538 EXPERIMENT STATION EECORD. [Vol. 35 



Some data are given on the range of soil temperatures during the season, and 

 the importance of using such records to determine dates for planting, methods 

 of irrigation, and rate of growth of vegetables until edible maturity is pointed 

 out. 



Observations and data secured from experiments in the station's European 

 and American grape vineyard during the fruiting seasons of 1914 and 1915 are 

 here summarized under the general headings of bearing habits of the plant, 

 systems of pruning, yields per season, date of blooming, weight of average size 

 bunches, date of picking, decrease in size of berries, decrease in number of 

 berries per ounce, comparison of yields for separate pickings from all hills of 

 each variety, and yield of fruit. 



In an olive orchard planted late in March and early in April, 1914, it was 

 noticed early in May that many of the trees were discolored. Near the middle 

 of the month a considerable increase in the cankered areas was noted, but all 

 attempts to isolate an organism gave negative results. A further study showed 

 that the trouble made its appearance on the trees first on the south or south- 

 west side and near the ground. 



Some experimental work was carried on in which plantings were made under 

 various conditions, and it was found that sun scald of newly planted olive trees 

 occurs under certain conditions. Small, weak-growing trees usually died before 

 sun scalding took place, while large growing stems were not affected. Shading 

 the trees did not prevent sun scald, while flooding with irrigation water and 

 the use of hot soil as a surface mulch, with subirrigation, favored the scalding. 

 Medium-sized trees that gave up their water slowly were found most susceptible 

 to the injury. Scalding took place only during periods of intense heat, and 

 under average field conditions is limited to the area just above the ground. 

 Fall, winter, or early spring planting is deemed more desirable than late spring 

 planting, and trees should be headed back at the time of planting in order to 

 reduce the evaporation as much as possible. 



Report of the horticultural department, J. E. Higgins {Hawaii Sta. Rpt. 

 1915, pp. 20-27, pis. 2). — The work of the department was continued along 

 lines previously noted (E. S. R., 32, p. 741). 



The station is cooperating in experiments in Florida and in California with 

 the view of extending the culture of litchi (Litchi chinensis) . Some successful 

 experiments in transporting these short-lived seeds under refrigeration from 

 Honohilu to San Francisco and thence by ordinary express and by mail in moist 

 sphagnum moss to Washington, D. C, and to various localities in California 

 are noted. All of this seed germinated well, thus indicating that litchi seeds 

 may be transported where refrigeration for fruit is available. 



In the work with mangoes some preliminary studies have been made on the 

 flowers of certain varieties and on methods of pollination. Several mango 

 seedlings less than nine months old, which had been grafted by inarching, were 

 found to be producing flower clusters above the point of union, and in most 

 cases the scion also was flowering. The mango tree ordinarily does not flower 

 until it is from five to six years old. No cause is ascribed for these phenomena, 

 except the grafting. An instance of bud mutation is reported in which a single 

 branch of one of the trees bearing green fruit produced a pink fruit rather 

 smaller in size than the regular type but otherwise resembling the variety. 

 Bark grafting the mango, which has previously been successfully applied by the 

 Porto Rico Experiment Station, has proved to be well adapted under Hawaiian 

 conditions to the work of top gi-afting established trees. The process is here 

 described. 



