We grew velvetleaf (Abutilon theophrasti Medic.) and cotton (Gossypium hirsutum L. var. Stoneville 213) at three irradiances and determined the photosynthetic responses of single leaves to a range of six irradiances from 90 to 2000 mueinsteins m(-2)sec(-1). In air containing 21% O(2), velvetleaf and cotton grown at 750 mueinsteins m(-2)sec(-1) had maximum photosynthetic rates of 18.4 and 21.9 m...

Seeds from natural populations of fierce thornapple and velvetleaf collected in a corn-growing area in central Spain were incubated at a range of constant temperatures and water potentials to model the progress of germination on the basis of the accumulation of hydrothermal time. Previous to the germination tests, the seeds were treated in two different ways: (1) dark storage under dry conditio...

Growth analysis, absorption and translocation studies were conducted to compare a 1-aminomethanamide dihydrogen tetraoxosulfate (GLY-A) formulation of glyphosate with two isopropylamine (GLY-IPA-1, GLY-IPA-2) formulations of glyphosate on velvetleaf. The two isopropylamine formulations differed by the presence of a surfactant in the formulation, GLY-IPA-1 containing surfactant whereas GLY-IPA-2...

Synthetic seed banks are a useful tool for tracking how weed populations change over time. By sowing a known number of seeds of a given species within a quadrat with defined boundaries, an investigator can measure the number remaining and thereby calculate demographic rates (e.g., mortality). The alternative is to use in situ seeds and estimate their initial population density via sampling. To ...

The reactivity o f the bleaching herbicide clom azone with reduced glutathione (GSH) was studied under in vitro conditions. C lom azone at 1.3 m M and GSH a t 100 m M were reacted in a phosphate buffer (pH 8.8) at 25 CC for 3 days. The resulting synthetic product was identified as a G S-conjugate o f clom azone by means o f TLC , H PLC , and mass spectrom etry (chemical ionization) procedures. ...