Pest Susceptibility Research Articles

A synergy of participatory design and indigenous knowledge to address rice (Oryza sativa L.) cultivation challenges of Sadivayal village, Tamil Nadu, India

ABSTRACT This research employed a participatory co-design approach to improve sustainable agricultural practices in Sadivayal village, Tamil Nadu. Smallholder tribal farmers faced challenges like pest vulnerability, middlemen influence, and limited awareness of sustainable rice production technologies. The COVID-19 pandemic worsened these issues, leading many farmers to lease their land to middlemen who practiced chemically intensive farming. This created confusion, as farmers were uncertain whether to let middlemen continue or switch to chemically intensive farming themselves, abandoning traditional methods. The study involved farmers in defining problems, planning interventions, and conducting treatment demonstrations, integrating indigenous and scientific knowledge. Three treatments including organic, chemically intensive, and integrated farming were tested on four indigenous rice varieties and one commercial variety (CO55). Results showed CO55 was preferred due to its high-yielding capacity (4622 kg ha−1) and drought avoidance due to short duration (121 days), while Karuppu Kavuni was valued for its pest and disease resistance. Seeraga Samba was the least preferred due to high pest susceptibility and poor yield (1828 kg ha-1). Farmers favored a combination of organic and inorganic practices, and the study has led to the adoption of CO55 (54%), Karuppu Kavuni (24%), and Mappilai Samba (12%) in the 2023 season. The study features the value of participatory approaches in addressing local challenges and promoting sustainable farming practices.

Evaluation of Alley-cropping Agroforestry System and Conventional System of Agriculture on the Productivity of Cabbage (<i>Brassica oleracea </i>L.) in Dschang, West Region of Cameroon

Cabbage is one of the main vegetable crops grown in Cameroon. However, production is limited by rising prices and the scarcity of chemical fertilisers on the market. The rise in cost of fertilizers leaves some farmers reluctant to use fertilisers and as a result leads to lower yields, hence, low crop profitability. The aim of this study was to compare the two systems of agriculture; agroforestry system with the conventional system on the growth of cabbage (<i>Brassica oleracea</i> L.). Research plots were established on the campus of the University of Dschang, in the West Region of Cameroon. The comparisons were made on the basis of productivity, pest abundance and economic profitability. Data on yield and pest susceptibility variables were collected during the field trials. It was realised that the slug (<i>Deroceras reticulatum</i>) population was higher in the agroforestry system (4.62±2.41 slugs) than in the conventional system (1.03±0.55 slugs). The aphid population (<i>Brevicoryne brassicae</i>) was higher in the conventional cropping system (25.31±38.94 aphids) compared with the alley-cropping agroforestry system (0.71±0.62 aphids). Productivity variables showed that cabbage yield did not vary between the two production methods. It was 66.08 t/ha and 66.76 t/ha respectively for the agroforestry system and the conventional system. The economic analysis showed that the agroforestry system was more profitable than the conventional system. Thus, growing cabbage in an agroforestry system is an ecological and profitable strategy for agriculture that is more resilient to climatic variations.

Chili cultivars vulnerability: a multi-factorial examination of disease and pest-induced yield decline across different growing microclimates and watering regimens

BackgroundAs identified by the research, it is imperative to develop effective ways to address the pressing problem of disease and pest susceptibility in chili agriculture and secure sustainable crop yield. The research examines the impact of various growing microclimates, watering regimens, and chili cultivars on disease incidence, pest attacks, and yield loss.ResultsThe study, which took place over a season, used a randomized complete block design to evaluate how well Tanjung, Unpad, and Osaka cultivars performed in four different watering regimens (100, 75, 50, and 25% ETc) and different microclimates (greenhouse, rain shelter, screen house, and open field). The findings exhibited that watering regimens and microclimates greatly influenced disease and pest occurrence, but cultivars had a minimal effect on these variables. Disease and pest attack rates were highest in the open field and lowest in the screen house. A correlation was found between lower disease and pest incidence and optimal irrigation levels (75% and 100% ETc). At lower watering regimens of 25% ETc and in the open field, yield loss was the greatest.ConclusionThe results emphasize how crucial controlled environments and appropriate irrigation techniques are to reducing crop loss and increasing production. Enhancing watering regimens and implementing screen house cultivation are two strategies for improving the productivity and sustainability of chili output.

