OSCINELLA FRIT L. IN SOUTH WALES. THE RELATIONSHIP BETWEEN SOWING DATE, PLANT DEVELOPMENT AND PROGRESS OF ATTACK IN SPRING OATS

The degree of lateness of sowing of spring oats in south Wales is reflected in a proportional increase of frit-fly damage to the shoots. Late-sown crops are also more subject to heavy attacks on grain than those sown earlier. Equations are given relating the development of frit-fly attack both to the growth of the plant and to the date of sowing.