Character association and assessment of yield loss in pigeonpea cultivars infested by pod fly and bruchid

Transcription

1 LR-3896 [1-5] Legume Research, Print ISSN: / Online ISSN: AGRICULTURAL RESEARCH COMMUNICATION CENTRE Character association and assessment of yield loss in pigeonpea cultivars infested by pod fly and bruchid B. Kiran Gandhi*, Sanjay M. Bandi, S.J. Satheesh Naik, S.K. Singh and Krishna Kumar ICAR- Indian Institute of Pulses Research, Kanpur , Uttar Pradesh, India. Received: Accepted: DOI: /LR-3896 ABSTRACT Field studies were conducted at IIPR, Kanpur, India to estimate the intensity of field infestation on pigeonpea by pod fly and bruchids, and whether or not the phenotypic characters of the pigeonpea related to infestation caused by these insects. A total 32 long duration pigeonpea cultivars and advanced breeding lines were planted in augmented design along with check Bahar and evaluated on the basis of exit holes and windows per pod, seed damage (%) by pod fly maggot and bruchid grub, 100 damaged seeds weight and relative resistant rating. Breeding line IPA-92 and a cultivar MA-3 were found to be highly resistant against pod fly, preventing them from crafting exit holes on pods and seed damage (%). Bruchid (C. chinensis and C. maculatus) was vulnerable to make windows on pods damaging the seeds of cultivars viz., IPA-15-1, IPA-15-5, IPA-15-7, IPA-15-10, IPA-15-12, IPA-15-14, MA-3, IPA-92, AZAD, IPA-234, BSMR-736, IPA-13-1 and IPA-37. Correlation studies revealed that pod fly infestation was the major biotic factor, which causes significant seeds damage and yield reduction in pigeonpea cultivars and advanced breeding lines. Those cultivars and breeding lines exhibited resistant reaction on pod fly and bruchids infestation might be used as donors in resistance breeding programme and including in IPM modules against these insect pests. Key words: Bruchid, Pigeonpea, Pod fly, Resistance, Rating. INTRODUCTION Pigeonpea [Cajanus cajan (L.) Millsp.] is an important pulse crop known to harbor more than 200 insect species. Amongst, only a few of them are of vital significance accounting substantial damage. Pigeonpea pod fly, Melanagromyza obtusa (Maloch) [Agromyzidae; Diptera] has gained the status of major pest causing moderate to heavy crop losses in India (Dias et al., 1981). Pod fly maggots feed on healthy seeds inside the pod and continue to damage the seeds by mining. Before pupation maggot cuts pin head size exit holes in the pod wall, leaving their circular layer of epidermis that is forced open by emerging adult fly. It is the most obnoxious pest, causing the grain/seed damage ranging from 20 to 80 per cent (Subharani and Singh, 2009). Yield reduction up to 80 per cent was recorded due to the pod fly (Durairaj, 2006) causing annual loss of US $256 million (ICRISAT, 1992). Bruchid or pulse beetle, Callosobruchus spp. (Bruchidae: Coleoptera) damage pigeonpea in both field and storage, eventually results in enormous yield losses to the pulses in the storage. Infestation of bruchid in pigeonpea initiated at field on green and till maturing pods. Field carryover populations of pulse beetle increase during storage after threshing. In the field, infestation is characterized by its insidious nature (Taylor, 1981); eggs are usually glued on the maturing or drying pods, the young first instar larvae bore into the seeds and at threshing, seeds either show slight or no apparent external damage. Matured pods retained with circular window with flap and adult emergence holes on seeds at the time of harvest. The seriousness of bruchid (Callosobruchus chinensis L.) has been reported by Siddiqui (1972) causes about 30 to 55 per cent grain/seed loss. Earlier, there were no studies on quantification and correlation of seed damage and weight loss caused