Assessing Storage Insect Pest infestations and Faecal dropping of Rodent in Stored Grains from two districts of Southwestern Ethiopia

This study was designed to assess the occurrence of major insects and rodent pest infestations in stored grain from two districts of Southwestern Ethiopia. Omo Nada and Bako Tibe districts were purposively selected because they are potential maize and sorghum growing regions with high postharvest losses. A total of 160 farmers’ stores from both the districts were randomly selected. The grain samples used in the present study were stored for five different time periods, ranging from 1 to 5 months and from the same farmers’ stores, to identify storage insect pest, determine grain weight loss and insect damage. The results showed that the dominant insect species in maize and sorghum grains were weevils (Sitophilus spp.) followed by the Angoumois gelechiid (Sitotroga cerealella Olivier) and flour beetles (Tribolium spp.). High number of insects were recorded from both plastered and un-plastered gombisa and polypropylene bags. Additionally, the amount of every insect pest in each storage container recorded per 100 g grain increased because the duration of grain storage increased. There have been 0.33-1.29g and 0.44-1g of rodent droppings per 100g sample of maize and sorghum grains, respectively. This showed that faecal dropping per 100 g grain increased along with increase in storage period. Grain damage showed significant (P<0.05) differences over the storage periods across the studied districts. A similar trend was observed for weight loss in each of the grains all districts. These results indicated that farmers are incurring a substantial grain loss to insects and rodent pests. Hence, there is an urgent need to devise appropriate tactics for protecting the losses in farm-stored maize and sorghum in Ethiopia.

Brown and Yellow Rust of Wheat in India –Significance of Climate on It’s Races and Resistance

Wheat is one of the most important staple food crops having global economic significance. Grown globally around 215 million hectares area with production of more than 600 million tons. Wheat is constrained in its production due to several biotic factors, among them yellow rust of wheat, Puccinia striiformis Westend. f.sp. tritici Eriks and Henn. (Pst) and brown rust of wheat, Puccinia recondita f.sp. tritici (Eriks. and E. Henn.) D.M. Henderson (Ptr) continues to be a serious threat and dominant factor limiting its yield potential globally. The estimated yield losses range from 10-70%, while in a severe epidemic the grain damage can be as great as 100%. Pathogens are considered to be favoured by the cooler areas but current races are more adaptable to high temperatures causing significant yield reduction in wheat. In India, prevalent pathotypes for yellow rust include 46S119, 110S119, and 238S119. Yr5, Yr10, Yr15, YrSp, and YrSk genes are resistant to Pst pathotypes in Indian conditions, while in the case of leaf rust of wheat, prevalent pathotypes are 77-5, 77-9, and 104-2. Lr9, Lr19, Lr24, Lr25, Lr29, Lr32, Lr39, Lr45, and Lr47 are the genes having resistance to Ptr pathotypes in Indian conditions. This publication provides a comprehensive overview of the stripe and leaf rusts of wheat in India and their virulent races, types of host resistance and provides a tool for effective management of wheat rust disease.

Study on Performance of Concentric Threshing Device with Multi-Threshing Gaps for Rice Combines

S concentric threshing device can improve rice crop separation and transportation capabilities. As one of the main factors affecting the threshing performance of rice combine harvesters, the threshing gap can influence the grain unthreshed rate and the grain damage rate directly. However, the clearance between any threshing cylinder tooth and the concave grid is constant for the traditional threshing device, named the single threshing gap in this paper, resulting in a consistently high total loss rate (the sum of unthreshed and damaged grains). Therefore, multi-threshing gaps are proposed in this paper for the concentric threshing device to solve the above problem. To compare the threshing performance between the single threshing gap and the multi-threshing gaps, the movement process of rice mixture (grain, short straw, and long straw) was simulated using the discrete element method (DEM). The simulation results showed that the separation and transportation abilities of the multi-threshing gaps were not decreased, but the distribution of threshed output mixture was more even for the multi-threshing gaps. Furthermore, a field experiment was also carried out on a combine harvester to compare the total loss rate. The experiment results showed that the total loss rate of the concentric threshing device with multi-threshing gaps was reduced by 0.0593%, which was 5.77% less than the total loss rate of the concentric threshing device with a single threshing gap.

