Phenology

Every two weeks, examine each of the treatments in Block 1 and note whether the plants have reached the major life stages listed: emerging growth, mature leaves, open flowers, ripe seeds, closed canopy, autumn leaf senescence, and leaf loss. On the data sheet, mark “yes” if at least 50% of the plot has reached that life stage. Also note if there is visible herbivore damage, leaf wilting, or extensive weed coverage.

Additional information on life stages

Emerging growth: Emergence occurs when plants are visible above-ground. For annual crops, it will be evident by green growth on bare soil. Only record the emergence of the main crop, not the cover crop or weeds; i.e., emergence should not occur until after planting. Emergence of perennials will be evident by green shoots appearing near the base of last year’s stalks. Poplar “emergence” is the presence of small leaves, just emerged from the buds.

Mature leaves: Mature leaves are >95% of their full size.

Canopy closure: In row crops, canopy closure occurs when the spaces between rows are covered by over-hanging vegetation. For instance, corn leaves in adjacent rows will be touching one another. In perennial plots, the space between plants will be covered by over-hanging vegetation and leaves of adjacent plants will be touching.

Autumn leaf senescence: Senesced leaves are dry and brown. Poplar leaves will turn yellow.

Leaf loss: Generally only applicable to poplars, in the fall. If it occurs in other plots, note the circumstances (e.g., drought).

Additional information on other observations

Leaf wilting: Leaf wilting is distinct from senescence and could occur as a result of drought, disease, or pests. Record “y” if wilting is evident in at least 50% of the plot.

Herbivore damage: Small amounts of herbivore damage are normal. If at least 50% of the plants have noticeable defoliation or extensive parts of leaves removed, record “y” on the data sheet.

Extensive weed growth: Scattered weeds are normal. If weeds cover at least 50% of the spaces between plants, then record “y” on the data sheet. This is not applicable in the old field treatment (G9).

Height

Measure the height of the plants 3 times per year, including once at peak biomass. To measure height, randomly select 10 plants in each plot, measure their height, and take the average. In G7, measure 10 plants of each of each species. In G9 and G10, randomly choose 30 plants.

If the cameras are working and the measuring devices are in place, then these data can be used instead of measured height.