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SUMMARY

Various control methods such as cultural (de-trashing the older leafs during July

and September) biological (release of 2nd

instars larva per plant on the appearance of the

 pest at fortnightly interval throughout the crop season), chemical ( application of 

Imidacloprid 200 SL @ 568 ml/ha on pest reaching at ETL by making path for passagewith the help of power sprayer) and botanical (application of neem seed kernel extract

5% @ 6.17 liter/ha twice in the season on August 26 and September 27, 2009) were

applied singly and in their possible combinations for the control of whitefly on a

resistant and a susceptible genotypes of sugarcane. There were sixteen treatments in total

including control. The experiment was sown in two sets (one for resistant genotype and

the other for susceptible) at three localities viz. in the farmer’s field near Shakarganj

Sugar Mills, Jhang, Kamalia Sugar Mills Toba Tek Singh and Chinar Sugar Mills

Tandlianwala, Faisalabad, following randomized complete block design with three

replications. The data on the population of whitefly ( nymphs + Adults) were recorded

at fortnightly interval from each locality. The results revealed that the population of 

whitefly in the farmer’s field near Shakarganj Sugar Mills, Jhang and Kamalia Sugar 

Mills Toba Tek Singh did not reach to a desired level, therefore, no plant protection

measure were taken. The results obtained from the farmer’s field near Chinar Sugar 

Mills, Tandlianwala, Faisalabad are summarized as under:

  Population count of whitefly revealed significant variation among dates of 

observation, treatments and between genotypes. The maximum control of 

whitefly was recorded to be 1.57 per leaf and 3.49 per leaf with maximum

 population reduction of 72.45 and 65.68% in resistant (HSF-242) and susceptible

(CPF-243) genotypes of sugarcane, respectively in those plots where all the

control methods were applied in combinations. The release of 2nd

instars larva per 

leaf of Chrysoperla carnea showed minimum control of whitefly with 4.40 and

8.22 individuals per leaf with minimum reduction in population of whitefly i.e.

22.80 and 19.17% in resistant and susceptible genotypes of sugarcane,

respectively. The population of whitefly was higher in susceptible genotype of 

sugarcane as compared to resistant genotype in all the treatments including

control.

  Cane yield (Kg/ha) also showed significant difference between genotypes, among

treatments and between the interaction of genotypes and treatments. The

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application of all the control methods in combination resulted in maximum cane

yield i.e. 114311.6 and 122446.0 Kg/ha in susceptible and resistant genotypes of 

sugarcane with maximum increase in yield over control i.e. 24.27 and 20.17%,

respectively. The release of  C. carnea showed discouraging results with

minimum cane yield i.e. 92410.8 and 106967.6 kg/ha with minimum increaseover control i.e. 0.46 and 4.97% in susceptible and resistant genotypes,

respectively.

  The application of Imidacloprid 200 SL @ 568 ml/ha twice in the season when

applied alone showed maximum cost benefit ratio i.e. 1: 4.25 and 1: 8.06 in

susceptible and resistant genotypes of sugarcane, respectively followed by de-

trashing of older leaves twice in the season showing CBR of 1: 2.17 and 6.31 in

susceptible and resistant genotypes of sugarcane, respectively. The minimum

CBRs were recorded to be 1: 0.07 and 1: 0.90 in those treatments where predator 

was released in susceptible and resistant genotypes of sugarcane, respectively.

Recommendations

The genotype CPF-243 was found to be the resistant against whitefly on

sugarcane crop showing minimum population of the pest and maximum yield of cane as

compared to the other genotypes included in the study. This genotype is recommended to

the farmers for cultivation in the fields and recommended for plant breeders that they

should incorporate this genotypes based on the physical and chemical plant traits in their 

genetic materials for further improvement.

Imidacloprid is recommended for the control of whitefly on sugarcane crop as it resulted

in maximum cost benefit ratio followed by de-trashing of older leaves.