Onions bulb according to day length and temperature. There are many varieties available so onions can be planted during different times of the year to bulb and be harvested over many different times of the year. Having the name Texas 1015 was a way to make it easy for people to know when to plant this variety in South Texas and similar areas around the world.
Why does cutting an onion make you cry?
Onions contain several sulfur compounds. The major ones are thiopropanal S-oxide, Methyl propyl disulfide, dipropyl disulfide and propyl propenyl disulfide. The onion also contains an enzyme allinase. When you cut an onion you break the cells and the enzyme mixes with thiopropanal S-oxide and creates a volatile sulfur that gets into your eyes and causes an irritation which in turn causes tearing.
If you bite into an onion the same thing happens and causes a slight irritation to mouth tissues. An uncut onion has no pungency or tearing effect because the enzyme and sulfur are separate. To demonstrate this either freeze or heat an onion to kill the enzyme, then cut or taste and you will not experience any tearing or pungency. Microwaving is a very easy way to kill the enzyme.