Parameters And Characteristics On Pneumatic And Collision Combined Pollination Of Hybrid Rice Seed Production

Pollination is the most critical link in the process of hybrid rice seed production, want to obtain high-quality, high-yield of the seed, pollination must be fully, uniformly. As traditional pollination, hand assisted pollination is labor intensive and low productivity, which can not adapt to the requirements of large-scale seed production. Pollination mechanization is the only way to improve the efficiency and yield of hybrid rice seed production. Based on systematic analysis of the status quo of research on mechanical pollination of hybrid rice at home and abroad, through combined with collision auxiliary pollination and pneumatic auxiliary pollination at home, the parameters and characteristics of pneumatic collision combined pollination were studied and explored in this paper.1.The theoretical model of pneumatic collision combined pollination for hybrid rice seed production was established under laboratory conditions, the principle of combined pollination was discussed, through theoretically analyse movement characteristics of pollen, distortion of plant stem, obtain the relationship equations between horizontal movement distance of pollen and airflow velocity, impact velocity.2.Through theoretical analyse airflow field of the jet pipe, the superposition jet model for two nozzle was established. discuss the movement characteristics of airflow field, obtain the relationship equations between jet cone angle and junction distance,and the relation equations between airflow velocity of nozzle and axial airflow velocity of cross section in airflow field.3. The relationship between the airflow field of jet flow, the parameters of jet pipe and airflow parameter were explored, select pipe diameter, pipe wall thickness and nozzle aperture for single factor and multi-factor orthogonal experiment. obtain the influence to jet cone angle, jet distance, pressure of orifice gas of jet pipe parameters.the regression model of jet cone angle were obtained by variance analysis and regression analysis, obtain the principal factors on jet cone angle and the optimized combination of parameters of jet pipe.4. Combined with collision pollination test unit and air blowing device, design the pneumatic collision combined pollination device and pollen collection boards, find the method to analysis characteristics of pollen movement and distribution when the pollen has the size of micron level. The device and method can be used for various mechanical pollination experiment of hybrid rice.5. Test study of single factor on pneumatic pollination and collision pollination.study the influence of airflow velocity, airflow acting position, airflow angle, collision velocity, collision position, collision angle to pollen distribution, from the three aspects of pollen diffusion amount, horizontal distribution and vertical distribution, obtain the influence rules of each factor, find out the ideal pneumatic parameters and collision parameters.6. According to the results of sigle factor experiment on pneumatic pollination and collision pollination, carried out pneumatic collision combined pollination experiment, select five parameters, jet pipe placed relative position, airflow velocity of nozzle, airflow tilt angle, nozzle diameter, nozzle hole center distance as influence factors, single factor and multifactor orthogonal experiments were conducted by select three evaluation index to evaluate combined influence on effective distribution area ratio, average distribution density, non-uniformity of pollen distribution. the regression equation about the evaluation index and various factors were established by range analysis, variance analysis, regression analysis on orthogonal experiment results.discuss the influence of various factors on the effect of pollen distribution. results show that pneumatic collision combined pollination obviously improve the effective distribution area ratio of pollen, a significant reduction in the degree of uneven distribution of pollen. obtain the principal factors and weights on the effect of pollination by matrix analysis of three layers judged model, optimize the result by Matlab. The optimal combination of the factors for pneumatic and collision combined pollination are collision speed of 6m/s,collision location at the bottom of panicle,collision angle of 0°,airflow speed of 6 m/s, jet pipe placed above collision rod 10 cm, nozzle hole'center distance of 25 mm, airflow inclined angle of up 20°, and nozzle hole diameter of 8 mm. The theoretical and experimental research provide parameter selection and the theory basis for further research on pneumatic collision combined pollination machinery and the form a complete set technology.