Does one still take off a portion of challa and burn it (without a bracha) even when making less than the amount for a bracha?

ב"ה Shalom There is no mitzva or requirement to take Challa even without a Bracha for amounts less than required. The Gedolim of our time have calculated the amount that must be kneaded to require a bracha into weight. According to the Chazon Ish zt"l, only an amount of 2.250kg or 4.95 lbs requires a Bracha. According to Rav Chaim Na'eh zt"l , 1.670kg or 3.675 lbs. From 1.200kg or 2.65 lbs Challa is taken but without a Bracha, but anything less than that no Challa is taken at all. (See הארץ ומצוותיה pg. 295) All the best