Serious damage means any specific defect described in this section; or an equally objectionable variation of any one of these defects, or any other defect, or any combination of defects, which seriously detracts from the appearance or the edible or marketing quality of the individual pecan. The following defects shall be considered as serious damage:

Adhering hull material or dark stains affecting an aggregate of more than 20 percent of the individual shell;

Broken shells when the missing portion of shell is greater in area than a circle one-fourth inch (6 mm) in diameter;

Worm holes when penetrating the shell;

Rancidity when the kernel is distinctly rancid to the taste. Staleness of flavor shall not be classed as rancidity;

Mold, on the surface or inside the kernel, which is plainly visible without magnification;

Decay affecting any portion of the kernel;

Insect injury when the insect, web or frass is present inside the shell, or the kernal shows distinct evidence of insect feeding;

Kernel spots when more than three dark spots on either half of the kernel, or when any spot or the aggregate of two or more spots on one of the halves of the kernel affects more than 10 percent of the surface;

Dark discoloration of the skin which is darker than dark amber over more than 25 percent of the outer surface of the kernel;

Internal flesh discoloration of a dark shade extending more than one-third the length of the kernel beneath the ridge, or an equally objectionable amount of dark discoloration in other portions of the kernel; and,

Undeveloped kernels having practically no food value, or which are blank (complete shell containing no kernel).