农户生产水平的“腾格里”无芒隐子草种子脱粒与清选技术研究

“腾格里”无芒隐子草是2016年由我国草品种审定委员会审定登记的野生栽培品种(登记号:499),抗旱性极强,在干旱半干旱地区的生态治理、园林绿化和草原恢复中具有非常重要的推广价值。但目前急需加快种子扩繁和解决种子脱粒与清选等技术问题。在甘肃省榆中县小区预试验基础上,进一步在河西走廊民勤县农户生产规模条件下开展了“腾格里”无芒隐子草适宜的种子脱粒和清选技术研究。结果表明,对农户生产规模下(3.5 hm²左右及以下)的无芒隐子草种子,在采用的50 kg石磙碾压不同遍数处理中,以45~55遍碾压处理的种子收获率最高,与手工完全脱粒对照相比,收获率达78%以上,并且对种子发芽率与活力无显著影响(P>0.05)。另外,利用4.5 m·s^-1风速并配以筛孔尺寸为0.7 mm的筛子过筛清选2遍,种子净度可达86%,与仅过筛而未风选的对照比较,种子净度提高了20个百分点。上述结果对“腾格里”无芒隐子草的规模化生产以及推广利用具有重要的指导意义。

An evaluation of smallholder seed threshing and cleaning technologies in seed production of Cleistogenes songorica cv. ‘Tenggeli’

Cleistogenes songorica ‘Tenggeli’ is a new “wild” grass cultivar registered by the Chinese Herbage Variety Registration Board in 2016 (Registration No: 499), which has excellent drought tolerance and soil stabilization capacity, and so plays an important role in ecological regeneration, landscaping, and grassland restoration in arid and semiarid areas. However, there is an urgent need to accelerate seed multiplication and to develop feasible seed threshing and cleaning techniques. Based on a preliminary trial we conducted at an experimental station in Yuzhong County, Gansu Province, further research was carried out in Minqin County in the Hexi Corridor, Gansu Province, to evaluate the suitability of the seed threshing and cleaning techniques developed, for use by smallholder farmers. For naturally dried seed-heads, 45-55 passes under a 50 kg roller resulted in the highest harvest rate (up to 78% of total seed present), without loss of seed quality. The optimum airflow velocity for seed cleaning was 4.5 m·s^-1, and seed purity attained with this airflow velocity and two passes over a sieve, was up to 86%. These data are of great importance for C. songorica ‘Tenggeli’ seed production, as improved seed availability will enhance the extension process and the user adoption of this important new cultivar.