Grafting in Horticultural Crop Species: Effective Pest and Disease Management Technique with Potential in Michoacan, Mexico

*Juan Carlos Álvarez-Hernández*

## **Abstract**

The grafting technique is an effective alternative in crop management, specifically for the management of pests and soil pathogens; therefore, it has been recognized in all agricultural areas, which makes the a horticultural production technique more respectful with the environment. In general, this technique has been widely used in fruit growing; however, it has also been of great importance in the production of vegetables worldwide. In vegetables, the same principles applied to the grafting of fruit trees are followed, as well as specific requirements, such as controlled climatic conditions and greater care. In Michoacan, Mexico, by the phytosanitary condition in cucurbits, Solanaceae, and Caricaceae, the use of rootstocks with specific resistance characteristics offers an option for the recovery of soils, without repercussion in the environment. Although in Mexico this technique has been little exploited, in Michoacan, it is innovative in crops of Solanaceae, Cucurbitaceae, and Caricaceae. The use of grafted plants helps to improve the conditions of the crop, but also, if this technique is included in a program of integrated management of pests and diseases, it ensures the success of the production.

**Keywords:** approach grafting, cleft grafting, grafting, papaya, rootstock, tomato, watermelon

#### **1. Introduction**

In theory, the graft is the union of two or more pieces of living tissue, which once joined together develops as a single plant [1]. This combination of desirable characteristics consists of the removal of buds of a plant that is called graft and the root that is provided by a plant that is called rootstock [2]. The production of plant grafts has been widely expanded for fruit tree and vegetable crops, and different studies have shown that the success of the crop depends on the rootstock selected when compared with non-grafted plants [3].

In some countries, the grafting technique has been integrated into the scheme of agricultural work as an effective alternative in the management of the crops. Therefore, it has been recognized in all agricultural areas, which makes it a technique of horticultural production more respectful with the environment [4]. With this technique, the tolerance of the root system of the rootstock and the favorable

productive characters of a susceptible variety are used. In vegetables the same principles applied to the grafting of fruit trees are followed, in addition to controlled environment requirements and greater post-graft care. So, the use of similar rootstocks strengthens and gives vigor to plants, therefore keeping nematodes and diseases controlled for longer than a plant that has not been grafted [5, 6].

Although there is evidence that the art of grafting was known to the Chinese from 1000 years ago before Christ [1], the grafting technique has its beginnings in the 1920s in watermelon grafted on pumpkin (*Cucurbita moschata* Duch) as rootstock, to confer resistance to wilt caused by *Fusarium*. Currently this technology is practiced successfully in Cucurbitaceae and Solanaceae in Asia and in Mediterranean countries [7]. The use of the grafting technique has been aimed at improving crops such as fruit trees and vegetables, to get their development under varied agronomic conditions [8]. It improves the resistance of crops to biotic and abiotic stresses such as salinity [9], drought tolerance [10], and nutrient deficiency [11], and this technique can be an important tool to improve fruit quality.

In Mexico, this technique is recent; however, the advantages of using it as a substitute for fumigants can counteract the main phytosanitary problems that limit the production of crops. Otherwise, in the State of Michoacan, like other states of the Mexico, the various contrasts give rise to different production systems, which favor the establishment of different crops. Despite being a predominantly agricultural territory, it has been severely affected by the production system of the monoculture type and the indiscriminate use of agrochemicals, which has caused resistance of pests and pathogens difficult to control by conventional systems. Therefore, among the management alternatives, we can see the use of the graft. Given the phytosanitary situation presented by Cucurbitaceae and Solanaceae in the State of Michoacan, the use of rootstocks with specific resistance characteristics offers an option for the recovery of soils, without repercussion in the environment. As mentioned, in our country this technique has not been fully exploited, in the State of Michoacan, it is new and innovative in the cultivations of Solanaceae, Cucurbitaceae, and Caricaceae.

#### **2. Productive importance of tomato, watermelon, and papaya with graft potential**

Mexico is located in a privileged geographic position, which favors the environmental conditions for the development of different crops in open field, and where the conditions are restrictive, crops are grown in greenhouses. Among the crops of economic importance and with potential of graft are tomato (*Solanum lycopersicum* L.), which is the second most important horticultural crop after potato; watermelon [*Citrullus lanatus* (Thunb.) Matsum. & Nakai], being an herbaceous creeping plant with 6 m in length in its branches and a highly valued product for its quality of freshness, mainly in hot seasons, and palatability in any season of the year; and papaya (*Carica papaya* L.), of the fast growing fruit species that is widespread in tropical and subtropical regions. The annual consumption *per capita* in these species is tomato, 14.3 kg; watermelon, 3.7 kg; and papaya, 6.4 kg [12].

