278 CROP GROWING AND CROP FEEDING 



present methods, but they feel justified in calling attention to certain appar- 

 ent advantages of the artificial soil for forcing purposes. 



For every 100 square feet of bench space there will be required 2,200 

 pounds sifted ashes and 63 pounds of dried peat or leaf mold to fill the bench 

 8 inches deep, and experiments may show that the peat is not necessary About 

 10 pounds of commercial fertilizers are needed for this much bench space, cost- 

 ing at present ton rates less than 21 cents. In very many cases, then, the 

 cost of filling the benches with the artificial soil will be very much less than 

 the cost of filling them with rich garden soil or compost. The tomato plants 

 grown in natural soil made much slower growth and were slower in fruiting 

 than those in artificial soil supplied with nitrates. Another consideration is 

 the freedom from insects and fungi in the ashes, which constitute 97 per 

 cent, of the bulk of the artificial soil, and even the peat which is hardly 

 needed, is not so apt to convey these as the rich garden soil. It was found 

 that there was a special freedom from the nematode worms which cause root 

 galls on plants. The rich garden soil becomes so infested with these that it 

 cannot be used for tomatoes more than one season. In the artificial soil 

 no nematodes were found beyond the ball of earth set with the plants, but they 

 were very abundant in the natural soil. 



We have given such full space to the tomato because, for both culture in 

 the open ground and under glass, it is about the most important of our vege- 

 table crops. It will readily be seen from the experiments of the Connecticut 

 Experiment Station, which we have given in detail, that the manurial re- 

 quirements of the tomato are mainly for nitrogen and potash, and it may be 

 remarked that this is the case with a large proportion of our garden crops, 

 few of which, if we except the cruciferous family, the cabbage and its allies, 

 require such a large percentage of phosphoric acid as is usually found in the 

 \arious brands of fertilizers sold ready mixed on the market. 



SHALL TOMATOES IN THE OPEN GROUND BE PRUNED? 



We have made a number of experiments in the pruning and training of 

 tomatoes. In the house, before the plants go into the frames, we do not hesi- 

 tate to top them if they threaten to get too tall, but we had rather not do 

 this, and would try to keep them growing slower. In the open ground there 

 have been numberless contrivances invented for the support of the plants, 

 and we have tried different methods of training and pruning. The conclus- 

 ions we have arrived at are these : When tomatoes are grown on a large scale 

 for market it will not pay to prune them or to make any effort to support 

 them. The rot is not caused by the tomatoes touching the ground, but from 



