642 Report of the Department of Horticulture of the 



straw or with coarse stable manure. In commercial plantations 

 such mulching will not take the place of cultivation. On heavy 

 clay soils plowing may be necessary at times, yet it must be done 

 with care or severe injury may be done to the shallow roots. After 

 the crop has been harvested the ground should be thoroughly worked 

 over and the soil put in fine condition for a cover-crop to be sown 

 in late July or early August, using about fifteen pounds clover 

 seed per acre or twenty-five pounds vetch or about one bushel of 

 oats or barley. Mixtures of the seed are sometimes used to ad- 

 vantage. A hoed crop may be grown between the plants the first year. 



Pruning. — Systematic pruning is essential to improve the size 

 of the fruit and to renew the old and weak wood. The bush-form 

 is preferable to the tree-form. The best fruit is borne at the base 

 of one-year-old shoots and on one-year-old spurs which develop 

 from the two- and three-year-old wood. Most of the wood over 

 three years old should be cut out, and only enough of the yearling 

 wood left to maintain a yearly supply of the younger wood. From 

 five to eight canes, well distributed to avoid crowding, are sufficient 

 per bush depending upon richness of soil and on the variety. Most 

 bushes are left too thick. An upright yet open habit of growth 

 should be encouraged. It is usually unnecessary to head back 

 the new canes but it is often an advantage to cut back very vigorous 

 shoots. Pruning may be done any time after the leaves have dropped 

 in the fall, or during the winter or in early spring before growth 

 starts. Black currants are borne on wood of the previous year. 



Pollination. — The few experiments that have been made indicate 

 that the currant is usually self-fertile. It is generally an advantage 

 to grow more than one variety to extend the picking season and 

 any possible advantage through cross-pollination may then be 

 secured. The cause of cluster ends failing to set fruit is not well 

 understood. 



Spraying. — Spraying is usually necessary each year. Disease or 

 insect pests are to be expected. The material used and the time 

 and manner of application depend on the kind of insect or disease; 

 some are very difficult to combat. Foliage must be protected against 

 their ravages or the present year's crop may be greatly decreased 

 and the bushes left in poor condition to develop fruit-buds for the 

 crop of the following year. The bushes should be sprayed with 

 a combined insecticide and fungicide soon after the fruit begins to 

 swell, and again, after the fruit has been harvested, with a fungicide. 



Insects. — Currant worm. Usually present each year attacking 

 and eating the foliage; eggs are laid on underside of leaves; two 

 broods a year, each having a long season. The worms may be 

 easily killed with an arsenical spray such as arsenate of lead, three 

 pounds to fifty gallons, applied as soon as they make their appear- 

 ance soon after the fruit begins to swell. This spray should be 

 combined with a fungicide, either bordeaux mixture, 3-3-50 formula, 



