EVALUATION OF INFESTATION RATES WITH BEMISIA TABACI (GENN.) AND LIMIT NUMBERS WITH APHIS GOSSYPII (GLOVER) ON SOME TOMATO VARIETIES AND THEIR EFFICACY AGAINST TOMATO YELLOW LEAF CURL VIRUS INFECTION

 

A.A.A. Abd-Allah and  I.Z.A. El-Shimi*

Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza, Egypt.

* Horticultural Research Institute, Agricultural Research Center, Dokki, Giza, Egypt.

 

 

ABSTRACT

The susceptibility of eight varieties of tomato (Lycopersicum esculintum L.) namely Super Marmand, Prichard, Giza 80, Cherry, Money Maker, Castlerock, CAL-ACE and GS 12 to infestation with the whitefly (Bemisia tobaci Gennadius, Homoptera, Aleyrodidae) and artificial infestation with aphids (Aphis gossypii glover, Homoptera, Aphididae) was investigated.

In order to evaluate the effect of infestation with whitefly and tomato yellow leaf curl virus (TYLCV), the disease severity rate (D.S.R.) was used. Money Maker variety was the highest resistant, while Castle Rock showed high susceptibility for TYLCV. Also, this study amid to develop alternative management practices to prevent annual damage from infestation with aphids at different levels. The experiments were carried out during winter season of 2004 – 05 at Agricultural Research Station, EL- Kassasien, Ismailia  Governorate , Egypt.

The results revealed that, Money Maker, Giza 80 and Castle Rock tomato varieties were the most resistant varieties as plants were attacked with few numbers of immature and adult stages of whitefly. Super Marmande and Prichard were the highest infestated varieties with whitefly stages. The, period of high infestation rates were January ,5^th  and January, 26^th  for adult  stage and December, 1^st  and December,29^th for Immature stages. This may be due to the use of pesticides  which affected badly the natural balance of the pest (Hafez and Khalifa, 1975).

On the other hand, a positive correlation existed between aphid population levels and damage severity on plant.

The results indicated clearly that, early infestation with a little numbers of aphids lead to more damage and decreasing of the yield. Further, the infestation with one or two pairs of aphids necessitates the start of efficient aphid control program within the second week maximum.

Also , some vegetative and yield characters was measured for the most tested characters of the eight tomato varieties.

Keywords: Infestation rates, Bemisia tabaci ,limit numbers, Aphis gossypii, tomato varieties.

 

 

INTRODUCTION

 

 Tomato plants, Lycopersicon  esculentum L. are one of the most vegetable crops in Egypt and allover the world being growing in several plantings dates during the year. Tomato plants are attacked during their vegetative growth by various pests, among which the whitefly Bemisia tabaci (Genn.) and aphid , Aphis gossypii (Glover) are considered as the important pests causing various degrees of damage, various diseases and lately yield losses (Faris et al., 2004)

 Because of the great current concern about the environment indicates a need to limit application of chemicals for plant pests control. Abroad and often over use of pesticides is ecologically harmful, toxic to many vertebrates, and may lead  to a development of pesticide resistance in the target pests (Ozeretskovskaya, 1995).

 Due to the  high costs of insecticides and hazards of spraying on edible crops. the possibility that tomato varieties may exhibit differential susceptibility to B. tabaci was explored (Kisha, 1984).

 Hence, the demand on vegetables free from any contamination with pesticides increased year after year. The search about new procedures to minimize the injurious effects of pests infestation and magnify the natural resistance of plants to infestation is increased.

 This study reviews the population density of B. tabaci and Aphis gossypii and its relation with different varieties of  tomatoes which can be used to obtain basic information for implementing a sound integrated pest management program. Also attempt to clarify factors influencing fluctuations in population density were studied . Therefore, the present work aimed to find out the susceptibility of different tomato varieties to whitefly, cotton aphid and its damage for investigated varieties and its affect on yield.

