CEREAL CROPS: ECONOMICS, STATISTICS AND USES tritici), Glume Blotch (Leptosphaeria Thrips Septoria nodorum)and Flag Smut tritici. A systemic fungicide recomm The larvae of tiny insects of the genus Haplothrips ind of other genera in the order Thysanoptera against Septoria on wheat is Tilt, a triazole. Flag al eloping inflorescence of wheat in western Smut can be controlled by seed treatment and by the dev wing), known as thrips, frequently attack the growing of resistant varieties Europe, but generally complete their develop. ment and leave the plants before the grain Ee/worm matures. In cold wet harvest years, however, the Wheat may be attacked by the eelworm adult insects occasionally fail to escape from the Anguina tritici, the grains becoming filled with plant, and become occluded in the crease(cf. p the worms, which are of microscopic dimensions. does not affect milling or baking quality of s 40: see Fig. 1.3. Attack by thrips apparentl Infected grains are known as"ear cockle(not to wheat but insects remaining in the crease are be confused with'corn cockle, the seeds of the fragmented during milling and contribute towards weed Agrostemma githago) the insect fragment count of the milled flour Kent,1969) Wheat bug Bugs of the species Aelia rostrata and eurygaster integriceps attack the wheat plants and puncture Rustic Shoulder Knot moth e immature grains, introducing with their saliva The larvae of the Rustic Shoulder Knot moth a proteolytic enzyme which modifies the protein, (Apamea sordens)feed on the developing wheat preventing the formation of a strong gluten( cf. grains in the field. The young larvae penetrate dough that collapses and becomes runny if more The fully developed larva may attain a length of han 5% of attacked grain is present. Steam 28 mm. Secondary effects of heavy attack by a treatment of the attacked wheat for a few seconds sordens are loss of flour yield, discoloration and (BP No. 523, 116)is beneficial in inactivating the an increased micro-organism count in the flour enzymes, which are localized near the exterior of (due to infection of the exposed endosperm the grain. The baking properties of flour milled surfaces by fungi). Attack, in Britain, is more from buggy wheat are improved by increasing the prevalent in Scotland and the north of England acidity of the dough, since the proteolytic enzyme than in the south in the bug saliva has an optimum pH of 8.5.Wheat bug damage is generally restricted to crops grown in the former Soviet Union . the mediterranean littoral, eastern Europe and the Near East Harvesting Dormancy Wheat blossom midge After the wheat appears to be ripe, it needs a The damage caused by the midge Sitodiplosis further period of maturation before it is capable mosellana varies greatly with year and locality. of germination(cf. p. 36); during this period the The female midge lays eggs in the wheat floret. wheat is said to bedormant'. Dormancy is a The feeding larvae use part of the plant juices valuable characteristic conferring a degree of for their development; in consequence, infested resistance to sprouting at harvest time. The factor grains become shrivelled. Secondary effects are appears to be related to enzymic activity; how reduced germination capacity and weight, ever, not all varieties show a period of dormancy, increased alpha-amylase activity, poorer and the factor appears to be linked genetically to baking quality of the flour. redness of bran colourCEREAL CROPS: ECONOMICS, STATISTICS AND USES 9 tritici), Glume Blotch (Leptosphaeria nodorum Thrips tritici) . A systemic fungicide recommended against Septoria on wheat is Tilt, a triazole. Flag Smut can be controlled by seed treatment and by the growing of resistant varieties. Eelworm = Septoria nodomm) and F1ag Smut (urocYstis The larvae oftiny insects ofthe genus Hap/&,.ips and of other genera in the order Thysanoptera (‘fringe wing’), known as thrips, frequently attack the developing inflorescence of wheat in western Europe, but generally complete their develop￾ment and leave the plants before the grain matures. In cold, wet harvest years, however, the adult insects occasionally fail to escape from the plant, and become occluded in the crease (cf. p. does not affect milling or baking quality of the wheat, but insects remaining in the creaSe are fragmented during milling and contribute towards the insect fragment count of the milled flour (Kent, 1969). Wheat may be attacked by the ee1wormy the worms, which are of microscopic dimensions. Infected grains are known as ‘ear cockle’ (not to be confused with ‘corn cockle’, the seeds of the weed Agrostemma githago). Wheat bug Bugs of the species Aelia rostrata and Eurygaster integriceps attack the wheat plants and puncture the immature grains, introducing with their saliva a ProteolYtic enzyme which modifies the Protein, preventing the formation of a strong gluten (cf. P. 200). Flour milled from buggy wheat gives dough that CollaPseS and becomes runny if more than 5% of attacked grain is present. Steam treatment of the attacked wheat for a few seconds (BP NO. 523,116) is beneficial in inactivating the enzymes, which are localized near the exterior of the grain. The baking properties of flour milled from buggy wheat are improved by increasing the acidity of the dough, since the proteolytic enzyme in the bug saliva has an optimum pH of 8.5. Wheat bug damage is generally restricted to crops grown Harvesting in the former Soviet Union, the Mediterranean littoral, eastern Europe and the Near East. Dormanc y After the wheat appears to be ripe, it needs a Wheat blossom midge The damage caused by the midge Sitodiplosis further period of maturation before it is capable mosellana varies greatly with year and locality. of germination (cf. p. 36); during this period the The female midge lays eggs in the wheat floret. wheat is said to be ‘dormant’. Dormancy is a The feeding larvae use part of the plant juices valuable characteristic conferring a degree of for their development; in consequence, infested resistance to sprouting at harvest time. The factor grains become shrivelled. Secondary effects are appears to be related to enzymic activity; how￾reduced germination capacity and seed weight, ever, not all varieties show a period of dormancy, increased alpha-amylase activity, and poorer and the factor appears to be linked genetically to baking quality of the flour. redness of bran colour. Anguina thtici, the grains becoming filled with 40: see ~i~. 1.3). ~~~~~k by thrips apparently Rustic Shoulder Knot moth The larvae of the Rustic Shoulder Knot moth (Apamea sordens) feed on the developing wheat grains in the field. The young larvae penetrate the grains at the brush end and hollow them out. The fully developed larva may attain a length of 28 mm. Secondary effects of heavy attack by A. sordens are loss of flour yield, discoloration and an increased micro-organism Count in the flour (due to infection of the exposed endosperm surfaces by fungi). Attack, in Britain, is more prevalent in Scotland and the north of England than in the south