VEGETABLE GARDENING 
358 
the same ground, several crops being marketed during 
the season. 
496. Cultivation. — Wheel hoes and hand hoes are used 
frequently. When sowing- in the open it is important 
to use land as free as possible from weed seeds, to avoid 
unnecessary expense in weeding and cultivating. 
497. Irrigation. — Few crops are benefited more than 
lettuce by irrigation. Crispness and high quality are 
the results of rapid growth, which is dependent upon 
a large amount of soil moisture. When the plants are 
provided with plenty of moisture they are not only more 
tender and of better quality, but they attain a marketable 
size much sooner, and the land thus becomes available 
in less time for another crop. 
498. Marketing. — -The half-barrel hamper (Figure 48. 
b) is the most popular package for shipping lettuce from 
the South. On Long Island and in Philadelphia County, 
Pa., barrels are often used. Various styles and sizes of 
baskets and crates are used on local markets. Refriger- 
ator cars are utilized in shipping lettuce when weather 
conditions require their use. 
499. Yields and returns. — An acre of lettuce should 
cut at least 30,000 heads, but a greater number is often 
produced. Henderson calls attention to a grower who 
realized a profit of $1,000 an acre. There are doubtless 
many small areas near good local markets that do as 
well. Prices for the shipped product vary greatly from 
year to year, or at different seasons of the same year. 
500. Enemies. — Plant lice are most troublesome under 
glass, though they may cause injury in the field. Drop, 
a fungous disease, is partially controlled by rotation and 
by seed-bed sterilization. Tip Burn may be due to ir- 
regular moisture supply, extremes of temperature, lack 
of sunshine, or other conditions, most of which are be- 
yond the control of the grower. Some varieties are more 
resistant to this trouble than others. 
