A thermal time analysis of ageing of maize ( Zea mays L.) seed can account for reduced germination in hot moist soil

• Published in: Field crops research 1999-09, Vol.63 (2), p.159-167
• Main Authors: Muthukuda Arachchi, D.H, Naylor, Robert E.L, Bingham, I.J
• Format: Article
• Language: English
• Subjects: Ageing; AGING; CONTENIDO DE AGUA EN EL SUELO; Deterioration; EMERGENCE; EMERGENCIA; ENVEJECIMIENTO; GERMINACION; GERMINATION; LEVEE; Maize; SEED; SEMENCE; SEMILLAS; Soil moisture content; SOIL TEMPERATURE; SOIL WATER CONTENT; TEMPERATURA DEL SUELO; TEMPERATURE DU SOL; TENEUR EN EAU DU SOL; Thermal time; VIEILLISSEMENT; ZEA MAYS
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/S0378-4290(99)00034-9

After sowing into moist soil, maize seed imbibe although the soil moisture content may be too low to permit seedling emergence. The hypothesis tested here is that in such circumstances, and especially at high temperature, the seed age in the soil with the result that when the moisture restriction is subsequently removed, germination and seedling emergence are reduced. First, maize seed were artificially deteriorated in the laboratory at four elevated moisture and five constant temperature regimes for four different periods in order to determine the effect of ageing on radicle and coleoptile emergence. Next, the responses when seed were deteriorated at alternating temperatures were shown to be the same when the temperature exposure was expressed as thermal time. A base temperature for thermal ageing time was estimated as about 30°C. Finally, when four Sri Lankan maize cultivars were sown in soil, the seed imbibed and experienced temperatures above 30°C with the result that final seedling emergence was reduced. The effect of ageing in the soil appeared greater than that in the laboratory because the moisture content of seed in the soil was not constant but increasing.