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Copyright of Journal of Nanjing Agricultural University / Nanjuing Nongye Daxue Xuebao is the property of Journal of Nanjing Agricultural University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nanjing Agricultural University / Nanjuing Nongye Daxue Xuebao is the property of Journal of Nanjing Agricultural University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives J Due to a genetic feature of the sterile 1 ine, there is a serious crack-glume in hybrid rice seeds. The crack-glume will cause the germination and seedling quality of rice seeds to be worse than normal seeds. Therefore, recognizing the crack-glume rice seeds and sorting them out can effectively improve the seedling quality of the seed and the yield of the field production. [Methods]In this study, a piezoelectric accelerometer was used to obtain the impact vibration signal generated by the rice seed falling and impacting the plate, which was made of 65Mn spring steels. The impact vibration signal was analyzed to recognise the normal and crack-glume of rice seeds. Orthogonal experiments were carried out to analyze the effects of metal plate thickness, length and seed falling height on the recognition rate of the crack-glume rice seed. [Results] The experimental results showed that the time-domain characteristic parameters of the impact vibration signal: voltage maximum, range, energy, root mean square, kurtosis, etc. could be used as the eigenvalues for distinguishing between normal and crack-glume rice seeds. Distinguishing effect by using energy was the best. The energy produced by the normal seed impacting the plate was generally greater than that of the crack-glume seed. When the plate thickness was 0.25 mm, the plate length was 200 mm, and the seed falling height was 250 mm, the comprehensive recognition rate was the largest. The comprehensive recognition rate of * Zhendao' Chuanyou 6203 * Quanyou 123 and ' Zhongyiyou 188' was 85.10%, 85.50%, 84.40% and 83.40%, respectively. [Conclusions] The method for recognising hybrid crack-glume rice seeds by the rice seed falling impact and impacting steel plate vibration is feasible. [ABSTRACT FROM AUTHOR]

[Objectives] Wheatear spikelet number and grain number directly reflect the yield of wheat,which are two very important parameters in the research of wheat phenotype. This measuring accuracy about the number of spikelet is very low at present,which can not meet the actual needs of breeding and estimating yield. The literature on measuring grain number has not yet appeared.[Methods] In order to measure these two parameters quickly,a parabolic segmentation method based on image processing technique for wheatear spikelet was presented in this paper,and the synchronously counting spikelet number and grain number were realized by using the wheatear front view image. Firstly,image preprocessing algorithm was used in order to obtain adjusted binary image of wheatear. Then the pixels were summed according to rows of binary image,and the curve of the row pixels sum was plotted. Then the smoothing curve was obtained by using smoothing filtering algorithm and the peaks and troughs of the smoothing curve were obtained by using extracting extremum. The stalk of the wheat was separated by setting a pixels threshold depending on the width difference between the stalk and the ear head. The number of peaks at the ear head in the smoothing curve indicated the number of spikelet. Then the abscissa values of the peaks and troughs were obtained,which represented the ordinal number Y of rows in binary image. A set of intersection points between the rows ordinal number Y and the boundary of the wheatear in binary image could be obtained. Then the midpoint coordinate of the wheatear boundary was obtained at the trough. And the maximum and minimum point coordinates of the wheatear boundary were obtained at the peak. Then three position points of fitting the parabolic curve for spikelet were ascertained according to the coordinate of peaks and troughs of the smoothing curve at the binary image. Finally,each spikelet in wheatear was segmented using the fitted parabolic curve. The area of each spikelet was extracted. Meanwhile,the grain number of each spikelet was counted manually. So then the relation between the area of each spikelet and the grain number was obtained by using threshold method.[Results]The wheatear images of three wheat varieties were identified to validate the spikelet number and grain number of each wheatear. The experiment results manifested that the average zero error rate of the spikelet number for three wheat varieties was 68.16%,the average absolute error of three wheat varieties of the spikelet number was 0.46,and the average relative error of the spikelet number for three wheat varieties was 2.99% by using aforementioned method to identify the spikelet number at wheatear. The recognition accuracy and the average zero error rate of the spikelet number were greatly improved by compared with the existing literature. And using aforementioned method to identify the grain number at wheatear,the average absolute error of grain number for three wheat varieties was 2.11,and the average relative error of grain number for three wheat varieties was 5.62%.The average measurable time for three wheat varieties was 7.99 s for a wheatear.[Conclusions] The automatically image counting wheat grain number and spikelet number for a wheatear with faster and higher precision can be realized. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanjing Agricultural University / Nanjuing Nongye Daxue Xuebao is the property of Journal of Nanjing Agricultural University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nanjing Agricultural University / Nanjuing Nongye Daxue Xuebao is the property of Journal of Nanjing Agricultural University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objectives] Soil hardsetting in paddy season and long-term shallow tillage are two main constraints for low grain yield of wheat in rice-wheat rotation. There is a need to investigate whether stratified rotary tillage is a suitable solution and how stratified rotary tillage can affect paddy soil physics. [Methods] Three tillage systems, i.e.no till (NT), conventional rotary till (CRT) and stratified rotary till (SRT) were conducted after paddy season to evaluate its effect on soil water holding capacity, soil porosity, water content and soil hardness during the ensuing wheat season. [Results] Stratified rotary tillage is a technically feasible tillage system for compacted paddy soils properties. Compared with NT and CRT, SRT significantly increased loosened soil layer depth, improved soil water holding capacity, reduced soil penetration while improved soil porosity. Water holding capacity in the 10-20 cm soil layer increased 3.6% and 3.5% as compared with NT and CRT, respectively. The mean soil bulk density decreased 0.14 and 0.13 t·m-3, respectively. SRT greatly improved soil water content, whose value was 0.24% and 1.21% higher than the CRT and NT, respectively. In 0-30 cm soil layer penetration resistance was sequenced as SRT,CRT, NT. SRT improved 10 cm more loosened soil layer than traditional treatment. [Conclusions] Rehabilitating paddy soil structure requires stratified rotary tillage systems. Stratified rotary tillage is an effective means to improve paddy soil physics properties and thus is beneficial for post-paddy wheat production. [ABSTRACT FROM AUTHOR]