Effect Of Plant Growth Regulator On Seed Yield And Yield Components Of Dactylis Glomerata

Dactylis glomerata is also called orchardgrass.It’s a cold-season grass widely cultivated in the world.（Dactylis glomerata.cv Dian bei）is a new excellent variety bred by Sichuan Agricultural University.It plays an important role in rocky desertification control,artificial and mixed grassland construction,crop and forage rotation,grass planting under forests,returning farmland to grassland,soil and fertilizer cycle and other ecological restoration and environmental engineering in Southwest China.In the extension of agricultural production,the demand for seeds is huge.In this study,the plant growth regulators were sprayed on the orchardgrass during the GS32.From 2016 to 2018,field trials of different concentrations of CCC(500,750,1000,1250g·hm^-2),TE(100,200,300,400g·hm^-2)and mixture of TE+CCC(500+50、500+150、1000+50、1000+150g·hm^-2)were conducted in the fields.（1）All the growth regulators increased the seed yield of orchardgrass.After spraying CCC,the highest seed yield was 241.7 k g·hm^-2in the first year and 284.4 k g·hm^-2in the second year,with an average increase of 21.5%.After spraying TE,The highest was286.7 kg·hm^-2in the first year and 299.4 kg·hm^-2in the second year.After mixed application of CCC and TE,the highest yield was 291.3 kg·hm^-2in the first year,which increased 46.2%and reached 309.1 kg·hm^-2in the second year.（2）The correlation analysis showed that spraying three growth regulators had different effects on yield components of orchardgrass seeds.The seed yield was positively correlated with the number of reproductive branches and the number of florets per spikelet by TE.There was a significant positive correlation between seed yield and number of reproductive branches,number of florets per spikelet and seed setting rate by the mixture of TE+CCC.（3）Compared with the three kinds of growth regulators,the effect of mixed application of growth regulators was the most obvious.The yield increased by 46.2%and 32.5%in two years,which were the highest among the three kinds of growth regulators.At the GS32 stage,the best mixture of TE+CCC was used,and the best mixture concentration was 150+500 g·hm^-2.