Effect of Microwave Power and Time on Total Phenolic Contents and Antioxidant Characteristics of Microwave Assisted Extracts of Watermelon Rind Powder Microwave Assisted Extracts of Watermelon Rind Powder

Watermelon is gaining importance as a functional food due to its therapeutic effect. The therapeutic effect of watermelon has been reported and has been attributed to antioxidant constitutes. The major component in watermelon rind is citrulline that has a strong antioxidant effect which protect body from free-radical damage. Objective: This study was conducted to investigate the effect of microwave powers (150 W, 300 W & 450 W) and time intervals (1, 3 & 5 minutes) on total phenolic content (TPC) and total flavonoid content (TFC) and antioxidant characteristics i.e. DPPH and ferric reducing antioxidant potential (FRAP) of microwave assisted extracts of watermelon rind powder. Methods: The extracts collected after Microwave assisted extraction (MAE) of watermelon rind wereanalyzed for their antioxidant potential through different tests including total phenolic contents (TPC), total flavonoid content (TFC), DPPH assayand FRAP. Results: Microwave assisted extraction by using ethanol as a solvent at different microwave powers and various time intervals showed that total antioxidant potential was significantly higher at low microwave power such as TPC ranges obtained at 150W for 1, 3 & 5 minutes of time intervals show ranges (159.84, 160.04 & 169.71 mg GAE/100 g). While TFC ranges at 150W for time 1, 3 & 5 minutes were (21.31, 24.15 & 42.20 mg CEQ/100g) whereas DPPH ranges at 150W for time 1, 3 & 5 minutes were (53.14, 54.87 & 68.17 % ascorbic acid inhibition) and FRAP values at 150W for time 1, 3 & 5 minutes were (201.71, 221.50 & 326.43 mg FE/100g). While high microwave power 450W can result in disruption of some antioxidants at various time intervals. Conclusions: Watermelon rind is a rich source of many antioxidants andmicrowave assisted extraction technique should be implemented in the food and nutraceutical industries and microwave assisted extracts of watermelon rind should be utilize for the development of new functional food to combat many health related problems

Wheat Productivity under Different Inputs and Crop Establishment Techniques in a Rice-Based Cropping System