Image processing algorithms in the assessment of grain damage degree

Objectives The paper presents preliminary results on the assessment of algorithms used in image processing of the grain damage degree. The purpose of the work is developing a tool allowing to analyse sample cross-sections of rye germs. Methods The analysis of the grain cross-sections was carried out on the basis of a series their photos taken at equal time intervals at a set depth. The cross-sections will be used to create additional virtual cross-sections allowing to analyse the whole sample volume. The ultimate plan is to generate two cross-sections perpendicular to each other. Based on volumetric data read from the sample section, a three-dimensional model of an object will be generated. Results The analysis of model surface will allowed us to detect possible grain damage. The developed method of preparing the research material and the proprietary application allowed for the identification of internal defects in the biological material (cereal grains). Conclusions The presented methodology may be used in the agri-food industry in the future. However, much research remains to be done. These works should primarily aim at significantly reducing the time-consuming nature of individual stages, as well as improving the quality of the reconstructed image.

Reactions of Some Varieties of Pearlmillet, Pennisetum glaucum (Linn.) R. Br. emend Stuntz. to Rice Moth, Corcyra cephalonica Staint.

Ten varieties of pearlmillet (RHB-173, RHB-177, MPMH-17, HHB-67, Pro Agro-9450, Pro Agro-9001, Pioneer 86 m 86, Pioneer 86 m 84, Pioneer 86 m 38 and Raj-171.) were evaluated for reaction to Corcyra cephalonica Staint. in the laboratory conditions. The adult emergence (F1), weight losses and susceptibility index in these varieties were ranged from 9.33-32.00, 10.44–31.69% and 2.77–6.82, respectively, the minimum in Pioneer 86 m 86 and maximum in Raj-171; other varieties were in the middle order. The seed damage recorded in different varieties ranged from 23.67–75.84%, the minimum in Pioneer 86 m 86 (23.67%), Pro Agro-9450 (25.55%) and Pro Agro-9001 (28.33%), these treatments were found at par each other. The Raj-171 was found to be badly infested (75.84% grain damage) which differed significantly over other varieties. The developmental period of the pest varied from 50.88–80.61 days in different varieties, minimum being in Raj-171 and maximum in Pioneer 86 m 86.

Microbial Volatile Organic Compounds from Tempered and Incubated Grain Mediate Attraction by a Primary but Not Secondary Stored Product Insect Pest in Wheat

There has been a dearth of research elucidating the behavioral effect of microbially-produced volatile organic compounds on insects in postharvest agriculture. Demonstrating attraction to MVOC’s by stored product insects would provide an additional source of unique behaviorally-relevant stimuli to protect postharvest commodities at food facilities. Here, we assessed the behavioral response of a primary (Rhyzopertha dominica) and secondary (Tribolium castaneum) grain pest to bouquets of volatiles produced by whole wheat that were untempered, or tempered to 12%, 15%, or 19% grain moisture and incubated for 9, 18, or 27 days. We hypothesized that MVOC’s may be more important for the secondary feeder because they signal that otherwise unusable, intact grains have become susceptible by weakening of the bran. However, contrary to our expectations, we found that the primary feeder, R. dominica, but not T. castaneum was attracted to MVOC’s in a wind tunnel experiment, and in a release-recapture assay using commercial traps baited with grain treatments. Increasing grain moisture resulted in elevated grain damage detected by near-infrared spectroscopy and resulted in small but significant differences in the blend of volatiles emitted by treatments detected by gas chromatography coupled with mass spectrometry (GC–MS). In sequencing the microbial community on the grain, we found a diversity of fungi, suggesting that an assemblage was responsible for emissions. We conclude that R. dominica is attracted to a broader suite of MVOC’s than T. castaneum, and that our work highlights the importance of understanding insect-microbe interactions in the postharvest agricultural supply chain.