Comparative transcriptome profile reveals insight into the antibacterial immunity mechanism of the loach (Misgurnus anguillicaudatus) fed with soybean fermented broth during lipopolysaccharide (LPS) exposure

Loach (Misgurnus anguillicaudatus) is a common freshwater commercial fish species in China. The meat of this fish is a good source of protein and other nutrients that are needed for human health. Aquaculture challenges such as diseases and pest susceptibility, excessive density, and nutritional deficiency result in low production of loach rather than increased demand. Due to a lack of knowledge about the immune system of loaches, we carried out this study to better understand its antibacterial molecular mechanism. Here, we performed RNA sequencing from liver tissue obtained from soya bean-fermented fed loach after subjecting it to the LPS challenge. The results revealed a total of 18,399 differentially expressed genes (DEGs) in the LPS-treated and control groups. There were 7482 DEGs that were upregulated and 10,917 DEGs were downregulated. The enrichment analysis of DEGs revealed that the majority of DEGs were found to be abundant in the pathways of DNA replication, spliceosome, nucleotide exception repair, cell cycle, and Herpes simplex virus 1 infection. Furthermore, qRT-PCR analysis of 21 selected DEGs demonstrated that the transcriptomic data is extremely reliable. Overall, this study provides insight into the molecular features and control mechanisms of genes that affect loach growth. The availability of this information will also contribute to the enhancement of the breeding and protection of loach resources.

Estimating nutritive, non-nutritive and defense foliar traits in spruce-fir stands using remote sensing and site data

The estimation of foliar traits has numerous potential applications, with the evaluation of ecosystem productivity generally regarded as one of the most widely used. In this study, we linked information regarding the concentration of various canopy traits to landscape-level forest health and pest susceptibility using remote sensing technology. Foliar traits that can affect insect herbivory, including nutritive elements such as nitrogen (N), phosphorous (P), potassium (K), and copper (Cu), non-nutritive elements such as iron (Fe) and calcium (Ca), and defensive parameters such as equivalent water thickness (EWT) and leaf mass per area (LMA), were estimated. We used Sentinel-2 and site data to develop trait estimation models in a forest dominated by spruce and fir. Several machine-learning algorithms, namely Random Forest (RF), Extreme Gradient Boosting (XGB), and Support Vector Machine (SVM) were tested. Based on the model performances, where normalized root mean square error (nRMSE) values were taken into account, XGB algorithm was selected to estimate Ca (nRMSE: 0.16), EWT (nRMSE: 0.12), Fe (nRMSE: 0.19), and K (nRMSE: 0.14). On the other hand, RF was used to model Cu (nRMSE: 0.18), LMA (nRMSE: 0.14), N (nRMSE: 0.16), and P (nRMSE: 0.22). Almost all best-performing models included Sentinel-2 red-edge indices and depth to water table (DWT) as the most important variables. We propose a novel framework to establish a connection between the concentration of foliar traits in SBW host foliage and tree susceptibility to the pest. This approach could allow for the assessment of host susceptibility on a landscape level based on the concentrations of foliar traits.

