RADIO-LOGLOLS L3ud the potassium fertilization, but not enough for dilution to 2ccount for the differences in Cs-137 contents. The absenceof radiocesium in the P-K treatment was associated with an unusually high klevel in the planttissue. Following this preliminary experiment with tomato, a further greenhouse trial was made with squash, variety Hubbard. Squash was used because it is one of the few herbaceousplants successfully cultivated in the northern Marshall Islands, The treatments were set up in triplicate, replication was good, and the plants grew wel] except for some chlorosis which was not entirely corrected by the applicationof 1.5 ms Fe per pot as NaFeEDTA(Fechelated by ethvlenediamine- tetraacetic acid). The plants were divided into upper leaf, lower leaf, and stem fractions at harvest. Since the results were qualitatively the same for the different fractions and space is limited, Table 1 presents the vields and Kk andCs analyses on the basis of the entire shoot. The results of this experiment were in general TABLE 1 Crusium axD PotassiuM CONTENTS OF SQUASH AND OF NATIVE SPECIES Description Average drv yield vem) meq K per 100 gm Csi? d/m/g! Squash in greenhouse pot culturcs (total shoot) No fertilizer N, Py Ke N; No N3 N3 Py Ky P,R: Pe Rs Py IX: Fe 45 8.0 T.4 33 5 4 10 2 29 6 $10+34 36 47 26 36 130 +14 15U~14 120 +16 220415 17 7 3 5 8 3 170= 11 Foweve coisected from woody plants on Rongciap Island Messerschmidia argentea (soit pit 25, upper leaves lower leaves 33 bo 6 240 +8 13U+7 (soil pit 25) Pandanus tectortus iwillage-2) lower leaves upper leaves lower leaves 12 18 3 5 9 15027 26345 133 = 4 Scacivla sericea upper leaves 33 MGa8 'Error given is 05% counting error. ‘Subscripts refer to rate of application per acre of N. P.O. or K,0 in hundreds of pounds. similar to those with the tomato, although there was no response in vield to potassium additions, and the tissue from the N..P,K, treatment contained Cs-137. In all cases the fertilizer amendments caused a sharp reduction in the Cs-137 content expressed on a d’m’gm drybasis, although this effect could not be associated with a particul ar fertilizer element. The depressive effect of fertilization on cesium uptake is also evident when the total Cs-187 in the shoot is calculated, indicating that dilution by a greater amount of dry yield cannot explam the reduced cesium content. In the different portions of the squash shoots, Cs-137 was in all treatments highest in the upper leaves, lowest in the lower leaves, and intermediate in the Stem. Squash plants grown on the same bench at the same time but in a greenhouse loamsoil contained no Cs-137. Results of analvses for Ca, Mg Na. and PQ, in the tissue do not offer anv obvious explanation for the differences in cesium uptake, although it should be noted that calcium levels