Lotus flower buds (N. nucifera Gaertn. spp. nucifera, cv. Saddabutra,
likely the same as cv. Album Plenum) were harvested in the
morning. The buds were picked at their normal commercial stage,
i.e. with the floral buds still fully closed but, if left uncut, opening
within about a day. Workers walked in the water of the lotus
pond, which stood about one meter deep, or collected stems by
boat. Stems were broken under water, close to their junction with
the rhizome. After harvest, the stems were held dry or were placed
in purified water (tap water, after passing through reverse osmosis
equipment). Stem length at harvest varied from 40 to 60 cm. In
some treatments the stems were recut under water in the field
(removing about 10 cm) and then immediately placed in purified
water. Stems were brought to the laboratory within about
1 h of harvest. In the laboratory the stems were recut in air, to
a length of 25 cm, and were then placed individually in glass
vials or glass graduated cylinders, containing purified water. The
flower stalks were held in a temperature-controlled room at 25 ◦C,
70% RH, and natural light supplemented with fluorescent light
(lights on from about 7 a.m. to 7 p.m., photon flux density about
15 mol m−2 s−1).