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Abstract
Soil mulches (clear, white, or white-on-black polyethylene or straw) were evaluated for their effects on growth and development of day-neutral ‘Fern’ and ‘Tristar’ strawberry (Fragaria × ananassa). Plants mulched with straw or white-on-black polyethylene flowered and yielded more than plants mulched with clear or white polyethylene. Conversely, more crowns per plant, runners per plot, and greater leaf, crown, and root dry weights were associated with plants mulched with clear polyethylene than with those mulched with straw or white-on-black polyethylene. In midsummer, late-afternoon soil temperatures were highest under clear followed by white, white-on-black, and straw mulches. The results suggest that flowering is most profuse and vegetative growth least when day-neutral cultivars are grown on mulches that moderate soil temperatures.
Abstract
Emerging primocanes of red raspberry, Rubus ideaus L. ‘Boyne’, were sprayed with naphthaleneacetic acid (NAA) at concentrations of 0.5, 1.0, and 1.5% when shoots were 7–13-cm-tall or at 1.0 and 2.0% when they were 13–20-cm-tall. Treated primocanes exhibited leaf cupping and epinasty followed by withering and death. Untreated floricanes and primocanes emerging after treatment were normal. Treatment with NAA at all rates restricted the height of primocanes emerging after treatment. Fruit yield the year following was reduced by NAA applied to shoots 13-20-cm-tall.
Abstract
Genetic variance components, narrow sense heritability, and combining ability effects of parents were determined for several traits from analysis of a partial diallel cross involving 17 parents. Parents included several Vaccinium species and interspecific hybrids. For fall growth cessation, general combining ability (GCA) effects were variable from year to year, and heritability was low. Variance due to GCA was more important than specific combining ability (SCA) variance for winter injury in each of the years. The heritability estimate over years was low for winter injury, although individual year estimates were higher. Lowbush parents had high GCA effects for winter injury in years with snow cover but low estimates for years without snow cover. Off-season flowering was observed in some progenies in both years studied. Certain V. angustifolium Ait. parents had high GCA effects for the occurrence of off-season flowering. The heritability estimate for off-season flowering in combined years was 0.47. Variation due to years and to GCA × year interaction was significant for all characters studied.