Phyllochron estimate for the teosinte crop

Abstract

The objective of this study was to estimate the phyllochron for teosinte crops across different sowing dates. An experiment was conducted on 12 sowing dates (10/08/2021 to  01/01/2022. The sowings were carried out in a 5-meter-long row, spaced at 0.80 meters between rows and 0.20 meters between plants in the row. For each sowing date, five plants were randomly marked, and the number of expanded leaves (NF) was counted weekly until male flowering. Throughout the experimental period, daily mean air temperatures in °C were recorded. Degree days (ºC day) were calculated considering the base temperature of 10°C. The accumulated thermal sum (ºC day) from emergence was obtained by summing up the degree day values. For each sowing date, a linear regression was fitted using the equation y = a + bx, where y is the mean number of leaves of the five plants, and x is the accumulated thermal sum from emergence. The phyllochron, in °C day leaf^-1, was determined by the inverse of the angular coefficient of the linear regression between NF and accumulated thermal sum (phyllochron = 1/b). The phyllochron for teosinte cultivation varied from 47.17°C day leaf^-1 (sowing on 01/01/2022) to 88.99°C day leaf^-1 (sowing on 12/04/2021), with an average across the 12 sowing dates of 70.14°C day for the emergence of a new leaf.