by both pod fly and bruchids in field with phenotypic characters in different pigeonpea cultivars, simultaneously. Considering this, an experiment was designed to see the reaction of different pigeonpea cultivars by correlating phenotypic characters with seed damage and weight loss caused by both pod fly and bruchid. MATERIALS AND METHODS A total of 32 long duration pigeonpea cultivars and advanced breeding lines were sown in an augmented design during July 2015 at Main Research Station, Indian Institute of Pulses Research, Kanpur along with local check Bahar, which was sown after every 5 genotypes. Each cultivar and advanced breeding lines were sown in four rows of 4m length and 70cm apart. To avoid the initial infestation caused by pod borers viz., spotted pod borer (Maruca testulalis) and gram pod borer (Helicoverpa armigera) an insecticide, profenofos *Corresponding author s bkg0530@gmail.com

2 2 LEGUME RESEARCH An International Journal (1mlL -1 of water) was sprayed at pod initiation stage. In later stages, plants were kept free from any insecticidal interventions so as to allow natural infestation of pod fly and bruchids. Phenotypic parameters viz., days to first flowering, days to maturity (duration), plant height, pod length, seeds per pod were recorded on 10 plants from each cultivar at appropriate period. At the time of harvest, randomly 100 pods from each cultivar and advanced breeding line were picked separately. Number of exit holes and windows formed by pod fly and bruchid, respectively was recorded by observing 100 pods from each cultivar. Per cent and weight of damaged seeds caused by the test insects infestation accounted with 100 randomly chosen seeds from different cultivars and check. The test cultivars were then graded using formulae: Seed damage (%) in check Seed damage (%) in test cultivar Seed Protection (%) = x 100 Seed damage (%) in check Invincibility of infestation (seed damage) resulted due to pod fly and bruchid at field level is very challenging. Therefore, based on per cent seed protection by cultivar from insect injury, a new scale was standardized ranging from 1 to 6 (Relative Resistant) rating and with respective category to classify long duration pigeonpea cultivars and advanced breeding lines (Table 1). Pigeonpea seed weight loss (%) was estimated by recording weight of 100 healthy and damaged seeds. Weight of 100 damaged seeds (g) Seed weight loss (%) = x 100 Weight of 100 healthy seeds (g) Seed/pod damage parameters were correlated with the phenotypic characters. Regression equation was developed for the characters, showing significant correlation. For correlation and regression studies SPSS 16.0 software was employed. Table 1: Relative Resistance (RR) rating based on seed protection (%) to categorize the long duration pigeonpea cultivars Seed Relative Resistance Category protection(%) rating (RR) Highly Resistant (HR) 70 to Resistant (R) 40 to Moderately Resistant (MR) 10 to Least Resistant (LR) -20 to Susceptible (S) < Highly Susceptible (HS) RESULTS AND DISCUSSION In present investigation, bruchid infesting the pigeonpea at field were identified as Callosobruchus chinensis and C. maculatus. It was noticed that pod fly maggot and bruchid grub preferably may damage the seeds of matured pod (Fig. 1). Out of 32 long duration pigeonpea cultivars and advanced breeding lines sown, two cultivars viz., IPA-92 and MA-3 were free from pod fly infestation symptoms like exit holes and seed damage, fall under highly resistant category with RR 1. While IPA-15-10, IPA-234, BSMR-736, IPA-13-1, PUSA 992 and NA-1 noticed with < 40 exit holes per 100 pods and < 12 per cent seed damage, rated as RR 2. Ovipositional non-preference and antibiosis are the proposed mechanism of resistance to pod fly in pigeonpea (Reed and Lateef, 