Presentation on theme: "Effect of Guava Fruit Colour and Size on Fruit Fly Incidence in Khartoum State Esam Eldin B. M. Kabbashi 1 and Osman E. Nasr 2 1. Food Research Centre,"— Presentation transcript:
Effect of Guava Fruit Colour and Size on Fruit Fly Incidence in Khartoum State Esam Eldin B. M. Kabbashi 1 and Osman E. Nasr 2 1. Food Research Centre, Ministry of Science and Telecommunication, Khartoum, Sudan. 2. Institute of Environment and Natural Resources, National Centre for Research, Ministry of Science and Telecom., Khartoum.
Guava (Psidium guajava L.) marketable sizes were standardized in Khartoum. Big (B) size (6 cm X 5 cm), Medium (M) (5 cm X 4 cm) and Small (S) (4 cm X 3 cm). The fruit fly infestation was assessed in these sizes and was found 13, 8 and 7 worm/ fruit, in the three sizes, respectively for the green (G) colour. The corresponding figures for the yellow green (YG) fruits were 20, 18 and 11 w/ f, respectively.
Moreover the infestation in the yellow fruits was 26, 17 and 18 w/ f, respectively. These results reflect a direct proportionality between the fruit fly infestation, the fruit size and fruit yellowness. The least significant difference (LSD) was highly significant (at 0.05 level) for the G and Y and G and YG and insignificant for the YG and Y fruits. It is (LSD) highly significant for the B and S, and B and M fruits and insignificant for the M and S fruits.
* Apple guava is one of the five major fruits in Sudan. It is known as a nutritious and medicinal crop as well. It is very rich in vitamin C as contains more than four folds that of orange. It also contains tryptophan animal amino acid. It is very rich in the anitcancer lycopene next to tomato but super to it in availability. Used as a remedy that mitigates diabetes, hypertension and/ or stops diarrhea.
®The guava fruit flies in Sudan The reported fruit flies from guava in Sudan include two genera (Ceratitis & Bactrocera) and four species (C. capitata, C. quinaria, C. cosyra and B. invadens). The Medfly (C. capitata )reported in the 1960s by Venkaterman and Elkhidir. The Rhodesian fruit fly (C. quinaria) reported later in the 1960s by Schmutterer. The mango (C. cosyra) fruit fly was reported in late 1980s by Deng.
The invader fly (B. invadens) was reported by Kabbashi in The impact of fruit fly infestation in guava is very tangible. Elbedri (1978) reported that the guava growers in Shendi (River Nile State) uprooted a lot of their trees due to this infestation. in 1990s the imports of guava and mango as well was sharply decreased due to the fly infestation. In 2005 the Federal Ministry of Agriculture considered the fruit flies as NATIONAL pests. An annual budget of about million USD.
* The Preharvest control practices include Spraying with some soft and botanical insecticides. Use of pheromone traps such as methyl eugenol traps. Avoiding the mix cropping with mango. This besides some pruning of the trees before the rainy season. * However, A lot of postharvest treatments are practiced and tested that include the following
allotted for the control programs of these pests. Attempts to control these pests include (1)Cultural practices (burying the rotten fruits in pits, collection of the spoilt fruits in closed polythene bags and subjected to direct sun, etc….). (2)Visual selection of the infested fruits was also practiced in Kassala. (3)Hot water dip was experienced by the federal department of horticulture. (4)The Food Research Centre recommends hot water treatment (55°C/ 15 minutes) and 2 KGy ɣ irradiation.
Materials and Methods * Kadaro (30 Km N Khartoum Centre) white guava were collected and brought to the lab at FRC. The fruits were stored thereafter. Three groups (each of 25 fruits) were then made using visual sense (Viz. small, medium and large). The same was done for the color experiment (yellow, yellow green and green). Measurements by a vernier were then done for the fruits of the groups mentioned. The proximal and distal ends for the length and the fruit body fro the width. The SPSS statistical program was used in the analysis.
RESULTS Table 1: Size Measurement of Guava Fruits ** Highly significant at 0.05 level (1/ and 2/ significance, respectively). Std. Error Std., Dev., Width Std. Dev., Length Mean Width**3 Mean Length**2 (cm) Size** Big Medium Small Total
The Size Measurement Results (1) Big (5.89 cm X 5.06 cm) approximately (6 cm X 5 cm). (2) Medium (4.66 cm X 3.9 cm) approximately (5 cm X 4 cm). (3) Small (3.86 cm X 3.39 cm) approx. (4 m X 3 cm). (4) Total Mean (4.8 cm X 4.12) approx. (5 cm X 4 cm).
Table 2: Effect of the Rind Colour and Fruit Size on Infest. in Guava (w/ f) (** highly significant at 0.05 level) Signific.LSDStd. ErrorMean** 2 Fruit Size** 1 Colour 13.04BigGreen (G) 8.28Medium 6.56Small (YG) - 711** (Y) – 11.15** Total 20.24BigYellow Green 18.42Medium 10.54Small (G) 7.11** (Y) – Total 25.66BigYellow 17.22Medium 18.44Small (G) 11.15** (YG) Total
* The mean infestation of fruit flies to guava fruits decreased with the fruit size. the total mean for G, YG and Y guavas are 9.29, 16.4 and 20.44, respectively. This may indicate the direct proportionality of yellowness and the inverse proportionality of greenness of guava fruits to fruit fly infestation. The total mean for big, medium and small guavas (for the three tested colours) are 19.65, and 11.85, respectively which reflect the direct proportionality of the fruit size to fruit fly infestation.
Table 3: Effect of the Fruit Size on Infestation in Guava (Dependent variable, w/ f) Sing.LSDMean**Fruit Size** Total (M) 5.01** (S) 7.80** 19.65Big (B) –5.01** (S) Medium (B) –7.80** (M) – Small 15.38Total
* The LSD is significant for the B & M, B & S and insignificant for M & S fruits. CONCLUSION The conclusion of this study necessitates the priority of recommendation for the medium size and medium colour (YG) guava an idea agrees with the natural and common preference of the different stakeholders.