Management and Final Disposal of Mango Waste in the State of Guerrero , Mexico : A Brief Review

One fruit trees crops with largest amount in Mexico is the mango (Mangifera indica L.). In 2017, Guerrero was the state with the highest production in the country. However, the waste generated after harvesting represents an environmental problem caused by high production and low opportunity in the national and international markets. Nowadays, there is no environmental policy to regulate this final waste disposal. Regularly, post-harvest waste has no value and most of the time, its disposal is inadequate. The lack of training and management knowledge, separation and use, has generated an imbalance in the environment, caused by inadequate elimination practices and excessive use of pest prevention activities, known as cultural control. The main objective of this review was to know about mango production in Guerrero State, its final disposal after harvest and the environmental impact generated by cultural control use.


Introduction
Pollution in the world is attributed to different actions.However, the base is found in the excessive use of natural resources, the lack of environmental education and anthropogenic activities.Nowadays, the final disposal inadequate of waste has generated environmental and health problems.
Agriculture in Mexico is an important productive sector.Its participation in the economic, social and environmental branch determines its greatest impact on the development of the country.For that reason, one of the long-term goals is the conservation and use of natural resources and environmental sustainability.Agricultural waste or byproducts represent an environmental problem, due to the lack of policies for its adequate management and final disposal (Quispe Limaylla, 2015).
The agricultural farming activities generate organic waste whose indiscriminate disposal can be prejudicial to the environment (De Sousa Oliveira et al., 2018).In Mexico, agricultural waste represents an environmental problem, because there are no adequate management practices, and most of the time, they are thrown into uncontrolled sites.The waste is converted into large volumes and only part is reused in the production of animal food, in the production of handicrafts and composting (Sumaya- Martínez et al., 2012).It is necessary to increase the exploitation of agricultural waste and to promote multidisciplinary work to generate research that helps to visualize opportunities and develop new products and innovate from them.

Mango Production
Mango (Mangifera indica L.) fruit belongs to the family of Anacardiaceae in the order of Sapindales and it is grown in many parts of the world (Jahurul et al., 2015).Mango farming is limited to tropical and subtropical climatic zones, its optimum growth temperature goes from 24 to 27 °C approximately and the soil water content is essential to the early development of mango fruit.Water supply is most critical during the first 42 days, of the fruit's development; drought can induce late-stage fruit dropping and reduce fruit mass via decreased size (Wei et al., 2017).
Although this fruit comes from India, it is now grown in almost all tropical and subtropical agroecosystems of the world.Around 95 countries have commercial plantations that produce 30 million tons, out of which the majority is consumed internally and only 3% is exported.Asian countries harvest 77% of world's production, Latin America contributes 13% and other producers contribute the remaining 10% (FAOSTAT, 2016).
The countries highlighted by their high production are India, China, Thailand, Indonesia, Mexico, the Philippines and Pakistan.However, mango production is growing outside traditional regions, such as Central America, South America, Australia, Southeast Asia, Egypt, Israel, among others (Tharanathan et al., 2006).The mature fruit is considered an excellent vitamins' C, B1, B2 and provitamin A source (Mukherjee & Litz, 2009).In addition to this, the mango pulp is rich in fermentable sugars and dietary fiber (Giraldo et al., 2007;Ajila & Rao, 2013).

Mango Production in Mexico
Fruit mango trees represent in Mexico a very important economic opportunity due to its high production per planted hectare.In 2017, the mango ranked fourth in fruit trees most planted and the fifth place in production, (Table 1).Source: SAGARPA-SIAP, 2018.
In Mexico, mangoes grow at an average altitude of 450 meters above sea level, they need an annual rainfall of 1200 to 1500 mm, temperatures between 24 and 27 °C, deep textured soils, drained and with pH 6.0 to 8.0.For this reason, the largest mango production volumes are located in the coastal states (Figure 1), one in every 25 mangoes consumed in the world is Mexican (SAGARPA-SIAP, 2018).

Economic Importance Pests in Guerrero State
The most important problems in Guerrero's fruit crops are caused by pests.They affect the production and the economic costs to the producer.Some of the most common pests in the orchards are the fruit fly, scale, thrips and mites (Duran-Trujillo et al., 2017).The fruit fly is considered one of the 10 most economically important agricultural pests in the world.The genus Anastrepha (Diptera: Teptitidae) is endemic to the new world and it is restricted to tropical and subtropical environments.It is distributed from south of the United States to north of Argentina; including most of the islands of the Caribbean.To date, they are 195 species described out of which, the most economically important are: Anastrepha ludens L., Anastrepha obliqua (Macquart), Anastrepha serpentina (Wiedemann) and Anastrepha striata (Schiner).They affect more than 30 species of fruit trees that are grown for commercial purposes and 60 that grow on a smaller scale (Munro-Olmos et al., 2008).
In Guerrero State, several programs and strategies have been applied to eradicate the fruit fly (Anastrepha spp), the most important regional program in phytosanitary control was "Moscamed" being (SENASICA, 2010).However, the program did not have any appropriate functions, because the effect of physiological maturity of fruit is was not considered, which can be determinant for the success of infestation and the development of insect larvae inside the fruit.
Fruit fly infestation has led to large losses in the yield and quality of fresh fruits and quarantine restrictions has made markets sensitive throughout the world.The lack of knowledge and limited awareness of stakeholders throughout the mango value chain is what generates an economic impact, lack of management strategies and knowledge of species (Billah et al., 2015).

