Mathematical modeling on tomato plants: A review

Download *pdf C. A. Medina-Ruíz, I. A. Mercado-Luna, G. M. Soto-Zarazúa and I. Torres-Pacheco and E. Rico-García*   Department of Biosystems, School of Engineering, Queretaro State University, C.U. Cerro de las Campanas, Querétaro, México. *Corresponding author. E-mail: ricog@uaq.mx  or garciarico@yahoo.com.mx.  Tel: (52) (442) 1921200 ext. 6016. Fax: (52) (442) 1921200. Ext: 6015. Accepted 31October, 2011

Abstract

Mathematical models allow for predictions of behavior under specific handling and environmental conditions, and are particularly useful in expensive studies or in studies where long term effects may be difficult to monitor. In mathematical modeling there are two main types of models: descriptive models and mechanistic models; the first are relationships between response and predictor which are not ruled by biological processes; the latter takes into account the basic processes in plants by means of differential equations to account for the development of plants. This requires a deeper knowledge of the physiological development of plants. This work reviews mathematical modeling on tomato plant. The TOMGRO model is modular and has been widely studied and calibrated under several climatic conditions which demonstrates that it is a robust model. As a future research the TOMGRO model is proposed to be adapted to other crops.   Key words: Differential equations, descriptive models, mechanistic models.

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Organic Philosophy

In the 1990 Farm Bill, the Organic Foods Production Act invested the U.S. Department of Agriculture with the power to set up a National Organic Program that determines the standards that organic food producers must meet and enforces compliance with those regulations. Organic agriculture standards apply to plant- as well as animal-based farming. 

Organic Philosophy 

In 1995, the USDA's National Organic Standards Board defined organic agriculture as practices aimed at promoting the health of the whole ecosystem rather than a single crop or livestock animal within that system. Organic practices, according to the NOSB, should increase biodiversity, respect biological processes, improve soil quality and make minimal use of off-farm inputs, all with the ultimate goal of improving ecological health. These ideas guide organic agriculture regulations.

Fertilizers and Pesticides 

With few exceptions, the National Organic Program forbids the use of synthetic products in fertilizers and pesticides. Instead, organic regulations require farmers to use soil fertility management practices that enhance soil health without harmful contaminants. Organic standards permit the use of plant- and animal-based fertilizers, including manures, ash and cover crops, as well as some minerals. The program encourages crop rotation. Sewage sludge and biosolids are not permitted. For pest control, regulations encourage prevention of problems through crop rotation and plant and soil health. To control pests, organic farmers may use beneficial insects and biological controls; non-synthetic lures, traps and repellents; mechanical removal; burning; and non-synthetic biological, botanical and mineral products.

Organic Seeds 

Organic farmers must use organic seeds or plants unless no organic alternative exists, in which case they may use conventionally grown seeds and plants. Perennial crops labeled as organic, such as fruit trees or asparagus, must have been maintained using organic methods for at least one year.

Livestock Feed and Care 

The feed given to organically raised livestock must also meet certification standards. Organic livestock feed cannot contain growth hormones, antibiotics, manure, slaughter byproducts or plastics. Feed supplements and additives are permitted only if needed to maintain the animal's health at that point in its life cycle. Cattle must be grazed throughout the entire grazing season, totaling at least 120 days. Livestock must also have outdoor access, space to move around and the ability to carry out natural behaviors. Brief confinement is permitted for inclement weather, care and breeding, illness, milking or shearing, shows and sales. The farm must manage all animals' manure in such a way that it poses no risk to the ecosystem.

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Sustainable Palm Oil

Major China-based producers and users of palm oil have committed support for sustainable palm oil, “an important boost for efforts to halt tropical deforestation,” WWF reported today.

The public statement, made at the 2nd International Oil and Fats Summit in Beijing on July 9, committed the companies to “support the promotion, procurement and use of sustainable palm oil in China,’”as well as “support the production of sustainable palm oil through any investments in producing countries.”

China is the world’s largest importer of palm oil, accounting for one third of all global trade.

“Increasing demand for palm oil, which is used in everything from soap to chocolate bars, is causing considerable damage to fragile rainforest environments, threatening endangered species like tigers, and contributing to global climate change,” WWF said.

Palm oil is the most produced vegetable oil in the world, with about 37 million tonnes produced per year around the world, according to WWF.

Although palm oil is a more sustainable source of vegetable oil than other crops such as soy and rapeseed (canola oil), there are concerns that growing global demand for palm oil for food and biofuel could lead to rapid and poorly managed expansion of oil palm production that could have serious environmental and social consequences.

Palm oil producers and buyers signing the statement of support for sustainable palm oil included Wilmar International, IOI Group, KLK Berhad, Kulim Malaysia Berhad, Asian Agri., Premier Foods and Unilever. Oxfam International, TransAsia Lawyers, and Solidaridad China have also signed the statement.

“Given the massive of volumes of palm oil now being purchased, any move China makes towards using sustainable palm oil will have a big influence on protecting tropical forest resources in South East Asia and other areas,” said WWF-China Country Representative Dermot O’Gorman. 

WWF and Unilever helped set up the international Roundtable on Sustainable Palm Oil (RSPO) in 2004, with the aim of establishing global standards for sustainable palm oil production and promoting the use of products containing sustainable palm oil.

A credible standard that defines sustainable palm oil production has been developed and a system for certification and trade mechanisms in certified sustainable palm oil are in place. However, there have been concerns that consumers worldwide have been slow to support products that use certified palm oil.

WWF-China first introduced sustainable palm oil to Chinese companies in 2004, and continues to encourage the country’s buyers, producers, and traders to participate in RSPO, the Switzerland-based environmental organization said.

“Sustainable palm oil received a massive boost in November 2008 when Dr. Huo Jiangguo, President of China Chamber of Commerce for Import and Export of Foodstuffs and Native Produce, attended the RSPO annual conference in Indonesia and announced that China supported the drive for more sustainable palm oil products.”

“Industry in China acknowledges that sustainability is one of the key criteria of ensuring competence in the global market,” said Bian Zhenghu, vice president of the China Chamber of Commerce during his opening address to the forum. “The Roundtable encourages the entire industry chain to make a move towards sustainability, and also gives Chinese stakeholders a big opportunity to play a significant role achieving the aims of RSPO.” 

Statement of Support: Promotion of Sustainable Palm Oil in China

This Statement of Support is a non-legally binding expression of support by the signatories on the promotion of sustainable palm oil in China.

Recognizing that

• China is the largest consumer of palm oil which is an important and versatile raw material for both food and non-food products, including biofuel

• It is important that palm oil is produced in a sustainable manner as defined by the Principles and Criteria of the Roundtable on Sustainable Palm Oil (RSPO)

• Certified sustainable palm oil is now available in commercial quantities The signatories of this Statement of Support commit themselves to

• Support the promotion, procurement and use of sustainable palm oil in China.

• Support the production of sustainable palm oil through any investments in producing countries that are consistent with the principles for sustainable palm oil production, national laws and China’s guidelines for sustainable agriculture.

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