Plant material and growth conditions
Cotton seeds (Gossypium
hirsutum L. cv. 71BRF [Bollgard II® Roundup Ready Flex®], CSIRO
Australia) were sown in 12 litre black plastic pots filled with
water-saturated composted bark and commercial potting mix soil
(Australian Native landscapes, Blayney, NSW), and pots were placed into
a naturally-lit, temperature-controlled glasshouse located at Western
Sydney University, Richmond, NSW, Australia. Emergence occurred
approximately 2 weeks after sowing, and plants were then thinned to one
individual per pot. In total, 80 individual plants were retained for the
experimental treatments. Plants were irrigated daily and fertilised with
Aquasol® (1.6 g/L) (23.0% N, 4% P, 18.0% K, 0.05% Zn, 0.06% Cu,
0.0013% Mo, 0.15% Mn, 0.06% Fe, 0.011% B) (Hortico, Victoria,
Australia) periodically to ensure growth was not water- or
nutrient-limited. During the establishment stage, temperature in the
glasshouse was set to 28/18 oC (day/night).
Temperature treatment was applied when seedlings reached ca. 5 cm
tall.