1,725 research outputs found
Relationship between seed harvesting method and seed physiological quality for a number of Pioneer maize hybrids
The seed germination and seed vigor of eight Pioneer Hi-Bred maize hybrids were evaluated immediately after harvesting
and a year later. The aim was to determine whether the seed showed loss of germination and vigor when
shelled mechanically. The seed was cleaned but not dressed, and then germinated according to the ISTA standard
procedure in four seed analysis laboratories. In addition, the seed of two randomly chosen hybrids was divided
into four fractions based on size and shape, and the germination of each fraction was examined separately. All the
germination results were acceptable according to the ISTA (2010) standard (over 90%), but a higher germination
percentage was observed after manual shelling than after mechanical shelling. The number of abnormal seedlings,
however, was higher for mechanically shelled seeds than for those harvested as whole ears. When the seed of
separate seed fractions was tested, the germination percentage was lowest for the medium-sized round fraction
and highest for the large flat fraction. The seed vigor of three of the hybrids was highest when maize seeds were
harvested shelled rather than on the ear. For all the hybrids the germination percentage was lower for both groups
when analyzed a year after harvesting. Better germination results were obtained for all the hybrids after whole ear
harvesting than in the shelled group, but the difference was not significant. In the vigor tests the results obtained
for mechanically shelled seed were superior to those for whole ear harvesting for the same three hybrids, but again
the difference was not significant. The experiments should be repeated over several years to determine whether
mechanically shelling maize seed negatively affects seed germination and vigor
Introduction of a new testing method (horizontal sorption) for the in-situ analysis of water absorption by porous stone surfaces and effect of surface treatments
The aim of this paper is to introduce the horizontal sorption technique and to demonstrate its applicability for the observation of porous materials and effect of surface treatments. The horizontal sorption testing method is a new technique, which was developed to facilitate the in-situ assessment of water absorption properties of porous materials. This new technique has some advantages compared to the already existing in-situ testing methods (Karsten pipe method, contact sponge method). It is easy to use, requires no supplementary electric devices, and tight attachment of the measuring tool onto the surface is not necessary. Moreover, the absorption of the water can be easily initiated and then documented. In the present paper several different ways of application of the technique are shown. The testing method was proven to be appropriate for the evaluation of the rate of water absorption, for determination of the sedimentary fabric of the rock (layers and orientation of the fabric results from its formation), as well as the effective depth and nature of three different types of surface treatments. These treatments were (i) organic and inorganic molecules activating bacteria in the stone, (ii) a conventional stone consolidant and (iii) a biomineralizing protective treatment. The new testing method provided valuable information about the nature of all the three treatments. Therefore the horizontal sorption method (HSM) seems to be a highly promising tool for the analysis of porous materials
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