Q. My neighbor has a great apricot tree, and I would like one just like it. Can I grow one from the seed or what would be the best way to propagate the tree?
A. Trees usually are grafted together with a rootstock at the bottom and a scion being the fruit variety on top. Each part has special characteristics that are important. Rootstocks can control the size of the tree, be resistant to diseases or tolerate a particular soil. The scion has fruit with certain yield, taste and color attributes. To propagate this tree, take a cutting to a nursery and see if they can graft it to a size-controlling rootstock good for our area.
Q. What is a chlorophyll meter that tests for nitrogen, and how does it work?
A. Chlorophyll is the green pigment in plants which turns light into energy through photosynthesis. The amount of chlorophyll level per area varies with nitrogen fertility levels. The chlorophyll meter, or SPAD meter, measures two wavelengths of light absorbed and transmitted (not absorbed) across the leaf blade. Red light at 650 nm is absorbed by plants and infrared light at 940 nm is not absorbed.
Plants are green because they reflect green light. The term Soil Plant Analysis Development (SPAD) units is an index to how green the plant is. Averaged over observations taken with the meter (minimum of 20 readings) divided by the reads of a known well fertilized plants, you get a relative SPAD reading. The relative SPAD reading is then calibrated to leaves with known deficiencies and optimum rates, and you have a calibration for nitrogen fertilization.
The chlorophyll meter can be an instantaneous determination if and how much more nitrogen fertilizer is needed.
-- Questions should be called in to the WSU Extension offices in Kennewick at 735-3551 or Pasco at 545-3511.