34 



BULLETIN" 1405, U. S. DEPARTMENT OF AGRICULTURE 



FREQUENT CROPPING LATE IN THE SEASON 



The results of an experiment to determine the effect of frequent 

 croppings to 1 inch above the ground after seed maturity are shown 

 in Table 10. 



The average yields per plant of Nevada blue grass and violet 

 wheat grass were much lower in the second year than in the first, 

 and considerably lower in the third year than in the second. These 

 excessive declines in yield per plant of violet wheat grass in three 

 years, varying from about 49 to about 62 per cent in the different 

 methods, are in striking contrast with the increases in the yield of 

 this plant in three years shown in Table 7, amounting to 176 per cent 

 when harvested at seed maturity and at the close of the growing 

 season, and 159 per cent when they were harvested only at seed 

 maturity. 



Table 10. — Results of frequent harvesting after seed maturity 



Plots Harvested Each Year at Seed Maturity, Then Cut Three Times at 10-Day Intervals, 

 and Aftermath Removed at End of Season (only Four Cuttings in 1923) 



Plot No. 



Plant 



Number of 

 plants ' 



Total yield 

 per plot (grams) 



Average yield 

 per plant (grams) 



Per cent 

 increase or 

 decrease 

 per plant 

 of Yield 

 in 1921 





1921 



1922 



1923 



1921 



1922 



1923 



1921 



1922 



1923 



1922 



1923 



P-l-15... 

 R-l-15... 

 Q-l-10... 



Nevada blue grass . . 

 Violet wheat grass... 

 Wild geranium.. 



15 

 15 

 10 



15 

 14 

 10 



14 

 13 

 10 



98.34 

 379. 20 

 222. 79 



60.19 

 157. 22 

 237. 43 



34.14 

 126. 51 

 240. 59 



6.556 

 25. 280 

 22. 279 



4.013 

 11. 230 

 23. 743 



2.438 

 9.732 

 24. 059 



-38.8 

 -55.6 

 +6.6 



-62.8 

 -61.5 

 +8.0 



Plots Harvested Each Year at Seed Maturity, Then Cut Twice at 15-Day Intervals, and 

 Aftermath Removed at End of Season (only Three Cuttings in 1923) 



P-16-30. 

 R-16-30. 



Nevada blue gr 

 Violet wheat gii 



15 



15 



15 158.71 



71.92 



51.41 



10. 581 



4.795 3.427 



-54.7 



15 



15 



15 316. 85 



219. 03 



162. 34 



21. 123 



14.602 10.823 



-30.9 



-67.6 

 -48.8 



Plots Harvested Each Year at Seed Maturity, Then Cut Once 20 Days Later, and Aftermath 

 Removed at End of Season (only Two Cuttings in 1923) 



P-31-45.. 



R-31-45.. 

 Q-ll-20.. 



Nevada blue grass. 

 Violet wheat grass.. 

 Wild geranium 



15 



15 



15 



204.45 



70.54 



52.03 



13. 630 



15 



15 



15 



303. 88 



186. 21 



115. 99 



20. 259 



10 



10 



10 



244. 81 



232. 07 



259. 98 



24. 481 



4.7031 3.469 



-65.5 



12. 414 j 7.733 



-38.7 



23.207 25.998 



-5.2 



-74.5 

 -61.8 

 +6.2 



i The number of plants shown in this table represents those living at the beginning of each year's 

 treatment. 



In 1922 and 1923 the grasses treated were inclined to be later in 

 reaching seed maturity than were untreated specimens. Most bunch 

 grasses produce considerable growth late in the fall, after seed ma- 

 turity, which if not removed affords an excellent protection for the 

 crown of the plant. This covering doubtless prevents the untreated 

 plants from being killed back as far as the treated ones, and by pro- 

 tecting plants from unfavorable climatic conditions in the early 

 spring enables them to start growth earlier. The results obtained 

 with geranium indicate that frequency of cropping the late growth 

 of that species has no detrimental effect on the vigor or subsequent 

 yield. In contrast to the results obtained with the grasses there was 

 no very perceptible delay in the growth of treated geranium plants 



