Of the 40 samples taken from these estates, the officials said the 23 were declared negative.
Further tests will still be done.
They say, the likelihood is difficult to find the source of the plague because it already happened a few weeks.
"The investigation is still continuing," said Lower Saxony Agriculture Ministry Monday (6/6) announced the first tests showed negative results.
Plantation in Uelzen South of Hamburg Sunday was estimated as a plague that killed 22 people and makes about 2,200 others fell ill.
Trial against dozens of other samples of complex agriculture that still continues.
The Agriculture Department says it is not Under Saxoni estimates there will be "brief conclusions" over the results of this test.