Orchard Cover Crops in Delaware. 199 



this time the injury was done and the poor stand in many plots is thus ex- 

 plained. A part of each plot was plowed the first week in May ; the remainder 

 was left unplowed to study the development of the cover crop, and to determine 

 what influence the crops had in removing soil moisture, as compared with the 

 moisture of plowed ground. The following notes were taken during the season : 



Canada peas {Pisum arvense, L.) 2 bushels per acre. — Two weeks after 

 sowing there was a fairly good stand 2 to 4 inches high. They made a slow 

 growth ; some were 15 inches high the last of September. The weather seemed 

 to be uncongenial for them ; they began to dwindle and die, so that by the end 

 of October there were few plants alive. There were a good many pea aphids on 

 the vines, but not enough to destroy them. The Canada peas were a failure 

 in all of the tests. 



Canada t^cas 2 bushels, and rye y., bushel per acre. — The peas, made the 

 same record as that mentioned above. The rye, naturally, from such a thin 

 seeding gave a thin stand. The plants grew well ; were 6 inches high the last 

 of September. They wintered well and made a good but uneven growth in the 

 spring, and by April 6 some plants were 15 inches high. It was from 4 to G feet 

 high and heading out by the middle of May. Even this small amount of rye made 

 pretty good cover. On May 22 it was cut to be used as a mulch for the) 

 plot and gave a yield at the rate of 7,293 pounds of green tops per acre. 



Hairy vetch 40 pounds and rye 30 pounds per acre. — At first the vetch 

 seemed to be rather thin on the ground, but it improved rapidly. Early in 

 its life it is a slow spreading grower. It formed a gocd, thick carpet for a 

 winter covering and came through the winter in good shape. The new spring 

 growth was from 4 to 12 inches by the first part of April. It began climbing ui» 

 on the rye for support and together they made a wonderfully fine tangled mass 

 of vegetation, the vetch being from 2 to 4 feet high and the rye 6 feet high May 

 20 when the vetch was just coming nicely into bloom (see Plate I, A). They 

 form an extra good cover crop and are a decided success. Of course in orchanl 

 operations it is not in the least desirable, nor is it .recommended to let these 

 crops attain such enormous growth. A part of this plot was allowed to grow 

 for experimental purposes. On the heavy clay at this Station it could safely 

 grow until the last of April without injury to the trees. A part of the plot was 

 mowed April .30 and gave a yield of 10,068 pounds of green matter per acre. 

 or 3,682 pounds of air-dry material. On May 22 the balance of the plot was 

 mowed. The weight of green tops was at the rate of 18,480 pounds per acre, 

 an increase of 2.412 pounds since April 30, or an increase of 110 pounds of 

 green matter per acre per day for that time. By taking the weight of the green 

 rye cut from the last plot, 7,203 pounds, and deducting this from 18.4S(» 

 pounds, the combined weight of rye and vetch, a rough estimate is obtained for 

 the weight of the vetch of this plot, namely, 11,187 pounds. The writer 

 does not recommend the practice of cutting the rye and vetch for stock food, 

 yet this could be done if it is absolutely necessary. Probably no better soiling 

 crop could be grown for early feeding. 



The orchardist should not make the mistake of letting a cover crop continue 

 growth after the ground is in condition to plow While it will of course add 

 more vegetable matter to the soil to do so, there is danger of injury to the trees 

 by drying out the soil too much. However, weather conditions will largely 

 control this feature ; if there is plenty of rain the crop may naturally be al- 

 lowed to grow longer before plowing under. 



The rye developed about the same as that mentioned above which was 

 sown with Canada peas. 



The combination of hairy vetch 40 pounds and rye 30 pounds per acre is 

 recommended as one of the best orchard cover crops that can possibly be used. 



Hairy vetch 20 pounds and Canada peas 1 bushel per acre— The vetch did 

 not do as well on this plot as it did on most of the others. The fall growth was 

 pretty good, but uneven. It made a fairly good covering during the winter, but 

 came out in poor condition in the spring. The few plants left made a good 

 spring growth and were in full bloom May 20. 



