In wet, growing weather, Peas are tolerably free from insects and fungi, but in dry seasons they are attacked by several. They are always, of course, liable to attack by other enemies.
Netting or some sort of guard is very useful for keeping birds off the seeds and young plants. If netting is employed it should be removed before the young plants become entangled in it, and twiggy shoots from the upper part of the Pea sticks placed along the rows. These do much to baffle the birds.
Mice will do no harm if the seeds are moistened with quassia water before being sown, or with paraffin, or with red lead after being damped with linseed oil.
This fungus is very bad, as a rule, in dry summers, and it may appear in wet seasons if the plants are growing in heavy, stagnant ground. The great thing is to keep the plants in healthy growth from first to last, and to secure this end the soil should be well drained and deeply tilled. Mulchings with soil and manure, and soakings of liquid manure in dry weather, are helpful in light soil. As an application to the plants, sulphide of potassium (liver of sulphur) at the rate of 1/2 oz. per gallon of water, may be tried.
This lively little insect causes great damage to late Peas in hot, dry seasons. It attacks the leaves and the pods, and the latter curl up instead of filling. I do not believe in any mere wash for this enemy, any more than I do for mildew. Cultural steps are the best, such as deep tillage, feeding and mulching, combined with the choice of a sort that is known to be a vigorous grower and not simply a big podder. Large pods are not of much account if they do not fill. The plants must be kept growing. If they come to a standstill the thrips can be kept in check only at an expense that the value of the crop fails to justify.
Pea growers often complain of small grubs in their pods, especially in a dry season. The pods are pierced by a weevil when quite young, and the grubs that hatch from the eggs laid attack the Peas. The best way to ensure comparative immunity is to produce vigorous, free-growing plants by good culture, supplemented by occasional dustings with soot and lime.
Fig. 33. A Pea Protector. This consists of two half-moon shaped pieces of board, one at each end of the row, and black thread strung across from one to the other.
Fig. 34. Another Bird Baffler. This is a framework of laths, 1, 2, 3, on which netting can be stretched.
Fig. 35. A "Cross" Protector. One of these at each end of a row serves instead of the half-moons shown in Fig. 33 if threaded.