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Silique observation and measurement are essential for rapeseed breeding. In this paper, an automatic detection method was proposed to replace the traditional manual method. A device was designed to acquire video of scattered siliques, based on pulling and vibrating stacked siliques. Silique videos were extracted to frames, and then, by using QR code as marker blocks in image, the key frames containing all siliques were effectively extracted and spliced into individual intact. Crossed siliques in frame caused an error in measurement. A cutting method of crossed siliques image based on concave point extraction and matching was proposed. By this method, all kinds of crossed siliques could be identified with accuracy rate of 98.0%. In the measurement of phenotypic parameters, a core diameter Otsu method was proposed to judge the posture of silique, by which elliptic long and short axis of the cross section of the silique was estimated, and then length, surface area and volume of the silique were calculated. Results demonstrated good accuracy and adaptability to different varieties of rape by this method. Estimation error of length, surface area and volume were less than 2.9%, 4.8% and 5.0% respectively. Thus the method could be an effective replacement of artificial way and provide key basic data for rapeseed and agricultural research fields. [ABSTRACT FROM AUTHOR]

In this paper we analyze the multi-week prediction bias and skill from the National Centers for Environment Prediction (NCEP) Climate Forecast System version 2 (CFSv2) based on its hindcasts for 1999-2012. The analyses focus on the prediction of the rainfall variability over South-East Asia during boreal warm seasons and the dependence of the prediction on the activity of intrasesaonal leading modes. It is shown that the prediction skill measured by anomaly correlation is comparable between the total anomalies and intraseasonal anomalies during the first 2 weeks. After week 2, the prediction skill drops substantially and the skill for total anomalies is largely from the prediction for the interannual variability. Moreover, the forecast skill tends to be higher when the amplitude of the Madden-Julian Oscillation and the Boreal Summer Intraseasonal Oscillation (BSISO) is larger, especially for the BSISO. It is noted that the prediction skill over South-East Asia depends on the phase of the BSISO. One deficiency in the CFSv2 is that the northward propagation of the forecast BSISO is generally slower than the observed. [ABSTRACT FROM AUTHOR]