chusetts it has never occurred during the summer, but on the other 

 hand it is only the black spores (teleutospores) which have predom- 

 inated, and these only .making tkeir appearance late in the season. 

 While the statement holds good in regard to localities, it must be 

 understood that it is not valid when we take into consideration the 

 number and size of the asparagus beds which were affected. It 

 unfortunately happened that the rust was most severe in those local- 

 ities where Asparagus is cultivated most extensively. 



During the past season this division has made use of every oppor- 

 tunity to gather data concerning the rust, as well as to experiment 

 upon control methods, and a number of days have been spent in 

 looking over the various fields.* 



Life History of the Asparagus Rust. 



Puccinia Asparagi D. C. 



The asparagus rust is caused by a fungus of the above name 

 which is one of the true rusts or Uredineae. Like many other rusts, 

 it appears in three different stages or forms of development. The 

 first of these forms, called the aecidial or cluster cup shape, appears 

 in early spring, but, since at that time the asparagus is being cut 

 for market, the fungus is able to develop only upon such scattering 

 stalks as are allowed to remain and grow up, and consequently is not 

 at all noticeable at this season. Indeed we have never observed it 

 in this state and know it only from the descriptions of Halstedf and 

 others. In this stage the fungus produces little eruptions on the 

 surface of the affected plants, each of which is a minute cavity in 

 which numerous spores are developed in the form of long chains, 

 which break up into separate roundish spores at maturity. These 

 spores are carried by the wind to other plants and produce on them 

 the second form of the rust. 



SUMMER OR RED RUST STAGE. (UREDO.) 



The rust is by far the most destructive in the red rust stage which 

 appears in July and August. The plants in the main bed have been 

 allowed to grow up by this time and if badly affected soon appear 



*\Ve wisli here to acknowledfje our indebtedness to IVfr. C. >V. Pi'escott and Mr. 

 Wilfred Wheeler and especiaUy to Mr. Thomas Ilollis who extended to us every 

 hospitality while at Concord. 



fBull. 129, New .Jersey Agr'l Exp't Sta. 



