ANNUAL REPORT, 1932 19 



Adherence to asexual propagation from the original Howard 17 don is apparently 

 effective in avoiding the disease. 



Forcing Gladiolus with the Aid of Artificial Light. (L.H.Jones.) In an 

 effort to determine how many nights gladiolus (Crimson Glow) should receive 

 artificial light (from 500- watt bulbs), a succession of plots was arranged to receive 

 artificial light for one, two, three, and so on up to, and including, fifteen weeks. 

 The check plot received no artificial light. Owing to poor soil, the results were not 

 wholly satisfactory, but the trend of results checked with the results of previous 

 experiments. Flowering spikes occurred when daylight was supplemented with 

 artificial light in growing Crimson Glow planted in early autumn. Practically 

 no flower spikes were developed when no artificial light was supplied. The greater 

 number of flowering spikes was found in the group of plots that received the light 

 for more than six weeks after the first leaf appeared above ground. Some flower 

 spikes were developed in the plots receiving light for three and four weeks, and they 

 bloomed earlier than flowering spikes receiving more light. This early blooming 

 is consistent with previous results which have shown that, although artificial 

 light aids in the development of flowering spikes, it also retards the date of bloom- 

 ing. 



Plant Containers. (L. H. Jones.) In a continuation of the investigation of 

 the effect of type of flower pot on plant growth, there has been no indication that 

 the degree of soil acidity was altered in its range of fluctuation by either a non- 

 porous wall or the absence of a drainage hole. Aeration of soils in both porous 

 and non-porous types of flower pots takes place through the surface of the soil. 

 By means of rubber vacuum discs, it was demonstrated that air did not pass 

 through the wall of a moist clay flower pot. Two-thirds of the evaporation of 

 moisture from fallow soils in clay pots on a dry surface took place through the 

 wall of the pot, indicating that there was twice as much movement of water 

 laterally as vertically. When the clay pot was on a moist surface, a considerable 

 proportion of the moisture lost was replaced from the moist surface, and this 

 replacement was inversely proportional to the amount of moisture in the soil of 

 the pot. 



Root development in the clay flower pot takes place, for the most part, adjacent 

 to the inside wall of the pot. However, in plant containers of paper, glass, and 

 metal, the root system ramifies through the soil mass with but a very small pro- 

 portion of the roots occurring next to the wall of the container. The type and 

 amount of root distribution is more closely related to moisture conditions in the 

 soil, and possibly to nutrient relations, than to soil aeration. 



Plant containers made of paper resistant to the decomposing action of soil 

 organisms have proved satisfactory for the germination of seeds, production of 

 seedlings, and development of plants. Paper pots made of heavy paper that 

 decomposed, induced a nitrogen deficiency in the soil. However, if the paper 

 was light weight, the pot was practically destroyed before a nitrogen deficiency 

 occurred. 



To moisten properly the soil mass in clay pots which became dry, two normal 

 waterings were necessary. F"or non -porous containers, one normal watering was 

 sufficient to accomplish the same object. 



Nutrient Factors in Relation to the Region of Root Distribution in 

 Plant Containers. (H. E). Haskins and L. II. Jones.) I'reliminary work has 

 laid the foundation for an investigation concerning the relation of nutrient move- 

 ment in plant containers to moisture movement as influenced by evaporation 

 forces. Bottom watering was followed by resulting incrustations on the surface 



