*1.1.2 Cuscuta* spp

*Cuscuta* spp. leafless, thin, threadlike wrapper has the body. The flowers are small and flower collected in cases. Petals (corolla) combined, usually five-piece rarely four or in three parts. Ovary (ovarium) two carpel and two seed pods in each compartment takes place. Fruit, capsule shaped, seed without cotyledons or in traces, embryos are in the form of threads (**Figure 2**) [17]. This plant is taxonomically the most difficult parasitic is one of the groups. *Cuscuta* breed diagnosis

#### *Figure 2.*

*Cuscuta* spp*. a, b,) damage of Cuscuta* spp*., c) damage of Cuscuta* spp. *of in tomato d) damage of Cuscuta*  spp. *of in potato (niscole.com; projectnoah.org; Cittaslav botanic; iriss.ca, Erdogan, P.).*

*Parasitic Plants in Agriculture and Management DOI: http://dx.doi.org/10.5772/intechopen.98760*

mostly is carried out according to flower and fruit characteristics. These features; stigma shapes, staminal braces shape and condition of filaments, capsules. Whether it is turned on or not depends on features such as [6]. In China, several *Cuscuta* species inflict severe damage on soybeans [18].

Seeds of *Cuscuta* spp. have been spread worldwide in contaminated shipments of crop plant seeds. *Cuscuta pentagona* is a major weed of tomatoes in California, causing yield losses of 50–75% [19]. Nemli and Ongen [20] reported that cayenne in alfalfa causes yield losses up to 91%. It was determined that *Cuscuta* species caused 60–70% decrease in the yield of alfalfa in India [21]. It has been reported that poisoning cases are encountered in animals fed with plants contaminated with coals [22]. In Turkey, species of *Cuscuta campestris* Yunck. and *Cuscuta approximata* Bab. are very common [23].

#### *1.1.3 Orobanche* spp

*Orobanche* spp. and *Phelipanche* spp. the most damaging weedy root parasites belong to the Orobanchaceae. One of the most important experts in the Orobanche taxonomy, Prof. Dr. Edward S. Teryokhin divided the genus Orobanche into two important parts, *Orobanche* and *Phelipanche. Phelipanche* was first given to *P. ramosa* by Auguste Pomel (1821–1898), and with the support of increasing molecular studies in recent years, *Orobanche* genus *Orobanche* and *Phelipanche.* It was accepted to be divided into two generals and *P. ramosa* (L.) Pomel and *P. aegyptiaca* (Pers.) Pomel started to be used instead of *O. ramosa* and *O. aegyptiaca* in weed research. The broomrapes (*Orobanche* and *Phelipanche)* are widespread in Mediterranean areas in Asia Southern and Eastern Europe [3, 8].

As a full parasitic weed, *Orobanche* spp. have not green leaves, so they do not contain chlorophyll and cannot perform photosynthesis. Therefore, its life depends on the food and water it receives from the host. In order for the seeds of *Orobanche* spp., which are among the smallest seed plants in the world, to germinate, the host plant they prefer must be planted. When it is a suitable host, the beast seeds under the soil germinate and attach to the root of the host plant by forming a tube, and then it continues its life with ready-made food from the host. An *Orobanche* plant produces between 5,000 and 100,000 seeds, and these seeds can remain in the soil for more than 10 years without losing their viability. Four types of *Orobanche* cause significant damage in agriculture. These species are *O. ramosa* L. and *O. aegyptiaca* Pers. Some vegetables, mainly tobacco and tomatoes, and lentils, *O. crenata* Forsk. mainly broad beans and other legumes and *O. cernua* Loefl. causes significant damage to sunflower. It is possible to see *Orobanche* spp. in many broad-leaved cultivated plants, but it causes significant damage especially in sunflower, tobacco, tomato, eggplant, pea, lentil, broad bean, chickpea, cabbage, oilseed rape, parsley, watermelon, common vetch and carrot [6]. In cases where contamination with this weed is very heavy, yield loss in cultivated plants can reach up to 100%. *Orobanche* spp. may cause loss of yield in the host plant as well as decrease in quality as in tobacco and sunflower. The yield loss they cause in *Orobanche* spp. culture plants may vary between 5 and 100% depending on the time and density of this parasite weed to attach to the culture plant. It was revealed that *Orobanche* spp. caused 33% in tobacco, 50–100% of the bean, sunflower at 33%, 24%, carrots, and tomatoes in the United States 21% 29 and 24% in Turkey [24]. It has been established that the seeds completely lose their vitality when *Orobanche* spp. is harvested fresh. It has been reported that the vitality of the seeds decreased only by 10% within the first 5 years of storage, and this rate decreased to 50% after 9 years. It is stated that the vitality will decrease if the seeds are kept at high temperature and humidity (**Figure 3**) [26].

**Figure 3.** *a) Cuscuta* sp. *in potato (Karahan. A.)., b, c) Cuscuta* spp. *(coms.wikipidi.org., d) eggplant in Cuscuta* sp. *[25].*

#### *1.1.4* Striga spp

The witchweeds (*Striga* spp.) plants are herbaceous plants. The genus is characterized with contrasting leaves, irregular bright-colored flowers corolla, divided into a tube that spreads lobes, herbaceous habitat, small seeds and parasitism. *S. hermonthica* has shiny to dark green leaves, erect and often branched stems grow 77 cm or more. Stems are sturdy and rectangular. The leaves are linear, lanceolate or lanceolate and 1–3 inches long, with acuminate or acuminate tips, multi-shell. The inflorescences have 6–10 open flowers, 1–2 cm in diameter. The flowers are pink, red, white, purple or yellow. The spike has occasionally more than 10 open flowers and the corolla normally drops a few days after fertilization [6]. The infection caused by some hemiparasitic weeds such as *Striga* causes more crop biomass depression than the biomass accumulated by the parasite. *Striga,* like other plant herbivores and pathogens, reduces host productivity by lowering crop photosynthesis rates (press). The impact of *Striga* is complicated further by its predilection for attacking crops already under moisture and nutrient stress, the conditions that prevail throughout the semi-arid tropics [27].