Susceptibility of grape berry moth, Paralobesia viteana (Clemens) (Lepidoptera: Tortricidae) to insecticides in Michigan vineyards

AbstractGrape berry moth is a major pest of vineyards across eastern North America. Increasing infestations in Michigan commercial vineyards under active pest management have raised concerns about insecticide resistance in this species. We tested the susceptibility of male moths of this pest from 5 vineyards in southwestern Michigan over 2 years using a range of concentrations, followed by probit analysis of the resulting mortality data. In 2021 and 2022, topical applications of phosmet and zeta‐cypermethrin were applied to moths collected from each vineyard, and the LC50, LC90 and LC99 values were calculated for each population. The LC50 values were similar among sites, whereas the LC99 values for phosmet were highly variable across years, with sensitivity 2.78 times higher in 2022 than 2021 at Farm 2 and 61.66‐fold higher in 2021 at Farm 3. Sensitivity to zeta‐cypermethrin was generally similar between years at the LC50 level, but it was variable at the LC99, with two sites showing lower sensitivity in 2022 compared to 2021 and three farms with an increased sensitivity in 2022. The response to carbaryl was similar for Farm 3 across both years. However, in 2022 the LC50, LC90 and LC99 values in Farm 3 were 2.34, 6.33 and 14.29‐fold, respectively, higher compared to those in Farm 5. In conclusion, our results show that sensitivity to insecticides in grape berry moth populations in southwest Michigan vineyards is highly variable between different farms and across years. These results highlight the need for continued monitoring of sensitivity to insecticides in this species, and development and implementation of alternative control strategies in vineyards to maintain pest susceptibility to insecticides.

Retraction: Pest susceptibility, yield and fiber traits of transgenic cotton cultivars in Multan, Pakistan.

Retraction: Pest susceptibility, yield and fiber traits of transgenic cotton cultivars in Multan, Pakistan.

Herbage and animal responses on continuously stocked ‘Ipyporã’ and ‘Mulato II’ brachiariagrasses

AbstractNew hybrid grass cultivars may enhance animal performance in forage‐livestock systems if they possess traits that address edaphoclimatic challenges and pest susceptibility. The objective was to assess herbage accumulation, plant‐part composition, nutritive value, and animal performance of ‘Ipyporã’ [Brachiaria ruziziensis Germ. & Evrard × B. brizantha (Hochst. ex A. Rich.) Stapf] and ‘Mulato II’ (B. ruziziensis × B. brizantha × B. decumbens Stapf) hybrids in the Brazilian Amazon biome. From May 2016 to May 2018, pastures were maintained under continuous stocking with variable stocking rates to maintain canopy height at 30‐cm. Herbage accumulation (HA) was greater in Mulato II (17,370 kg dry matter [DM] ha−1 year−1) than Ipyporã pastures (14,930 kg DM ha−1 year−1) across the years. In Year 1, Mulato II had greater stocking rate (1685 vs. 1215 kg body weight [BW] ha−1) and greater gain ha−1 (1130 vs. 850 kg) than Ipyporã. However, in Year 2, both cultivars had similar plant and animal responses. The Year 1 ADG was similar among cultivars or seasons but in Year 2, rainy seasons had 21 and 77% greater ADG than dry seasons for Mulato II and Ipyporã, respectively. Both cultivars can contribute to the diversification of pasture‐based livestock systems in humid tropical regions. Mulato II presented superior performance when soil moisture and fertility were not limiting (i.e., Year 1). However, both cultivars provide similar plant and animal responses in Year 2, offering viable alternatives for the diversification of pasture‐based livestock systems in the Amazon Biome.

Current Approaches to Genome Sequencing in Sugar Beet (Beta Vulgaris) and Its Wild Relatives

