Crown gall causes stunting of growth. Both loss of yield and stunting of growth may occur when seedlings or young cuttings are infected in the early stages of plant growth. The lack of vigor, reduction in foliage, and water stress are associated with chronically diseased root systems.
1. In probability theory, a probability density function (pdf), or density of a continuous random variable, is a function that describes the relative likelihood for this random variable to take on a given value.
A discrete random variable X is said to have a Poisson distribution with parameter Î» k = 0, 1, 2, ..., the probability mass function of X is given by: where. 1  e is Euler's number (e = 2.71828...). 2  k ! is the factorial of k.he coefficients of the polynomials have a combinatorial meaning. In fact, when the expected value of the Poisson distribution is 1, then Dobinski's formula says that the n th moment equals the number of partitions of a set of size n.