Light and temperature modulated expolinear growth model for potato (Solanum tuberosum L.)

Expolinear growth equations are robust and simple models for the early and middle stages of crop growth. Those proposed by Greenwood and by Monteith were compared for potato (Solanum tuberosum L.) crop biomass in well-managed fields in the Central Wisconsin Sand Plain, and the Monteith equation found preferable. A time-derivative form of the Monteith equation was coupled to daily solar radiation and air temperature. Solar radiation was linked to daily maximum absolute growth through light use efficiency, and daily maximum relative growth rate was made a function of temperature by assuming a doubling of biological processes with every 10°C increase (Q₁₀=2). The modified model predicted dynamic dry matter accumulation variation from year to year, and showed improved prediction of potato growth until senescence.