Abstract
The inheritance of resistance to Didymella bryoniae (Auersw.) Rehm (= Mycosphaerella citrullina C. O. Smith) in watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) plant introduction PI 189225 was determined in crosses with the susceptible cultivar ‘Charleston Gray’. Segregation of F2 and backcross populations indicated that resistance to D. bryoniae in PI 189225 is governed by a recessive gene.
Abstract
‘Pink Lady’ and ‘Sleeping Beauty’ are similar cultivars of hybrid, perennial rose mallow hibiscus developed by the Germplasm Resources Laboratory at the U. S. Plant Introduction Station, Glenn Dale, Maryland. Parentage of both hybrids includes Hibiscus coccineus (Medicus) Walter, H. militaris Cav. and H. moscheutos L. (3), all native to the eastern United States.
Abstract
Ilex (serrata ⨯ verticillata) ‘Apollo’, U.S. National Arboretum Accession No. 29739 and PI 422217, is a new introduction from the U.S. National Arboretum as part of its hybridizing program in Ilex for improved plants for landscape use (1). The selection is a large multi-stemmed deciduous staminate shrub as a preferred pollinator for its pistillate sibling selection ‘Sparkleberry’.
Abstract
The purpose of this paper is to present a theoretical account of the phosphorus nutrition of plants in soils, including some of the evidence and thinking related to it. Because these remarks are directed to the “nutrient-solution fraternity,” a comparison of nutrient solutions and soils in respect of certain aspects of phosphorus nutrition may be an appropriate introduction.
Technological achievements of the flower industry since 1978 in China are summarized into six sections, which include 1) main ornamental plant gemplasm resources and its utilization; 2) introduction, improvement and propagation of new cultivars; 3) flower seed industry. The development trends and problems of the flower industry are also analyzed, especially in the flower seed industry.
Abstract
‘Smokey’, a dense, low growing perennial selection of Dianthus plumarius L., is a joint release of the Nebraska Agricultural Experiment Station and the U.S. Department of Agriculture Science and Education Administration, Agricultural Research. It is a selection from Plant Introduction 371894.
Abstract
Pyracantha × ‘Apache’, the 5th U.S. National Arboretum introduction, combines disease resistance and compact dwarf growth habit. Pyracantha, commonly known as fire-thom, is a major nursery container-produced plant that is primarily grown for the spectacular fruit display. The four previously introduced cultivars are ‘Shawnee’, NA 28179 (1), ‘Mohave’, NA 32225 (2), ‘Navaho’, NA 38451, and ‘Teton’, NA 38450 (3).
Abstract
The inheritance of resistance to cowpea chlorotic mottle virus (CCMV) in southern pea, Vigna sinensis (L.) Savi., Plant Introduction 255811, was determined in crosses with the susceptible cvs. Knuckle Purple Hull, Mississippi Silver, and Princess Anne. Segregation of F2 and backcross populations indicated that resistance to CCMV in P.I. 255811 is governed by 1 major recessive gene pair.
Abstract
Watermelons Plant Introductions (PI) 189225, PI 271775, PI 271778, and PI 299379 were resistant to a population of Colletotrichum langenarium (Pass.) Ell. & Halst. in 3 states. Entries PI 203551, PI 270550, and PI 271779 were resistant in some field and greenhouse tests.
Abstract
No immunity to pickleworm damage was found among 40 plant introductions of muskmelon (Cucumis melo L). However, a Dudaim type, PI 273438, and two agrestis types, PI 137843 and PI 140471, showed significantly lower susceptibility in preliminary tests with 8 muskmelon botanical varieties.