 

MATERIALS AND METHODS

 

  Six true breeding of tomato varieties namely, Super Marmande Prichard, Giza 80, Money Maker, Castle Rock, CAL-Ace and two commercial varieties, Cherry and GS12, were sown at 16^th  September, 2004  ( winter season ). These genotypes were taken from the self- pollinated crops Dept. of. Horticulture Research Center Seedlings were transplanted at 13 October, in ridges of seven meters long and one meter width with 50 cm between hills. Normal agricultural practices were employed without  insecticide intervention.

  The following experiments were conducted in the experimental farm of East Delta Research Station in EL-Kassasien, Ismailia Governorate, Egypt during 2004/2005 winter season in a complete randomized blocks design with three replicates for each tomato variety. For each plot, at seedling stage, three tomato seedlings clean from any infestation were caged singly with thin white cloth cages, each 60x60x80 cm., while the rest area of each plot was considered as open field.

 

A-Fluctuation in Bemisia tabaci stages population:

Forteen day after transplanting at  Oct. 27^th  infestation of whitefly started and it was counted weekly until the harvesting time of each variety. Number of whitefly adults was visually counted before sunrise in the field on the lower surfaces of 10 randomly chosen leaves/plot (30 leaves/ variety). As for B. tabaci immatures (eggs & nymphs), 10 leaves were randomly picked form each replicate and were inspected under a stereo microscope. Also, numbers of infected plans by TYLCV were recorded according to (Smith, 1972).

 

B- Effect of different levels of aphid infestation on tomato varieties:

To study the effect of different levels of aphid infestation, artificial infestation with mature apterous adults of aphids (Aphis gossypii) were done at the levels of  1, 2 and3 pairs per each caged plant. The caged plants were kept under observation. The aphid numbers per plant, growth characters and levels of damage such as wilt, yellowness, shrinking, dwarfism, flower dropping, shoots killing and death were monthly recorded. The inspection for aphids were carried on the plants early in the morning. At the end of the experiment, fruits were harvested, weighted and physical characters were determined for each variety.

All the obtained results were statistically analyzes according to completely randomized blocks design using “ANOVA” analysis of variance by Duncan multiple range test (Duncan, 1955) for variables COSTAT program.

 

C- TYLCV evaluation :

Incidence of TYLC in infected plants was visually determined, at one month intervals, starting 30 days after transplanting. The number of infected plants in proportion to the total number of plants for each replicate was counted. Severity incidence of TYLCV in each plant was recorded, and disease severity rate (D.S. R.) for each replicate was calculated according to formula of Chastanger and Ogawa, (1979) that is:

  D.S. R.=   S x I / N

Where:   S = Average of severity infection, I = Infected plant number, N = Replicated plant number.

The severity of symptoms were classified on a 6 point rating scales, representing a TYLCV incidence ( Table 1 ).

 

D-Relationship between vegetative growth characters of tomato varieties and infection rates:

During the growing season, the following data were recorded:

 

Table (1): The reaction classification used as severity index of TYLCV symptoms, developed infested different tomato varieties on winter season 2004/2005.

Reaction class	Rating scale
No infection	0
Resistant	0-1
Moderately resistant	1-2
Moderately susceptible	2-3
Susceptible	3-4
Highly susceptible	4-5

 

1-     Plant height (cm); average of 10 plants for each variety in each replicate, 30 days after transplanting.

2-     Number of branches /plant: average of 10 plants for each variety for each replicate.

3-     Number of leaves /plant: average of 10 leaves for each variety in each replicate.

4-     Dry matter content (gm./plant):average of 10 plants for each variety in each replicate.

5-     Average fruit weight (gm.): average of 10 fruits for different plants for each variety in each replicate.

6-     Fruit length (cm.).                7- Fruit width (cm.).

8-  Flesh thickness.                    9- Total soluble solids (T.s.s.) contents.

The aforementioned characters were record for the plants infected with B. tabaci and the caged plants (without any infection or control).

 

 

RESULTS AND DISCUSSION

 

A. Relative susceptibility of tomato varieties to whitefly infestation:

The population density and dynamics of undeveloped and adult stages of whitefly during October, 2004 to March 05 (winter season) are presented in Table (2).

