Effects of environmental factors on germination and emergence of Amaranthus retroflexus

Detailed knowledge about the environmental conditions required for weed seed germination and establishment in soil is an important prerequisite for the development of integrated and biological weed control strategies. Germination and establishment of Amaranthus retroflexus were studied at different temperatures, planting depths, soil types, nitrogen supply, and water potentials. The minimum temperature for seed germination was > 5 C; maximum germination occurred between 35 and 40 C. At temperatures between 25 and 35 C, an additive effect on germination rate was observed when temperature and water availability were increased. For all soils tested, the percentage emergence of seeds placed on the soil surface and 4 cm deep was significantly lower than seeds placed between 0.5 and 3 cm. Emergence in the four sandy soils was generally greater than in the two heavier soils included in the study. There was a highly significant interaction between seed depth and soil type. Plant growth was also greatest in the lighter soils. Plant height, number of leaves, leaf area, fresh and dry weight, and nitrogen and carbon percentage in plant tissues of A. retroflexus increased significantly with increasing soil nitrogen supply.

[1]  F. Corbineau,et al.  Interrelated effects of temperature, light and oxygen on Amaranthus caudatus L. seed germination , 1992 .

[2]  C. S. Tan,et al.  EFFECT OF TEMPERATURE AND SOIL MOISTURE ON TIME OF EMERGENCE OF TOMATOES AND FOUR WEED SPECIES , 1988 .

[3]  L. R. Oliver,et al.  A Model for Predicting Large Crabgrass (Digitaria sanguinalis) Emergence as Influenced by Temperature and Water Potential , 1994, Weed Science.

[4]  C. W. Smith,et al.  Amaranth Seedling Emergence as Affected by Seeding Depth and Temperature on a Thermogradient Plate1 , 1987 .

[5]  Peter J. Gregory,et al.  Effects of Temperature and Water Potential on Germination, Radicle Elongation and Emergence of Mungbean , 1989 .

[6]  J. Cardina,et al.  Phytochrome-mediated Amaranthus germination I: effect of seed burial and germination temperature , 1998, Weed Science.

[7]  J. P. Mahlstede,et al.  Variation in Seed Weight and Germination in Populations of Amaranthus Retroflexus L. , 1968 .

[8]  D. Schroeder,et al.  Biological control of pigweeds (Amaranthus retroflexus, L. A. Powellii, S. Watson and A. bouchonii Thell.) with phytophagous insects, fungal pathogens and crop management , 1997 .

[9]  J. Cardina,et al.  Weed seed bank emergence across the Corn Belt , 1997, Weed Science.

[10]  M. Kaufmann,et al.  The osmotic potential of polyethylene glycol 6000. , 1973, Plant physiology.

[11]  R. Zimdahl,et al.  Competition between Barnyardgrass (Echinochloa crus-galli) and Redroot Pigweed (Amaranthus retroflexus) , 1984, Weed Science.

[12]  R. Webster.  THE MEASUREMENT OF SOIL WATER TENSION IN THE FIELD , 1966 .

[13]  P. B. Cavers,et al.  The ecology of pigweeds (Amaranthus) in Ontario. I. Interspecific and intraspecific variation in seed germination among local collections of A. powellii and A. retroflexus , 1975 .

[14]  A. M. Wiese,et al.  Calculating the Threshold Temperature of Development for Weeds , 1987, Weed Science.

[15]  D. Koller,et al.  Control of the Germination Responses of Amaranthus retroflexus L. Seeds by their Parental Photothermal Environment , 1977 .

[16]  K. Singh.  Stress physiological studies on seed germination and seedling growth of some wheat hybrids , 1982 .

[17]  A. Takenaka,et al.  Germination responses of a non‐dormant seed population of Amaranthus patulus Bertol. to constant temperatures in the sub‐optimal range , 1984 .