PLANTING DATE PLANTING DATE 



Figure 4. — First-season survival of western larch planting stock under four storage regimes, planted 

 throughout the spring season. Figures in parentheses are average survivals over all planting dates. 

 Significance differences attributable to storage are shown by * and ** (p = 0.05 and 0.01,- respec- 

 tively) and connecting arrows. 



PHASE II. FIELD SURVIVAL AND 

 GROWTH TESTS, 1973 



While the 1972 moisture stress plot evaluation of the storage 

 regimes and planting dates provided some valuable leads, testing 

 under field conditions was needed to verify trends. The validity 

 of the moisture stress plot technique also needed testing, espe- 

 cially when planting date was a study variable. Consequently, a 

 small, single-season field test was installed on the Coeur d'Alene 

 National Forest in 1973. 



Methods 



The same three species (Engelmann spruce, lodgepole pine, 

 and western larch) were tested. Storage treatments were frozen, 

 refrigerated, and fresh, all conducted in the same manner as in 

 the 1972 study. Snow cache storage was omitted in the interest of 

 economy — we felt that the technique already had been ade- 



quately field tested. Stock for overwinter storage was lifted be- 

 tween November 27 and December 1, 1972, preconditioned at 

 34° to 38° F (1° to 3° C) until December 7, then packed in 4-mil 

 polyethylene bags, sealed, and placed in 28° F (-2° C) storage 

 until removed for planting. All trees for regular refrigerated stor- 

 age were lifted on March 19, 1973, packed in polyethylene-lined 

 Kraft bags, and placed in 34° to 38° F (1° to 3° C) storage. All 

 frozen stock was removed from storage 4 to 5 days prior to 

 planting and held at 34° to 38° F (1° to 3° C) until the day of 

 planting. Fresh stock was lifted the day before planting (table 6). 



A total of 3,600 trees were planted, 1 ,200 of each species, in 

 100-tree lots, each with a specific treatment/species/planting 

 date combination. Each lot was planted in two 50-tree rows sepa- 

 rated by the other rows of species and treatments for that plant- 

 ing date. Spacing of trees was approximately 3 ft by 3 ft (1 m by 

 1 m). All trees were hand planted in auger-drilled holes. Each 

 tree was staked and identified to allow accurate survival checks. 



The study site provided uniformity of soil, aspect, and site 

 preparation treatment. The area is approximately 8 miles east of 



6 



