-6- 



A plant which is livin^^ so near the verge of starvation ought to respond 

 markedly to an application of fertilizer it would seem. An experiment was start- 

 ed in the spring of 19^3 to see what beach plijims would do if given rather heavy 

 amounts of fertilizer. In one field, five-bush ^olots were fertilized with a 

 7_7_7 fertilizer at rates of 2^0, 500,, 1000., and 2000 pounds per acre. The fer- 

 tilizer on the 250-pound plot was applied in early April, On the other plots 

 half v/as applied in early Apiril aixi half about June 1, Each year a record was 

 made of yield and the amount of terminal grovrth. Leaves were analysed for total 

 nit-rogen to determine if nitrogen from the fertilizer had been picked up and 

 whether differences in amount applied would be reflected in the amount found in 

 the leaves The three-year averages are given in the following table; 



Fertilizer 

 applied 

 Pounds per 

 acre 



Pounds of 

 fruit per 

 plot 



Average terminal 

 growth per bush 

 in inches 



Percent 

 nitrogen 

 in leaves 



It is apparent that an application of as much as a ton of 7-7-7* which would 

 supply lUO pounds of actual nitrogen per acre, had very little, if any, effect on 

 the yield and groiTth of the bushes or the nitrgen content of their leaves. The 

 bushes on the 2000-pound plot were smaller initially than those on the other plots 

 T/hich accounts for the poor yield on that plot. 



The lack of response of the beach plums to such heavy applications of fertil- 

 izer was not anticipated. It is probably associated vo.th Yrater relations* The 

 soil on which these beach plums are planted is sand underlaid with gravel and it 

 drys out very rapidly. Although the total rainfall for the grawmg season, April 

 through September, was not low for any of the three years, the distribution was 

 poor. There were dry periods of considerable duration in each season. Lack of 

 viater appeared to be the limiting factor. 



In another location some beach plums along a stone wall vrere fertilized with 

 enough nitrogen carrying fertilizer to give 200 pounds of actual nitrogen per 

 acre. During a two-year period the fertilized bushes averaged 17.8 inches of 

 terminal grovrth, the unfertilized 7,6 inches. These bushes failed to bear because 

 beach plums are self -sterile and cross pollination was not provided. The greater 

 growth at this location probably resulted partly from no crop and partly from a 

 better soil and more moisture. These bushes are near a planting of cultivated 

 blueberries which indicates that moisture is available most of the time. 



These experiments re-emphasize the fact that water can be a limiting factor 

 even mth a plant which is adapted to living in dry places. Where water is limit- 

 ing, any attempt to increase grovrth and yield by other means than adding vrater has 

 little chance of success. Deriving profits from planting beach plums in dry sandy 

 locations appears to have some limitations, 



— J, S. Bailey 



//////////////// 



