12 



MASS. EXPERIMENT STATION BULLETIN 419 



Table 3. Effect of the Amount and Kind of 5-8-7 Fertilizer 

 ON the Yield of Trellis Tomatoes. 



Yields per Acre, Pounds 



Treatment of Plots 



Waltham 



Amherst 



Early 



Total 



Early 



Total 



Combined Crop 

 Early Total 



36,756 

 41,845 

 38,655 

 41,560 

 41,275 



No fertilizer 10,300 



1 Ton 5-8-7 (Check Plot) 11,796 



2 Tons 5-8-7 10,425 



1 Ton 5-8-7 in row 11,742 



1 Ton Special 5-8-7* 10,890 



1 Ton 5-8-7-}- 



Y2 Ton Superphosphate . . 1 1,503 



1 Ton 5-8-7 + 



Nitrogen Top-Dressing. . 11,724 41,231 



*?4 of nitrogen in organic form. 



6,618 

 8,002 

 7,936 

 7,416 

 8,158 



40,618 

 48,750 

 54,560 

 54,364 



51,748 



8,459 

 9,899 

 9,180 

 9,579 

 9,524 



38,687 

 45,297 

 46,607 

 47,962 

 46.511 



43,555 8,210 49,214 9,856 46,384 



Table 3 shows the yields of tomatoes for these three levels of fertilizer at 

 Waltham and Amherst. The application of 1 ton of fertilizer per acre produced 

 the best results at Waltham, and 2 tons per acre definitely depressed both the 

 early and the total yield. At Amherst, 1 ton of fertilizer per acre produced the 

 greatest early yield but 2 tons per acre produced the largest total yield. It is 

 evident from these results that each soil will respond differently to fertilizer 

 treatment. 



It is questionable whether the increase in yield obtained by using 2 tons of 

 fertilizer would pay for the extra fertilizer. In fact, the plants produced re- 

 markably well with no fertilizer at all except the 12 cords of manure. The 

 importance of ample fertilizer in years of excessive rainfall, such as 1938, was 

 emphasized; for that year the total yield of tomatoes from the plots that received 

 1 ton of fertilizer per acre was 29,430 pounds, while the plots that received no 

 fertilizer produced only 14,974 pounds per acre. The early yield was in about 

 the same ratio. 



A good crop of trellis tomatoes will require approximately 1 ton of 5-8-7 

 fertilizer per acre. If the land is very rich, or if large quantities of manure are 

 being used, then the amount of fertilizer can safely be reduced to 1500 pounds 

 per acre. If the soil is poor or has very little residual fertility, then it would be 

 best to apply 1 ton per acre at the time of planting and follow this with top-dress- 

 ing during the growing season. 



Extra Phosphorus 



The value of adding extra superphosphate to the soil was tested in one treat- 

 ment where the regular 5-8-7 fertilizer plus }4 ton of 16 percent superphosphate 

 was applied. The yields from this treatment are also presented in Table 3. At both 

 Waltham antl Amherst the extra phosphorus did not affect the early yield and 

 the increase in total yield was only slight. 



New land or land that has not been kept to a high level of fertility might 

 respond much better to extra phosphorus than the soils used for this experiment. 



