"drastically delayed" is correct and usable in written English.
You can use it to describe a situation in which something has been significantly delayed from its expected timetable. For example, "The construction project was drastically delayed due to bad weather."
By the time Kittinger wrenched himself free, he was drastically delayed.
As I've written in the past, humans hold robots to very high standards, to the point where their adoption can be drastically delayed.
The drastically delayed data about what happened at Fukushima is only a recent example.
By 48 hpf, most parp3 morphants have not hatched, lack inner ears and pectoral fin buds (Fig. 1B), and their pigmentation is drastically delayed (Fig. 1C, D).
Deactivation of cathepsins, via either inhibitors or RNAi, drastically delayed or prevented L3 molting in D. immitis and O. volvulus[ 48– 50].
All mutants grew comparably well to the WT in the absence of UV irradiation (Fig. 1A), whereas the growth of most rad2CΔ and rad2Δ mutants was drastically delayed following UV irradiation, (Fig. 1B).
Although a smoker's intention to quit may not necessarily lead to immediate smoking cessation, the lack of intention may drastically delay smoking cessation.
It is shown that the optimized patterns for implants of heterogeneous porous media, occupying approximately only 5% of the overall volume, can drastically delay the steady-unsteady transition of the 2D natural convection flow in a square differentially heated cavity with thermally perfectly conducting horizontal walls.
Leading a socially, physically and mentally engaged life will not only improve the quality of our lives, but will drastically delay or even prevent the need for many of the services that Older Americans Month provides.
The inhibition of the v8 reaction does, however, drastically delay the activation of ERK and limit the amplitude of the signal response.
It has been shown that high initial levels of dissolved oxygen in milk can drastically delay acidification by Lactococcus starter strains [ 22, 23].
