansas experienced the highest estimated percentages of crop loss of grape ( Vitis spp .), strawberry ( Fragraria × ananassa Duch.), blueberry ( Vaccinium spp.), and blackberry ( Rubus subgenus Rubus Watson). Kentucky and Tennessee also reported high percentages of small fruit crop loss. Temperatures preceding the freeze event in the affected region were unusually warm and many of the crops were at a more advanced stage of growth than they would have been under more usual conditions. Although frost/freeze warnings were issued, the terminology used by different weather forecasters was inconsistent. Growers used various cold protection methods, but these were generally ineffective because of the stage of plant development and/or the advective nature of the freeze. Actual grape and blueberry crop losses may not be known for several years because of secondary injury to plant tissues from various pathogens.

The growth and development of three strawberry cultivars commonly grown in a plasticulture system were documented. Strawberry plants were harvested monthly and divided by roots, crown, leaves, flowers, and fruit and then dried in an oven. The dry matter production and resource allocation proceeded along a predictable pattern of development. The establishment phase was characterized by an active period of growth of root, crown and leaves in the fall. Through the winter, the plants underwent slow growth, ending in a transition period in the late winter/early spring when resources were allocated to both vegetative and reproductive growth. In the spring, all plant parts received significantly increased allocation of, or redistribution of, resources. Cultivars of California origin, `Chandler' and `Camarosa', displayed similar trends in yield, dry matter production, seasonal resource allocation, and growth analysis variables throughout the season. `Sweet Charlie', a cultivar from Florida, showed lower dry matter accumulation and relative growth rate in the spring, higher harvest index and lower yield than the California cultivars.

Blackberries (Rubus spp.) are the fourth most economically important berry crop worldwide. Genome assemblies and annotations have been developed for Rubus species in subgenus Idaeobatus, including black raspberry (R. occidentalis), red raspberry (R. idaeus), and R. chingii, but very few genomic resources exist for blackberries and their relatives in subgenus Rubus. Here we present a chromosome-length assembly and annotation of the diploid blackberry germplasm accession “Hillquist” (R. argutus). “Hillquist” is the only known source of primocane-fruiting (annual-fruiting) in tetraploid fresh-market blackberry breeding programs and is represented in the pedigree of many important cultivars worldwide. The “Hillquist” assembly, generated using Pacific Biosciences long reads scaffolded with high-throughput chromosome conformation capture sequencing, consisted of 298 Mb, of which 270 Mb (90%) was placed on 7 chromosome-length scaffolds with an average length of 38.6 Mb. Approximately 52.8% of the genome was composed of repetitive elements. The genome sequence was highly collinear with a novel maternal haplotype-resolved linkage map of the tetraploid blackberry selection A-2551TN and genome assemblies of R. chingii and red raspberry. A total of 38,503 protein-coding genes were predicted, of which 72% were functionally annotated. Eighteen flowering gene homologs within a previously mapped locus aligning to an 11.2 Mb region on chromosome Ra02 were identified as potential candidate genes for primocane-fruiting. The utility of the “Hillquist” genome has been demonstrated here by the development of the first genotyping-by-sequencing-based linkage map of tetraploid blackberry and the identification of possible candidate genes for primocane-fruiting. This chromosome-length assembly will facilitate future studies in Rubus biology, genetics, and genomics and strengthen applied breeding programs.