TY - JOUR AV - restricted A1 - Soman, P TI - Development of a technique to study seedling emergence in response to moisture deficit in the field - The seed bed environment UR - http://dx.doi.org/10.1111/j.1744-7348.1990.tb06617.x JF - Annals of Applied Biology SN - 0003-4746 PB - Association of Applied Biologists N1 - I thank Professor J. L. Monteith, Drs K. B. Lareya; F. R. Bidinger and N. Seetharama for critically reviewing the manuscript and Mr R. Jayachandran for assisting in data collection and analysis. N2 - The ability of crops of sorghum (Sorghum bicolor (L.) Moench) to establish in farmers' fields depends largely on its capacity to germinate and emerge under limited soil moisture conditions. Studies on germination under moisture stress have been previously conducted using osmotic media which do not wholly reproduce the conditions of the seed bed in the field. Hence the need for a field screening technique. A line source irrigation system was used to provide five moisture regimes ranging from -0.08 MPa to -0.92 MPa. The drying rate of the soil and the soil temperature depended largely on incident radiation, and the relationship between the moisture content and daily soil temperature and daily radiation was consistant. Total porosity of the seed bed, derived from bulk density measurements and particle density ranged from 43.8% to 45.3%, which would allow sufficient aeration when as in the experiments conducted here, water content was low (> 0.14 g/g). Under these seed bed conditions the pattern of response of emergence to the moisture gradient was linear or curvilinear. Genotypic differences existed for emergence and its response to water level. The field method developed is useful for identifying genotypes able to germinate and emerge under conditions of low seed bed moisture KW - Moisture deficit; sorghum; seedling emergence; seed bed; soil temperature; soil aeration; genetic improvement Y1 - 1990/// SP - 357 ID - icrisat7686 EP - 364 VL - 116 IS - 2 ER -