Biological, physical, chemicophysical and chemical characteristics of fruits of 48 sugar beet diploid lines were examined in laboratory experiments. Effects of these properties on germination, emergence and growth were investigated in field trials

Seed germination culminates in the initiation of embryo growth and the resumption of water uptake after imbibition. Previous applications of cell growth models to describe seed germination have focused on the inhibition of radicle growth rates at reduced water potential. An alternative approach is presented, based upon the timing of radicle emergence, to characterize the relationship of seed germination rates to water potential. Using only three parameters, a 'hydrotime constant' and the mean and standard deviation in minimum or base water potential among seeds in the population, germination time courses can be predicted at any water potential or normalized to a common time scale equal to that of seeds germinating in water. The rate of germination of lettuce (Lactuca sativa L. cv Empire) seeds, either intact or with the endosperm envelope cut, increased linearly with embryo turgor. The endosperm presented little physical resistance to radicle growth at the time of radicle emergence, but its presence markedly delayed germination. The length of the lag period after imbibition before radicle emergence is related to the time required for weakening of the endosperm, and not to the generation of additional turgor in the embryo. The rate of endosperm weakening is sensitive to water potential or turgor.

Established seedlings were used to infer the patterns of past seed dispersal and germination events. A greater spatial distribution of seedlings resulted where the seed source was scattered, compared with a more compact seed source. The potential for recolonisation exists, and will be determined by biotic interactions, edaphic factors, and physical factors (such as fire regime).

Physicochemical and sensory characteristics of products made from cowpeas that were ungerminated (UN) or germinated at 25 or 30 degrees C for 24 h (G25 and G30, respectively) were assessed. Nitrogen solubilities of UN, G25, and G30 were similar. Electrophoresis revealed minor changes in proteins due to germination. Pastes of G25 or G30 had higher flow consistency (n) and apparent viscosity and possessed better frying characteristics than paste of UN. Germination increased the hardness, elasticity, gumminess, and chewiness of akara (fried cowpea paste) but did not affect cohesiveness. The derived instrumental color function (deltaH) was higher for G25 and G30 flour and akara than for UN products. Among sensory measurements, germination significantly improved the crust color of akara but slightly reduced the ratings for moistness, tenderness, and flavor. Overall acceptability was not reduced by germination.

Field observations indicated that Euphorbia prostrata strongly interferes with Cynodon dactylon (L.) Pers. Analysis of some physical and chemical soil factors indicated that competition was not the dominant factor of that interference. Soil collected from under E. prostrata stands was very inhibitory to seed germination and seeding growth of some of the test species including C. dactylon. This suggests the presence of inhibitory compounds in soil of E. prostrata stands. Subsequent experiments showed that aqueous extract, decaying residues, and root exudates of E. prostrata were inhibitory to most of the test species including C. dactylon. Thus, it appears that allelopathy is the major component of the interference, with competition probably accentuating its effect. It also was found that allelopathy is an important component of the interference by E. prostrata against Amaranthus retro-flexus, Medicago sativa, and Gossypium hirsutum.