Stimulant Plants

On the other hand, it has been demonstrated that the addition of CO2 to greenhouses iacreases the growth rate of plants so that an iacrease ia the partial pressure of CO2 ia the air could stimulate plant growth making possible shorter growing seasons and iacreased consumption of carboa dioxide from the air. CO2 is also used ia water-treatmeat appHcatioas. Because it is significantly safer than mineral acids, it can be used to reduce the alkalinity of treated water. 

Humic substances have been proved to stimulate plant growth and nutrient accumulation (for review see Refs. 4,49, and 50). Various studies performed on excised roots or whole plants show that usually the uptake of cationic and anionic... 

Coca is arguably the most infamous of the stimulant plants. The number of Americans who have tried cocaine rose from 5.4 million in 1976 to 21.6 million in 1982. In 1995, an estimated 1.5 million Americans used cocaine, and 500,000 used it on a weekly basis (Bolla et al. 1998). 

All of the stimulants discussed have some potential for abuse, varying with environmental factors, context of use, and individual predispositions. Still, pharmacology plays a major causal role drugs with direct or indirect actions on dopamine systems are more likely to be used compulsively. Stimulants have important roles in the cultures that use them. Whether used for positive or negative purposes, it is likely that our relationships with stimulant plants will long continue. 

Saliva and especially urine contain epidermal growth factor, a small protein, which may be very important to stimulate plant growth (Dyer, 1980). Epidermal growth factor from mouse urine stimulates growth in sorghum seedlings and the effect is proportional to the amount used. 

Shoots of a range of grass species were toxic to other grasses and clover when decomposed anaerobically (Table VII). Ttie phytotoxicity seemed to be caused by organic acids and was less after 20 days of decomposition than after 10. Festuca rubra > Agrostis stolonifera/ and Alopecurus pratensis residues were the most toxic which to an extent is consistent with field observations that residues of the former two species are particularly difficult to seed into. When the shoots were decomposed aerobically, some were toxic after 10 days but this toxicity disappeared after 20 days when some residues could stimulate plant growth (Table VII). 

The aforementioned capability of podolactones to inhibit or stimulate plant growth was again verified in a study carried out by Macias and Barrero s groups [14]. In this study the allelopathic activity of 11 natural... 

The physiological effects of the kaempferol and quercetin derivatives are uncertain they inhibited indole-3-acetic acid oxidase in vitro they may induce dormancy, uncouple oxidative phosphorylation, stimulate plant... 

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