testing a new nutrient line
Then , divide the amount harvested by each plant by the number of days it took to grow them to calculate the grams per day ( GPD ) produced . For example , a plant that harvested 35 grams after a 70-day season produced an average of 0.5 GPD . A plant that harvested 30 grams after a 60-day season also produced 0.5 GPD , so this method allows for the comparison of harvests from the lengths of different seasons . If the only concern is to maximize production , then simply compare the average GPD of the control group versus the average of the experimental group . Whichever method results in a higher GPD is more productive ( within the margin of error ). If the control group produced an average of 0.5 GPD and the experimental group produced an average of 0.75 GPD , the experimental group would have been more productive .
“ PRODUCTION improvements are indicated by an increase in the average amount produced per day for the duration .”
OTHER FACTORS TO CONSIDER
If expense is a concern , it can be factored in as well . Dividing the total cost of the nutrients used by the total number of days will give an average cost per day . If a gardener spends $ 140 over a 70-day grow , then they are spending $ 2 a day on nutrients . Dividing that number by the number of plants gives the amount spent on each plant per day . If an average of $ 2 a day on nutrients is spent to feed 20 plants , then each plant costs an average of 10 cents a day in nutrients . Comparing the GPD and the cost of nutrients can give a clearer picture of the expense versus the return . An increase in the daily cost of nutrients should be at least matched with an increase in production to be cost-effective . Which is to say , any increase in price should be covered by enough additional harvest to offset the difference in cost . Other improvements , such as the quality of flavor , may be less tangible and more subjective . Blind testing can help minimize bias when judging differences . To set up a blind test , start with an identical container for each sample . Have an assistant who won ’ t be involved with the evaluation prepare the samples . Have them write the identity of the sample on a small piece of paper , 84 grow cycle