Hoagland’s solution

Culture Conditions of Plants. Red kidney beans were started in sand, transferred to Hoagland s solution in quart Mason jars, and grown under greenhouse conditions. At the time when the primary leaves were fully expanded, and the terminal bud was about 2.5 cm. long, the plants were treated as described later. 

The dwarf mutant corn (d-1) plants were germinated in soil-vermiculite, transferred when they were nearly ready for bioassay treatment (14), and grown in a growth chamber at about 25° to 30° C. with continuous white fluorescent light of about 450 foot-candles. The roots of the com were supported on filter paper wetted with Hoagland s solution and affixed to slanting glass plates, sup-... 

In test tubes (i.e., closed system unpublished data) containing 1 g air-dried autoclaved Cecil Ap - horizon soil (pH 5.0), 82 pg p-coumaric acid, Hoagland s solution (all solutions adjusted to pH 5.0), and soil extract for inoculum (total of 1.5 ml) the average linear transformation rates for p-coumaric acid over 48 hr, once microbial utilization was evident, were 3.6 x 10"4 + 1.7 x 10"4 picomole/CFU of p-coumaric acid utilizing bacteria/h, about 130 times slower than what was observed for the mean utilization in the steady-state continuous flow system. The CFU of p-coumaric acid utilizing bacteria/g soil in the test tube system averaged 1.46 x 108 over the 48 h interval. Initial CFU of p-coumaric acid utilizing bacterial populations/g soil 24 hr after addition of inoculum were 105+15. Utilization of p-coumaric acid by microbes in the test tubes was determined by 0.25 M EDTA (pH 7.0) extractions at 6 h intervals and HPLC analyses.2 CFU for bacteria that utilized p-coumaric acid as a sole carbon source were also determined at 6 h intervals by... 

JACOBSON It s possible but I doubt it because we were able to grow healthy lettuce plants with half-strength Hoagland s solution. It is used traditionally as a balanced source of nutrients, so that doesn t necessarily mean that it was, but I doubt it. 

Maize plants iZea mays L. cv. LG 11) were grown in a glasshouse at ambient temperature (-25 ="C) and a minimum PPFD of 500 pmol m " s " . The plants were developed in hydroponic culture with complete Hoagland s solution (C-plants) and in the same medium without iron (D-plants). All determinations were made in the second fully developed leaf. 

Uptake studies Small waterhyacinth plants floating in a defined medium (Hoagland s solution) were treated with known amounts of Mn(EDTA) and manganese (II)-54, or Fe(EDTA) and iron(III)-59, or phosphorus-32 as orthophosphoric acid and orthophosphate (18). Rates of radioactivity were counted appropriately using portions of roots or portions of stems at various times. By... 

For a given pH in Hoagland s solution, the carbonate ion concentration is constant, and right-hand portions of the two equations are equal to each other. Thus, rearranging yields... 

Fig. 3.10 Effects of a 7-phenolic acid solution modeled after phenolic acids found in wheat stub-ble/soybean (no-till) soil extracts (pH 5) on radicle and hypocotyl lengths of crimson clover as modified by solute potential of PEG (polyethylene glycol a r = 0.61) and Hoagland s solution (b r = 0.37) based on freezing point depression (mOsm, mUliosmoles) of solutions. The 7-phenohc acid mixture was composed of 10% caffeic acid, 9% ferulic acid, 35% p-coumaric acid, 15% p-hydroxybenzoic acid, 4% sinapic acid, 10% syringic acid, and 17% vanillic acid. Figures based on regressions from Blum et al. (1992). Plenum Publishing Corporation, regressions used with permission of Springer Science and Business Media...

Adding Hoagland s solution in addition to sunflower tissues eliminated the inhibitory effects of sunflower tissues on pigweed seedling biomass. Thus, it would appear that nutrients in plant tissues mixed into soil might modify plant-plant allelo-pathic interactions differently than nutrients/fertilizer directly applied to surface of the soil or mixed into the soil. The functional role of nutrients in small grain and clover cover crop residues is presently not known. 

Con 5 Roots and associated microbes rapidly modified nutrient/soil solution, and rhizosphere/rhizoplane pH. In case of Hoagland s solutions (contains only nitrate as N source) the pH shift was towards the neutral side. Effects of phenolic acids on... 

---