Table 3.

Rating system for root fibrosity of Q. ithaburensis cultivated under FL, L20AP67, AP673L, G2, AP67, and NS1 light treatments at the end of the 28 days experimental period in the growth chambers.

Light treatments	No of FOLR with d > 1 mm	Rating	Fibrosity class	Description of root system appearance
FL	1.4b	1b	Very low	No 2nd order long roots; zero or few short roots present
L20AP67	2.5b	3a	Moderate	3–5 2nd order long roots; moderate density of higher order long and short roots
AP673L	5ab	5a	Very high	5 > 5 2nd order long roots; high density of higher order long and short roots
G2	3.6ab	4a	High	>5 2nd order long roots; moderate density of higher order long and short roots
AP67	6.3a	>5a	Very high	5 > 5 2nd order long roots; high density of higher order long and short roots
NS1	6.6a	>5a	Very high	5 > 5 2nd order long roots; high density of higher order long and short roots

Different letters within the column indicate significant differences among the light treatments at p < 0.05. Data are mean values (n = 5) ± SE. The rating is based on visual assessment of the approximate number and type of high order lateral roots per 10 cm segment of primary FOLRs (those with a diameter > 1 mm, branching from the taproot). Rating: (1) Very low (no second order long roots; zero or few short roots present); (2) Low (one–three second order long roots; low density of higher order long and short roots); (3) Moderate (three–five 2nd order long roots; moderate density of higher order long and short roots); (4) High (> five 2nd order long roots; moderate density of higher order long and short roots); (5) Very high (> five 2nd order long roots; high density of higher order long and short roots). Long roots are >5 mm and are likely to contain branches of the next highest order. Short roots are <5 mm; they do not support roots of higher order (Hatchell and Muse, 1990).