The invention discloses a rooting-promoting, 
disease-resistant and 
plant-strengthening agent for cotton and a water, 
fertilizer and 
pesticide integrated application method. The rooting-promoting, 
disease-resistant and 
plant-strengthening agent is mainly prepared from a 
growth regulator, a microelement, a 
signal molecule donor and an 
elicitor capable of improving the 
disease resistance of the cotton, wherein the 
growth regulator is prepared from 
indolebutyric acid, 
sodium nitrophenolate, 
naphthylacetic acid and 
diethyl aminoethyl hexanoate through compounding, the microelement is prepared from 
zinc sulfate, 
ferrous sulfate, 
ammonium molybdate, 
amino acid powder and 
ammonium hydrogen phosphate through compounding, the 
signal molecule donor is NO donor 
sodium nitroprusside, and the 
elicitor is a 
penicillium dry 
mycelium extracting solution. The problems that a 
drip irrigation technology does no good to root development and severe diseases are caused by successive 
cropping to the cotton are solved, the 
growth regulator accelerates growth of root systems, the 
physiological function time of the root systems is prolonged, the disease-resistant 
elicitor enhances the resistance of cotton plants, growth of lateral roots is further promoted in combination of the 
signal molecule donor, and the disease-resistant response of the cotton 
plant is promoted. The rooting-promoting, disease-resistant and plant-strengthening agent can promote growth of roots and 
resist diseases in multiple angles; the agent can be injected into 
irrigation water through a 
fertilizer pump, integrated application of water, 
fertilizer and pesticides in the 
drip irrigation cotton field of the northwest inland is realized, and the agent can promote growth of roots, 
resist diseases and strengthen seedlings and has remarkable disease resisting and yield increasing effects.