三节臂机载式疏花机的研制与试验

Development and test of three arms tractor-mounted flower thinner

为减小疏果环节繁重的用工压力、提升果园作业效率和降低用工成本,该文基于自主研发的三节臂机载式疏花机,在"Y"字棚架形翠冠梨园中进行了疏花试验研究。以达到50%的花蕾保留率为疏花目标,结合疏花绳击打力度测试,确定了疏花轴在0.44 m/s行进速度下的最佳作业转速:254 r/min。疏花机田间性能试验中,研究疏花机疏花与人工定果、手持式疏花器疏花与人工定果、人工疏花与定果3种作业方式相比于只人工疏果作业方式,对花蕾保留率、坐果率、作业效率、果实产量及品质的影响。试验结果表明:机械疏花与人工疏花在作业质量上无明显差异,但疏花机作业稳定性较其他作业方式高;疏花机可降低梨树的绝对坐果率,虽然对幼果坐果量有一定的影响,但是经过定果环节后并不影响后期果实的产量及品质;疏花机的疏花效率在所有试验组中最高,相比于单一的人工疏果方式可节约66.17%的时间,适合机械化梨园大规模作业;手持式疏花器的作业效率仅次于疏花机,相比于单一的人工疏果方式作业时间可节约37.26%,适用于中小规模梨园。该试验研究有利于提高疏花机作业质量,为梨园机械化管理提供参考。

Thinning is one of the three labor-consuming sections(pruning, thinning and harvesting) in orchard management process. Chemical thinning, not only unstable but also reduces fruit safety, has been banned gradually in recent years. Pure artificial thinning, especially artificial fruit thinning, needs larger workload and higher labor cost, unsuitable seriously for the requirements of modern orchard planting. Two kinds of pear mechanical flower thinners were designed in the paper. They were three arms tractor-mounted flower thinner(TMFT) and hand-held flower thinner(HHFT), to alleviate the heavy labor pressure in the process of thinning and improve the efficiency of orchard operation. The width of TMFT was controlled by hydraulic cylinder that range from 1.2 to 1.7 m. TMFT rotation speed of thinning shaft that range from 0 to 300 r/min was controlled by electronic governor. The length of HHFT can change through adjusting the extension rod that range from 0.95 to 1.6 m. HHFT rotation speed of thinning shaft that range from 0 to 900 r/min was controlled by electronic governor too. ‘Y’ trellis ‘Cuiguan’ pear was taken as the research object in the paper. TMFT impact forces of thinning rope with different rotation speed of thinning shaft and thinning distance were measured in bench test, to find the working range of rotation speed. Field test setting 50% flower bud preserved rate(it is easier to thin flower buds than flowers) and 0.44 m/s tractor work speed, and the best rotation speed of thinning shaft was ensured: 254 r/min. Flower bud reserve rate, fruit set rate, work efficiency, fruit yield and quality of four kinds of operation methods were tested, which were TMFT combined with artificial fruit thinning, HHFT combined with artificial fruit thinning, artificial flower fruit thinning and artificial fruit thinning only. Twenty-four ‘Y’ trellis pear trees(6 a) with almost same size were selected for four operation methods. The canopies of each tree were divided into the upper middle lower three layers and five branches were selected as samples in each layer. In order to reduce the operation error, except the TMFT, the operation of each group was completed by two workers with experienced job skill. Field test show that three flower thinning methods can meet the requirement of 50% flower bud preserved rate, the coefficient of variation all less than 15%. There is no obvious difference between TMFT and artificial method in thinning quality and the stability of TMFT is the highest among test groups. Mechanical and artificial flower thinning can significantly reduce about 50% absolute fruit set rate. TMFT will damage the young fruits in a certain degree, but does not affect the yield and quality in the last. Work efficiency of TMFT was highest among flower thinning methods and 66.17% artificial fruit thinning time can be saved. TMFT has a higher requirement for pear orchard mechanization degree, suitable for large-scale mechanized pear orchard. Work efficiency of HHFT is second only to TMFT, 37.26% artificial fruit thinning time can be saved. HHFT is suitable for small and medium sized pear orchard. For fruit yield and quality, total and high quality fruit yield per tree of pure artificial fruit thinning group is higher 11.37% and 8.59% respectively than average values of three kinds of flower thinning group, but the average weight of high quality fruit and brix of sugar solids of is lower 6.58% and 1.55% respectively. The research is helpful to improve the working quality of flower thinner and provide reference for the mechanization management of pear orchard.