It was indicated that infestation to different varieties of tomato plants with B. tabaci stages started early when plants were in the seedling stage. This may be due to  the adults which are attracted firstly the green host plants in the environment, then females are able to distinguish the suitable hosts for its progeny. In this respect, Valishampayan et al. (1975) indicated that Trialeurodes vaporariovum females can discriminate between their hosts only after the physical contact with the plant.  The illustrated data indicate that Prichard variety was highly susceptible to different stages of whitefly (53.08 mean of individual adults/compound leaf).

Super Marmande, too appeared highly susceptible to adult stage (53.24), and it was little affected by nymphs stage (36.05).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

On the other hand, Money maker and Giza 80 were the lowest susceptible varieties to adult and nymph  stages of whitefly infestation (18.62), 25.67 and 25.57, 22.95) individual/leaf, respectively .The tested varieties showed different dynamics of population as well as different peaks of infestation.

It is clearly evident to notice the occurrence of great infestation with two highest peak on January 5^th  and January, 26^th . The average numbers of adult stage on the 1^st peak were; 94, 125,48, 65, 44, 68,78 and 133 individual/leaf and while the 2^nd peak were, 126,160,50,60,33,99,80and 110 individual/leaf for Super Marmande, Prichard, Giza 80, Cherry, Money Maker, Castle Rock, CAL-ACE and GS 12 respectively .Also, the studies showed two peaks for undeveloped stage, the 1^st in December,1^st  while the 2^nd peak  in December,29^th .

The difference between these varieties proved to be highly significant (Table 3). It is clearly evident to notice the differences in population density of whitefly adults on the eight plant varieties at the beginning of experiment on October, 27^th  (13,18) individual. adult/compound leaf for Money Maker, GS 12 and (10, 27) individual. nymphs/comp. leaf for Super Marmande and Castle Rock, respectively.

Therefore, population density  was gradually increased by  the lapse of  time and reached the maximum on the previous peaks. All tomato varieties injured with whitefly different stages during  all  time of winter season but with different levels of  infestation.

Regarding plant age, it was clear evident that the mean population of undeveloped  stages start with high populations during  the first two weeks of December till the end of December (average of 97, 91 and 85 individual./compound. Leaf ) at December,  1^st ,70, 75 and 56 individual./ comp. leaf)at December, 29^th  for Prichard, Castle Rock and Money Maker, respectively.

Considering the results of the five inspection dates  (from seedling stage  to  the obtained yield), it is clear that CAL-ACE, Castle Rock, GS 12 and Super Marmande gave highest yield. It’s gives 1.450, 1.410, 1380 and 1.300 Kg./plant, but  the same varieties gives, 1.750, 1.630,1.650 and 1.850 Kg./plant when caged and isolated from any infestation with insects.

These results agree with Abd-El-Wahab, Horia et al. (1997) which found that tomato variety Castle Rock when adult and nymphs counted at November. The average numbers were:20.48, 13.68 at 1995 and 29.68,23.72 individual/comp. leaf respectively.

Also, El-Sayed et al., (1991) found that the average numbers  of whitefly (ummature stages) on ACE  tomato variety was 29.3 and 32.9 individual/comp. leaf at 1984 and 1985 respectively.

Also, Youssef (1999) found that the average numbers of whitefly (adult) on GS tomato variety was 40.6 individual.

Regarding the mean yield Kg./plant, there was significant  differences among the tested varieties until the season end.

Super Marmande/and CAL-ACE gave  the highest mean yield under caged (1.850 and 1.750Kg. /plant), while, Money Maker and Cherry gave the lowest yield (1.130 and 0.550 kg./plant) , respectively.

These results were in agreement with the findings of Iskander  (1992), who found that super Marmande variety  gave the higher yield.