According to SIAP-SAGARPA [13], in the last years at national level, the cultivated area has presented variable trends in tomato and watermelon, with greater amount of hectares cultivated in the year 2010, and as the years pass until the year 2017, they were reduced in 11% and 14%, respectively. However, this trend differs in the total production and the yield per hectare, since percentage of the year 2010 to the year 2017 for the tomato increased 33% and 22%, respectively, and for the

**51**

**Year** **Cultivated area (ha)**

> 2017

2016 2015 2014 2013 2012 2011 2010 **Table 1.**

54,238

2,058,424

42.104 *The trend in tomato, watermelon, and papaya areas of cultivation, total production, and yield in Mexico country from 2010 to 2017 [13].*

48,667

1,016,215

23.375

16,261

648,235

46.49

56,025

1,670,454

41.758

47,387

1,002,506

25.006

17,142

646,002

44.909

55,504

2,459,874

47.102

38,288

1,011,667

27.307

16,725

680,204

49.241

44,504

2,052,126

49.101

37,482

937,378

26.086

15,952

734,522

51.542

50,850

2,320,109

48.777

35,511

955,186

28.092

16,071

840,497

57.445

49,530

2,570,284

56.077

36,197

1,003,213

28.71

17,530

48,840

2,769,611

59.336

39,903

1,129,219

30.544

19,442

957,415 879,363

56.895

48,394

3,055,861

64.832

42,105

**Total production (t)**

**Yield (t·ha−1**

**Cultivated area** 

**Total production** 

**Yield** 

**Cultivated area** 

**Total production** 

**Yield** 

**(t·ha−1**

**)**

**(t)**

964,702

57.82

**(t·ha−1**

**)**

**(ha)**

**(t)**

1,296,767

32.015

19,114

**)**

**(ha)**

**Tomato**

**Watermelon**

*Grafting in Horticultural Crop Species: Effective Pest and Disease Management Technique…*

55.426

*DOI: http://dx.doi.org/10.5772/intechopen.89288*

**Papaya**



*Grafting in Horticultural Crop Species: Effective Pest and Disease Management Technique… DOI: http://dx.doi.org/10.5772/intechopen.89288*

*Horticultural Crops*

quality.

Cucurbitaceae, and Caricaceae.

**potential**

productive characters of a susceptible variety are used. In vegetables the same principles applied to the grafting of fruit trees are followed, in addition to controlled environment requirements and greater post-graft care. So, the use of similar rootstocks strengthens and gives vigor to plants, therefore keeping nematodes and

diseases controlled for longer than a plant that has not been grafted [5, 6].

Although there is evidence that the art of grafting was known to the Chinese from 1000 years ago before Christ [1], the grafting technique has its beginnings in the 1920s in watermelon grafted on pumpkin (*Cucurbita moschata* Duch) as rootstock, to confer resistance to wilt caused by *Fusarium*. Currently this technology is practiced successfully in Cucurbitaceae and Solanaceae in Asia and in Mediterranean countries [7]. The use of the grafting technique has been aimed at improving crops such as fruit trees and vegetables, to get their development under varied agronomic conditions [8]. It improves the resistance of crops to biotic and abiotic stresses such as salinity [9], drought tolerance [10], and nutrient deficiency [11], and this technique can be an important tool to improve fruit

In Mexico, this technique is recent; however, the advantages of using it as a substitute for fumigants can counteract the main phytosanitary problems that limit the production of crops. Otherwise, in the State of Michoacan, like other states of the Mexico, the various contrasts give rise to different production systems, which favor the establishment of different crops. Despite being a predominantly agricultural territory, it has been severely affected by the production system of the monoculture type and the indiscriminate use of agrochemicals, which has caused resistance of pests and pathogens difficult to control by conventional systems. Therefore, among the management alternatives, we can see the use of the graft. Given the phytosanitary situation presented by Cucurbitaceae and Solanaceae in the State of Michoacan, the use of rootstocks with specific resistance characteristics offers an option for the recovery of soils, without repercussion in the environment. As mentioned, in our country this technique has not been fully exploited, in the State of Michoacan, it is new and innovative in the cultivations of Solanaceae,

**2. Productive importance of tomato, watermelon, and papaya with graft** 

Mexico is located in a privileged geographic position, which favors the environmental conditions for the development of different crops in open field, and where the conditions are restrictive, crops are grown in greenhouses. Among the crops of economic importance and with potential of graft are tomato (*Solanum lycopersicum* L.), which is the second most important horticultural crop after potato; watermelon [*Citrullus lanatus* (Thunb.) Matsum. & Nakai], being an herbaceous creeping plant with 6 m in length in its branches and a highly valued product for its quality of freshness, mainly in hot seasons, and palatability in any season of the year; and papaya (*Carica papaya* L.), of the fast growing fruit species that is widespread in tropical and subtropical regions. The annual consumption *per capita* in these spe-

According to SIAP-SAGARPA [13], in the last years at national level, the cultivated area has presented variable trends in tomato and watermelon, with greater amount of hectares cultivated in the year 2010, and as the years pass until the year 2017, they were reduced in 11% and 14%, respectively. However, this trend differs in the total production and the yield per hectare, since percentage of the year 2010 to the year 2017 for the tomato increased 33% and 22%, respectively, and for the

cies is tomato, 14.3 kg; watermelon, 3.7 kg; and papaya, 6.4 kg [12].

**50**

