6 BULLETIN 208, U. S. DEPARTMENT OF AGRICULTURE. 
fn the last column of Table I the annual yield has been omitted in 
those rows harvested during the growing season, for reasons already 
stated. An average of the others gives a yield for the portion har- 
vested during the crop’s dormant season of 40.463 tons per acre per 
annum. Omitting rows 20 to 22, inclusive (which is justifiable on | 
account of the poor stand), the average yield per acre per annum is 
43.557 tons. It should be borne in mind that a part of this is aver- ~ 
aged for two years’ growth and a part for a three-year period. In 
other words, rows 20 to 27 were harvested after two seasons’ growth 
and rows 35 to 48 after they had attained the growth of three seasons. 
The species of prickly pear grown in these experiments were a 
mixture of the three discussed on page 3, but Opuntia gommei and 
Opuntia cyanella greatly predominated. The quantity of the other 
species grown was negligible. 
In addition to what has been said regarding the handling of this 
plantation, it should be stated that no cultivating at all was done 
after the second season. Cuttings were set in this planting, as-in 
the other, in 8-foot rows, no attempt bemg made to space them 
exactly. Under these conditions, the plants had bridged over the 
8-foot rows at the close of the second year’s growth to such an extent 
that animals could not pass through and cultivation had to be 
abandoned. (PI. II, fig. 1.) 
CONDITION OF THE PLANTATION. 
The condition of the plantation was first class during the entire 
period up to late in the winter of 1913. At this time the common 
fungous diseases of the region began to be alarmingly prevalent; 
indeed, so much material had to be discarded in feeding that accurate 
estimates of yields could not be secured after the first of March. 
The cause of this condition was not difficult to interpret. The season 
of 1912-13 had an abnormal rainfall and a winter temperature with 
a high minimum. Weeds and grass grew thick among the plants 
and remained green for the most part during the entire winter. The 
pear itself had grown into an impenetrable thicket, furnishing the 
best conditions possible for the development of the net 
In this region it seems as though the age of the plantation when 
harvested will have to be considered more than in any other in which we 
have worked, because of the liability of the development of various 
diseases when the thicket becomes so dense as to prevent the aeration 
of the inner delicate vegetative parts. It is possible that when grown 
under usual conditions it will be necessary, in order to secure the best 
results, to harvest at from 18 to 36 months rather than let the crop 
stand for longer periods, as is possible in the San Antonio region or 
farther inland in general. The common diseased condition of the 
prickly pear in the brush about Brownsville points to its suscepti- 