 

B- The effect of different levels of aphid infestation on tomato varieties:

The average number and damage characters were graphically presented in Fig. (1) and Table (3). The lowest level of the number of aphids was over 5.27 individuals to show  the first character of damage (i.e. wilt). After two months of infestation with 1 and 2 pairs of aphids,  the maximum character of damage was shrinking and dwarfism appeared on Super Marmande, CAL-ACE and GS 12.

Regarding the infestation by 3 pairs of aphids, only three varieties of the infested plants were killed after three  months from infestation date. Such information indicates clearly  that infestation of one month old tomato plants with one pair of aphids necessitate aphid control within maximum three  weeks. Under the  infestation with 2 pairs of aphids, aphid control must be undertaken within one month especially on Super Marmande, CAL-ACE and GS 12 . The delay of aphid control will result in more progressive and serious injury  to tomato seedlings, i.e. yellowness, shrinking, dwarfism followed  by death of plants Fig. 1, under   the infestation with 3 pairs of aphid.

After 3 months from infestation, 3 pairs of aphids reached 45.33 on Money Maker, 51.67 or Gs 12, 53.33 on both of Castle Rock and CAL – ACE and this level of aphid infestation was the maximum reached on Super Marmande (58.33 individual/leaf).

Experimental results indicated clearly that, infestation of Super Marmande, CAL – ACE and GS 12 with one or two pairs of aphids necessitate to start of efficient aphid control program within the second week maximum. Infestation with 3 pairs of aphids, necessitate to start of the aphid control program within the 1^st  week after infestation .

The present study direct our attention toward the fact that the earlier discovery and control of spot infection with aphid is the better strategy.

 

C- TYLCV evaluation:

Evaluation of eight tested tomato varieties, for TYLCV depended on morphological characteristic of viruliferous foliage symptoms of natural infection in the field.

This symptoms include the following five stages :

1-  Leaf yellowing                                      2- Leaf curl (shrinking)

3- Leaflet size reduction                             4- Stem and branch stunting

5- Flower drop.

Values of TYLCV resistance, as disease severity rate (D.S.R.), for eight   tomato varieties, are presented in Table (4). It was clear from D.S.R. data, that large

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table (4): Severity index (D.S.R.) of TYLCV disease in different varieties of tomato  plants within winter season 2004/2005 at El-Kasassasien station.     

(a) According to a 0-5 rating scale.                 * Average of D.S.R .for three replicates.

N. = Plant numbers/rep.                                       I. = Plant infected numbers.

S.= Infection severity.

 

differences in viral infection levels were present among the varieties studied. The statistical analysis revealed positive significant differences among the resistance varieties for TYLCV, also between these varieties and control. Castle Rock variety was considered susceptible for TYLCV.

On the other hand, Table (4) showed that the maximum resistance was obtained with Money Maker variety.

The rest varieties can be arranged between adjective of resistance and adjective of susceptible varieties according to the reaction classification used as a severity index of TYLCV symptoms in Table (1) Therefore, the variety was considered least resistant or the more susceptible to TYLCV infection when compared with Money Maker variety (as a standard).

It is clearly evident to no significant differences between varieties in the infestation rate with B .tabaci adults and the percentages of TYLCV infection.

These results agree with those obtained by Abd-EL-Wahab, Horia et al. (1997) found that, Castle Rock variety showed the highest susceptibility to TYLCV infestation on the other hand, results of GS 12 variety contradicted with Yossef (1999) who stated that GS 12 variety had not any tolerance against virus infection.

 

D- Effect of artificial infestation and covering on vegetative and fruit physical characteristics:

• Vegetative  growth parameters:

Data in Table (5) revealed that, caged plants  had a good performance against infected  plants.  For  instance,  all  the  vegetative  characteristics e.g  plant height,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

number of branches, number of leaves and dry matter content  had the highest values for caged plants than infected, mean while, data presented in Table (5) indicted that, Money Maker cv. Had the highest value for plant height, while this values strongly decreased by infection.

At the same time CAL-ACE cv. had the highest values for number of branches and dry matter content while Giza 80 cv. had the highest value for number of leaves. The infected plants were greatly affected by infection, which stunted for all the vegetative growth characters. The most affected variety was Super Marmande and Prichard cvs. for plant height and number of branches, while Super Marmande and Prichard cvs  were the more affected by infection for number of leaves, and Giza 80 cv was  the least for dry matter content.

