SUGARCANE VARIETY P.O.J. 2878 IN PUERTO RICO 19 
P.O.J: 2725 had more sprouted roots and clinging leaf pieces than 
did either P.O.J. 2878 or Mayaguez 28. Due to their recumbent 
position, the canes of B.H. 10(12) had a higher proportion of joints 
with sprouted roots than did the canes of any other variety. There 
was little difference in the ease of trashing P.O.J. 2878 and Mayaguez 
28; both trashed much more freely than did P.O.J. 2725, and some- 
what more so than did B.H. 10(12). 
Quality oj cane. — To determine the relative amounts of pithiness, 
the cut surfaces of 2,000 harvested cane pieces of each variety were 
examined (table 13). Pithiness was pronounced for P.O.J. 2725, 
P.O.J. 2714, and P.O.J. 2878; rather pronounced for Mayaguez 3; 
slight for Mayaguez nos. 7, 28, 42, and 49; and negligible for S.C. 
12/4 and for B.H. 10(12). Hollow centers were found in 5 to 8.5 
percent of the canes of the 3 Javan varieties, in only 1 to 2 percent 
of those of the 5 Mayaguez seedlings, and in 0.5 percent of those of 
S.C. 12/4. No hollow centers were found in the canes of B.H. 10(12). 
The canes of P.O.J. 2878 were less solid than those of Mayaguez 28. 
Dry top rot. — P.O.J. 2714 suffered badly from dry top rot (Plas- 
modiophora) . Most of its cane tops died before harvest, whereas 
those of the other varieties were practically unaffected. Not only 
were there nearly twice as many more P.O.J. 2714 cane pieces per 
1,000 with dry top rot than were found in any other variety, but also 
the dry top rot extended over a much greater area, generally occupying 
over half the area of the cut surface examined (table 13). Practically 
no difference in the amount of dry top rot of the P.O.J. 2878, Maya- 
guez 28, and P.O.J. 2725 canes was observed. B.H. 10(12) and 
Mayaguez 42 had solid canes and were practically free from the 
disease. The data on dry top rot for the two series of plats were 
similar. 
Borer infestation. — Wolcott 8 states that cane-borer counts taken 
in plats of carefully controlled small-scale experiments are not 
dependable. The data presented (table 13), however, are valuable in 
indicating that none of the varieties are extremely susceptible. As 
has been observed repeatedly near Central Aguirre, S.C. 12/4 and 
B.H. 10(12) were found to be comparatively free from borer attack. 
P.O.J. 2878 was consistently less susceptible than P.O.J. 2725 at 
Coloso. The higher borer counts of P.O.J. 2725 are probably due to 
the larger proportion of clinging leaves, which may have harbored 
insects. 
GENERAL FIELD PLANTINGS AT CENTRAL COLOSO AND AT ISABELA 
Despite wide spacing that induced the formation of water sprouts 
and decreased the percentage of sugar in cane, results with P.O.J. 
2878 in 1931 at Central Coloso were in general favorable, as shown 
in table 14. 
8 Wolcott, G. C. on methods of determining borer abundance in cane fields. Internatl. Soc 
Sugar Cane Technol. Proc. Bui. 88, 2 p., 1932. 
