The timing of the male and female functional stages of all varieties varied throughout the monitoring period, often not conforming to the standard flowering sequence. Both the time of flower opening in general and the flowering cycle were delayed by low temperatures, particularly for type B varieties. During flowering, temperatures were regularly lower than the ideal 25/20°C maximum/minimum cycle (Sedgley and Annells 1981), and shown in Figure 4.
The type B flowers were particularly affected by the variable temperatures. The female functional stage often was not being seen during the early flowering period when temperatures were low. It was occasionally recorded not opening until late afternoon, after 5pm (1700 hours) and sometimes appearing to remain open until the next morning. The male functional stage was far more prevalent and often seen throughout the day.
Figure 5 shows the recorded opening flower stages for Ettinger, a type B variety.
The Hass flowering sequence was also affected by variable temperatures experienced during the flowering period. During the initial period of flowering when the average maximum temperature was below 20°C and the minimum temperature was below 10°C, the opening of the stages was so affected that the flowers in one period opened as functionally female in the afternoon and functionally male the next morning, essentially mimicking the type B timing cycle (Figure 6).
Once the temperature increased closer to 25/15°C maximum/minimum, the flowering cycle started to behave more as expected with some overlap period in the middle of the day (Figure 7). This normal sequence was quickly lost again with any drop in temperature. During the Hass flowering in 2009, there were only a few short periods of two to three days of near preferred temperatures (see Figure 7).