The PH Value Adjustment In Peat By Using Dolomite Powder And Its Influence On The Growth And Development Of Several Potted Flowers

In the paper, we observed the change of medium-pH and the relationship between pH and dolomite powder content. The new method of adjusting medium-pH was explored by inputting dolomite powder of different contents in the medium based on peat. Based on it, the acid-base property of culture medium was researched and adjusted of four common flowers: Dahlia hybrida, Tagetes erecta, Celosia cristata, Begonia×hiemalis. The aim was to offer theoretical argument for regulating the growth of flowers and blooming date. These results indicated that:1. The change rule was basically the same despite of different the inputing dolomite powder, but the elevatory amplitude of pH was different. The more dolomite powder was input, the more the elevatory amplitude of pH was, the faster the elevatory speed of pH was. The most rapid increase in pH occurred in the first five days of incubation, especially in the first two days. In general, pH reached near-equilibrium values within fifteen days, although pH continued to increase slightly thereafter.2. Compared with the control of no-inputing dolomite powder( treatment A, pH value of the initial 5.03) , the treatment of inputing dolomite powder increased the overground plant biomass of flower. In planting Dahlia hybrida, we could adequatly regulate pH to subacidity enviroment (pH value of 6.38), which could assure plant good growth. Medium- pH had less influence on the growth of Tagetes erecta, and Tagetes erecta could grow well in alkalscence to neutrality environment (pH value of 6.95). After treatment of dolomite powder, Celosia cristata undergone the great change, which showed that Celosia cristata was sensitive to medium- pH. Begonia×hiemalis could grow well in slightly acid environment conditions, and the treatment A (pH value of 5.43), was the best one for their vegetative growth among all treatmenrs. Slightly acid medium could improve the quality of the flowers obviously seen from the two targets of flower numbers and flower diameter.3. Because of the different varieties, flowers had different fitting ranges to culture medium-pH. Dissimilar culture medium-pH had different inflence on morphological and physiological features, such as plant height, stem-diameter, leaf number, chlorophyll of flower and plant. Thus culture medium-pH affectted the flowers number and flower diameter.4. Medium-pH also made a certain degree of control to early blooming, and different plants had different performance. The regulatory functions was the most obvious for Celosia cristata , followed by Dahlia hybrida and Begonia×hiemalis, Tagetes erecta relatively had a poor result. Improving Medium-pH could make the early blooming of Dahlia hybrida and Celosia cristata ahead of time, but delay the early blooming of Begonia×hiemalis.