**2.1. Susceptibility to** *Bactrocera oleae*

It is well known that cultivars have a differentiated susceptibility to olive fly infestations. In this paragraph are chronologically arranged some of papers devoted to the comparison of susceptibility of cultivars to the major insect pest of the olive. The cultivars Carboncella di Pianacce, Gentile, Bardhi i Tirana, Kokermadh i Berat and Nociara showed an infestation level significantly lower (less than 10%) than the cultivars Carolea, Cassanese, Cucco, Giarraffa, Intosso, Kalinjot, Nocellara del Belice, Picholine and Santa Caterina (more than 20 %) during two years of observations (1997-1998) (Iannotta et al., 2001) (Table 1). Other cultivars investigated by the same authors (Dritta di Moscufo, Leccino, Maiatica di Ferrandina and Mixan) showed intermediate infestation levels. Among these cultivars has been observed that cultivars showing a low infestation level had a higher percentage of sterile oviposition stings.

Susceptibility of Cultivars to Biotic Stresses 83

**Figure 1.** Correlation between oleuropein content of drupes and olive fly infestation

Studies carried out in Sicily (Iannotta et al., 2002) highlighted the low susceptibility to olive fly infestations of the cv. Turdunazza antimosca compared to cvs. Tonda Iblea, Moresca and Verdese in the same olive grove. In this case, the low suceptibility of the cultivar Turdunazza antimosca seems to be related to the repellent action against the olive fly of that

Iannotta et al. (2006a) observed a very low active infestation (percentage of drupes with living stages of the olive fly, such as eggs, larvae or pupae) rate along the ripening season for cvs. Cellina di Nardò and Cima di Mola, strongly reducing drupes damages and avoiding any kind of pesticide use for the production of a high quality olive oil (Table 2). The cv. Ogliarola del Vulture showed a low infestation level only until the end of October and this lead to an anticipated harvesting for producing a high quality olive oil without field pesticide applications. The cv. Leccino registered a high infestation only during the first period of the olive ripening, while during October and November infestation was lower than the 20% (Table 2), i.e. tollerable for obtaining high quality olive oil. Other cultivars, mainly cv. Maurino, Moraiolo and Grossa di Spagna, showed a high susceptibility to olive fly attacks, showing active infestation levels higher than the 20%. For last cultivars the field applications of pesticides are needed. Percentages of sterile oviposition stings were higher at the end of September for cultivars with low susceptibility, when the content of oleuropein within drupes is the highest of the ripening season. These results confirmed previous observations that demonstrated the role of oleuropein for increasing the mortality of eggs and reducing the hatching rate of young

These data underline that increasing studies on cultivar susceptibility could effectively

Iannotta et al. (2006b) obtained results concerning 16 Italian cultivars (Table 3), displaying data concerning different development stages of the olive fly, active and total (active

produce significant results under a perspective of olive growing sustainability

(from Iannotta et al., 2001, modified).

larvae (Iannotta et al., 2002).

cultivar.

Iannotta et al. (2001) also underlined that the cultivars having a high amount of oleuropein in the pulp of drupes are those with the lowest level of infestation in the period considered optimal for the harvesting (end of October-beginning of November) (Table 1). In fact, the cultivars Carboncella di Pianacce, Gentile di Chieti, Bardhi i Tirana, Kokermadh i Berat and Nociara have an amount of oleuropein higher of 30g/kg of fresh pulp, while the cultivars with higher infestation level have an amount of oleuropein lower than 20g/kg of fresh pulp. From these data emerge a correlation between olive fly infestation and oleuropein content of drupes (Fig. 1).


**Table 1.** Percentages of olive fly infestation showed by olive cultivars growing in the same pedoclimatic conditions. Letters indicate significant statistical differences (P<0.01; ANOVA test) (from Iannotta et al., 2001, modified).

**Figure 1.** Correlation between oleuropein content of drupes and olive fly infestation (from Iannotta et al., 2001, modified).

Cultivar Sterile Oviposition

It is well known that cultivars have a differentiated susceptibility to olive fly infestations. In this paragraph are chronologically arranged some of papers devoted to the comparison of susceptibility of cultivars to the major insect pest of the olive. The cultivars Carboncella di Pianacce, Gentile, Bardhi i Tirana, Kokermadh i Berat and Nociara showed an infestation level significantly lower (less than 10%) than the cultivars Carolea, Cassanese, Cucco, Giarraffa, Intosso, Kalinjot, Nocellara del Belice, Picholine and Santa Caterina (more than 20 %) during two years of observations (1997-1998) (Iannotta et al., 2001) (Table 1). Other cultivars investigated by the same authors (Dritta di Moscufo, Leccino, Maiatica di Ferrandina and Mixan) showed intermediate infestation levels. Among these cultivars has been observed that cultivars showing a low infestation level had a higher percentage of

Iannotta et al. (2001) also underlined that the cultivars having a high amount of oleuropein in the pulp of drupes are those with the lowest level of infestation in the period considered optimal for the harvesting (end of October-beginning of November) (Table 1). In fact, the cultivars Carboncella di Pianacce, Gentile di Chieti, Bardhi i Tirana, Kokermadh i Berat and Nociara have an amount of oleuropein higher of 30g/kg of fresh pulp, while the cultivars with higher infestation level have an amount of oleuropein lower than 20g/kg of fresh pulp. From these data emerge a correlation between olive fly infestation and oleuropein content of drupes (Fig. 1).

