**21. Disease, pest and physiological disorders**

#### **21.1 Diseases**

#### *21.1.1 Powdery mildew and leaf spot*

If left unchecked, this fungus can produce a significant amount of defoliation. It is possible to remove powdery mildew by using commercial pesticide washes and neem oil sprays (Oidium sp.).

#### *21.1.2 Bacterial blast*

It is caused by *Pseudomonas syringae* and *P. solanacearum*. It affects the shoot and leaves. *Anthracnose (Colletotrichum gloeosporioides).*

#### *21.1.3 Anthracnose* (Colletotrichum gloeosporioides)

The damage it inflicts is immense. Good orchard management can help lower the risk of pest and disease control in markets that demand immaculate fruit. As long as the nursery is kept clean, predator insects can reduce the need for chemical pesticides.

#### **21.2 Viral diseases**

#### *21.2.1 Tamarillo mosaic virus (TaMV)*

TaMV symptoms include a mosaic mottling on the leaf and ugly irregular spots on the fruit skin that are a darker red than the cultivar's typical skin color. Inside the fruit, there are no visible symptoms, and the eating quality is unaffected. Due to the milder background color typical of this variety of fruit, the darker red splotch on golden

*Tamarillo (*Cyphomandra betacea *(Cav.)) Origin, Cultivation, Breeding and Management DOI: http://dx.doi.org/10.5772/intechopen.106601*

tamarillos is particularly ugly. The plants grow stunted as a result. TaMV can only be controlled after symptoms occur by removing trees that are seriously infested [79].

#### *21.2.2 Cucumber mosaic virus and potato virus Y*

These not only diminish the plant's strength and health but also distort the leaves, produce skin blemishes, and lower the plant's marketability. They result in fruit mottling and yield loss. The severity of the symptoms will be greater if multiple viruses have simultaneously attacked the plant and will be worse on young or sickly plants. In the valleys of Ecuador's Pichincha region, PLRV, ToRSV, PVY, and AMV were the most often discovered viruses linked to symptoms of viral diseases [80]. Alfalfa mosaic virus (AIMV), tomato spotted wilt virus (TSWV), arabis mosaic virus (ArMV), tobacco streak virus (TSV), and tomato aspermy virus (TAV) are other viruses that have affected the tamarillo, albeit the losses they cause are not as severe as those produced by TaMV [56]. The Colombian tamarillo crop's declining yield is caused by a virus complex [81]. Phytosanitary problem, among which anthracnose (*Colletotrichum acutatum*) and viruses (PLCR, CMV, Potyvirus and ToMV) and others, apparently less influential (AMV, ToRSV and TSWV) has major effect on expansion plans of the tamarillo cultivation in Colombia [82]. Good orchard hygiene, pruning and burring infected plants and a good pest management programme will help to reduce pests and diseases in crop. A suitable spraying schedule can also be helpful. However, there is no cure for a virus once it has infected a plant; the only option is prevention. Since aphids are the primary transmitters of viruses, it is crucial to have effective control over them. Since there is no proof that viruses affecting the tamarillo may be propagated by seed, seed-based reproduction is a strategy for restricting their spread.

#### **21.3 Nematodes**

The plant is also harmed by *Pseudomonas solanacearum* wilt, root knot (Meloidogyne sp.), root rot, crown rot, and other diseases. Good cultural norms ought to help prevent these issues.

#### **21.4 Physiological disorders**

#### *21.4.1 Abnormality*

In order to make jam, small, hard, irregular, semi-transparent stones that are present in the flesh of tree tomatoes must be strained out. If these resemble the two grit-filled bumps in the fruit's wall, that is unknown. Probably in the form of silicates, borates, aluminum-magnesium-oxygen complexes, aluminates, or magnesium oxides, these stones are highly concentrated sources of sodium and calcium.

#### *21.4.2 Fruit scarring*

Tamarillo fruit scarring is a cosmetic condition that costs New Zealand's tamarillo growers significantly lost revenue [83]. According to estimates, the condition affects 10–20% of the fruit, which will result in considerable economic losses. When the scars are about 3 cm long, they first appear as little, dark lines on the skin of young fruit. As the fruit grows, the scars turn into corky lesions. Phillips et al. [84] reported that a

physical injury caused the scarring. A dark, uneven, and crazy corky scar was routinely produced when the epidermal layer was scratched with a toothbrush. Physical injury such as wind rub has been reported to cause corky scarring in other fruits also, such as avocado [72]. Wounding fruitlets by scratching or removing a patch of epidermis resulted in the characteristic scarring, which suggests that any type of physical epidermal damage incurred early in fruit development may result in scarring.

