Where NODWT is a user-defined cultivar parameter to reflect differences in biomass among cultivars (Tan and Cock, 1979b), and Tfac(LFG) is a temperature factor (Eq. (4-5)). NODWT is estimated from observations of the average weight of a node located within the first 20 nodes of the main stem, i.e., the stem formed directly from the planted cutting, when the development age of the plant is around 3400 ºCd with no water or nutrient stress. When the node reaches its maximum length (ie when leaf expansion stops) this length should be compared to the variety coefficient for length to provide a factor (Could be node length factor NLF) which is then used in equation 4-23 to reduce node weight increase of the cohorts which do not reach maximum node length. A little bit more complicated would be in the leaf expansion phase also modify the NLF by comparing the node length at that moment with the potential with no restrictions.
From James: