The effect of natural and simulated rainfall after anthesis on wheat seed and grain quality

The effect of natural and simulated rainfall during seed development and maturation on wheat (Triticum aestivum L.) seed quality development, particularly changes in subsequent air-dry longevity (stored hermetically at 40°C with 15% moisture content), was investigated in poly-tunnel (2010) and field experiments (2011 and 2012). Avoiding rain during seed development and maturation accelerated the rate and reduced the duration of seed filling and thus reduced final seed weight, while increase in rainfall slowed down the rate and increased the duration of seed filling and increased seed weight in wet and cold weather (2011), but dry and warm weather (2012) had the opposite effect. Maximum germination of seeds dried after harvest was attained at 39-49 days after anthesis (DAA) and maintained throughout until 70 DAA. Seeds not dried attained ability to germinate slightly later with subsequent fluctuations, probably associated with dormancy. Potential longevity increased during this period, reaching a maximum at 53-56 DAA, coinciding with harvest maturity, and then declining in 2012 but not in 2011. Wetting ears reduced longevity at all stages of seed development when seeds were harvested soon after the event, and more so after two wettings, but considerable recovery in subsequent longevity occurred when seeds were harvested after 1 or 7 days re-drying after wetting. Reduction in rainfall significantly reduced crude protein and the incidence of blackpoint in both years. Hagberg Falling Number (HFN) decreased in 2011, but increased in 2012, perhaps due to wetter and cooler conditions in 2012. Rainfall affected seed quality development but the extent of damage varied amongst developmental stages, being greater at later developmental stages although considerable ability for recovery with re-drying was noted. Rainfall had a negative effect on most of grain quality parameters except crude protein concentration.EThOS - Electronic Theses Online ServiceGBUnited Kingdo