Bhardi i Tirana 27.5 C 8.5 A 36.60 Carboncella di Pianacce 26.0 C 9.5 A 34.09 Carolea 13.0 AB 22.5 CDE 20.21 Cassanese 17.0 ABC 24.5 E 16.12 Cucco 23.5 ABC 26.5 E 19.11 Dritta di Moscufo 26.0 C 11.0 AB 18.51 Gentile di Chieti 26.0 C 9.5 A 31.37 Giarraffa 16.5 AB 23.5 DE 10.81 Intosso 18.0 ABC 31.0 E 24.04 Kalinjot 12.5 A 23.0 DE 9.29 Kokermadh i Berat 26.5 C 10.0 AB 31.18 Leccino 21.5 ABC 20.0 BCDE 29.01 Maiatica di Ferrandina 19.5 ABC 12.5 ABCD 27.88 Mixan 19.0 ABC 11.5 ABC 19.80 Nocellara del Belice 18.5 ABC 23.0 DE 16.47 Nociara 25.0 BC 9.5 A 32.73 Picholine 17.0 ABC 24.0 E 19.58 Santa Caterina 16.5 ABC 23.5 DE 16.83

**Table 1.** Percentages of olive fly infestation showed by olive cultivars growing in the same

pedoclimatic conditions. Letters indicate significant statistical differences (P<0.01; ANOVA test) (from

(%) (%) (g/Kg f.p.)

Stings Infestation Oleuropein

**2.1. Susceptibility to** *Bactrocera oleae*

sterile oviposition stings.

Iannotta et al., 2001, modified).

Studies carried out in Sicily (Iannotta et al., 2002) highlighted the low susceptibility to olive fly infestations of the cv. Turdunazza antimosca compared to cvs. Tonda Iblea, Moresca and Verdese in the same olive grove. In this case, the low suceptibility of the cultivar Turdunazza antimosca seems to be related to the repellent action against the olive fly of that cultivar.

Iannotta et al. (2006a) observed a very low active infestation (percentage of drupes with living stages of the olive fly, such as eggs, larvae or pupae) rate along the ripening season for cvs. Cellina di Nardò and Cima di Mola, strongly reducing drupes damages and avoiding any kind of pesticide use for the production of a high quality olive oil (Table 2). The cv. Ogliarola del Vulture showed a low infestation level only until the end of October and this lead to an anticipated harvesting for producing a high quality olive oil without field pesticide applications. The cv. Leccino registered a high infestation only during the first period of the olive ripening, while during October and November infestation was lower than the 20% (Table 2), i.e. tollerable for obtaining high quality olive oil. Other cultivars, mainly cv. Maurino, Moraiolo and Grossa di Spagna, showed a high susceptibility to olive fly attacks, showing active infestation levels higher than the 20%. For last cultivars the field applications of pesticides are needed. Percentages of sterile oviposition stings were higher at the end of September for cultivars with low susceptibility, when the content of oleuropein within drupes is the highest of the ripening season. These results confirmed previous observations that demonstrated the role of oleuropein for increasing the mortality of eggs and reducing the hatching rate of young larvae (Iannotta et al., 2002).

These data underline that increasing studies on cultivar susceptibility could effectively produce significant results under a perspective of olive growing sustainability

Iannotta et al. (2006b) obtained results concerning 16 Italian cultivars (Table 3), displaying data concerning different development stages of the olive fly, active and total (active


infestation plus exit holes of adults) infestation levels, detected amounts of oleuropein and cyanidine and weight of 100 drupes.

Susceptibility of Cultivars to Biotic Stresses 85

Oleuropein (ppm)

> 7974.1 3595.4 1419.0

> 8165.2 1482.1 0.0

> - 2469.8 0.0

> 8919.3 4889.6 42.9

11860.3 681.7 149.2

7831.2 1292.0 561.4

11810.7 5162.9 1771.3

8727.3 666.9

Cyanidine

0.0 17.1 129.3

79.0 1019.7 1690.0

> - 17.4 9.9

> 27.3 0.0 0.0

0.0 96.7 503.1

> 12.7 0.0 0.0

0.0 33.9 337.6

> 10.5 56.6

Active percentage within the limit of 15% is compatible with a high qualitative product (olive oil) avoiding the use of pesticides. It allows the achievement of the fixed aims, consisting in ecosystem and biocoenotic balances safeguard, which make economically

> Larvae (pupae)

7.5 (3.5) 12.0 (6.0) 24.5 (4.0)

0.0 (0.0) 2.5 (1.0) 12.5 (2.5)

0.0 (2.0) 0.0 (0.0) 4.5 (3.5)

4.5 (0.0) 16.0 (2.5) 2.5 (7.5)

3.0 (2.0) 8.0 (0.5) 15.5 (4.5)

0.0 (0.0) 3.0 (0.0) 7.5 (4.5)

3.5 (0.0) 0.5 (3.0) 12.0 (4.5)

1.5 (0.0) 9.0 (0.0)

Exit holes

> 5.5 15.0 13.0

> > 0.0 0.0 6.5

> > 3.0 4.5 6.0

2.0 7.5 17.5

0.0 3.5 14.5

> 0.0 1.0 2.0

> 0.5 1.0 5.0

> 0.5 6.5

(ppm) Fertile

Infestation

Active (total)

31.0 (49.0) 30.0 (55.0) 42.0 (65.0)

3.5 (9.0) 9.0 (14.5) 17.0 (29.5)

11.5 (24.0) 11.5 (38.0) 13.5 (33.5)

12.5 (24.5) 26.5 (45.5) 17.0 (52.0)

12.0 (27.5) 12.5 (23.0) 27.5 (49.5)

6.5 (18.5) 9.0 (19.5) 17.0 (23.0)

11.5 (20.0) 16.5 (27.0) 22.5 (36.5)

4.5 (14.0) 13.5 (31.0)

positive the ecocultivation (organic and integrated farming).

oviposition stings

> 10.0 8.0 7.5

> > 4.5 5.0 3.5

8.5 17.0 10.0

7.5 11.0 16.5

13.5 6.5 5.5

> 9.0 9.5 3.5

> 5.5 5.5 8.5

9.0 11.0

Eggs Sterile

(Aborted)

19.0 (2.5) 10.0 (2.0) 13.5 (2.5)

3.5 (1.0) 5.5 (0.5) 2.0 (2.5)

9.5 (1.0) 11.5 (5.0) 5.5 (4.0)

8.0 (2.5) 3.0 (0.5) 7.0 (1.0)

7.0 (2.0) 4.0 (0.5) 7.5 (2.0)

6.5 (3.0) 6.0 (0.0) 5.0 (0.5)

8.0 (2.5) 13.0 (4.0) 5.5 (0.5)

3.0 (0.0) 4.5 (0.0)

 Weight 100 drupes (g)

*Ascolana tenera* 676.1 725.3 842.7

*Cellina di Nardò* 125.7 131.1 143.3

*Cima di Melfi* 247.4 271.0 260.8

*Dolce Agogia* 181.2 209.5 227.2

*Dolce di Rossano* 133.7 186.6 175.5

*Frantoio* 157.6 175.3 221.4

*Moraiolo* 163.6 183.0 231.2

*Nera di Cantinelle* 226.2 253.3

**Table 2.** Active infestation trend. Letters indicate significant statistical differences (P<0.01; ANOVA test), from Iannotta et al. (2006a), modified.

