PATHOLOGICAL STUDIES ON PARASITIC NEMATODES
AFFECTING STRAWBERRY .
A Thesis
Presented to the Graduate School ,
Faculty of Agriculture, Damanhour Branch ,
Alexandria University
In Partial Fulfilment of the Requirements
for the Degree of
MASTER OF SCIENCE
In
PLANT PATHOLOGY
By
Deiaa Ekram Mohamed Fared El-Habashy
B.Sc. Agric., Alexandria University (Damanhor, Branch)(2003 )
Augusts 2010
SUMMARY
Results obtained in the present investigation can be summarized as follows :
- 1 A total of 224 soil and root samples were collected from the rhizosphere of strawberry plants in three governorates in Egypt. The surveyed governorates and their respective samples were as follows: El-Behira 113, El-Ismailia 63, and El-Qaliuobia 48. Results of the survey study revealed that 10 genera of plant-parasitic nematodes were found in strawberry soil samples. The root-knot nematodes, Meloidogyne spp. were the most prevalent with 35.6% FO and an average number of 704.5 juveniles / kg soil and prominence value 4203.5 The nematode genera Aphelenchus, Hoplolaimus, Ditylelenchus and Tylenchus showed 6.69, 9.38, 16.53 and 26.32 % FO respectively. While, nematode genera Tylenchorhynchus, Trichodorus, Pratylenchus, Aphelenchiodes and Xiphinema showed 3.59, 4.45, 4.46, 5.35 and 2.22 % FO respectively. The root-knot nematodes, Meloidogyne spp. Showed 41.3 % FO in soil sampeles of Ismailia, 30 % FO in soil samples of El- Qaluobia and showed 35.5 % FO in soil samples of El-Behira governorate .
- 2 Identification of root-knot nematodes was bassed on the morphological characteristics of the perineal patterns of adult females. The results clarify the presence of M. incognita on strawberry from El- Behira governorate, M. javanica and M. arenaria on tomato from El- Behira governorate .
- 3 Reaction of four strawberry cultivars (K 14– Chandler- Festival- Sweet Charli) to M. incognita, M. javanica and M. arenaria was investigated .
All the tested strawberry cultivars were susceptible to M. incognita, M. javanica and M. arenaria. Strawberry cultivar Festival was highly susceptible. While, strawberry cultivar K14 was less susceptible against the tested root-knot nematodes( M. incognita, M. javanica and M. arenaria .)
- 4 Effect of chemical and Biological nematicides on strawberry cv. Festival infected with M. incognita was investigated .
The obtained data showed that Vydate 10G caused significant reduction in numbers of galls, egg-masses and number of larvae / 250 g soil. Also, the biological nematicides Nemacont and Bionema significantly reduced numbers of galls, number of egg-masses and number of larvae / 250 g soil compared with untreated control. All the teseted nematicides Rugby, Furadan, vydate, Nemacont and Bionema improved root and shoot growth of strawberry cv. Festival infected with M incognita compared with untreated control .
- 5 In vitro test: Effect of different plant oils Black cumin, Argel, Fennel and Garlic at concentrations 125, 250, 500 and 1000 μl/liter on M. incognita eggs hatching percentage after 3days, 5days and 7 days from treatment was recorded. The obtained data revealed that all the tested plant oils significantly reduced eggs hatching percentage compared with untreated control. Oil concentration of 1000 μl/liter was the best concentration to reduce eggs hatching percentage followed by concentration of 500 μl/liter .
Generally, Garlic oil was the best oil followed by Argel oil to reduce M. incognita eggs hatching. While, Fennel oil cause the lowest effect in reducing eggs hatching compared with the other tested oils .
The maximum reduce in eggs hatching percentage caused by the tested oils was found after 7 days from treatment .
- 6 In vitro test: Effect of different plant oils Black cumin, Argel, Fennel and Garlic at concentrations 125, 250, 500 and 1000 μl/liter on mortality percentage of M. incognita J2 was determined after 12, 24 and 48hrs. The obtained data showed that all the tested oils concentrations significantly increased the mortality percentage of M. incognita J2 after 12, 24 and 48hrs compared with untreated control. The maximum percentage of J2 mortality was found after 48 hr from oil treatment. Oil concentration at 1000 μl/liter was the best concentration to increase J2 mortality after 48 hr. Garlic oil followed by Argel oil were the best oils to increase J2 mortality after 12, 24 and 48hrs .
7- The effect of Garlic oil at concentrations of 12.5, 25 and 50 μg / mL on strawberry cv. Festival infected with M. incognita under greenhouse conditions was investigated. Our results showed that all the
tested concentrations of oil Garlic caused significant decrease in number of galls, egg-masses and number of second stage juveniles (J2) / 250 g soil compared with untreated control.Garlic oil at 50 μg / mL gave the highly significant reduction in root galls, egg-masses and number of J2 / 250 g soil compared with control. Garlic oil at concentration of 12.50 μg / mL had the lowest effect in reducing nematode galls, egg-masses and number of J2 / 250 g soil. Also, the rsults showed that garlic oil improved root and shoot growth of strawberry cv. Festival compared with untreated control