[Yield loss model and yield loss mechanism of high-yielding summer maize infected by Physoderma maydis].

A total of 21 different disease-grading summer maize groups were formed by fixed-point natural infection of maize brown spot in the field, and mass loss estimation models of single ear mass and 100-grain mass were constructed by stepwise regression with DPS software. The mass loss estimation models of single ear and 100-grain were Y = -4.012 + 0.

[Effects of DA-6 on leaf photosynthetic carboxylase and protective enzyme activities and grain yield of high-yielding summer maize].

A field plot experiment was conducted to study the effects of foliar spraying DA-6 at the rates of 10, 20, and 40 mg x L(-1) at jointing stage on the leaf photosynthetic carboxylase and protective enzyme activities and grain yield of high-yielding summer maize cultivar Denghai 661. Comparing with the control (foliar spraying surfactant and water), spraying 10, 20, and 40 mg x L(-1) of DA-6 increased the grain yield of Denghai 661 significantly, with the increment being 10.0%, 8.