The same table shows that cvs. Ascolana tenera and Nostrana di Brisighella turn out to be significatively the less infested cultivars, both for active and total infestation in all observed ripening times. Cellina di Nardò shows the lowest susceptibility to olive fly attacks (9.83% of active infestation and 17.67% of total infestation). Also cvs. Nera di Cantinelle, Frantoio, Tonda di Strongoli, Nolca, Cima di Melfi and Termite di Bitetto exhibit low susceptibility (active infestation lower than 13%), while cvs. Dolce Agogia, Dolce di Rossano, Nostrale di Fiano Romano, Ogliarola del Bradano, Ogliarola garganica and Ogliarola del Vulture display intermediate susceptibility values. The active and total infestations, obtained as mean values for any cultivars concerning the different ripening times, turn out to be increasing during the season (Table 4).

The results obtained for 9 non-Italian cultivars show cvs. Gordal sevillana and Hojiblanca with the lowest level of active infestation (<15%), cv. Konservolia the most infested and cvs. Arbequina, Kalamata, Koroneiki, Lucques, Manzanilla and Picual register intermediate infestation percentages (Table 5).

The results of Iannotta et al. (2006b) confirm a different behavior of olive cultivars concerning their susceptibility to olive fly attack. Investigated genotypes in the area of observation displayed a contained percentage of attack lower than 13% in the Italian cvs. Cellina di Nardò, Nera di Cantinelle, Frantoio, Tonda di Strongoli, Nolca, Cima di Melfi and Termite di Bitetto and lower than 15% in non-Italian cvs. Gordal sevillana and Hojiblanca. Active percentage within the limit of 15% is compatible with a high qualitative product (olive oil) avoiding the use of pesticides. It allows the achievement of the fixed aims, consisting in ecosystem and biocoenotic balances safeguard, which make economically positive the ecocultivation (organic and integrated farming).

84 Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy

cyanidine and weight of 100 drupes.

test), from Iannotta et al. (2006a), modified.

increasing during the season (Table 4).

infestation percentages (Table 5).

**Cultivar** 

infestation plus exit holes of adults) infestation levels, detected amounts of oleuropein and

Cellina di Nardò 16,50 D 6,50 D 14,50 CD Cima di Mola 22,00 BCD 15,50 CD 13,00 D Coratina 49,00 ABC 79,50 A 51,50 ABCD Dolce Agogia 41,00 ABCD 20,50 CD 23,00 BCD Frantoio 39,50 ABCD 35,00 BCD 45,00 ABCD Grossa di Spagna 21,50 CD 16,50 CD 74,50 AB Leccino 44,50 ABCD 15,00 CD 17,00 CD Maurino 26,00 BCD 38,50 BCD 77,50 A Moraiolo 56,00 A 49,50 ABC 65,00 ABC Ogliarola Barese 32,00 ABCD 41,00 BCD 38,50 ABCD Ogliarola Vulture 25,00 BCD 16,50 CD 71,00 AB Peranzana 51,00 AB 66,00 AB 70,50 AB Pisciottana 24,00 BCD 43,50 BC 53,00 ABCD **Table 2.** Active infestation trend. Letters indicate significant statistical differences (P<0.01; ANOVA

The same table shows that cvs. Ascolana tenera and Nostrana di Brisighella turn out to be significatively the less infested cultivars, both for active and total infestation in all observed ripening times. Cellina di Nardò shows the lowest susceptibility to olive fly attacks (9.83% of active infestation and 17.67% of total infestation). Also cvs. Nera di Cantinelle, Frantoio, Tonda di Strongoli, Nolca, Cima di Melfi and Termite di Bitetto exhibit low susceptibility (active infestation lower than 13%), while cvs. Dolce Agogia, Dolce di Rossano, Nostrale di Fiano Romano, Ogliarola del Bradano, Ogliarola garganica and Ogliarola del Vulture display intermediate susceptibility values. The active and total infestations, obtained as mean values for any cultivars concerning the different ripening times, turn out to be

The results obtained for 9 non-Italian cultivars show cvs. Gordal sevillana and Hojiblanca with the lowest level of active infestation (<15%), cv. Konservolia the most infested and cvs. Arbequina, Kalamata, Koroneiki, Lucques, Manzanilla and Picual register intermediate

The results of Iannotta et al. (2006b) confirm a different behavior of olive cultivars concerning their susceptibility to olive fly attack. Investigated genotypes in the area of observation displayed a contained percentage of attack lower than 13% in the Italian cvs. Cellina di Nardò, Nera di Cantinelle, Frantoio, Tonda di Strongoli, Nolca, Cima di Melfi and Termite di Bitetto and lower than 15% in non-Italian cvs. Gordal sevillana and Hojiblanca.

