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.