New York Agricultural Experiment Station. 415 



Test No. 4- — This experiment was located about three miles 

 northeast of Geneva in a cabbage field belonging to Mr. William 

 Baker. The field consisted of twelve rows, having about three 

 hundred plants to the row. On May 11 tar pads were attached 

 to the plants in two rows. On June 21 many of the untreated plants 

 showed the effect of maggot work. Eight per ct. of the checks 

 and two-thirds of one per ct. of the treated plants were badly wilted 

 or killed. Here again the protected plants were larger than those 

 in the adjacent rows. 



Commercial tests with tar pads during 1913 : Test No. 1. — This 

 experiment was conducted on the farm of Mr. Henry Cook, north 

 of Geneva. Four hundred tar pads were applied to four alternate 

 rows, but maggots were present in such small numbers that there 

 was no difference between the treated and check plants. Attention 

 is called to the fact that for two successive seasons no noticeable 

 injury by maggots occurred on this farm, although on neighboring 

 farms the pest has, during both seasons, done a great amount of 

 damage. 



Test No 2. — ■ This planting of cabbage belonged to Mr. William 

 Baker and was located a short distance from the field mentioned 

 in Test No. 4 of the previous season. The soil was a light sand 

 and well tilled. The seedlings were of good size, with long straight 

 stems. The cabbages were planted on April 29 and 30. On May 3 

 about seven hundred tarred disks were placed on six alternate rows. 

 During the following two weeks adults of the cabbage maggot were 

 numerous in this field and eggs were observed in conspicuous num- 

 bers about the stems of the plants. By June 5 there was a very 

 marked difference between the treated and check rows. Many of 

 the cabbages in the untreated rows were wilted or dead and the 

 plants averaged much smaller than those protected by tarred disks. 

 This condition is well shown in Plates XXI, XXII, XXIII. The 

 plants illustrated in Plate XXIV were given the same care in all 

 particulars, and the difference in their comparative size is due to the 

 continued root injury by a few maggots, which was sufficient to check 

 their growth. It was estimated on June 9 that 93 per ct. of the pro- 

 tected plants and 45 per ct. of the checks would make marketable 

 heads. The results in yields and financial returns from the treated 

 and untreated rows in this experiment are shown in detail in 

 Table III. 



