N. M. G. S. B Navaratne, M. D. S Anjalo
Abstract: To monitor respiratory climacteric behavior of grains due to global warming, a study was conducted using paddy, green gram, corn and cowpea at initial moisture contents of 10.9 %, 8.6 %, 8.9 % and 10.6 % respectively. These grains were packed in gunny and poly sack bags in 5kg separately and placed in four temperature controlled insulated chambers where inside temperatures were maintained at 40, 270 (Ambient), 350, 400 & 450C respectively. Thereafter, moisture content and 1000 grain weight of each commodity were taken for every 15 days intervals with three replicates in order to calculate dry matter loss against period of storage, stored temperature and type of packing materials. After 4 months of storage, the dry matter loss of paddy in poly sacks and gunny at 40, 270, 350, 400 & 450C temperatures were 3.07 %, 4.46 %, 5.38 %, 5.30 %, 5.61 % and 2.35 %, 2.54 %, 4.03 %, 4.72 %, 5.22 % respectively. In the case of corn these losses were 6.69 %, 6.80 %, 6.89 %, 8.35 % and 9.22 % and, 7.12 %, 7.12 %, 7.76 %, 8.88 % and 9.89 % respectively. For green gram, they were 6.42 %, 6.76 %, 7.03 %, 6.78 %, 6.90 % and 6.44 %, 7.40 %, 7.79 %, 7.41 %, 7.31 % respectively and for cowpea which was 4.22 %, 8.96 %, 9.17 %, 9.26 %, 9.63 % and 5.97 %, 9.91 %, 9.99 %, 10.17 %, 11.22 %. Since, dry matter loss of paddy, green gram, corn and cowpea were occurred on 3 variables, a regression analysis was performed to formulate a quantified relationship. Paddy stored in gunny bags shows less dry mass loss because; thick seed coat of paddy acts as a heat insulator and contributes to accumulate heat during respiration. Hence, paddy needs a porous type of packing material like gunny to flush out buildup heat. Whereas, other types of grains need tight and less porous packing like poly sack to prevents direct contact of atmospheric oxygen with thin seed coat which facilitates to high rate of respiration.
Keywords: Global Warming, climacteric behavior, Dry matter loss, Poly sack, Gunny, Paddy, Greengram, cowpea, corn