miles away, lammas production was abundant. 



The exaci cause of lammas shoot formation is unknown. Accord- 

 ing to Biisgen and Munch (10) several factors seem to be involved 

 including nutrition, the accumulation of food reserves and an 

 abnormal water supply. Brown (8), in a stud) of forking in haul 

 woods in southern England, found late branching Largely dependent 

 upon degree of shading. I Ee observed less lammas growth on strongly 

 shaded plants. Above-normal summer rainfall, such as the prolonged 

 midsummer rains of 1956, appeared to promote lammas growth. In 

 the present stud) trees, with and without lammas shoots, were found 

 in the field with their branches intermingled. Therefore, it appeals 

 that inherited tendencies as well as environmental factors are im- 

 portant in relation to late summer shoot extension. 



Lammas shoots occurred on Douglas-fir in the Camden, Cortland, 

 and Cheningo plantations in 1955, 1956, and 1957. Two distinct 

 stages of R. pseudotsugae infections were observed in the Cortland 

 area in November 1955. On lammas needles initial yellow spotting 

 was just becoming apparent, while on spring needles intense mot- 

 tling had developed and the needles were somewhat brown and dry. 



Once lammas infection was established, and the 1955 and 1956 

 seasons indicate this to be frequent, the fungus developed on a 

 schedule somewhat behind that of the spring infection. Even though 

 late infections occurred, many of them appeared to be very weak, 

 as if the spores were less pathogenic or, late shoots possessed more 

 resistance to the pathogen than did spring shoots. These apparently 

 weaker infections needed more time to develop and produce mature 

 fruit bodies. Lammas needles with incipient apothecia were observed 

 as late as the second winter. Many needles dried and fell prior to 

 apothecial maturation, but some remained to produce inoculum the 

 following spring. 



During the spring and summer of 1956 the time of bud develop- 

 ment was observed at the three study areas. Details are given for the 

 Camden area only, since bud development appeared about one week 

 later in a similar pattern in the other two areas. On June 8, less than 

 a month after spring buds burst at Camden, terminal buds were 

 observed on some of the branches. On June 15, many of these ter- 

 minal buds were one-quarter inch long while the laterals were 

 nearly one-eighth inch long. At this time the majority of the 1955 

 spring-infected needles had been cast but the greater portion of the 

 1955 lammas needles remained and were still developing apo- 



43 



