Estimation Of Damage Caused By Root Grub Holotrichia Reynaudi Blanchard In Groundnut In Different Dates Of Sowing

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K. SUNIL KUMAR*, T. MURALI KRISHNA, K. SREEDEVI, K. MANJULA, R. SARADA JAYALAKSHMI DEVI, B. RAVINDRA REDDY AND K. DEVAKI

ARS, Utukur, ANGRAU, Kadapa Dist., A.P.

ABSTRACT

Holotrichia reynaudi Blanchard is one of the predominant species of root grub in groundnut ecosystem of Rayalaseema region, Andhra Pradesh. Two field experiments were conducted at the research farm of Agricultural Research Station, Utukur, Kadapa during kharif, 2014 and 2015 to estimate the damage caused by root grub, H. reynadui in groundnut under three different dates of sowing. The studies revealed that, in June IInd FN sown crop, the average per cent plant mortality per m2, number of grubs per m2 in unprotected and protected plots were 23.36 per cent, 2.23 grubs m-2 and 6.20 per cent, 0.39 grubs m-2 respectively. In July Ist FN sown crop, they were 21.20 per cent, 2.08 grubs m-2 and 5.41 per cent, 0.37 grubs m-2 and in July IInd FN sown crop they were 20.46 per cent, 1.95 grubs m-2 and 5.14 per cent, 0.34 grubs m-2 respectively. The pod yield in June IInd FN sown unprotected and protected plot were 1063.50 kg ha-1 and 1680.50 kg ha-1, in July Ist FN sown it was 1148.50 kg ha-1 and 1745 kg ha-1 and in July IInd FN sown it was 1175 kg ha-1 and 1771kg ha-1. In June IInd FN sown crop the per cent loss in yield was higher (36.74%) followed by July Ist FN sown plot (34.19%) and July IInd FN sown plot (33.65%).

KEYWORDS:

Holotrichia reynaudi, plant mortality, assessment of loss, damage, groundnut.

INTRODUCTION

Groundnut (Arachis hypogaea L.) is a principal oilseed crop of India. In Andhra Pradesh, it is cultivated in an area of 8.72 lakh ha, out of which 95 per cent of area belongs to Rayalaseema region (adpdes.ap.gov.in). Groundnut crop is known to be infested by more than 360 species of insect pests in different parts of the world (Wightman and Amin, 1988). The insects that live in the soil of groundnut fields are responsible for higher levels of yield loss than foliage feeders. Soil insects are difficult to manage because farmers usually do not know that they are present until plants die (or) until the crop is harvested. One of the most important soil pests affecting groundnut is root grub. The root grubs or white grubs belonging to the family Scarabaeidae are some of the diverse and devastating pests of several crops and assumed national importance due to high per cent yield losses (Sreedevi and Tyagi, 2015). Root grubs are universally known as May beetles, June beetles or cockchafers because adults become active during the month of May/June with the onset of monsoon

, once active, adults fly to trees at dusk for feeding and mating, female subsequently lay eggs in the soil. Groundnut planting in Rayalaseema region mostly coincides with the onset of monsoon. The root grubs cause damage by

feeding on the roots and underground parts of the plant from one to several inches below the soil surface. The plant turns yellow and wilts resulting in patchy growth in fields. Affected plants when pulled shows feeding symptoms i.e., cut ends of the roots.

The root grub causes damage to other agricultural crops such as sugarcane, pearl millet, sorghum, maize, pea, potato etc. (Vasanth et al., 2014). In endemic areas, the damage to groundnut ranges from 20-100 per cent. The presence of one grub/m2 can cause 80-100 per cent mortality (Yadava and Sharma, 1995), damage upto 39.40 per cent (Umeh et al., 1999) and 12-60 per cent (Pokhrel, 2004) . About 80,000 ha of groundnut has been reported to be affected by white grubs in Andhra Pradesh (Wightman, 1995). Though a lot of work has been done on biology, ecobiology and management of white grubs in groundnut ecosystem, not much attention is paid on the estimation of damage caused by root grubs in groundnut ecosystem of Andhra Pradesh. Hence an attempt was made to know the extent of damage caused by root grub, H. reynaudi in groundnut.