*Parasitic Plants in Agriculture and Management DOI: http://dx.doi.org/10.5772/intechopen.98760*

**Figure 4.** *a, b, c, d) Striga* spp. *(photo: Oisat.org.; Africanplants.sckenberg.de; researchgate; tr.Gaz.Wiki).*

In tropical Africa the most damaging parasitic weeds are *Striga* spp. obligate root parasites of grain grasses and legumes, which endanger food supply in many developing countries. The most destructive species on cereals are *S. hermonthica* and *S. asiatica*, followed by *S. aspera* and *S. forbesii,* parasitising important food crops like rice, pearl millet, sorghum and maize in much of Africa and some parts of Asia. *S. gesnerioides* is an important pest of Fabaceae, especially cowpea). Moreover, the *Striga* epidemic is going to increase and the parasite is likely going to become a more serious threat to crop production [9]. The area infested by *Striga* in sub-Saharan Africa is estimated to be more than 50 million hectares of arable farmland under grains [28]. The area infested by the parasite in West Africa is estimated to be about 17.2 million hectares, and sorghum and millet cover about 64% of the total area [29]. The parasite also causes indirect losses, including human migrations in response to changes in production strategies, land abandonment, and severe invasions in extreme cases (**Figure 4**) [30].

### **2. Management**

*Viscum album* L.; the way to prevent the spread of mistletoe, which is mostly propagated by birds, is also through birds. At this point, it is very important to create alternative food sources for birds. Mechanical control is the most effective control technique. Mechanical control is done by removing the mistletoe before the seed binds and pruning the infected branches 20–30 cm below. In severe epidemics, the tree should sometimes be removed completely to prevent contamination to other trees. Kotan et al. [31] reported that five bacterial strains (two *Burkholderia cepacia,* one each of *Bacillus megaterium, Bacillus pumilus* and *Pandoraea pulminicola*) were HR and pathogenicity positive when injected but none of them when sprayed on mistletoe. When fungi were injected, 32 isolates were pathogenic but only thirteen when sprayed on mistletoe. *Alternaria alternata* VAS, -202, VAS, -205, VAS, -217 and *Acremonium kiliense* VA-11 fungal isolates were the most effective ones and caused strong disease symptoms on mistletoe (**Figure 5**).

*Orobanche* spp.; prevent contamination is the most important method to control *Orobanche* spp. Clean seeds and seedlings should be used, and firstly should be preferred certified seed. Beast agricultural tool used in the field contaminated with grass, or machines, without using in the dishwasher field make sure that it is very well cleaned first. in the fields contaminated with monster weeds long-term with non-host cultivars alternation should be made. Seen in fields or greenhouses before the beast weeds bloom, pull them separately by hand It must be burned somewhere or buried very deep. Especially resistant in sunflower cultivation attention should be paid to the use of varieties. In the control against monster weeds solarization is a highly effective method especially in greenhouse plants cultivation solarization should be carried out. *Linum usitatissimum* L. (Lineaceae) is used as a trap plant to control *Orobanche* spp. [24].

*Cuscuta* spp.; control dodder is also particularly effective in preventing spreading. Emphasis on measures and methods of cultural practice should be given. Plants that are found to be dull by visiting the areas contaminated with dodder should be cut in a way that does not leave any residue behind and destroyed immediately. In the vineyards, in the spring at the beginning of May, in order to prevent the germination of the seeds that have fallen to the soil or clinging to the grape branches before the grape leaves take off, they should first pour straw 5–10 cm thick, wider than the crown width, under the vines that are found to be dull, and the straw should be burned after the sprouts are formed and wrapped in straw. Sticks should not be taken from dish washed ties and vines for the purpose of production and should avoid contamination of uncontaminated areas with this path and other

**Figure 5.** *Infected mistletoe plant samples used for isolating of bacteria and fungi [31].*

*Parasitic Plants in Agriculture and Management DOI: http://dx.doi.org/10.5772/intechopen.98760*

forms. Similarly, dodder is an important factor in clover. If alfalfa is to be grown, control should be a problem. Clean and certified seeds should be used the weeds in which there is dodder in the area around the clover field are removed and should be burned [32].

*Striga* spp.; Oswald [33] reported that planting nonhost trap crops that induce suicidal germination is perhaps the most effective strategy currently available for *Striga* control. Recent researchers in this field focused on identifying and assessing the effectiveness of potential trap crops [34, 35]. Botanga et al. [36] revealed that the possibility of breeding for increased Parasitic Plants in Agriculture 131 production of germination stimulants.

The use of nitrogen-binding legumes as trap crops has the advantage of increasing soil fertility, which can further assist in *Striga* spp. control because *Striga* spp. thrives in poor soils [6]. Legumes have also proven useful as part of a novel "pushpull" (stimulodeterrent) pest management approach that illustrates the utility of increased plant diversity, simultaneously reducing *Striga* spp. and lepidopteran stemborer infestations [37].