**Second ripening period (%)** 

**Third ripening period (%)** 

**First ripening period (%)** 



Susceptibility of Cultivars to Biotic Stresses 87

Infestation Oleuropein

Active (total)

14.0 (25.5) 18.0 (26.0) 16.0 (35.0)

10.0 (22.5) 16.0 (28.5) 17.0 (35.5)

3.5 (18.5) 20.5 (33.5) 21.0 (44.0)

13.5 (32.0) 15.0 (18.5) 29.0 (35.0)

16.0 (30.5) 16.5 (37.5) 31.0 (43.5)

7.0 (19.5) 18.0 (27.5) 28.5 (42.5) (ppm)

508.9 101.8 1956.4

3994.2 1764.8 35.4

5808.2 5424.5 -

10571.0 3644.6 240.7

5761.2 3203.6 234.2

6987.9 2029.9 5774.4 Cyanidine

11.5 23.2 0.0

17.6 77.7 140.7

0.0 187.5 -

> 0.0 22.0 0.0

187.5 122.0 36.9

> 0.0 0.0 0.0

Tukey test

Ripening time Active

(Aborted)

11.5 (1.0) 6.0 (1.0) 5.5 (0.0)

10.0 (0.5) 10.5 (1.0) 4.5 (2.0)

2.0 (3.0) 3.5 (0.0) 4.5 (0.0)

11.5 (3.5) 5.0 (1.0) 11.0 (2.0)

13.5 (3.5) 8.5 (1.5) 12.0 (1.5)

3.5 (0.0) 5.5 (0.5) 9.5 (1.5)

Weight drupes (g)

*Arbequina*  149.6 195.1 191.0

*Gordal sevillana*  506.9 803.6 922.3

*Hojiblanca* 

219.6 290.8 322.6

197.9 298.3 301.0

*Konservolia* 

322.9 465.3 508.4

> 93.0 87.3 89.7

*Koroneiki*

*Kalamata* 

infestation

(Capital letters: P<0.01; small letters: P<0.05; ANOVA test).

oviposition stings

> 9.5 4.5 5.0

12.0 7.5 9.5

11.5 8.0 5.0

14.0 0.0 1.0

8.5 10.5 7.5

10.0 4.5 7.5

Eggs Sterile

Tukey test Total

Emergency holes

> 1.0 2.5 14.0

> > 0.0 4.0 7.0

0.5 5.0 18.0

> 1.0 2.5 3.0

> 2.5 9.0 3.5

> 2.5 4.5 5.0

(ppm) Fertile

26 Sept. 2006 12.38 B 28.81 c C 26 Oct. 2006 15.69 B 35.88 b B 29 Nov. 2006 21.28 A 49.06 a A **Table 4.** Data concerning the comparison among the different investigated ripening times referred to Italian cultivars (from Iannotta et al., 2006b, modified). Letters indicate significant statistical differences

> Larvae (pupae)

2.5 (0.0) 9.5 (1.5) 7.5 (3.0)

0.0 (0.0) 4.0 (1.5) 10 (2.5)

1.5 (0.0) 15.0 (2.0) 15.0 (1.5)

2.0 (0.0) 6.5 (3.5) 11.5 (6.5)

2.5 (0.0) 5.5 (2.5) 16.0 (3.0)

3.5 (0.0) 10.0 (2.5) 14.0 (5.0)

infestation

**Table 3.** Detailed data obtained in the different theses and ripening times concerning olive fly infestation and oleuropein and cyanidine drupe contents. For any cultivar, the observation was performed in three different ripening times (from Iannotta et al., 2006b, modified).


oviposition stings

> 13.0 6.5 8.0

> 10.5 8.0 16.0

> 10.5 0.0 6.5

> > 6.0 6.0 5.0

16.5 13.5 4.0

11.5 6.0 21.0

8.0 6.5 11.0

7.0 11.0 6.5

Larvae (pupae)

2.5 (0.5) 3.5 (6.0) 13.5 (5.0)

3.5 (3.5) 6.0 (3.5) 3.0 (4.5)

12.5 (8.0) 5.0 (6.5) 15.5 (8.0)

2.5 (1.0) 4.5 (2.0) 11.0 (5.0)

1.0 (0.0) 1.5 (3.5) 10.0 (5.0)

1.5 (0.0) 7.0 (2.5) 12.5 (3.0)

4.5 (0.0) 10.0 (0.0) 5.5 (5.5)

1.0 (1.0) 3.0 (0.0) 7.0 (4.0)

**Table 3.** Detailed data obtained in the different theses and ripening times concerning olive fly infestation and oleuropein and cyanidine drupe contents. For any cultivar, the observation was

performed in three different ripening times (from Iannotta et al., 2006b, modified).

270.9 4.0 (0.0) 6.5 7.5 (2.5) 16.5 14.0 (37.0) 39.1 210.1

Exit holes

> 2.5 7.0 10.0

> 12.0 8.5 15.5

> 5.0 19.5 29.5

> > 1.5 3.0 7.5

1.0 5.0 13.5

2.5 3.0 13.5

1.5 14.0 10.0

2.0 1.0 10.5

(ppm) Fertile

Infestation

Active (total)

4.0 (19.5) 11.5 (27.0) 21.0 (41.0)

17.5 (42.0) 19.0 (37.0) 15.0 (46.5)

36.0 (54.0) 22.0 (42.0) 39.0 (77.0)

13.5 (22.0) 20.0 (32.5) 16.0 (28.5)

9.5 (31.5) 13.5 (33.0) 20.5 (39.0)

6.0 (22.0) 13.0 (23.0) 27.5 (65.5)

9.0 (18.5) 12.0 (32.5) 17.5 (39.5)

9.5 (19.5) 11.5 (23.5) 13.5 (31.0) Oleuropein (ppm)

> 155.9 0.0 0.0

3174.0 463.4 93.8

6444.0 5002.3 454.0

3830.2 2238.0 88.8

5387.2 641.6 444.0

9082.3 6669.3 588.0

1654.4 345.6 229.4

8299.6 4153.3 557.1

Cyanidine

91.1 601.8 1120.3

> 34.0 25.4 13.8

> 0.0 17.2 0.0

> > 0.0 0.0 0.0

71.6 46.3 705.6

> 36.9 21.4 0.0

34.0 513.5 1647.1

> 0.0 0.0 15.5

Eggs Sterile

(Aborted)

1.0 (0.0) 2.0 (2.0) 2.0 (2.0)

10.5 (2.0) 7.0 (1.5) 7.5 (0.0)

