Growth stage pictures of Merit and Whitebird for the week of 5/24/99

Growing degree days for week of 5/17 - 5/23 = 160.5
Accumulated growing degree days (emergence to 5/23) = 595

Scroll down to see pictures (3 for Merit, 2 for Whitebird)

Merit: 2-row spring barley.  Picture taken 5/24/99 at early jointing stage.   Zadoks scale: 31, Feekes scale: 6, Haun scale: 6.5.

Merit: 2-row spring barley.  Picture taken 5/24/99 at early jointing stage.   Zadoks scale: 31, Feekes scale: 6, Haun scale: 6.5.
Merit has likely produced all the tillers that will be present on the plant. There are the following potential heads on this plant: main stem, three primary tillers, T0 tiller, secondary tillers coming from tillers 1 and 2. Tiller 3 has 2 fully developed leaves and the start of leaf 3. If tiller 4 was going to develop, it should be only one leaf behind tiller 3. Several of these tillers will not survive to produce seed. The numbers that survive is dependent on environmental conditions, plant density, weather, and other factors. The plant has started to joint and the first detectable joint is about 2 inches above ground level. When the main stem was dissected, the developing head could be seen and is 5/16ths inch long (see picture below). Maximum spikelet number has been set in this head for over 1 week and the tillers are undergoing this process at present. For those tillers that will likely produce grain, maximum kernel number has been set. The adventitious roots have become quite numerous and are becoming the main roots feeding the plant.

Picture taken 5/24/99.  Developing head from Merit (2-row spring barley) at early jointing stage.

Whitebird: soft white spring wheat..  Picture taken 5/24/99 at tillering.  Zadoks scale: 23, Feekes scale: 2, Haun scale: 5.7. 

Whitebird: soft white spring wheat..  Picture taken 5/24/99 at tillering.  Zadoks scale: 23, Feekes scale: 2, Haun scale: 5.7.  Whitebird has not yet reached the jointing stage but when examined closely, the first joint was evident but still below the soil level (jointing officially starts when the first joint is detectable above the soil level. This plant has a mainstem tiller, three primary tillers plus the T0 tiller. Secondary tillers are not yet developing. The developing heads are not yet visible to the unaided eye. From a physiological stage, the wheat is similar to where the barley was last week.

Any moisture, nutrient, or other stress will have the effect of reducing tiller number and/or head size giving a reduced yield. The plants are starting into a very rapid phase of growth (dry matter accumulation). The cooler than normal temperatures that southern Idaho has experienced during the period from seeding to present have favored development of additional tillers and larger heads. Warmer temperatures through this period will result in fewer tillers and smaller heads. Recent changes to warmer temperatures will put stress on irrigation systems and the plants will change from one stage to another very rapidly.

[ Home ]  [ Go Back ]  [ Week of 5/31 ]