The second of two uncredited appearances playing an Interpol Officer in the series by Zena Marshall, the other being in E1, The Thirteen Innocents (1959).
The vine pest mentioned here is Phylloxera, a microscopic louse that lives on and eats roots of grapes. Highly infectious, it can infest a vineyard from the soles of vineyard worker's boots or by naturally spreading from vineyard-to-vineyard.
The first of four uncredited appearances by Louis Matto, the others being E20, Game for Three Hands (1960), E24 Checkmate (1960) and E31 A Foreign Body (1960).
The first of four appearances as Captain Pagano by George Pastell, the others being E14, The Man's a Clown (1959), E18 The Thousand Mile Alibi (1960) and E26 The Girl with Grey Hair (1960).