Important roles for biotic agents in integrated weed management include preventing seed production and weed emergence from the seed bank. Seed-attacking microorganisms have been described for a limited number of economically important weeds and serve as examples illustrating the potential for reducing weed seed production. Innundative releases of seed-feeding insects have also successfully redu...

Biochar (BC) is increasingly applied in agriculture; however, due to its adsorption and degradation properties, biochar may also affect the efficacy of fumigant in amended soil. Our research is intended to study the effects of two types of biochars (BC-1 and BC-2) on the efficacy and emission of methyl isothiocyanate (MITC) in biochar amendment soil. Both types of biochars can significantly red...

Light availability has a profound effect on plant growth and development. One of the ways to study the effects of light intensity on plant growth and development without the confounding problem of photosynthate availability is sucrose injection/supplementation. A greenhouse experiment was conducted to evaluate the effects of light levels (0% and 75% shade) and sucrose injection (distilled water...

Cotton (Gossypium hirsutum L. var. ;Stoneville 213'), velvetleaf (Abutilon theophrasti Medic.), redroot pigweed (Amaranthus retroflexus L.), and hemp sesbania (Sesbania exaltata [Raf.] Cory) were grown in a controlled environment room at 31/25 C day/night temperature and three irradiances: 90, 320, and 750 mueinsteins meter(-2) second(-1). From total dry weights and leaf areas determined at int...

Weed interference in annual cropping systems can be highly variable from year-to-year, as well as spatially heterogeneous. These factors have confounded efforts to develop simple methods for predicting competitive outcomes early in the growing season. A 2-year study was conducted with maize in competition with four annual weed species (Setaria faberi, Abutilon theophrasti, Chenopodium album and...

Weed seed predation by invertebrates and vertebrates was compared between a simple (large crop fields embedded in a matrix of widely scattered woodlots and hedgerows) and a complex (small crop fields embedded in a matrix of numerous hedgerows and woodlots) agricultural landscape in southern Michigan. The structural differences between landscapes were evaluated by analysis of aerial photographs ...

Abstract Velvetleaf is an economically important weed in agronomic crops Nebraska and the United States. Dicamba applied alone usually does not provide complete velvetleaf control, particularly when taller than 15 cm. The objectives of this experiment were to evaluate interaction dicamba, fluthiacet-methyl, glyphosate or a mixture two- three-way combinations for control dicamba/glyphosate–resis...

Although many studies have examined the effects of elevated carbon dioxide on plant ‘‘growth,’’ the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO2 responses as a single ‘‘response ratio’’ thus obscures two qualitatively distinct kinds of effects. ...