Two diverse genotypes of tall fescue, Festuca arundinacea Schreb (6X=42), with normal fertility, produced upon intercrossing, vigorous F
₁
hybrid plants that were sterile. One parent genotype (P₁)
was from P. I. 234-906, introduced from Switzerland and the other
(P₉) was an introduction from Turkey, P. I. 174-209. P₁
and...
Twenty-one rice cultivars were evaluated to determine the difference between populations of Sogatodes oryzicola (Muir) (Homoptera: Delphacidae) in Costa Rica and Colombia, Survival, mortality and population development of S. oryzicola on five selected cultivars was used to determine levels of plant resistance. The importance and potential of the parasitoid-predator Haplogonatopus...
Meadowfoam (Limnanthes spp.) is a potential oil seed
crop being developed for commercial production in the
Willamette Valley. The seeds are characterized by poor
germination at warm temperatures. It would be desirable
to overcome this temperature-related dormancy problem so
that better stand establishment could be realized from
early fall planting....
A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations...
California brome (Bromus carinatus Hook & Arn), is
considered an important weed infesting wheat and grass seed
fields in the Willamette Valley of Oregon. Field and
greenhouse experiments were conducted to study some
biological aspects to develop more efficient management
strategies.
A field experiment was conducted to determine the
effect...
E8,E10-dodecadien-1-ol, the primary component of the female sex pheromone of codling moth, Cydia pomonella L., has no attraction to male Oriental fruit moth (OFM), C. molesta (Busck). However, this compound when added to the OFM pheromone blend of Z8-dodecenyl acetate (85.5%), E8-dodecenyl acetate (5.5%), and Z8- dodecen -1 -ol (9.0%),...
A micropropagation system was developed for hazelnut cultivars and
rootstocks. Culture establishment was affected by explant source, explant collecting
season, and type of explant. The highest frequency of culture initiation and lowest
tissue oxidation and contamination were obtained from internodes with single axillary
buds from grafted greenhouse-grown plants early in...
A portion of this study was initiated to provide the
basis for implementing a chill unit accumulation procedure
in Yemen. Most continuous or daily minimum, maximum
temperature models severely underestimated chilling units,
and slight modifications offered little improvement for the
complex models. Only the Crossa Raynaud formula approximated
generally accepted...