Evaluation of improved grain storage practices for the management of groundnut bruchid caryedon serratus olivier (coleoptera: bruchidae)

Swathi, Y (2016) Evaluation of improved grain storage practices for the management of groundnut bruchid caryedon serratus olivier (coleoptera: bruchidae). Masters thesis, Professor Jayashankar Telangana State Agricultural University.

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Supervisors

Supervisors NameSupervisors ID
Rajanikanth, PDepartment of Entomology,College of Agriculture, PJTSAU,Rajendranagar, Hyderabad
Sathyanarayana, JDepartment of Entomology,College of Agriculture, PJTSAU,Rajendranagar, Hyderabad
Sudini, H KICRISAT (Patancheru)

Abstract

Groundnut (Arachis hypogaea Linn.) is an important food legume and an oilseed crop in India and is cultivated in an area of 5.53 million ha with a production of 9.67 million tons and productivity of 1750 kgha-1 (FAO, 2013-14). Groundnut production is usually hampered by several biotic and abiotic constraints during pre-harvest which to a greater extent are tackled by integrated management approaches while in the post-harvest, storage is a big challenge especially for farmers as groundnut bruchid, Caryedon serratus (Olivier) causes severe damage to groundnut pods when stored in improper storage conditions. In view of the importance of groundnut bruchid during storage, laboratory studies on “Evaluation of improved grain storage practices for the management of Groundnut Bruchid, Caryedon serratus Olivier. (Coleoptera: Bruchidae)” were conducted at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad. Studies were contemplated on estimation of oxygen requirement to bruchid, performance of triple layer bag as a tool of hermetic storage technology to manage bruchid, Aspergillus flavus growth and aflatoxin contamination in groundnut pods stored at 10 and 14 per cent moisture regimes and effect of C. serratus and A. flavus on changes in important biochemical constituents viz., oil, protein and fatty acid composition of groundnut kernels under different storage conditions.The mode of action of hermetic storage on groundnut bruchid was investigated to determine the actual requirement of oxygen by the bruchid and to understand the dynamics of change in oxygen and carbon dioxide concentrations and its effects on insects. The results revealed that a single bruchid from egg to pupal stage used approximately 39.97 ml of oxygen and simultaneously produced 26.21 ml of carbon dioxide. It is observed that any reduction in level of oxygen availability (hypoxia) than the requirement and increase in level of carbon dioxide concentration (hypercarbia)than optimum level, in storage conditions caused cessation of feeding and eventually death of insects. The performance of triple layer plastic bag as source of hermetic storage technology was evaluated for managing groundnut bruchid, C. serratus and storage fungi, A. flavus by storing groundnut pods with 10 and 14 per cent moisture contents and observing the development of bruchid and fungus at 2, 4 and 6 months of storage. The results revealed that groundnut pod with varying moisture contents stored in triple layer bag for a period of six months recorded 100 per cent mortality of bruchids and retained seed integrity significantly better than the pods stored in traditional bags such as jute, polythene and jute bag treated with insecticide. The percentage of damaged pods and test weight in triple layer plastic bag were unchanged at 10% (76.9g) and 14% (77.93g). The impermeability of triple layer plastic bag impeding diffusion of gases or exchange of gases with outer environment caused decrease in oxygen and increase in carbon dioxide concentrations and resulted in total cessation of egg development, larval feeding and ultimately caused adult mortalityIn contrast, the traditional bags recorded 94 per cent of pod damage, 22 per cent weight loss of pods and ultimately recorded reduction in test weight of pods to be 56.67 grams. This loss to stored pods is attributed to the fact that availability of congenial conditions in traditional storage bags which promoted insect growth leading to increase in number of eggs up to 312, emergence holes up to 73.63, number of pupae up to 29.43 and a massive increase in live insects up to 97 for every 100 pods. The germination percentage after two and four months of storage was found to be reduced to 75.00- 58.33 per cent and 57.66 - 37.00 per cent respectively in traditional bags. Significantly low reduction in germination per cent to 85 and 77 was observed in triple layer plastic bags after two and four months of storage periods, respectively. No germination of seed was recorded after six months of storage in all types of bags. The loss in germination percentage was due to influence of abiotic factors like high relative humidity and high moisture contents and biotic factors like high insect activity and high rate of storage fungal growth in traditional bags compared to triple layer plastic bags.The triple layer plastic bags recorded minimum aflatoxin accumulation compared to traditional bags. It is quantified that only 11.99μgkg-1 and 14.01μgkg-1 of aflatoxin was accumulated in the pods containing 10 and 14 per cent moisture, respectively when stored for two months. Similarly 456.0μgkg-1 and 700.23μgkg-1 of aflatoxins were observed after four months and 2444.46μgkg-1 & 2701.93μgkg-1 was recorded after six months of storage from pods containing 10 and 14 per cent moisture contents, respectively. The maximum aflatoxin content of 5093.53μgkg-1 was recorded in traditional jute bag at 14 per cent moisture. The low production of aflatoxins in triple layer plastic bags is due to low oxygen availability and reduced insect activity. It is observed that apart from oxygen availability and insect activity the presence of moisture within the pods also governed production of aflatoxin, thus pods stored at 10 per cent moisture recorded less aflatoxin compared to pods stored at 14 per cent moisture however a gradual increase in aflatoxin content was observed with increase in storage period in all the bags.The impact of insect activity and aflatoxin accumulation in storage and their effect on important biochemical constituents of stored groundnut pods was investigated. The results revealed that among fatty acids significant minimum decrease in linoleic acid and oleic acid and increase in palmitic and stearic acid was recorded in pods stored in triple layer plastic bags compared to traditional bags. Similarly a significant reduction in total oil and protein contents was recorded in pods stored in traditional bags compared to triple layer plastic bags. It is observed that the undesirable changes in biochemical constituents were more in traditional bags compared to triple layer plastic bags and also in the produce stored at higher moisture content (14%) compared to produce sufficiently dried (10%) and stored. It was also found that the undesirable changes increased with increase in duration of storage period. It is concluded from the present investigation that the triple layer plastic bags using hermetic technology efficiently managed insect pests and mycotoxin producing storage fungi compared to traditional storage bags. The study also revealed that triple layer plastic bags protected the biochemical constituents and germination of the stored seed and could be best alternative for traditional storage bags for short and medium term storage, provided the produce is sufficiently dried (<10%) before storage.

Item Type: Thesis (Masters)
Divisions: RP-Grain Legumes
CRP: CGIAR Research Program on Grain Legumes
Uncontrolled Keywords: Groundnut, Food Legumes, Oilseeds, Production
Subjects: Mandate crops > Groundnut
Depositing User: Mr T L Gautham
Date Deposited: 14 Oct 2016 09:44
Last Modified: 14 Oct 2016 09:44
URI: http://oar.icrisat.org/id/eprint/9723
Acknowledgement: UNSPECIFIED
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