A Review of Non-Chemical Weed Control Practices in Christmas Tree Production

A review of non-chemical weed management

A Non-Chemical System for Online Weed Control

Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with t...

Non-chemical methods of weed control: benefits and limitations

Non-chemical methods of weed control will become increasingly important in Europe due to a lack of herbicides, increasing resistance and a new European Union (EU) requirement for use of IPM. Compared with herbicides, non-chemical methods tend to be less effective, more variable, more expensive, may not reduce the requirement for herbicides, provide little visual evidence of success, may have ad...

A Christmas tree cataract

A 70-year-old man referred for cataract surgery, had on examination a palette of colored needle-shaped opacities in the cortex and anterior nucleus of the lens, consistent with unilateral Christmas tree cataract. This type of cataract result from the accelerated breakdown of membrane associated proteins. The peptides and amino-acids accumulate in the lumen of the reticular meshwork, and cystine...

Morphologic characteristics and chemical composition of Christmas tree cataract.

PURPOSE Christmas tree cataract consists of highly refractile multicolored "needles" crisscrossing the lens fibers of the deep cortex. The fact that the colors vary according to the angle of the incident light, and that in retroillumination only a dim outline of the cataract is seen, would suggest that Christmas tree cataract is a diffractive phenomenon. This study was performed to unravel the ...