13.5 (2.5) 3.5 (0.5) 15.5 (2.0)

10.0 (1.0) 13.5 (3.5) 0.0 (0.0)

8.5 (4.5) 8.5 (1.0) 2.5 (1.0)

4.5 (2.0) 3.5 (1.0) 12.0 (3.5)

4.5 (0.0) 2.0 (0.0) 2.5 (1.0)

7.5 (1.0) 8.5 (0.0) 2.5 (0.5)

*Nostrale di Fiano Romano*

*Nostrana di Brisighella*

*Ogliarola del Bradano* 

*Ogliarola Garganica*  261.2 238.2 250.6

*Ogliarola del Vulture*  195.4 188.8 265.4

*Termite di Bitetto*  228.0 268.8 382.9

*Tonda di Strongoli*  389.7 448.7 453.3

 Weight 100 drupes (g)

*Nolca* 

250.2 327.0 325.1

255.5 262.4 342.3

481.7 801.2 674.9

153.9 171.6 235.4




Susceptibility of Cultivars to Biotic Stresses 89

Reinfested by

0.0 (2.5) 9.0 (2.0)

0.0 (0.0) 0.5 (1.0) 7.5 (0.0)

0.0 (0.0) 2.5 (0.0) 4.0 (0.0)

0.0 (0.0) 5.0 (0.5) 12.0 (0.0)

0.0 (0.0) 8.0 (2.5) 4.0 (1.5)

0.0 (0.0) 4.0 (0.0) 5.5 (1.0)

0.0 (0.0) 4.0 (0.0) 2.0 (0.0)

0.0 (0.0) 0.0 (0.0) 0.0 (0.0)

Emergence holes

> 11.0 21.5

> 0.5 7.0 17.0

> 5.0 9.5 12.0

> 8.0 8.5 17.5

> 4.0 10.0 9.0

> 2.5 10.0 11.0

> 2.5 13.5 16.0

> > 0.0 3.0 3.5

Weight drupes (g)

> 390.70 463.46

> 228.09 285.48 312.36

Gentile di Chieti 511.35 495.03 524.06

> 606.61 711.97 771.70

Nocellara del Belice 349.88 408.33 496.77

> 163.15 196.58 211.31

> 416.12 422.25 466.44

Tonda nera dolce 242.92 301.60 298.97

referred to 100 drupes.

Cassanese

Giarraffa

Nociara

Picholine

Eggs Sterile

Fertile

4.0 (1.0) 1.0 (1.0)

5.0 (0.0) 8.5 (0.5) 7.0 (2.5)

14.0 (0.5) 10.0 (3.0) 6.5 (0.0)

5.0 (0.5) 5.0 (1.0) 2.5 (0.0)

5.0 (1.0) 0.5 (1.0) 7.5 (1.5)

12.0 (6.5) 5.5 (0.0) 7.5 (2.5)

5.0 (0.5) 6.5 (0.5) 10.0 (2.0)

2.0 (0.5) 5.0 (2.5) 4.0 (0.5) stings

1.0 5.5

5.5 3.0 1.0

19.0 5.5 7.0

15.0 6.5 2.0

10.0 3.0 4.0

18.5 5.5 4.5

14.0 5.5 1.0

3.5 10.5 12.5

Larvae (pupae)

22.0 (4.0) 18.0 (5.5)

2.5 (0.0) 13.5 (0.0) 19.0 (2.0)

4.0 (0.0) 12.5 (3.0) 14.5 (1.0)

6.0 (0.0) 20.0 (4.0) 23.0 (6.0)

3.0 (0.5) 20.5 (5.0) 19.0 (4.0)

5.0 (0.0) 20.0 (3.0) 16.0 (5.0)

1.0 (1.5) 13.0 (1.5) 25.0 (5.0)

0.0 (0.0) 3.5 (0.0) 4.0 (0.0)

**Table 6.** Detailed percentages obtained in the different cultivars and ripening times concerning olive fly infestation (from Iannotta et al., 2007a). Observations were performed in three different ripening times (03rd October, 04th November and 5th December) for any investigated cultivar. Reported values are

Drupes weight increased during the season, according to the physiological processes involved in fruit maturation. Fertile eggs were more abundant than aborted ones, which did not exhibit a trend related to ripening times. For many observed cultivars, sterile oviposition stings were much more abundant in the first ripening time. Few pupae were registered within drupes in respect to larvae. As expected, emergence holes increased during the

(Aborted) Larvae (pupae)

**Table 5.** Detailed percentages obtained in the different theses and ripening times concerning *B. oleae* infestation and oleuropein and cyanidine drupe contents. For any non-Italian cultivar, the observation was performed in three different ripening times (from Iannotta et al., 2006b, modified).

The susceptibility to *B. oleae* of other ten cultivars has been investigated by Iannotta et al. (2007a). Observations were carried out detecting the percentages of sterile oviposition stings, active infestation (presence of pre-imago stages: eggs, larvae and pupae) and total infestation (emergence holes, feeding tunnels and pre-imago stages) on olive fruit samples, 200 drupes per cultivar. Samples were collected in three different times during fruit ripening (Table 6).




Larvae (pupae)

6.5 (3.0) 6.5 (5.5) 12.5 (3.0)

1.5 (0.0) 7.5 (2.5) 18.0 (2.0)

3.5 (0.0) 10.0 (5.0) 17.5 (1.5)

was performed in three different ripening times (from Iannotta et al., 2006b, modified).

