Dry weight is that weight that remains constant after drying in sun ie; if we were to consider fresh bio mass, the same is called ‘fresh weight”. Allow this to dry under sun. Weigh it on alternate days. In span of 5 to 7 days when no loss of weight will be observed; that is dry weight.
Q How is this knowledge applied in understanding or calculating the yield of crop?
A. Through experiments and analysis it is understood that plants prepare 3 gms of dry matter/sq ft area of canopy. Out of this
1 gm is utilized by the plant in metabolism activities.
1 gm is uitilised for building branches, roots, leaves etc…
1 gm is uitilised for making fruits
So if we measure the canopy area, we can calculate the dry matter prepared by plant, and thereafter calculate the expected yield.
This knowledge also helps us understand the need of development of a proper canopy, which in turn depends on proper root growth arising out of a nutrient rich live soil.