Small Hot Water Treatment (SSHWT) Units for Fruit Fly Control Installed at Six Mango Farm Clusters

Pakistan with the production of almost two million tons of juicy, sweet and fragrant mangoes is the sixth largest producer in the world. In 2014 Pakistan exported over 77,000 tons of mangoes valued at US $ 41 million. Every year Pakistan exports only around 5% of its production and almost 40% of the produce is wasted due to numerous reasons.

One cause of the wastage is infestation by fruit flies. Since fruit flies are classified as “quarantine insects’, the whole consignment may be rejected and totally destroyed, if even a single fruit infested with fruit fly larvae is detected.

Mango consignments found infested are intercepted, confiscated and destroyed in incinerators at the European ports of entry, thereby causing major economic losses for many exporters and the entire mango sector – the main economic generator for the Pakistani horticultural exports. The local and regional mango markets may also be deeply affected by this issue.

As a member of the WTO – and therefore in order to meet its commitment to comply with the Sanitary and Phytosanitary Agreement – and in order to protect its exports, Pakistan is expected to demonstrate its best efforts in managing and controlling the fruit fly.

The idea to use the SSHWT to control the fruit fly infestation was conceived during the EU/TRTA II/UNIDO sponsored training of researchers from the Mango Research Station (MRS) and Citrus Research Institute (CRI) on Postharvest Technology Management and Extension (Mango and Citrus) at the Post Harvest Training and Research Centre, University of the Philippines from 6-15 April 2014. There, the researchers observed and discussed the use of HWT in the mango farming communities of Philippines and were impressed by the adaptation of this simple technology by the local growers.

TRTA II programme supported MRS to prepare a model SSHWT unit which could be replicated. The researchers of MRS with the help of TRTA II experts modified the SSHWT unit according to the requirements of Pakistani mango.

In Pakistan, most of the rural farmers do not have access to the commercial facilities for the HWT therefore; do not treat the mangoes to increase shelf life. This is one of the reasons for mango wastage. The growers have small land holdings, so they cannot afford to establish and maintain the commercial facilities for the HWT. In this situation the small-scale extended Hot Water Treatment (HWT) unit being used in the Philippines is a very viable alternative.

This simple Hot Water Treatment unit has the ability to control the fruit fly infestation by killing its eggs and maggots if they are present inside the fruit. It is a very simple unit with a heating source, fruit holding tank and water circulation unit. It eradicates the fruit fly infestation and as a result the post-harvest losses are minimised.

The design of the SSHWT unit is based on simple concepts of heating water in a tank and submersion of the fruit in water for the required temperature and duration. Water is heated by portable Liquefied Petroleum Gas (LPG) cylinders and circulated by a manual or simple motor. Any further and elaborate configuration of the equipment design could be added and this would be left to the needs of the ‘grower-users’ and their analysis of its impact on the quality of mango.

The TRTA II experts held meetings with MoC, MNFS&R, Trade Development Authority of Pakistan (TDAP), Pakistan Agriculture Research Council (PARC) and National Agriculture Research Centre (NARC) to present and promote the proposal for the introduction of small scale HWT unit with a capacity of 200-250 Kg/hour.

Subsequently the MoC and MNFS&R agreed on the initiative as a means to address the on-going issue of fruit flies in mangoes.

MoC through TDAP/EDF has mobilized the funds (US$ 200,000) for the manufacturing of the SSHWT units to be placed at the mango farm clusters receiving TRTA II support.

The SSHWT units have now been installed at the six farm clusters receiving TRTA II support at Vehari, Multan and Rahim Yar Khan. It is expected that in the current season (July – September 2015) these SSHWT units which provide extended HWT will not only be helpful in providing protection against post harvest diseases like Stem End Rot and Anthracnose but also help increase the shelf life of mango by effectively destroying the fruit fly in the infected mangoes. The farmers are in contact with the Department of Plant Protection to certify these SSHWT units for treating the mangoes destined for export.

SSHWT Unit installed at Joiya Farms, Jalalpur, Pirwala-Multan
SSHWT Unit installed at Joiya Farms, Jalalpur, Pirwala-Multan
SSHWT Unit installed at Zarpak Mango Farms & Pack house, Shujabad-Multan
SSHWT Unit installed at Zarpak Mango Farms & Pack house, Shujabad-Multan