The effect of delayed harvest on moisture content, insect damage, moulds and aflatoxin contamination of maize in Mayuge district of Uganda

Abstract

Field drying is a traditional practice carried out by farmers in Uganda and it is one of those practices reported to affect the postharvest quality of maize. A study was therefore conducted to establish the effects of delayed harvest on moisture content, insect damage, moulds and aflatoxin contamination of maize in Mayuge district. Sixteen farmers were selected from Bayitambogwe sub-county, eight from each of the villages of Bugodi and Musita. Maize was sampled from each farmer's field in 2003B and 2004A seasons at harvest stages of physiological maturity and after delayed harvest for 1, 2, 3 and 4 weeks. Each sample was analysed for mould incidence, moisture content, insect damage and aflatoxin contamination. In each season, mould incidence, insect damage and aflatoxin levels significantly (P < 0.05) increased with delayed time of harvest. Moisture content reduced with delayed harvest time but the maize did not dry to the required safe storage moisture content of ≤15%. Seasonal effects were only significant for moisture content: the 2003B crop had consistently lower moisture content than 2004A crop. These results indicate that, for improved harvest quality of maize, farmers should harvest no later than 3 weeks after maize has attained physiological maturity.

Aspergillus species and Aflatoxin Contamination of Pre and Post- Harvest Maize Grain in West Gojam, Ethiopia

“…These results were also higher than reported in Kenya which was 22.97% of total aflatoxin contamination in pre-harvest maize [21]. The high total aflatoxin contamination in pre-harvest may be due to delayed harvesting (high likelihood of kernel damage by pests, insect injury), differences in temperature, humidity, using crop resistance variety, crop rotation system and maintaining adequate irrigation schedule [18]. Genotype, soil types, drought and insect activity are also important in determining the likelihood of pre-harvest contamination [1].…”

“…Extended field drying of maize increased insect infestation and fungal contamination. Aflatoxin levels increased by about 4 times by the third week and more than 7 times when maize harvest was delayed for 4 weeks [18].…”

“…Which means total aflatoxin level was significantly increase from pre-harvest to post-harvest pre-harvest maize. The reasons for high increment of aflatoxin level in post-harvest may be poor harvest and post-harvest practices of the maize [18,21] and once the crop becomes infected under field conditions, the fungal growth continues with increasing at post-harvest and storage conditions [23].…”

Aflatoxins in Mozambique: Etiology, Epidemiology and Control

“…This line of research was not new [37,38] but it was a good initiative to reproduce in the Mozambican context to see what would happen. Harmsen et al [4] commented on the storage techniques, suggesting jutting bags rather than plastic.…”

<b>Harvest time and agronomic performance of maize hybrids with contrasting growth cycles

“…The grain yield and seed quality are potentially higher when the harvest is carried out right after physiological maturity (Araujo, Araujo, Sofiatti, & Silva, 2006;Marques, Dalpasquale, Vidigal Filho, Scapim, & Reche, 2011;Galvão, Conceição, Araújo, Karstein, & Finger, 2014). However, when maize grains are stored in the field and harvested with less than 20% moisture content, they may lose weight due to respiration (Kaaya, Warren, Kyamanywa, & Kyamuhangire, 2005;Lauren, Smith, & Di Menna, 2007). In addition, the removal of grain with low moisture from the field promotes mechanical damage at harvest.…”