These indicated that the  artificial infestation of tomato variety had led to a great depresion in growth characters. These findings were in agreement  with those obtained by Hassan et al (1991) and Moustafa and Hassan  (1993).

               

Yield component and fruit physical characters:

Data in Table (5) generally showed that,  in, the yield components e.g. average fruit weight, fruit length, fruit width and yield (ton/fed.) were deeply affected by infection of B.tabaci or aphis, gossypi. These findinges were found from data in Table (5) which showed that, CAL-ACE cv. had the greatest values for fruit weight,  fruit length fruit width and total soluble solids under caged  plants, while these parameters were deeply decreased  by artificial  infestations, which showed Prichard cv. great depressions in fruit weight reached to 50%.

Also,  the artificial infections, and rates of infections, had a significant effect in yield component which decreased fruit length, fruit width and  total soluble solids, reached   to 40% for all characteristics. These findings were obtained by Moustafa and Nakhla (1990), Mostafa and Hassan (1993) and faris et al. (2004).

 

 

REFERENCES

 

Abd-El-Wahab, Horia; Soad A. Ibrahim; Shanhazy El-Deeb and M.F. Befai  (1997). Evaluation and residual effects of some insecticides against  the whitefly Bemisia tabaci (Genn.), and their efficacy against tomato yellow leaf curl virus infestation. J.Agric. Sci.Mansoura Univ., 22 (10): 3326 – 3338.

Chastanger, G.A. and Ogawa, J.M. (1979). A fungicide treatment to suppress Botrytis cinera and protect freshmarket tomatoes. Phytopathology, 69:59-63.

Duncan, D.B. (1955). Multiple range and multiple F-test. Biometrics,11:1-42.

El-Sayed A.M.; F.F. Shalaby and A.A. Abdel–Gawad (1991). Ecological studies on Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) infesting different host plants. Egypt.J. Agric.Res., 62 (1):193-207.

 

Faris, F.S.; Nadia H.Habashy and Aida K.F. Iskandar (2004). Relationship between infestation with different stages of the spider mite, Tetranychus  urtica  Koch on fifteen  tomato varieties and plant age with special reference  to vegetative and yield physical characters. J. Agric. Sci. Mansoura Univ., 29 (6): 3567-3579.

Hafez, M. and A. Khalifa (1975). Report on cotton culture and cotton pest control in Egypt . FAO/UNAP Consultation on pest Mnageamant System for the control of cotton pests , Karachi , 13-16 Oct., 1975 )

Hassan, A.A.; M.s. waif; N.E. Quronfilah; u.A. Obaji; M.A. Al–Rayis, and F. Al- Izabi (1991). Evaluation of wild and domestic Lycopersicon accessions for tomato yellow leaf curl virus resistance. Egypt. J. Hort., 18  (1): 23-43.

Iskandar, N. N. (1992). Studies on the tomato whitefly Bemisia tabaci (Genn.).Agric. Res. Rev., Cairo,73:269-281.

Kisha, J.S.A. (1984). Whitefly B.tabaci infection on tamato varieties and wild lycopersicon species. Ann. Appl. Biol., 104 (5): 124-125. Kluwer Academic publisgers. Kuc. “Development in Plant Pathology” (4).

Moustafa, S.E. S. and M.K. Nakhla. (1990). An attempt to develop a new tomato variety resistant to tomato yellow leaf curl virus (TYLCV). Assiut. J.Ahric. Sci., 21 (3): 167 – 183.

Moustafa, S.E.S. and A.A. Hassan. 1993. Tomato cultivar evaluation with emphasis on  tomato yellow leaf curl virus tolerance. Assiut. J. Agric. Sci., 24 (1): 155 – 172.

