Effects of drought after pollination on grain yield and quality of fresh waxy maize

Waxy maize is consumed as a vegetable when harvested at fresh stage (23-26 days after pollination) in China. Fresh waxy maize is normally grown under rain-fed conditions and suffers drought frequently during plant growth. The effect of drought on grain development of fresh waxy maize is not known.

Two years of pot trials showed that drought decreased fresh grain number and weight, which consequently reduced fresh ear and grain yields, especially in Yunuo7. Moisture and starch contents in grains were not affected but protein content was increased under drought treatment in both varieties. Grain soluble sugar content response to drought was not affected in Suyunuo5 but was decreased in Yunuo7. Pasting and gelatinization temperatures, trough viscosity, final viscosity, setback viscosity, gelatinization enthalpy and springiness of grain were little affected by drought. Drought decreased peak viscosity, breakdown viscosity and adhesiveness (absolute value), whereas it increased hardness. The retrogradation percentage was increased in both varieties in both years.

Drought after pollination decreased the fresh waxy maize yield. Grain quality was reduced through decreased peak viscosity and adhesiveness (absolute value), while its hardness and retrogradation percentage were increased, which might be due to the increased protein content.