Table I. Information needed to create graphical tracking curves. 



target range of heights throughout the production 

 season. In the example crop, the growth curve was 

 scaled so that the pinch height on August 5 was b.75 

 inches, and the final target height at shipping on No- 

 vember 8 was between 16 and 19 inches. 



If you have more than one shipping date or culti- 

 var, you will need to make several graphical track 

 curves. Each graph will apply to a group of plants 

 that has the same pinching and shipping date, culti- 

 var, and temperature and light control location in 

 your greenhouses. 



person measure each time and measure the same 

 plants (as long as they continue to represent the av- 

 erage crop height) to keep your monitoring as consis- 

 tent as possible. 



If sample plants are touched regularly during mea- 

 surement, they will elongate more slowly than the 

 rest of the crop, so make sure you are not inadvert- 

 ently adding an extra height control to your sample! 



Use a yardstick to measure total plant height, in- 

 cluding the pot. We recommend making a crossbar 

 that slides over the yardstick. The crossbar can be 



Step 2. Monitoring the crop. 



Once or twice a week dur- 

 ing the production season, 

 measure plant height from 

 a sample of at least five 

 plants for each graph. 

 Make this regimen part of 

 the regular work plan so 

 that, for example, every 

 Monday and Thursday, an 

 employee measures 



heights and plots them on 

 the graph. The sample 

 plants should be spread 

 out across the area the 

 crop occupies and should 

 represent the average crop 

 height. Have the same 



Figure I. An example 

 graphical tracking curve for 

 a pinched poinsettia crop. 



OCTOBER 8. NOVLMBER 



