Predict Field Emergence Research Articles

Value of laboratory germination and viability tests in predicting field emergence of Urena lobata L.

Seeds of Urena lobata L. were tested for viability by a topographical tetrazolium test and for germination in petri dishes. Significant correlations were found between the results of laboratory tests and the emergence of seedlings of two cultivars in field trials carried out on three soil types over a 2-yr period. The regression equations obtained were used to predict field emergence. fairly close agreement was found between predicted and observed values. The use of either the viability or the germination test to predict emergence at specific sites resulted in similar confidence limits which, at the 95% level, ranged from ± 12 to ± 17%. General equations for use at all sites were computed which predicted field emergence with 95% confidence limits of ± 15%.

Relationship Between Laboratory Cold‐Test Methods and Field Emergence in Maize Inbreds1

AbstractReliable estimates of field emergence under adverse planting conditions are required for maximum crop management. The “cold‐test” is widely used as such a parameter. Various versions of the laboratory cold‐test for corn (Zea mays L.) were studied on 15 inbred lines. Substrates ranged from sterile Kimpak to sand‐soil mixtures to a test utilizing pure soil. All procedures incorporated a 10 C 7 day stress period followed by a grow‐out period at approximately 25 C. Variability between test results on the same sample was as much as 60%. The lowest coefficient of variability was achieved with a method incorporating a cellulose substrate covered with a small amount of soil. The test utilizing the sterile substrate was found to have laboratory performance characteristics similar to the soil tests. It appears that for the inbreds studied, much of the cold‐test response is due to the temperature stress and little to the soil.The ability of any of the tests to predict field emergence was quite variable. The lowest correlation and predictability was recorded with the method suggested by the AOSA Vigor Committee, while the sterile substrate test exhibited intermediate correlation performance compared to the other methods involving soil or soil mixes.The cold‐test is not a consistently reliable predictor of early field emergence. The variability inherent in the test makes comparison between laboratories difficult.

Evaluation of Vigor Tests in Soybean Seeds: Relationship of the Standard Germination Test, Seedling Vigor Classification, Seedling Length, and Tetrazolium Staining to Field Performance1

Laboratory tests for standard germination, seedling vigor classification, seedling length, and tetrazolium staining were performed on 144 and 81 seed lots of soybean [Glycine max (L.) Merr.] in 1975 and 1976, respectively. Results from the laboratory tests were compared with emergence and stand data obtained from these same seed lots on two sites (sandy and heavy soil types) and three dates of planting (early, pre‐optimum, and optimum) each year. Yield was obtained for the heavy soil type, optimum planting date.Most laboratory test measurements were significantly correlated with field emergence, but r values were <0.8. Overall, the correlations showed a trend that was dependent on soil type but not date of planting. Generally, the laboratory test measurement was correlated with emergence for all planting sites and dates of planting. The corresponding correlations for plant stand and emergence were similar. Correlations of laboratory test measurements with yield were low, r≤0.340 and r≤0.282 in 1975 and 1976, respectivelyLaboratory test measurements were used to develop models predicting field emergence. Combinations of three laboratory test measurements in the model gave near maximum R2 values. Four such models were able to predict emergence at five of the six planting date and site combinations each year.

Relationships Among Cottonseed Vigor and Emergence1

AbstractBetter predictive methods of field emergence of cotton (Gossypium spp.) seedlings are needed than are presently available. In this paper we report on two types of relationships for predicting seedling emergence. The first is the association between field emergence and a vigor term of germinating seedlings called % transfer (ratio of plant axis weight to total weight of seedlings). The second is the relationship between time to 50% total emergence (ET50) and total emergence. Seed of diverse origin were germinated in the laboratory at 15 C for 8 days or at 25 C for 4 days and % germination, and % transfer were determined. Several field plantings were made, and periodic counts were made as seedlings emerged. The time course of germination of two lines that responded differentially in germination and field studies was examined by taking weights and seedling axis lengths repeatedly for 4 days at 25 C and 14 days at 15 C. Germination at 15 C for 8 days did not consistently predict field emergence better than germination at 25 C for 4 days. Some improvement occurred when germination parameters were averaged for the two temperatures. Combining % transfer with % germination into a term called “germination index” did not consistently aid in predicting field emergence over use of % germination alone, apparently because seed with high viability generally produced vigorously germinating seedlings. Percent transfer was negatively correlated with ET30. Predictability of the germination parameters was improved by extending the length of the germination period. Total emergence decreased linearly with increase in ET50. The average decrease ranged from just under 2% per day of ET50 to over 4% when the test involved a salt‐affected soil. We conclude that incorporation of these seed vigor terms into seed testing will not aid in predicting potential for cottonseed emergence. The relationship between emergence and ET50 should serve as an aid in making early decisions about replanting, although the nature of the relationship will probably depend upon local soil conditions.

Correlation of Field Emergence Rate and Seed Vigor Criteria in Barley Cultivars1

Thirteen seed vigor parameters were compared in two 2‐row and four 6‐row barley (Hordeum vulgare L.) cultivars to determine selection criteria for predicting rate of field emergence. The materials also represented four spring and two winter types. Seed weight, 3‐day seedling adenosine triphosphate (ATP) content, 3‐day seedling total adenosine phosphates (TAP), 5‐day endosperm α‐amylase activity, 3‐day endosperm c~‐amylase activity, 4‐hour hydrated embryo TAP, 4‐day hydrated embryo ATP content, 7‐day seedling dry weight, 3‐day seedling dry weight, and 3‐day seedling shoot length were all significantly correlated (P≤0.01) with field emergence rate but in decreasing order, respectively. Based on the results of stepwise multiple regression analysis, it appeared that seed weight, 3‐day seedling ATP content, TAP content of hydrated embryo, and 7‐day seedling dry weight would be good seed vigor indices for predicting field emergence rate.

Seed Germinability Tests for Predicting Field Emergence of Rice Seeds Infected with Helminthosporium oryzae and Trichoconis padwickii

Seed Germinability Tests for Predicting Field Emergence of Rice Seeds Infected with Helminthosporium oryzae and Trichoconis padwickii