Occurrence and Trends of Weed Seed Contaminants in Fine Fescue Seed Lots in Oregon
Steve C. Alderman,* Sabry G. Elias, Andrew G. Hulting
Fine fescues are highly valued cool-season turf species. Nearly all of the fine fescue seed grown in the United States is produced in Oregon, although little is known about the occurrence of weed seed contaminants in these seed lots. This study was conducted to assess the diversity and frequency of occurrence of weed seed in chewings (Festuca rubra subsp. commutata), creeping red (Festuca rubra subsp. rubra), and hard fescue (Festuca trachyphylla) samples submitted to the Oregon State University Seed Laboratory.
contaminants, occurring annually, were rattail fescue (Vulpia myuros), annual bluegrass (Poa annua), and downy brome (Bromus tectorum). Among these, rattail fescue was the most common, occurring in 30% to 61% of seed samples, depending on the year. The number of weed species varied among years and increased as the number of seed lots tested per year increased. During the past decade, the number of new weed species contaminants detected increased at a rate of approximately three per year.
Container Material and Chemical Treatment Affect Storage of Quality Protein Maize (QPM) Seeds
J.A. Adetumbi,* S.A. Olakojo and M.O. Ajala
Vulnerability of Quality Protein Maize (QPM) genotypes to storage pests in tropical agro-environments is of major concern. The effects of storage container materials (brown paper, polyethylene and hessian bags) and storage chemicals [aluminum phosphide (Forcetoxin™), pirimiphos-methyl (Actel lic 25 EC™) and thiamethoxam + metalaxyl-M + difenoconazole (Apron Star™)] on seed quality of some newly developed QPM varieties were evaluated to determine options that will preserve seed quality under conditioned storage.
damage, viability loss and insect population counts. Results showed that storage materials, chemicals and varieties tested were significant for all the parameters tested. Quality Protein Maize seeds stored in paper bags were better in terms of appearance rating, seed damage and insect count but recorded highest viability loss. Similarly, Apron Star preserved seeds against insect pests better than other storage chemicals but was harsh on the viability of the seed. Among the QPM varieties tested, storability of ART/98/SW1 was similar to field corn and was recommended to be used to improve seed storage characteristics of other QPM varieties.
Quality and Germination of Maytenus vitis-idaea Seeds
N.J. Carnevale, C. Alzugaray* and A.R. Salinas
The goals of this work were to study the physiological quality and germination requirements of Maytenus vitis-idaea seeds, and determine the effects of salinity on seed germination and vigor. Maytenus vitis-idaea is a shrub, 2 to 5 m high, of the Celastraceae family and a typical species of the Chaco region of Argentina.
Comparative Germination and Seedling Growth Response to Drought and Salt Stresses in a Set of Safflower (Carthamus tinctorius) Varieties
Lamyae Zraibi, Abdelghani Nabloussi,* Miloud Kajeiou, Ahmed Elamrani, Ahmed Khalid and Hana Serghini Caid
Soil salinization and drought co-occur frequently in nature, but there is little information on the comparative effects of salt and water stresses on crops, and particularly on safflower. In this research, we investigated the comparative response of seed germination and seedling growth, two crucial stages of plant establishment, of different safflower (Carthamus tinctorius) varieties to salt and water stresses, determining factors responsible for stress inhibition in relation to salt toxicity and osmotic effect.
Treatments to Improve Germination of Prosopis kuntzei
Sandra Bravo,* Roxana Abdala, Fidelina Abraham and Marta Pece
The objective of this work was to evaluate seed coat physical treatments and different substrates on germination of Prosopis kuntzei. Physical treatments included seed coat nicking, mechanical scarification, room temperature water soaking and soaking in boiling water followed by cooling to room temperature. Treated and control seeds were sown on paper towels and sterile river sand.