Ozeretskovskaya,  O.L. (1995).  Induced resistance in the Solanaceae.  In: Induced resistance to disease in plants. PP. 31-36. Eds. R.Hammerschmidt & J. Kuc. “Development in plant pathology” (4). Kluwer Academic Publishers.

Smith, K.M. (1972). Atext Book of Plant Virus Diseases. Longman Groups ltd. London, 685 pp.

Valishampayan, S.M; Walbauer, Gp and Kogan, M. (1975).  Visual and olfacorv responses in orientation to plants by the green house whitefly Trialeurodes vaporiourm (Homoptera Aleyrodidae). Ent.  Exp. & Appl., (8): 41 – 42.

Youssef, H.I. (1999). Selected applications in  tomato fields against the whitefly Bemisia tabaci Gennadus. Ann. Of Agric. Sc., Mosht. Vol. 37 (3): 1979 – 1985.

 

 

 

 

 

 

 

 

تقییم معدلات إصابة الذبابة البیضاء وأعداد محددة من مّن القطن على بعض أصناف الطماطم وعلاقتها بالإصابة بفیروس تجعد الأوراق الأصفر

 

عاطف عبد الفتاح أحمد عبد الله   ـــ  إبراهیم زکی عبد الوهاب الشیمی*

معهد بحوث وقایة النباتات – قسم بحوث آفات الخضر- مرکز البحوث الزراعیة – الدقی – جیزة - مصر

معهد بحوث البساتین قسم بحوث الخضر- مرکز البحوث الزراعیة – الدقی – جیزة- مصر.

 

 

درست قابلیة إصابة ثمانیة أصناف من الطماطم وهی:

 Prichard, Super Marmande , GS 12 , CAL-ACE, Castle Rock, Money Maker, Cherry, Giza 80,  للإصابة بذبابة الطماطم البیضاء ، وکذلک درست العدوى الصناعیة لنباتات الطماطم بثلاث مستویات من منّ القطن، کما درست نسبة الإصابة بفیروس تجعد الأوراق الأصفر للطماطم باستخدام معادلة قیاس شدة المرض ، حیث وجد أن الصنف Money Maker هو أکثر الأصناف مقاومة للمرض بینما وجد أن الصنف Castle Rock هو أکثرها حساسیة للمرض.

کما تهدف هذه الدراسة إلی معرفة الإجراءات النسبیة لمنع تطور الضرر الناشئ من الإصابة بمستویات مختلفة من المن، وقد تمت هذه التجارب فی الموسم الشتوی بمحطة البحوث الزراعیة بالقصاصین عام 2004 – 2005م والتابعة لمحافظة الإسماعیلیة.

وقد أوضحت النتائج أن الأصناف Money Maker, Giza 80, Castle Rock هی الأعلى مقاومة للأطوار الکاملة والحوریات للذبابة البیضاء حیث وجد علیها أقل تعداد حشری بینما کان Super Marmande  و Prichard الأعلى إصابة بأطوار الذبابة البیضاء.

کما أوضحت النتائج أنه توجد قمتان للحشرة الکاملة للذبابة البیضاء فی أول ینایر و 26 ینایرو قمتان للأطوار غیر الکاملة للذبابة البیضاء فی أول دیسمبر و 29 دیسمبر.

وهنا یمکن القول بأن الاستخدام السیئ للمبیدات الحشریة یؤثر بشدة على التوازن الطبیعى للآفة.

وعلى الوجه الآخر . وجد أن شدة الضرر على النبات ینشأ عن مستویات عددیة مختلفة من المن حیث أوضحت النتائج أن الإصابة المبکرة بأعداد قلیلة من المن تؤدی إلى ضرر أکثر کما تؤدی إلی إنخفاض فی المحصول. لذلک یکون من الضروری الإسراع فى برامج المکافحة بمجرد ظهور زوج أو زوجین من المن خلال أسبوعین على الأکثر.

کما درست بعض الصفات الخضریة والصفات الطبیعیة للمحصول لأصناف الطماطم المختبرة حیث کان أفضلها, CAL-ACE Castle Rock ,  GS 12و Super Marmande

 

 

 

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