The effect of Canada thistle on major yield components of spring wheat was characterized using path coefficient analysis, which provides insight concerning which yield components are most sensitive to Canada thistle competition. Increasing Canada thistle density decreased wheat stand in each of three years. Canada thistle also reduced spikes per plant and seed per spike to varying extents depending on year, but Canada thistle had comparatively little effect on wheat seed weight per 1000 seed. In the path coefficient model proposed, Canada thistle was assumed to reduce yield by directly reducing wheat yield components and through them, indirectly reducing yield. Path coefficient correlation analysis showed that Canada thistle reduced spring wheat yield chiefly by indirect effects of decreasing wheat density, the earliest formed yield component. Canada thistle reduced wheat density which, in turn, reduced wheat yield. These data suggest that Canada thistle must be controlled either before or shortly after wheat emergence if detrimental effects on wheat yield are to be minimized.

In eight of nine trials spanning 5 yr, relative yield of semidwarf hard red spring wheat (yield expressed as a percent of estimated weed-free yield) decreased linearly as Canada thistle shoot density increased when measured in late July to early August in the northern Great Plains. Differences between yield loss assessment (YLA) equations could not be distinguished statistically between no-tillage and chisel-plowed production systems. Multiple linear regression equations of relative wheat yield versus wheat density plus Canada thistle shoot density accounted for more variability in YLA equations than simple linear regression equations of wheat yield versus Canada thistle shoot density alone. Estimated weed-free wheat yield and negative slope (b) for yield loss assessment equations increased as cumulative growing-season (April to August) rainfall increased. Thus, relative wheat yield was decreased more by increasing Canada thistle density (slope b became more negative) in years of greater growing-season rainfall.

Plants, miracle of nature, are able to synthesize hundreds of chemical compounds for various metabolic functions. Numerous phytochemicals (secondary metabolites) with potential biological activity have been identified in most of the plant species. In order to determine the proximate composition, phytochemical analysis and antioxidant capacity of three well known selected plants species, a study was carried out during June 2016 in Khyber Pakhtunkhwa Peshawar. The plants under study were Aloe vera Linn (leaves), Cannabis sativa Linn (whole plant) and Mentha longifolia Linn (whole plant) in PCSIR Labs Complex Peshawar. The results from proximate analysis indicated that the plants contained crude protein in the range 0.447 to 0.953%, crude fiber ranged from 12.33 to 28.47 % and crude fat in the range of 5.87 to 14.86%. Furthermore, analysis showed the presences of important phytochemicals such as tannins, flavonoids, alkaloids, glycosides and saponins in the investigated species. Antioxidant activity of the selected plants by DPPH (2,2-diphenyl-1-picrylhydrazyl radical) scavenging assay and using ascorbic acid as a standard indicated that Cannabis sativa and Aloe vera has the strongest and nearly the same activity with IC50353µg/ml. These plants can be used as herbal products.

The goal of this research was to determine whether crop management practices could substitute for a herbicide for managing mixed populations of green and yellow foxtail in hard red spring wheat. Crop yield and foxtail growth were measured in two years of field research in North Dakota. Spring wheat yields were as great or greater when early seeding date or 2× seeding rate were substituted for POST diclofop3at 0.75 kg ai ha−1for managing foxtail in spring wheat. Yield of spring wheat competing with foxtails was greater for the high seeding rate (2× = 270 kg ha−1) than both the normal (1× = 130 kg ha−1) and low (0.5× = 70 kg ha−1) seeding rates for early or middle seeding dates, but not for the late seeding date. For both early and middle seeding dates, wheat yield at the 2×seeding rate without diclofop was equal to or greater than that of the 1× seeding rate with diclofop. Late-seeded wheat did not yield well in competition with dense foxtail stands for any treatment combination. Early and middle seeding dates favored the relative increase of green foxtail over yellow foxtail in wheat, whereas late seeding favored yellow foxtail over green foxtail. Economic analysis demonstrated that early seeding date was the most critical factor in determining the stochastic dominance of treatments without diclofop over treatments with diclofop. Seeding rate was much less important than seeding date in determining the ranking of treatments in stochastic dominance analysis.

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