1990). Obviously these have prevented pod fly infestation in IPA-92 and MA-3 cultivars. Ovipositional behaviour reportedly had been associated with pod trichomes, the quantum of tannin-like substances beneath the outer epidermis and thickness of fibrous cell layers above the inner epidermis (Sithanantham et al. 1981). However, Lal and Yadava (1994) produced sufficient evidence that non-preference to oviposition is an operating character in pod fly resistance. Bruchid unable to oviposit and inflict on cultivars viz., IPA-15-1, IPA-15-5, IPA-15-7, IPA-15-10, IPA-15-12, IPA-15-14, MA-3, IPA-92, AZAD, IPA-234, BSMR-736, IPA-13-1 and IPA-37, were grouped under highly resistant category RR 1. Cultivars viz., IPA-15-2, IPA- Fig-1: (a) exit hole of pod fly (b) window of bruchid (c) galleries made by pod fly maggot on seeds (d) bruchid adult emerged seeds

3 Vol. Issue, () Table 2: Variability in seed damage and relative resistance of different pigeonpea genotypes against pod fly and bruchid Genotypes No. of Pod Relative Category No. of Bruchid Relative Category Weight of Weight of Seeds Yield Pod fly Exit fly damaged Resistance Bruchid damaged Resistance 100 healthy 100 damaged weight (kg/ha) holes /100 pods seeds (%) rating (RR) windows/ seeds (%) rating (RR) seeds (g) seeds (g) loss (%) 100 pods IPA LR HR IPA MR R IPA MR HS IPA S R IPA LR HR IPA LR HR IPA S HR IPA S HR IPA MR MR IPA R HR IPA LR HS IPA MR HR IPA MR R IPA LR HR IPA LR LR IPA LR LR IPA MR LR IPA LR R IPA LR LR MA HR HR MAL MR R PUSA R R IPA HR HR AZAD MR HR IPA R HR BSMR R HR IPA R HR IPA MR HR IPA MR R UPAS MR LR NA MR R IPA MR MR BAHAR (CHECK)

4 4 LEGUME RESEARCH An International Journal Table 3: Association between pigeonpea phenotypic characters and damage parameters Pod fly exit Bruchid windows Per cent Pod Per cent Bruchid Weight of holes /100 pods /100 pods Fly damaged seeds damaged seeds 100 damaged seeds Days to maturity Days to first flowering Plant height Pod length ** Seeds per pod * Yield * ** Correlation significant at the 0.01 level * Correlation significant at the 0.05 level Table 4: Relationship between pigeonpea phenotypic characters and damage parameters Parameter Regression Equation R 2 Correlation (r) Dependent (Y) Independent (X) Per cent Pod fly damaged Seeds Pod fly exit holes /100 pods Y= X ** Per cent Pod fly damaged seeds Weight of 100 damaged seeds Y= X ** Per cent Bruchid damaged seeds Bruchid windows /100 pods Y= X ** Yield (kg/ha) Pod fly exit holes /100 pods Y= X * Weight of 100 damaged seeds Pod length Y= X ** Weight of 100 damaged seeds Seeds per pod Y= X * ** Correlation significant at the 0.01 level * Correlation significant at the 0.05 level 15-4, IPA-15-13, IPA-15-18, MAL-13, PUSA 992, IPA-61 and NA-1 were ranked in RR 2. Numerous hairs present on pigeonpea pod surface (Reddy, 1990; Silim Nahdy, 1995) and low oviposition on these pigeonpea cultivars may probably linked to this character. No seed weight loss was observed in MA-3, IPA-92 and BSMR-736, whereas in remaining 30 cultivars, seed weight losses ranged from (IPA-15-15) to (IPA-15-17) per cent. Seed yield in different cultivars varied from 630 kgha -1 (IPA-15-4) to kgha -1 (IPA-15-2) (Table 2). Correlation between phenotypic characters and damage parameters revealed that pod length is significantly correlated (r= 0.567; P < 0.01) with damaged seed weight. Present finding are in conformity with Lal et al. (1988) report, asserting significant correlation between seed damage and both pod width and pod length. Similarly, seeds per pod and weight of damaged seeds (r= 0.378; P < 0.05), pod fly damaged seeds and pod fly exit holes (r= 0.76; P < 0.01), pod fly damaged seeds and weight of damaged seeds (r= 0.454; P < 0.01), bruchid damaged seeds and bruchid windows (r= 0.813; P < 0.01) were associated and positively