Variation in Growth and Flowering Habits of Junebearing and Everbearing Strawberries

Abstract

Variation in vegetative and reproductive growth patterns leading to summer flowering and fruiting was evaluated in everbearing and in representative Junebearing strawberry (Fragaria × ananassa Duch) clones under simulated summer conditions in the greenhouse and in growth chambers. Summer flowering intensity, periodicity, fruit set, and maturation were related to plant architectural parameters such as crown, leaf and runner production, number of meristems produced and differentiated, leaf areas and petiole length, plant volume, and dry weight allocation patterns. A continuum of growth habits and flowering behavior precluded rigid classification of summer flowering response, but useful arbitrary distinctions were made on the bases of: photoperiod reaction into short-day (Junebearing) vs. weak, intermediate, or strong day-neutrals; or summer fruit expectation into essentially none (Junebearing) vs. sporadic or consistent everbearers. Critical criteria for separating Junebearers from everbearers include degree of summer flowering and fruiting (fresh or dry weight basis), plant volume (and its components, petiole length, and average leaf area), and the dry weight allocation ratios—root : shoot and reproductive : vegetative. Everbearing (or day-neutral) types could be distinguished by plant volume and composition differences (size, number, and percentage of developed meristems, leaf area ratio, reproductive dry weight, etc.) and continuity of individual plant flowering. Three basic models of shoot growth and inflorescence positioning are proposed from evidence for alternative modes of flowering site generation in everbearing strawberries.

Evaluation of different strawberry genotypes for flower characters under Punjab conditions

“…The germplasms 'Chandler' (V 1 ), 'Camarosa' (V 3 ) and 'Winter Dawn' (V 2 ) took 78.67 days, 79.67 days and 82 days respectively to produce flower after planting. The variation in days to flowering after planting in different genotypes may be probably due to variability in chilling requirement of germplasm under investigation where some of the genotypes reflected early flowering with little chilling period (Craig and Brown, 1977 [9] ; Nicoll and Galletta, 1987) [10] . The maximum (21.67) flowers count per plant was registered in 'Camarosa' (V 3 ) which was at par with 'Winter Dawn' (V 2 ) (20.66) and 'Chandler' (V 1 ) (19.67) while genotype 'E-22' (V 11 ) had produced the minimum flower per plant.…”

The habit of strawberry flowering is the key for runner propagation, where the photoperiod is the main environmental factor - A review

“…The words "dayneu tral" (DN) and "everbearing" (EB) are interchange able and refer to a physiological insensitivity to day duration in flower bud initiation and a realistic expec tation of strawberry producing. Weak, moderate, and strong dayneutral cultivars can be used to categorise the everbearing strawberry cultivars (Nicoll and Galletta, 1987).…”

Initial Bare-root Crown Size and Early-season Flower Cluster Removal Has Little Effect on Subsequent Plant Performance in Day-neutral Strawberry

“…Flowers arise from the crown and represent a sink for plant energy reserves, and their removal can increase the proportion of leaf area to inflorescence number and result in a more vigorous plant (Nicoll and Galletta 1987). Flower removal is frequently practiced by California strawberry growers to delay fruiting and with the intention to promote vegetative growth, and costs in the area of $200 to $400 per acre (Bolda MP, unpublished data).…”

“…Because the number of flowers has been positively correlated to crown size (Nicoll and Galletta 1987), the relation of these two factors is an important part of this study, along with their observation independent of one another. The purpose of this study was to evaluate the interaction of bare-root crown size at planting and early-season flower cluster removal and subsequent plant performance in the day-neutral strawberry varieties Cabrillo and Monterey on the Central Coast of California.…”