Cultural Control Application
At present, it is not possible to exploit the fruit of mango with high yields and competitive prices without the use of protective measures, among which, chemical pesticides continue to have a considerable participation (Noriega-Cantú et al., 2014).The fruit orchards are very susceptible to pests, since the fruits are rich in nutrients that help the growth of bacteria, fungi, flies and native fauna.Producers usually use chemicals (fumigations), biologicals control (fungi or modified insects) and cultural controls to mitigate or prevent them.
The cultural control consists of eliminating the fruit or the tree that presents the anomaly, to reduce the infestation percentage caused by the pests.If the farmer correctly applies the control, he can reduce 50% the flies presence (Noriega-Cantú et al., 2014).However, the excessive use of pesticides is generating microorganisms resistance, soil deterioration and water pollution, modifying the life quality of people's quality of life and generating impact in all trophic chains.
To apply cultural control, one must know the host, the pathogen and the climate; that is, the mango growth phases, epidemiological studies of the pathogen and climatological information, as well as the susceptibility of the cultivate, which indicates that the application of contact products with preventive character makes a lot of sense to diminish the pathogens.
In the State of Guerrero, cultural control is mostly used due to its low cost.These activities are applied in the fruits' harvest when farmers detect the presence of pests accumulated in the fruits, they spray with insecticide or incinerate all trees (Rodríguez et al., 2002;Acosta et al., 2003;Mukherjee & Litz, 2009).These practices alter habitats to create less suitable environments for pests but directly affect all ecosystems (Jenkins and Isaacs, 2014).

Alternatives for the Use of Mango Waste
One of the main factors that does not allow the economic sector's competitiveness of the mango system and its wastes, is the lack of innovation products with added value to diversify the industrialized mango market and to value the waste generated in each one the stages of its productive chain.
Nowadays, mango wastes have little impact in the industry; only a few of the producers take advantage of waste to obtain new products.However, there is a sector committed to innovation products from waste.Currently, mango pulp in green physiological state and cotyledons, are used to obtain starch; a biopolymer very useful in obtaining biodegradable plastics, in the cosmetic and food industry (Martínez et al., 2010;Lorenzo-Santiago et al., 2017).The fibrous endocarp as cellulose source, is used as a reinforcement for biodegradable films and, in order to obtain paper (Cordeiro et al., 2014;Lorenzo-Santiago et al., 2016); the peel contains pectin and it is used as natural thickeners in food industry (Serna-Cock & Torres-León, 2015).In addition, mango byproducts are used as raw material in the production of reducing sugars, microbial biomass, organic acids production and to obtain alcohols (Giraldo et al., 2007).
Other alternatives for the use of agricultural residues, is the obtaining of bioplastics or biomaterials composed of natural polymers and biomass (Rubio-Anaya & Guerrero-Beltrán, 2012).These could offer some solutions to solve environmental problems, among them contamination by plastic waste that threatens all ecosystems, among them, being the oceans the most affected (O'Brine & Thompson, 2010;Webb et al., 2012).

Conclusions
The use of agricultural waste as a source to obtain biodegradable materials would provide benefits from waste and reduce the impact generated by the intentional burning and excessive use of pesticides as cultural control.For this reason, it is necessary to determine the number of tons of waste that is generated before and after the harvest, as well as the production of waste generated by orchards that are not in the SAGARPA registry and thus, to be able to influence the normative to help reduce the impact generated by the inadequate disposal of these wastes.

Table 1 .
Fruit crops with higher production per planted hectare in Mexico . It is estimated 2.40% annual growth in Mexico from 2016 to 2030 (SAGARPA-SIAP, 2017).Manila variety occupies the largest planted amount in Mexico.However, a small volume is exported.Its consumption is local because it has a very short shelf life.
jas.ccsenet.Source: SA 2.2 Mango org AGARPA-SIA o Production in oduction in Gu (Figure 2).The r.The region w covered with 4 8.3, 5.2 and 0 n Guerrero Sta uerrero State is e harvest begin with the highest 46.6% area wit .6%,respectiv Figure 2. M 11.Journal of A ure 1. States pr ate s in the econom ns in February t production an th Ataulfo vari vely.