significant with each other. However, yield and pod fly exit holes (r= ; P < 0.05) were significant and negative correlation (Table 3). Regression equations developed for those parameters exhibited significant correlation (Table 4). In present study, it was noticed that rise in the weight of damaged seeds as number of seeds per pod increases. Significant seed damage and yield reduction caused by pod fly over bruchid in tested pigeonpea cultivars. Coefficient of determination (R 2 ) showed 57.8 and 20.6 per cent change in pod fly damaged seeds for every unit (X) change in the exit holes of pod fly per 100 pods and weight of 100 damaged seeds, respectively. Similarly, for every unit shift in the windows formed by bruchid there will be 66.2 per cent variation in the bruchids damaged seeds. Presumably, the crop yield (kg/ha) will be affected up to 12.1 per cent with every unit change in the exit holes of the pod fly. Unit change in the pod length and seeds per pod will altogether affect the weight of 100 damaged seeds up to 32.2 and 14.3 per cent, respectively. Since both the insect pests i.e., pod fly and bruchid are the major threat for long duration pigeonpea, to reduce infestation caused by former pest, IPA-92, MA-3 cultivars and by bruchid, IPA-15-1, IPA-15-5, IPA-15-7, IPA-15-10, IPA-15-12, IPA-15-14, MA-3, IPA-92, AZAD, IPA-234, BSMR-736, IPA-13-1, IPA-37 cultivars, which imparted high resistance can be included in breeding programme. Thus, information generated would be useful not only in host-plant resistance studies but also in developing IPM module against these insects. ACKNOWLEDGEMENT The authors are thankful to Dr. N. P. Singh, Director, Indian Institute of Pulses Research, Kanpur for providing resources in conducting experiment. REFERENCES Dias, C.A.R., Lal, S.S. and Yadava, C.P. (1981). Relative susceptibility of pigeonpea cultivars against pod fly, Melanagromyza obtusa Malloch under field conditions. In: Proc. International Workshop on Pigeonpea, 2: Durairaj, C. (2006). Evaluation of certain neem formulations and insecticides against pigeonpea podfly. Indian J. Pulses Res., 19 (2):

5 Vol. Issue, () ICRISAT (1992) The Medium Term Plan, A International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India. Lal, S. S,,Yadava, C. P. and Sachan, N. J. (1988). Studies on some aspects of oviposition and damage of pod fly in relation to the host phenology. Indian J. Pulses Res., 1: Lal, S. S.and Yadava, C. P. (1994). Ovipositional response of pod fly Melanagromyza obtusa Malloch on some resistance pigeonpea selections. Indian J. Agri. Sci. 64(9): Reddy, L. J. (1990). Pigeonpea: morphology. In The Pigeonpea, [ed. Y. L. Nene, S. D. Hall and V. K. Sheila], ICRISAT, CAB International, Wallingford. pp Reed, W. and Lateef, S. S. (1990). Pigeonpea : Pest management. In:. The Pigeonpea. Nene, Y. L., Hall, S. D. and Sheila, V. K. Wallingford, CAB International, pp Siddiqui, P. M. (1972). Studies on longevity, oviposition, fecundity and development of Callosobruchus chinensis (L.). Zeitschift Fur Angewantee Entomologie, 72: Silim Nahdy, M. (1995). Biotic and abiotic factors influencing the biology and distribution of common storage pests of pigeonpea. Ph.D. thesis. University of Reading. Sithanantham, S., Lateef, S. S. and Reed, W. (1981). Pod fly susceptibility in pigeonpea. Some aspects of oviposition preference. In: Proceedings of the International Workshop on Pigeonpea, ICARISAT, Patancheru, Andhra Pradesh, India.Vol 2, pp Subharani, S. and Singh, T.K. (2009). Yield loss assessment and economic injury level of pod borer complex in pigeonpea. Ann. Plant Prot. Sci., 17: Taylor, T. A. (1981). Distribution ecology and importance of bruchids attacking grain legumes in Africa. In: The Ecology of Bruchids Attacking Legumes (Pulses) Labeyrie V. The Hague, Junk, pp