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

Abstract

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%.