Rice-wheat cropping system (RWCS) has been the major production practice in NWFP, Pakistan. Late sowing of wheat in a conventional way after late harvest of rice reduce wheat yield. The objective of this study was to determine the effect of various tillage techniques on wheat productivity in combination with herbicides, N fertilizer levels and seed rates under RWCS. Three field experiments were carried out on wheat at Agronomic Research Farm, Faculty of Agriculture, Gomal University, D.I.Khan, Pakistan in 2007-08 and 2008-09. In experiment I, five herbicides (2,4-D ester @ 1.25 L ha-1, Puma supper 75 EW @ 1.25 L ha-1, 2,4-D + Puma supper 75 EW @ 1.25 L ha-1 each, Affinity 50 WDG @ 2 kg ha-1, and control) and three tillage techniques [zero (ZT), reduced (RT) and conventional tillage (CT)] were studied. In experiment II, five nitrogen levels (0, 80, 120, 160, and 200 kg N per ha) and three tillage techniques (as in experiment I) while in experiment III, four seed rates (70, 100, 130, and 160 kg per ha) and three tillage techniques (as in experiment I) were evaluated in RCB design with split plot arrangement replicated 4 times. Tillage was allotted to main plots in all the 3 experiments while herbicides, N levels and seed rates were applied to subplots in experiment I, II & III, respectively. Herbicides and tillage alone or in combination significantly influenced weeds density per m2, fresh and dry weed biomass (FWB & DWB), leaf area per tiller, leaf area index (LAI), plant height, spike length, tillers per m2, spikes per m2, grains per spike, 1000 grain weight, biological yield (kg per ha), grain yield (kg per ha), harvest index % (H.I), net benefit and benefit cost ratio (BCR). Higher leaf area per tiller- (141 cm2), LAI (3.4), plant height (88.2 cm), spike length (11.5 cm), tillers per m2 (237.7), spikes per m2 (228.1), grains per spike (72.4), 1000 grains weight (46.2 g), biological yield ( 15492 kg per ha), grain yield (6906.9 kg per ha), H.I (44.6%), net benefit (Rs.124824 per ha) and BCR (6.3:1) were recorded from Affinity. Maximum weeds density per m2 (75.5), FWB (845.3 g per m2) and DWB (220.4 g per m2) were recorded in control. The highest net benefit (Rs.98069 per ha) and BCR (5.5:1) were obtained from ZT, while maximum tillers per m2 (222.2), spikes per m2 (212.8), biological yield (13617 kg ha-1) and grain yield (5583.8 kg ha-1) were obtained from RT. Maximum H.I (43.3%), weeds density per m2 (48.3), FWB (536.6 g per m2) and DWB (136.5 g per m2) were observed in CT. In experiment II, N and tillage alone or in combination had significant effect on leaf area per tiller, LAI, plant height, tillers per m2, spikes per m2, grains per spike, 1000-grain weight, biological yield (kg per ha), grain yield (kg per ha), H.I, net benefit, BCR, N agronomic efficiency (AE), physiological efficiency (PE) and N recovery efficiency (RE). Maximum leaf area per tiller (132.9 cm2), LAI (4.0), plant height (90.8 cm), spike length (10.6 cm), tillers per m2 (305), spikes per m2 (294.8), grains per spike (63.8), 1000-grain weight (42.4 g), biological yield (20777 kg per ha), grain yield (6844.6 kg per ha), net benefit (Rs.121163 per ha) and BCR (5.7:1) were recorded from 200 kg N per ha, while maximum AE (27.1 kg per kg) and RE (56.8 %) were recorded from 160 kg N per ha. Maximum PE (49.7 kg kg-1) was recorded from 120 kg N per ha, while maximum H.I (37.3 %) was recorded from 0 kg N ha-1. Maximum leaf area per tiller (111.8 cm2), LAI (3.0), spike length (9.8 cm), tillers per m2 and spikes per m2 (255.4) were recorded from ZT, while plant height, grains per spike, 1000-grain weight, biological yield, grain yield, H.I, net benefit, BCR, nitrogen AE, PE and RE (%) were not significantly influenced by tillage. Relative grain yield (95 %) was recorded at 180, 160 and 150 kg N per ha for ZT, RT and CT, respectively. In experiment III, seed rates and tillage alone or in combination had significant effect on leaf area per tiller, LAI, spike length, tillers per m2, spikes per m2, grains per spike, 1000-grain weight, biological yield (kg per ha), grain yield (kg per ha), H.I, net benefit and BCR. Maximum leaf area per tiller (110.9 cm2), spike length (10.1cm), grains spike-1 (57.2), 1000-grain weight (44.5 g) and H.I (38.4 %) were recorded at 70 kg per ha seed rate, while maximum LAI (2.5), tillers per m2 and spikes per m2 were recorded at highest seed rate of 160 kg per ha. Maximum biological yield (13463 kg per ha), grain yield (4844.9 kg per ha), net benefit (Rs. 81454 per ha) and BCR (4.4) were recorded at 130 kg ha-1 seed rate. Maximum LAI (2.4), tillers per m2 (237.8), spikes per m2 (232.5), biological yield (12723 kg per ha), grain yield (4654.6 kg per ha) and net benefit (Rs.78190 per ha) were obtained from RT, while maximum BCR (4.4) was recorded from ZT. CT and ZT produced similar spike length (9.6 cm). Tillage showed non significant effect on leaf area per tiller, plant height, grains per spike, 1000-grains weight and H.I. Relative grain yield (95%) for ZT, RT and CT was obtained at 95, 89 and 117 kg per ha, respectively. It is concluded that affinity was the most effective against broad leaf and grasses in combination with ZT and resulted in highest net return. ZT was more economical at higher N compared to RT or CT. ZT at 130 kg per ha seed rate resulted in the highest BCR and net return. ZT and RT performed better than CT.