We find congruences for the $t$-expansion coefficients of Drinfeld modular forms for $\Gamma_{0}(T)$. We determine all the linear relations among the initial $t$-expansion coefficients of Drinfeld modular forms for $\Gamma_{0}(T)$.

In this note we suggest a construction of the Morse-Novikov theory for a class of non-transversal gradients and generalize to this class the basic results of the classical Morse-Novikov theory including its non-abelian version.