Digestive enzymatic activity and nutritional responses of Autographa gamma (L.) (Lepidoptera: Noctuidae), an important insect pest of sugar beet, on nine sugar beet cultivars (Peritra, Karolina, Paolita, Lenzier, Tiller, Ardabili, Persia, Rozier, and Dorothea) were studied. The highest proteolytic activity of fourth and fifth instar of A. gamma was in larvae fed on cultivar Persia. The highest ...

BACKGROUND AND AIMS Growth of grass species in temperate-humid regions is restricted by low temperatures. This study analyses the origin (intrinsic or size-mediated) and mechanisms (activity of individual meristems vs. number of active meristems) of differences between Bromus stamineus and Lolium perenne in the response of leaf elongation to moderately low temperatures. METHODS Field experime...

The effect of high temperatures on harvest index (HI) and morphological components that contribute to HI was investigated in two lines (Bd21 and Bd21-3) of Brachypodium distachyon, a C3 grass recognized as a tractable plant, to address critical issues associated with enhancing cereal crop yields in the presence of global climate change. The results demonstrated that temperatures ≥32 °C eliminat...

Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be...

Aims Variation in precipitation strongly influences plant growth, species distributions and genetic diversity. Intraspecific variation in phenotypic plasticity, the ability of a genotype to alter its growth, morphology or physiology in response to the environment, could influence species responses to changing precipitation and climate change. Despite this, the patterns and mechanisms of intrasp...

Mortality of tillers in barley (Hordeum vulgare L.) is an important developmental event affecting spike number and yield potential of the crop. It has traditionally been thought that increased shading of young tillers by the developing canopy initiates the premature senescence of tillers. A series of field experiments were conducted in 1982, 1983, and 1984 at St. Paul, MN on a Waukegan silt loa...

From 1997 to 1999, Schizaphis graminum (Rondani), intensity (number per tiller) was estimated on 115 occasions from hard red winter wheat fields located throughout the major wheat growing regions of Oklahoma. A total of 32 and 83 fields was sampled during the fall and spring, respectively. The parameters of linear regressions relating the mean number of greenbugs per tiller (m) and the proporti...