## **22. Package and transport**

Fruits are sorted by size as small, medium, large and packed in paper-lined wooden boxes for marketing. Polythene films can also be used to reduce water loss and maintain fruit quality [85]. Packaging usually consists of wooden or cardboard boxes containing one tray of tamarillos or preformed plastic trays with 3–8 fruits. Because of its firm flesh and tough skin, the fruit can be transported to long distances without bruising. However, it deteriorates rather rapidly under ordinary storage conditions.

#### **23. Postharvest handling and storage**

Different studies carried out to improve post harvesting ripeness showed that application of ethylene or ethephon is helpful to decrease the risk of crop failure and an earlier delivery to the consumer, thereby enhancing the marketability of tamarillo [67]. The fragile lateral branches can break easily when loaded with fruits, so premature harvest helps to reduce this risk and allows storage of fruits up to 20 days at room temperature. Tamarillos can be stored for about 12–14 weeks at 3.5–4.5°C. A cold water dipping process, developed by the New Zealand Department of Scientific and Industrial Research also allows further storage of 6–10 weeks. At higher temperatures, postharvest diseases multiply rapidly. One of the main causes of postharvest loss is bitter rot caused by a *Colletotrichum* sp. Applications of postharvest fungicides greatly reduce the number of fruits affected. Another alternative for postharvest disease control is to dip the fruit in water at 5°C for 10 min [86]. Temperatures below 7°C will reduce softening, weight loss, TA reduction, and color change, among other postharvest handling characteristics that might impact quality. On the other hand, extremely low temperatures (between 0 and 2°C) raise the danger of chilling injury and worsen stem and calyx discolouration.

#### **24. Processing and value addition**

Pomegranate can be used in both savory and sweet dishes, and it can even be eaten raw. Fruits can be used to make preserves because of their high pectin content. However, if they are left untreated, they will oxidize and eventually fade. Yellow fruit is preferred for industrial production. As it turns out, it can be utilized in the same way as tomatoes are used in many other cuisines. Simply slice the tomatoes in half, sprinkle them with sugar, then consume the pulp and flesh by scooping it out. Chopped bacon and cream cheese go on top of sandwiches. Diced fruits, bread crumbs, butter, and seasonings are used as a stuffing for roast lamb. Dessert in the form of a pie sliced tree tomatoes, either on their own or accompanied by an apple,

*Tamarillo (*Cyphomandra betacea *(Cav.)) Origin, Cultivation, Breeding and Management DOI: http://dx.doi.org/10.5772/intechopen.106601*

are available. They may be filled with water or sugar syrup, then packed into plastic containers with 50% sugar syrup and quickly frozen for later use as pie fillings or puddings. In a blender or on the stove, puree the peeled fruits, remove the seeds, and freeze in containers. Before blending, add some lemon juice into the purée to enhance the flavor even further. Several slices of fresh tree tomato are placed on top of the gelatin, milk, sugar, and lemon juice-cooked fruits. Cooking tree tomatoes with sugar, lemon zest, and juice results in a jam or chutney; the tomatoes can also be cooked with onions and apples for chutney, depending on the desired consistency. Chutney for the commercial market is made in an Auckland, New Zealand, facility. Pectin in the fruit makes it simple to turn into jelly, but the fruit quickly oxidizes and discolors if not treated further. Using whole, peeled fruits and sugar, a thick sauce is cooked to serve with ice cream. The peeled fruits can be used for tomatoes in tomato sauce. Tamarillo jelly can be made from tomatoes with a 50°C Brix sugar concentration, sucrose, and 2% pectin.

#### **25. Conclusions**

Tamarillo is a very unique fruit with not only a distinct flavor but also a fascinating history. This fruit is immensely popular in New Zealand, despite the fact that it is native to South America. Tamarillo grows best in a subtropical climate, although it can also be grown in areas where citrus crops are grown. Although it is currently grown in many countries, it is only commercially farmed in New Zealand and a few parts of South America. It rarely bears fruit in low-lying tropical places. It grows quickly and bears fruit in about 18 months. It reaches a height of around two meters and has a lifespan of about 7 years. Seeds or cuttings are commonly used for propagation, with plant trimming for efficient production varying according on the propagation method. Tamarillo plants are wind-sensitive and should be planted in naturally sheltered regions or protected by windbreaks. It is a really attractive fruit with a smooth and shiny skin on the outside. Vitamins, minerals, fiber, and antioxidants abound in this fruit. It has a very low-calorie count. It can be eaten after harvesting, much like most fruits. Juices, concentrates, jams, gelatins, and desserts are all made from it. It could be exported as fruit pulp or concentrate if processing facilities and suitable transportation are available. The tamarillo provides a chance to diversify fruit production in many subtropical fruit production locations as a high-value cash crop, with fine fruits fetching premium prices in niche markets in Europe, North America, and Japan.

### **Conflict of interest**

The authors declare no conflict of interest.
