14 MASS. EXPERIMENT STATION BULLETIN 419 



Top-Dressing with Nitrogen 



Long-season crops such as tomatoes are general!}' benefited by a top-dressing 

 of nitrogen fertilizer during the growing season. Where heav>' applications of 

 complete fertilizer are made, the value of this top-dressing is questionable. 

 Consequently, this treatment was included in the experiment. 



Nitrate of soda was applied to the plots that received the regular manure and 

 5-8-7 fertilizer treatments. An application was made on July 10 and July 30, 

 each at the rate of 300 pounds per acre. Records on this treatment were com- 

 pleted only at Waltham, and are presented in Table 3. Early and total yields 

 for the plots top-dressed with nitrogen were just the same as for those receiving 

 only the basic fertilizer application. 



The failure of nitrogen top-dressing to increase the yield is probably due, as 

 was the case with other fertilizer treatments, to the fact that 1 ton of the 5-8-7 

 supplied all the plant food that the plants could possibly use. If less fertilizer 

 had been used, or if the soil had been less fertile, no doubt the top-dressing would 

 have increased the yields. When tomatoes are planted on light, sand)- soil heavy 

 rains are likely to wash out all the soluble nitrogen and under these conditions 

 top-dressing will be of value. 



Double-Strength or High- Analysis Fertilizer 



A special double-strength fertilizer was originally included in these experi- 

 ments but its manufacture was discontinued. Two other treatments approx- 

 imating double-strength 5-8-7 were used for short periods. The fertilizer was 

 applied so as to provide the same amount of plant food as the regular 5-8-7. 

 In all the work with these high-analysis materials the yields were about the 

 same as those obtained from the use of single-strength material, or at times 

 slightly higher. 



When double-strength fertilizer materials are properly applied, it is evident 

 that they will produce just as satisfactory yields as the single-strength. 



Building the Trellis 



The trellis to support the tomato plants can be constructed either before or 

 after the plants are set. Most growers put in the plants, furrowing out with a 

 plow to aid in the setting, and construct the trellis along the row after the plants 

 have started to grow. If the trellis is put up before the plants are set, there will 

 be no danger of damaging them with posts, wire, or tools; but when the plants 

 are set the holes nmst be dug with trowel or shovel. 



There are many types of trellis, but the most common is one having substantial 

 end posts, such as 4 x 4 inch or 3 x 4 inch. (Figure 5.) These are anchored with 

 a guy wire or stake 4 or 5 feet beyond the posts. The supporting posts are placed 

 15 to 25 feet apart along the row. These can be of 1-inch or larger pipe, 2 x 4's 

 or 3 X 4's, but they must be strong enough to support considerable weight. The 

 wire (No. 9 or 1 1) is then strung along the top of the posts. It should be stretched 

 as tight as possible so that there will be little sag when the plants become heavj-, 

 and can be kept in place on the wooden posts by stapling, and on the pipe by 

 inserting a loop of wire over it and into the pipe. A smaller wire, No. 18 or 19, 

 along the bottom on which to tie the strings completes the trellis. It is generally 

 considered better to have this bottom wire and to tie the strings somewhat 