**Table 5.** Detailed percentages obtained in the different theses and ripening times concerning *B. oleae* infestation and oleuropein and cyanidine drupe contents. For any non-Italian cultivar, the observation

The susceptibility to *B. oleae* of other ten cultivars has been investigated by Iannotta et al. (2007a). Observations were carried out detecting the percentages of sterile oviposition stings, active infestation (presence of pre-imago stages: eggs, larvae and pupae) and total infestation (emergence holes, feeding tunnels and pre-imago stages) on olive fruit samples, 200 drupes per cultivar. Samples were collected in three different times during fruit ripening

> Larvae (pupae)

0.5 (0.0) 4.5 (0.0) 12.5 (1.0)

1.5 (0.0) 11.0 (5.5) 17.5 (3.5)

321.34 11.0 (1.0) 11.0 8.5 (2.0) 3.5 0.0 (0.0)

(Aborted) Larvae (pupae)

Emergency holes

> 5.0 6.5 13.5

> > 3.0 6.0 8.5

> > 0.0 6.0 7.0

(ppm) Fertile

Infestation Oleuropein

Active (total)

15.5 (22.0) 14.0 (32.5) 20.5 (39.5)

13.0 (24.0) 15.0 (31.0) 25.5 (41.0)

11.5 (27.0) 21.5 (31.0) 23.5 (36.0)

> Emergence holes

> > 0.5 4.5 7.0

5.0 9.5 10.5 (ppm)

3557.7 2119.3 0.0

10517.0 6028.2 519.1

8915.3 5663.4 2596.7 Cyanidine

12.6 96.4 12.4

85.6 742.6 186.1

21.81 178.5 1695.6

Reinfested by

0.0 (0.0) 0.0 (0.0) 2.5 (0.0)

0.0 (0.0) 0.0 (0.0) 1.0 (1.0)

oviposition stings

> 0.0 12.0 5.5

> > 5.5 9.0 55

14.0 1.0 3.5

Eggs Sterile

Fertile

9.5 (2.0) 2.5 (0.5) 7.5 (1.0)

11.0 (0.5) 9.5 (0.5) 9.5 (1.5)

stings

9.0 9.0 6.0

16.5 9.5 5.5

Eggs Sterile

(Aborted)

6.0 (1.5) 2.0 (0.0) 5.0 (0.0)

11.5 (2.5) 5.0 (1.0) 5.5 (1.5)

8.0 (1.5) 6.5 (2.5) 4.5 (2.0)

Weight drupes (g)

> 515.7 623.9 853.3

*Manzanilla* 

376.3 353.2 423.8

364.5 435.1 507.1

(Table 6).

Weight drupes (g)

Carboncella di Pianacce 100.86 128.96 129.91

Bardhi Tirana 309.69 358.91 415.48

Carolea

*Picual*

*Lucques*

**Table 6.** Detailed percentages obtained in the different cultivars and ripening times concerning olive fly infestation (from Iannotta et al., 2007a). Observations were performed in three different ripening times (03rd October, 04th November and 5th December) for any investigated cultivar. Reported values are referred to 100 drupes.

Drupes weight increased during the season, according to the physiological processes involved in fruit maturation. Fertile eggs were more abundant than aborted ones, which did not exhibit a trend related to ripening times. For many observed cultivars, sterile oviposition stings were much more abundant in the first ripening time. Few pupae were registered within drupes in respect to larvae. As expected, emergence holes increased during the

season showing a low value in the first ripening time. Very low value of reinfestation were observed according to female egg laying behavior.

Susceptibility of Cultivars to Biotic Stresses 91

Cacaredda, Capolga, Caprina Casalanguida, Caprina vastese, Carbonchia, Carpinetana, Cavalieri, Cellina Rotello, Colombina, Corneglia, Cornia, Corniola, Corniolo, Correggiolo, Dolce Andria, Fosco, Gentile Larino, Gentile Colletorto, Giusta, Gragnaro, Gragnan, Grappolo, Grossa Venafro, Grossale, I/77, Laurina, Lavagnina, Mantonica, Marina pugliese, Marzio, Minna di vacca, Morfa, Morchiaio, Morellona Grecia, Morinello, Nasitana, Nebbio Chieti, Nocellara etnea ovale, Ogliara, Ogliastro grande, Oliva grossa, Olivastra seggionese, Olivastro Bucchinico, Olivo da olio, Olivo della Madonna, Orbetana, Ortice, Pampagliosa, Pennulara, Piangente, Piantone Moiano, Pignola, Posola, Posolella, Precoce, Puntella, Racioppella, Rastellina, Raza, Razzo, Remugnana, Resciola Venafro, Romanella molisana, Rosciola coltodino, Rosciola Rotello, Rustica, Saligna, Sammartinara, Sammartinenga, San Benedetto, San Francesco, Santa Maria, Sperone di gallo, Tombarello, Tonda Alife, Tonda dolce, Tonda dolce Partanna, Tunnulidda, Vicio, Zinzifarica) and no cultivar with a percentage of infection equivalent to 100% was observed, emphasizing the presence of genetic resources in Italian germplasm for olive knot disease prevention. Among analysed non-Italian cultivars, 41.9% showed a percentage of infection included between 0 and 20%, with 5 cultivars showing no sign of attack (Bardhi, Chetani, Hojiblanca, Lucques, Salonenque); 23.3% included between 20 and 40%; 4.7% included between 40 and 60%; 4.7% between 60 and 80%; 23.3% included between 80 and 100%. Cultivars Drobnica, Koroneiki and Vasilikada showed an infection equivalent to 100%. This different susceptibility evaluated under the same agro-environmental conditions, confirms a different response to the pathogen in relation to the ratio plant/parasite and appears tightly dependent from

The different susceptibility of olive cultivars to knot disease has been observed by several authors. Iannotta and Monardo (2004) observed that both percentage of the number of leaves infected and surface occupied on leaves by the symptoms of the disease are significantly different in observed cultivars. These authors observed that out of 35 cultivars studied cultivars Bardhi i Tirana, Carboncella di Pianacce, Cassanese, Dritta di Moscufo, Gentile di Chieti, Kalinjot and Leccino did not show any kind of symptoms of the disease, while cultivars Bosana, Carolea, Nocellara del Belice, Nera di Villacidro, Maiatica di Ferrandina, Itrana and Tonda di Cagliari were clearly infected by *Spilocaea oleagina*. The others observed cultivars showed intermediate values of the disease incidence (Table 7). The same authors related the cultivar susceptibility to the oleuropein content of leaves showing a direct relation between oleuropein content and cultivar susceptibility. In fact, low susceptible cultivars are those with the highest oleuropein content in leaves. Iannotta & Monardo (2004) affirmed that oleuropein could play an important role in determining the

Results are similar to those obtained by Iannotta et al. (2001) concerning the relation among oleuropein content of drupes and susceptibility to olive fly infestation, demonstrating that studies devoted to the exploration of genetic variability of olive cultivars is a focal subject, to

cultivars tolerance to low temperatures.

