Abstract: In order to clarify the effects of tillage methods on grain filling characteristics and senescence process of tartary buckwheat, three tillage treatments, namely, no-tillage, constant tillage and deep tillage, were set up with Qianyu No.5, a tartary buckwheat variety, as the experimental material. The effects on grain filling dynamics, root morphology and physiology, photosynthetic pigment content in leaves, antioxidant enzyme activity and malondialdehyde (MDA) content, agronomic characters and yield formation indexes of tartary buckwheat were studied. The results showed that the morphological parameters (N value) of the three tillage methods were all less than 1, and there was no significant difference among the three tillage methods, and when the initial potential of filling (R₀) and the maximum filling rate of (G_max) were maximum, the grain filling rate of the three tillage methods was less than 1. The growth increment (W_{max. G}) was the largest and no-tillage treatment was the least. The difference between the increment of the maximum grouting rate and the final value of grain growth (I) between different tillage methods was small. The deep-tillage treatment can promote the root growth of tartary buckwheat, and the total length, the surface area, the volume and the average diameter of the root system all showed the change tendency of the single-peak curve along with the advance of the growth period and the maximum in the grouting period. The root activity of the deep-tillage treatment was higher than the normal tillage and no-tillage treatment in all periods, and the photosynthetic pigment content, the superoxide dismutase (SOD) and the peroxidase (POD) in the tartary buckwheat leaves were increased with the development of the growth period. The activity increased firstly and then decreased, and the treatment of deep tillage was the highest among tillage methods, while the content of MDA increased continuously with the advance of growing period, with the maximum in the no-tillage treatment and the minimum in the deep tillage treatment. Deep tillage treatment can significantly improve the agronomic characters and yield of tartary buckwheat. In all, deep tillage can promote grain filling of tartary buckwheat, delay senescence, increase yield and income.

Key words: tartary buckwheat, tillage method, grain filling, senescence, yield