are the result of mutation or of cross-pollination between similar varieties. When cucumbers appear in musk- 
melon fields or vice versa, a mechanical mixture is responsible. 
When hybridization is used in the crossing of two varieties to accomplish a definite purpose such as dis¬ 
ease resistant characteristics, one parent is usually immune to a certain plant disease. Through the process of in- 
breeding that desirable feature may eventually become a hereditary characteristic in the new progeny. The new 
variety may combine the desirable qualities and otherwise resemble one of its parents with the addition of the 
disease resistance of the immune parent. Continuous inbreeding eventually establishes a true variety which en¬ 
vironmental conditions does not change to any marked degree. This is the procedure which has been used to 
develop the mildew resistant cantaloupes, wilt resistant watermelons, and other recent introductions designed to 
withstand certain plant diseases. This field offers much possibility to the plant breeder who is equipped to carry 
on the work. In our opinion many new features will be developed as time goes on and many of our present 
standard varieties will eventually be immune to the more serious diseases as well as certain of the insect pests. 
Immunity to disease can also be accomplished by careful selection work and has proven satisfactory in some 
cases. It is necessary to start with a single plant which shows a high resistance and continue to develop it un¬ 
til it has reached perfection. 
GERMINATION 
The laws governing germination requirements on garden seeds are becoming increasingly severe in inter¬ 
state commerce. Many States now require purity and germination tags as well as the date of tests and state in 
which the seeds were grown. It has long been the custom in field seed but the vine seed crops especially are not 
likely to include foreign seeds so far as purity is concerned. The standard requirement in germination is 85 
per cent. Many features enter in to affect tests in vine seeds but for the most part they are conditions surround¬ 
ing the curing and harvesting processes. 
We have observed especially in watermelon seed a tendency to absorb moisture and thus delay gennination 
in some cases. This has occured chiefly where the seed is stored in climates where damp weather is prevalent. 
Ordinarily all the Cucurbits will retain their vitality over a period of about five years. On many occassions 
longer periods have been recorded. 
PLANTING METHODS 
In the production of seed crops, more seed is planted per acre than is usually required for commercial fields. 
Cultural conditions often govern the size of fruits as well as maturity dates, quality and flavor. Planters with a 
wide experience in these matters state that they can very closely control the size and maturity dates by the prop¬ 
er methods of planting and care. When size is desired, the distance between rows and distance of plants in the 
row play an important part in determining these features. Most of the Cucurbits will readily adapt themselves 
to climatic conditions and respond to the proper care. 
ONE HUNDRED FORTY-TWO 