**2.3. Susceptibility to** *Spilocaea oleagina*

development inhibition of the fungus within the leaves.

date not sufficiently developped but of great importance.

Infestation values due to preimago stages seem to be generally related to the investigated ripening time rather than to the single investigated cultivar. More evident trends were determined by the olive plant phenology, however some cultivars showed an interesting and peculiar behavior in relation to attack levels of olive fly.

Results show that the less susceptible cultivars to *B. oleae* attacks are cvs. Tonda nera dolce and Bardhi Tirana while cvs. Carolea, Carboncella di Pianacce, Gentile di Chieti, Giarraffa, Nocellara del Belice, Nociara and Picholine displayed a considerable susceptibility (Table 6). The low susceptibility observed for cvs. Tonda nera dolce and Bardhi Tirana could be attributed to different causes. The high amount of oleuropein present in the drupes of Bardhi Tirana, according to previous studies (Iannotta et al., 2001; 2002; 2006a), could be involved in processes determining a low incidence of olive fly attack. It hasn't been observed an high presence of the glycoside in cv. Tonda nera dolce while a considerable amount of cyanidine in the drupes was registered. The high value of cyanidine in cv. Tonda nera dolce could determine the observed low susceptibility. Probably, the dark color given by anthocyanins, achieved ever since in the early ripening stages, could confuse female olive flies in drupe recognition with a consequent decreased ovideposition.

The results obtained in the present research confirm those ones achieved in previous investigations, proving the need to explore the existent olive germplasm to search genetic resistance sources. It suggests the utility to achieve these results both to transfer directly to farmers' world and to emphasize ecosystem health and biodiversity conservation.

### **2.2. Susceptibility to** *Pseudomonas savastanoi*

To keep under control the olive knot disease, the use of preventive measures turns out to be essential. Among these ones, the use of less susceptible cultivars emerged to be promising. Behavioural investigations showed a large variability in severities of olive disease caused by *Pseudomonas savastanoi* (Smith). A study carried out in the spring of 2005 by performing a large-scale investigations on the different responses to the pathogen of 262 Italian and 43 non-Italian cultivars, in the germplasm conservation field, where plants are cultivated under the same environmental and growing conditions (Iannotta et al., 2006c). The response to pathogen was evaluated by examining the symptomatology on the basis of the quantity of tubercles present on branches, arranged in classes of infection. During this time, several adverse meteorological events took place, including record minimum temperatures which influence the onset of the disease. Results displayed a different behaviour of olive cultivars to *P. savastanoi* in relation to their different susceptibility to the pathogen. Among observed Italian cultivars, 61% showed an infection's percentage ranging from 0 to 20%, 22.5% ranging from 20 to 40%, 11.1% ranging from 40 to 60%, 5% ranging from 60 to 80% and 0.4% ranging from 80 and 100%. Among investigated cultivars, 86 displayed no symptom of disease (Abunara, Aitana, Ascolana dura, Ascolana semitenera, Aurina, Bianchera, Cacaredda, Capolga, Caprina Casalanguida, Caprina vastese, Carbonchia, Carpinetana, Cavalieri, Cellina Rotello, Colombina, Corneglia, Cornia, Corniola, Corniolo, Correggiolo, Dolce Andria, Fosco, Gentile Larino, Gentile Colletorto, Giusta, Gragnaro, Gragnan, Grappolo, Grossa Venafro, Grossale, I/77, Laurina, Lavagnina, Mantonica, Marina pugliese, Marzio, Minna di vacca, Morfa, Morchiaio, Morellona Grecia, Morinello, Nasitana, Nebbio Chieti, Nocellara etnea ovale, Ogliara, Ogliastro grande, Oliva grossa, Olivastra seggionese, Olivastro Bucchinico, Olivo da olio, Olivo della Madonna, Orbetana, Ortice, Pampagliosa, Pennulara, Piangente, Piantone Moiano, Pignola, Posola, Posolella, Precoce, Puntella, Racioppella, Rastellina, Raza, Razzo, Remugnana, Resciola Venafro, Romanella molisana, Rosciola coltodino, Rosciola Rotello, Rustica, Saligna, Sammartinara, Sammartinenga, San Benedetto, San Francesco, Santa Maria, Sperone di gallo, Tombarello, Tonda Alife, Tonda dolce, Tonda dolce Partanna, Tunnulidda, Vicio, Zinzifarica) and no cultivar with a percentage of infection equivalent to 100% was observed, emphasizing the presence of genetic resources in Italian germplasm for olive knot disease prevention. Among analysed non-Italian cultivars, 41.9% showed a percentage of infection included between 0 and 20%, with 5 cultivars showing no sign of attack (Bardhi, Chetani, Hojiblanca, Lucques, Salonenque); 23.3% included between 20 and 40%; 4.7% included between 40 and 60%; 4.7% between 60 and 80%; 23.3% included between 80 and 100%. Cultivars Drobnica, Koroneiki and Vasilikada showed an infection equivalent to 100%. This different susceptibility evaluated under the same agro-environmental conditions, confirms a different response to the pathogen in relation to the ratio plant/parasite and appears tightly dependent from cultivars tolerance to low temperatures.

### **2.3. Susceptibility to** *Spilocaea oleagina*

90 Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy

and peculiar behavior in relation to attack levels of olive fly.

flies in drupe recognition with a consequent decreased ovideposition.