MATERIAL AND METHODS

The crop (variety Dharani) was sown on three dates i.e., June IInd FN, July Ist and IInd FN during kharif, 2014 and 2015 with two treatments protected and unprotected. In protected plot, seeds were treated with chlorpyriphos 20 EC @ 6 ml/kg seed 12 hours before sowing. No seed treatment was done in unprotected plot. Data was recorded on per cent plant mortality, larval incidence per m2 on 10 randomly selected spots at 30, 50, 70 and 90 days after sowing. Pod yield in each plot was recorded after harvest. Per cent yield loss was calculated with the pod yield parameters of protected and unprotected treatments. Per cent plant mortality and per cent yield loss was calculated as under

Per cent plant mortality =Number of dead plants due to white grubs / m2 u100
Toal number of plants / m2

Per cent yield loss = Pod yield in unprotected plot u100

Pod yield in protected plot

RESULTS AND DISCUSSION

In June IInd FN sown crop, per cent plant mortality increased from 30 to 90 DAS, while in July Ist and IInd FN sown per cent plant mortality increased from 30 to 50 DAS and decreased from 50 to 90 DAS. In June IInd FN sown crop the pooled average per cent plant mortality m-2, number of grubs m-2 in unprotected and protected plots were 23.36 per cent, 2.23 grubs m-2 and 6.20 per cent, 0.39 grubs m-2. Whereas in July Ist FN sown crop, they were 21.20 per cent, 2.08 grubs m-2 and 5.41 per cent,

0.37 grubs m-2 and in July IInd FN sown crop they were 20.46 per cent, 1.95 grubs m-2 and 5.14 per cent, 0.34 grubs m-2. Pooled highest per cent plant mortality m-2 due to root grub was observed in unprotected plots of June IInd FN sown crop (23.36%) followed by July Ist FN sown crop (21.20%) and July IInd FN sown crop (20.46%). Highest protection over unprotected plot (74.87%) was observed in July IInd FN sown crop followed by July Ist FN sown crop (74.48%) and June IInd FN sown crop (72.88%).

The pooled pod yield in June IInd FN sown unprotected and protected plot was 1063.50 kg ha-1 and 1680.50 kg ha-1, in July Ist FN sown it was 1148.50 kg ha-1 and 1745 kg ha-1 and in July IInd FN sown it was 1175 kg ha-1 and 1771 kg ha-1. Highest pod yield in protected plots was recorded in July IInd FN sown crop (1771 kg ha-1) followed by July Ist FN sown crop (1745 kg ha-1) and June IInd FN sown crop (1680.50 kg ha-1). In June IInd FN sown crop highest pooled per cent plant mortality was observed hence the pod yield might have decreased in unprotected plot (Table 2).

In June IInd FN sown crop the per cent loss in yield was 36.74 per cent followed by July Ist FN sown plot (34.19%) and July IInd FN sown plot (33.65%). The present results are in close agreement with those of Umesh et al. (1999) who reported that white grub cause damage in groundnut upto 39.40 per cent. Hussain (1974) also reported that the grubs of Holotrichia reynaudi feed on roots of groundnut and cause damage upto 70 per cent. Adsule and Patil (1990) reported the losses caused by white grub to the extent of 25 to 100 per cent in sugarcane, paddy, maize, groundnut, potato, vegetables and other crops.

REFERENCES

  1. Adsule, V.M and Patil, S.M. 1990. Leucopholis lepidophora: a new white grub pest of groundnut in Western Maharashtra. Groundnut News. 2(2): 7.
  2. Hussain, M. 1974. Some observations on the biology and control of Phyllophaga consanguinea Blanch, a potent pest of groundnut in Andhra Pradesh. Indian Journal of Plant Protection. 2: 107-110.
  3. Pokhrel, M.R. 2004. Field survey of white grubs and laboratory and evaluation of Metarhizium anisopliae (Metsch.) Sorokin for its control with side effects on Bombyx mori Lin. M.Sc., Ag. Thesis (Unpublished), Tribhuvan University, Institute of Agriculture and Animal Science, Rampur, Chitwan, Nepal, p. 134.
  4. Sreedevi, K and Tyagi, S. 2015. Species diversity of white grubs associated with Sugarcane ecosystem of Western Uttar Pradesh – A Case Study. Current Biotica. 8(4): 404-410.
  5. Umeh, V.C., Waliyar, F., Traoré, S and Egwurube, E. 1999. Soil pests of groundnut in West Africa Species diversity, damage and estimation of yield losses. Insect Science Application. 19, 131-140.
  6. Vasanth, T.S., Patil, S.B. Ghadage, M.K., Birhade, D.N and Gaikwad, A.N. 2014. Investigation on effect of Theretia peruviana (Pers) on the mortality of Holotrichia serrata (Fab.) adults (Coleoptera: Scarabaiedae). International Research Journal of Pharma. 5: 212-14.
  7. Wightman, J.A. 1995. White grubs (Coleoptera:
  8. Scarabaeidae) the hidden pests of groundnut.
  9. Submitted to FAO Plant Protection Quarterly. 23.
  10. Wightman, J.A and Amin, P.W. 1988. Groundnut pests and their control in the semi-arid tropics. Tropical Pest Management. 34: 218-226
  11. Yadava, C. P. S and Sharma, G. K. 1995. Indian white grub and their management, All India Coordinated Research Project on white grubs, Technical Bulletin No. 2, Indian Council of Agriculture Research
  12. www.apdes.ap.gov.in. 2014-15. District-wise area, Production and productivity of groundnut in Andhra Pradesh. 2014-15.
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