Cost effectiveness of selected post harvest pod handling techniques against damage, mouldiness and aflatoxin contamination of shelled groundnut in Ghana

2007

English

Some post harvest pod handling methods were evaluated at Ejura and at KNUST, Kumasi to determine the costs and effectiveness of the methods in minimising post harvest damage, mouldiness and ajlatoxin (AF) contamination of shelled groundnut. The study was conducted in 2002 (dry season) and repeated in 2003 (wet season). four treatments were imposed on pods from I 80 m2 plots at harvest. The treatments were (i) inverted windrowing (lwk) followed by drying of the pods on mats (3wk) (ii) random windrowing (Iwk) followed by drying of the pods on mats (3wk) (iiiJ stripping and drying of pods on mats (4wk) and (iv) storage of pods without drping (control). Costs involved in carrying out the treatments were estimated. Fungi associated with the kernels and AF levels were also determined at harvest and at 4 weeks. In both seasons, Aspergillus niger wa,,· the most common fungus as:-wciated with kernels at harvest and after the 4 wk pod handling periods. Aspergillus Jlavus was also encountered at both periods. When pods were dried for 4 wk, the amounts of damaged/mouldy ones that were rejected were low (2. 7-13.1%; av. 8.6 %) compared with undried p{}[ls where 18.9-25.94% (av. 22.08%) were rejected. Ajlatoxins were not detected in kernels at harvest and generally, dried pods had lower levels of AFs (0 0. 7µglkg) than the un­dried control pods (7278.lµglkg). Visibly healthy pods .,·orted from the dried lots had kernel AF levels of 0.2 0.6µglkg which were similar to the 0 0. 7µglkg levels associated with the unsorted ots. Sorting, however, cost an extra ¢31,354/100 kg lot (¢8,200 = $ USI), making the practice un­economical for well dried pods. Total cost of pod drying up to 4 wk was the same for the random and the inverted windrowed crops (¢89,980/100 kg pod) but was ¢95,440 when pods were dried on mats immediately after stripping. When pods were not dried, cost of handling was ¢69,600/100 kg pods but due to the high AF contamination (7278.lµglkg), kernels from such pods constitute total loss. Thus, both windrow and mat drying of groundnut pods are cost effective in controlling dam­age/mouldiness and AF contamination but costs are lower when windrowed.

Amoako-Attah, I.; Awuah, R. T.; Kpodo, K. A.; Fialor, S. C.; Jolly, C. M.