**2.2. Susceptibility to** *Pseudomonas savastanoi*

observed according to female egg laying behavior.

season showing a low value in the first ripening time. Very low value of reinfestation were

Infestation values due to preimago stages seem to be generally related to the investigated ripening time rather than to the single investigated cultivar. More evident trends were determined by the olive plant phenology, however some cultivars showed an interesting

Results show that the less susceptible cultivars to *B. oleae* attacks are cvs. Tonda nera dolce and Bardhi Tirana while cvs. Carolea, Carboncella di Pianacce, Gentile di Chieti, Giarraffa, Nocellara del Belice, Nociara and Picholine displayed a considerable susceptibility (Table 6). The low susceptibility observed for cvs. Tonda nera dolce and Bardhi Tirana could be attributed to different causes. The high amount of oleuropein present in the drupes of Bardhi Tirana, according to previous studies (Iannotta et al., 2001; 2002; 2006a), could be involved in processes determining a low incidence of olive fly attack. It hasn't been observed an high presence of the glycoside in cv. Tonda nera dolce while a considerable amount of cyanidine in the drupes was registered. The high value of cyanidine in cv. Tonda nera dolce could determine the observed low susceptibility. Probably, the dark color given by anthocyanins, achieved ever since in the early ripening stages, could confuse female olive

The results obtained in the present research confirm those ones achieved in previous investigations, proving the need to explore the existent olive germplasm to search genetic resistance sources. It suggests the utility to achieve these results both to transfer directly to

To keep under control the olive knot disease, the use of preventive measures turns out to be essential. Among these ones, the use of less susceptible cultivars emerged to be promising. Behavioural investigations showed a large variability in severities of olive disease caused by *Pseudomonas savastanoi* (Smith). A study carried out in the spring of 2005 by performing a large-scale investigations on the different responses to the pathogen of 262 Italian and 43 non-Italian cultivars, in the germplasm conservation field, where plants are cultivated under the same environmental and growing conditions (Iannotta et al., 2006c). The response to pathogen was evaluated by examining the symptomatology on the basis of the quantity of tubercles present on branches, arranged in classes of infection. During this time, several adverse meteorological events took place, including record minimum temperatures which influence the onset of the disease. Results displayed a different behaviour of olive cultivars to *P. savastanoi* in relation to their different susceptibility to the pathogen. Among observed Italian cultivars, 61% showed an infection's percentage ranging from 0 to 20%, 22.5% ranging from 20 to 40%, 11.1% ranging from 40 to 60%, 5% ranging from 60 to 80% and 0.4% ranging from 80 and 100%. Among investigated cultivars, 86 displayed no symptom of disease (Abunara, Aitana, Ascolana dura, Ascolana semitenera, Aurina, Bianchera,

farmers' world and to emphasize ecosystem health and biodiversity conservation.

The different susceptibility of olive cultivars to knot disease has been observed by several authors. Iannotta and Monardo (2004) observed that both percentage of the number of leaves infected and surface occupied on leaves by the symptoms of the disease are significantly different in observed cultivars. These authors observed that out of 35 cultivars studied cultivars Bardhi i Tirana, Carboncella di Pianacce, Cassanese, Dritta di Moscufo, Gentile di Chieti, Kalinjot and Leccino did not show any kind of symptoms of the disease, while cultivars Bosana, Carolea, Nocellara del Belice, Nera di Villacidro, Maiatica di Ferrandina, Itrana and Tonda di Cagliari were clearly infected by *Spilocaea oleagina*. The others observed cultivars showed intermediate values of the disease incidence (Table 7). The same authors related the cultivar susceptibility to the oleuropein content of leaves showing a direct relation between oleuropein content and cultivar susceptibility. In fact, low susceptible cultivars are those with the highest oleuropein content in leaves. Iannotta & Monardo (2004) affirmed that oleuropein could play an important role in determining the development inhibition of the fungus within the leaves.

Results are similar to those obtained by Iannotta et al. (2001) concerning the relation among oleuropein content of drupes and susceptibility to olive fly infestation, demonstrating that studies devoted to the exploration of genetic variability of olive cultivars is a focal subject, to date not sufficiently developped but of great importance.


Susceptibility of Cultivars to Biotic Stresses 93

*C. dalmaticum* 

Infection LSD test

*C. dalmaticum* 

Infection LSD test

less infected and cv. Gordal sevillana the most affected by mycosis (Table 9). The study proves the utility of further investigations in order to characterize the different cultivars

behaviour in relation to their parasites, so as to define their specific susceptibility.

Ascolana tenera 12.00 A Cellina di Nardò 3.33 BC Cima di Melfi 4.67 BC Dolce Agogia 3.17 BC Dolce di Rossano 1.67 BC Frantoio 0.67 C Moraiolo 4.00 BC Nera di Cantinelle 3.17 BC Nolca 4.33 BC Nostrale di Fiano Romano 3.67 BC Nostrana di Brisighella 11.17 A Ogliarola del Bradano 4.50 BC Ogliarola garganica 2.83 BC Ogliarola del Vulture 6.00 B Termite di Bitetto 3.67 BC Tonda di Strongoli 1.50 BC **Table 8.** Mean values concerning *C. dalmaticum* infection referred to each Italian cultivars. Letters indicate significant statistical differences (P<0.01; ANOVA test). (from Iannotta et al., 2006d, modified).

Arbequina 3.33 b Gordal sevillana 7.50 a Hojiblanca 3.83 b Kalamata 5.00 ab Konservolia 5.50 ab Koroneiki 4.50 ab Lucques 5.50 ab Manzanilla 5.00 ab Picual 3.00 b

**Table 9.** Mean values concerning *C. dalmaticum* infection referred to each non-Italian cultivars. Letters indicate significant statistical differences (P<0.01; ANOVA test). (from Iannotta et al., 2006d, modified).

Trials performed by Iannotta et al. (2007a) in the collection field of the CRA OLI compared susceptibility to *Camarosporium dalmaticum* of cultivars planted in the same environmental

Cultivar

Cultivar

**Table 7.** Percentage of infected leaves (FI%) and percentage of surface occupied by symptoms on leave's surface (SI%) of 35 cultivars (from Iannotta and Monardo, 2004). Letters indicate significant statistical differences (P<0.01; ANOVA test).