Reactions of Some Varieties of Pearlmillet, Pennisetum glaucum (Linn.) R. Br. emend Stuntz. to Rice Moth, Corcyra cephalonica Staint

Ten varieties of pearlmillet (RHB-173, RHB-177, MPMH-17, HHB-67, Pro Agro-9450, Pro Agro-9001, Pioneer 86 m 86, Pioneer 86 m 84, Pioneer 86 m 38 and Raj-171.) were evaluated for reaction to Corcyra cephalonica Staint. in the laboratory conditions. The adult emergence (F1), weight losses and susceptibility index in these varieties were ranged from 9.33-32.00, 10.44-31.69% and 2.77-6.82, respectively, the minimum in Pioneer 86 m 86 and maximum in Raj-171; other varieties were in the middle order. The seed damage recorded in different varieties ranged from 23.67-75.84%, the minimum in Pioneer 86 m 86 (23.67%), Pro Agro-9450 (25.55%) and Pro Agro-9001 (28.33%), these treatments were found at par each other. The Raj-171 was found to be badly infested (75.84% grain damage) which differed significantly over other varieties. The developmental period of the pest varied from 50.88-80.61 days in different varieties, minimum being in Raj-171 and maximum in Pioneer 86 m 86.

Assessment of Insecticidal Potency of Eggshell Powder Against Maize Weevil

Efficacy of chicken eggshell powder at concentrations 0, 0.25, 0.5, 1.0 and 2.0 g /100 g maize, for control of Sitophilus zeamais, were compared with permethrin at dosage rate of 0.167g / 100 g of yellow maize. Experiments were conducted at Biotechnology laboratory (NSPRI), Ilorin under ambient condition (26±3oC 65±5% RH). Mortality of S. zeamais increased with increasing dosages of the CESP as well as with days of exposure. CESP at 2.0g gives 96.67% mortality which is not significantly different from the positive control. The mean progeny emergence (0.00%), weight loss (1.11%), and percentage grain damage (19.68%) by S. zeamais was significantly (P ≤ 0.05) decreased with increased dosage of CESP. However, CESP did not significantly affect seed germination. Total coliform count at 2.0 g (2.48 x 102) was significantly different from both positive and negative controls at p<0.05 Therefore, CESP can serve as a good maize protectant which can be used as substitute for synthetic chemicals.

​Efficacy of Biopesticides against Pod Bug, Clavigralla gibbosa Spinola (Heteroptera; Coreidae) in Pigeonpea

Background: Pigeonpea is the major pulse crop of India. In reproductive stage pigeonpea is exposed to biotic pests causing damage to flowers, pods and grains. Pod bugs, Clavigralla gibbosa Spinola are one of the major biotic constraints in reducing productivity of pigeonpea. Nymphs and adults suck the sap from pods and cause loss of seed yield. Chemical residues will remain in the grains affecting health of the consumer. Eco-friendly molecules are best alternatives to manage pod bugs. Methods: Efficacy test of biopesticides viz., Lecanicillium lecanii, Beauveria bassiana, Metarhizium anisopliae, NSKE 5%, Neemazol 1% and Sasyarakshak against C. gibbosa was conducted in pigeonpea during Kharif 2017-18 and 2018-19 at Agricultural Research Station, Kalaburagi, Karnataka, India under field conditions with seven treatments including control in three replications. Two sprays were taken at tender pod stage and population was recorded. Pod damage and grain damage was assessed at harvest. Result: NSKE 5% was superior in reducing pod bug population, pod damage and grain damage followed by L. lecanii and neemazol 1%. M. anisopliae was found to be ineffective in reducing the population, pod damage and grain damage. The average grain yield of 1229.10 kg/ha was highest in NSKE 5% followed by L. lecanii (1223.48 kg/ha) and neemazol 1% (1199.53 kg/ha). The B:C was 2.45 in NSKE 5% and 2.43 in L. lecanii were higher than other treatments. Therefore, these two biopesticides can be used for effective management of pod bug in pigeonpea.