Population Dynamics and Management of Mango Hopper IdioscopusniveosparsusLeth under Konkan Region of Maharashtra
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Date
2016
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MPUAT, Udaipur
Abstract
Investigations on “Population Dynamics and Management of Mango Hopper IdioscopusniveosparsusLeth under Konkan Region of Maharashtra” were conducted at the Regional Fruit Research Station, Vengurle, Maharashtra (Dr. B. S. KonkanKrishiVidyapeeth, Dapoli) during 2013-14 and 2014-15. The study revealed that the incidence of I. niveosparsusinitiated in the 31st and 32nd SMW with the population of1.28 and 1.04 hoppers/panicle;the population gradually reached the first peak at vegetative stageduring 45th and 44th SMW with the population of 8.90 and 9.30 hoppers/panicle;thereafter, the population declined and again reached the second peak of 18.40 and 15.78 hoppers/panicle at flowering stage in the 3rd SMW during 2013-14 and 2014-15, respectively.
The mango hopper exhibited significant positive correlation with maximum temperature (r = 0.393*) only during 2013-14 and sunshine hours (r = 0.445* and 0.351* ) during 2013-14 and 2014-15, respectively; whereas, the hopper population had significant negative correlation with minimum temperature (r = - 0.569* and -0.707*), mean temperature (r = - 0.350* and -0.559*), evening humidity (r = - 0.539* and -0.410*) and rainfall (r = - 0.413* and -0.381*), respectively, during 2013-14 and 2014-15. The studies on multiple linear regression analysis showed that maximum temperature, minimum temperature, morning RH, evening RH, rainfall and sunshine hours had a significant impact on themango hopper population during both years. The respective valuesof coefficient of determination (R2 ) were 0.44 and 0.58, during 2013-14 and 2014-15.
During flowering and fruiting season of both the years, thenatural enemiesviz., spiders,chrysopids and coccinellid beetles were recorded to be associated with the hopper population.The spider population was maximum (1.20 spider/quadrant) in the 11th and 12th SMW during 2013-14 and 2014-15, respectively. It exhibited significant negative correlation with minimum temperature (-0.6844*), mean temperature (-0.6133*), evening humidity (-0.6985*) and mean relative humidity (-0.4991*) during 2013-14; whereas, during 2014-15 there was significant positive correlation with morning humidity (0.5217*) and significant negative correlation with maximum temperature (-0.4228*).The population of chrysopidwas maximum (0.65 and 0.75 chrysopid / quadrant) in the 7th and 6th SMW during 2013-14 and 2014-15, respectively. The chrysopid population exhibited significant negative correlation with minimum temperature (-0.6117* and -0.6364*) and mean temperature (-0.5415* and -0.6084*), during both the years. The chrysopid also exhibited significant positive correlation with mango hopper (0.4270* and 0.5173*) during 2013-14 and 2014-15, respectively.The coccinelid beetle population was maximum (0.45 and 0.65 coccinelids / quadrant) in the 7th and 5th SMW during 2013-14 and 2014-15, respectively. It exhibited significant negative correlation with minimum temperature (-0.7296* and -0.6939*) and mean temperature (-0.6971* and -0.6572*) during both the years. Similarly, the correlation between hopper and coccinellid was significantly positive (0.4560* and 0.6441*) during 2013-14 and 2014-15, respectively.
Among the fifteen mango varieties screened, maximum hopper population (19.40 and 17.70 hoppers/panicle) was recorded on variety Alphonso during both the years. The least hopper population was recorded on exotic varieties Keitt (11.70hoppers/panicle) and Lily (9.60 hoppers/panicle) during 2013-14 and 2014-15, respectively.The maximum growth of black sooty mould was recorded on variety Alphonso (47.50 and 45.42% leaf area covered) and the minimum growth was recorded on variety Lily (32.50 and 31.04%) during 2013-14 and 2014-15, respectively.
The results of relative efficacy studies revealed that 24 hours after spray the treatment acetamiprid + spreaderrecorded maximum reduction in hopper population (90.95 and 91.04%), respectively during 2013-14 and 2014-15; whereas, seven days after spray the treatmentthiamethoxam + spreader was most effective with 98.49 and 96.67 per cent reduction during 2013-14 and 2014-15, respectively. Similarly,14 days after spray the treatment thiamethoxam + spreader was most effective with 99.59 and 98.74 per cent reduction.
The results of relative efficacy against black sooty mould revealed that the treatment acetamiprid + spreaderwas most effective with the least growth of black sooty mould (7.87 and 7.81% leaf area covered) during 2013-14 and 2014-15, respectively.The highest yield of 60.00 and 53.23 kg/tree was recorded in the treatmentthiamethoxam + spreader during 2013-14 and2014-15, respectively. The lowest yield (42.33 and 35.13 kg/tree) was recorded in the treatment azadirachtinduring both the years.
The maximum cost benefit ratio (1.85 and 1.84) was recorded in thetreatment acetamipridduring both the years. The maximum avoidable yield loss (50.50 and 51.66%) was recorded in the treatment thiamethoxam + spreader during 2013-14 and 2014-15, respectively.
In mature fruits the residues of treated insecticides were below detectable limit.
Description
Studies on the Population Dynamics and Management of Mango Hopper IdioscopusniveosparsusLeth under Konkan Region of Maharashtra
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Citation
Munj and Rana, 2016