A split-rooted containerized system was developed by approach grafting two, 1-year-old apple (Malusxdomestica Borkh. cv 'Gala') trees to investigate the effect of soil moisture heterogeneity and total soil moisture content (θv) on tree water relations, gas exchange, and leaf abscisic acid (ABA) concentration [ABA[subscript leaf]]. Four irrigation treatments comprising a...
Hornets of the genus Vespa are recognized as efficient and devastating predators of honey bees, especially in tropical and subtropical biomes. Of the four species of honey bees in the genus Apis only A. dorsata Fabr., the giant honey bee, appears free from attack by hornets (Seeley et al. 1982)....
A recent identification of the two-component aggregation pheromone of the invasive stink bug species, Halyomorpha halys (Stal), in association with a synergist, has greatly improved the ability to accurately monitor the seasonal abundance and distribution of this destructive pest. We evaluated the attraction of H. halys to black pyramid traps...
Seeds provide food, feed, fiber and fuel. They are also an important delivery system of genetic information, which is essential for the survival of wild species in ecosystems and the production of agricultural crops. In this review, seed traits and genes that are potentially important for agricultural applications are discussed....
Zoysiagrasses (Zoysia Willd.) are a slow-growing, tetraploid (2n = 4x = 40) turfgrass that can be successfully managed with less input than many other warm-season grasses. Despite extensive genetic and morphological variation, genotypes with the ability to recuperate quickly from damage are rare. Therefore, a long-term effort to increase vegetative...
The US Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository in Corvallis, Oregon, preserves more than 800 accessions of hazelnut (Corylus), including C. avellana cultivars and representatives of 10 other recognized shrub and tree species. Characterization and study of genetic diversity in this collection require cross-transferable markers, such...
Rubus seed has a deep double dormancy that restricts germination due to seed coat structure and chemical composition. Improved germination of diverse Rubus species required for breeding improved blackberry and raspberry cultivars is partly dependent on the seed coat structure. This study evaluated the seed coat structure of three species...
The hepatotoxic alkaloids known to occur in tansy ragwort (Senecio jacobaea L.) are also present in honey produced from the nectar of this species. These alkaloids, which include senecionine, seneciphvlline, jacoline, jaconine, jacobine, and jacozine, are potentially carcinogenic, mutagenic and teratogenic and may pose health hazards to the human consumer.
The area devoted to pear production in the United States (U.S.) is declining due to lack of precocity and high
cost of production. The U.S. pear industry currently lacks "modern" orchard systems characterized by compact
trees that produce early, high yields of large, high quality fruit. Tall, shaded canopies are...
Organic production of blackberries is increasing, but there is relatively little known about how production practices affect plant and soil nutrient status. The impact of cultivar (Black Diamond and Marion), weed management (nonweeded, hand-weeded, and weed mat), primocane training time (August and February), and irrigation (throughout the summer and none...