Şeker pancarı (Beta vulgaris L. ssp. vulgaris), hem gıda hem de şeker üretimi için yetiştirilen, ekonomik olarak önemli kültür bitkilerinden biridir. Yetiştiriciler, istekleri doğrultusunda bitki özelliklerini geliştirmek için ıslah çalışmaları sürdürmektedirler. Şeker pancarı ıslahı ile birlikte; verimli, şeker içeriği yüksek, dayanıklı üstün çeşitler geliştirilmektedir. Bununla birlikte, kültür pancarlarındaki düşük genetik çeşitlilik, hastalık ve zararlılara hassasiyet gibi özellikleri iyileştirmek amacıyla yabani akrabalarından yararlanılmaktadır. Yabani akrabalar belirli habitatlara adapte olduklarından, pancar yetiştirme havuzu için önemli bir genetik kaynak oluştururlar. Genom dizileme yoluyla pancarda bulunan genlerin ve alellerin sayısı, kimliği ve çeşitliliği hakkında bilgi edinmek, pancarlarda yeni özellikleri tanıtmak ve geliştirmek için önemlidir. Bitkinin yabani akrabalarında bulunan özellikler olan tolerans ve direnç özelliklerini kültür çeşitlerine aktarmak için bu özelliklerin belirlenmesi gerekir. Bu amaçla şeker pancarının genetik tabanının genişletilmesi, ekolojik açıdan önemli özelliklerin korunması açısından önemlidir. Bunun için kültür pancarı ve yabani akrabalarının genetik bilgilerinin belirlenmesi ve birbirlerine göre filogenetik sınıflandırılmaları çok önemlidir.

Screening of Some Long Duration Pigonpea (Cajanus cajan (L.) Millsp.) Genotypes against Major Insect Pests in Varanasi

Pigeonpea (Cajanus cajan (L.) Millsp.), an important grain-legume of semi arid tropics is severely attacked by many insect species, resulting in losses of quantity and nutritional quality. In the present study, fifteen long duration genotypes of pigeonpea were assessed against the attack of M. obtusa, C. gibbosa and H. armigera for two years (2017-2018 and 2018-19) in Varanasi. Resistance to pigeonpea genotypes was evaluated by measuring pod and grain damage per cent in accordance with their yields. Pest susceptibility rating revealed that none of the genotypes fell in resistant/highly-resistant categories. However, genotypes IVT705, IVT-706 and IVT-907 were found to least susceptible for all the three insect pests (except for IVT-907 for C. gibbosa) and also showed higher yields. In other words, yield losses were lower in genotypes which shown less pod/grain damage by insects. Pod damage of some other genotypes viz. IVT-208 (M. obtusa-31.3%, C. gibbosa-12.6%, H. armigera-4.8%), IVT-12-904 (M. obtusa-29.5%, C. gibbosa-12.8%, H. armigera-7.3%) also accounted for their lower levels of susceptibility to the insect pest complex.

Screening of Some Long Duration Pigonpea (Cajanus cajan (L.) Millsp.) Genotypes against Major Insect Pests in Varanasi

Pigeonpea (Cajanus cajan (L.) Millsp.), an important grain-legume of semi arid tropics is severely attacked by many insect species, resulting in losses of quantity and nutritional quality. In the present study, fifteen long duration genotypes of pigeonpea were assessed against the attack of M. obtusa, C. gibbosa and H. armigera for two years (2017-2018 and 2018-19) in Varanasi. Resistance to pigeonpea genotypes was evaluated by measuring pod and grain damage per cent in accordance with their yields. Pest susceptibility rating revealed that none of the genotypes fell in resistant/highly-resistant categories. However, genotypes IVT-705, IVT-706 and IVT-907 were found to least susceptible for all the three insect pests (except for IVT-907 for C. gibbosa) and also showed higher yields. In other words, yield losses were lower in genotypes which shown less pod/grain damage by insects. Pod damage of some other genotypes viz. IVT-208 (M. obtusa-31.3%, C. gibbosa-12.6%, H. armigera¬-4.8%), IVT-12-904 (M. obtusa-29.5%, C. gibbosa-12.8%, H. armigera¬-7.3%) also accounted for their lower levels of susceptibility to the insect pest complex.

Can Comparable Vine and Grape Quality Be Achieved between Organic and Integrated Management in a Warm-Temperate Area?

The high demand for wine in Europe has increased the impact of viticulture on the environment. In line with European objectives, more sustainable agronomic practices have spread as an alternative to traditional management. This study aimed to compare, in a vineyard of Pinot blanc and Rhine Riesling in northeast Italy, the integrated agronomic practices (INT) with two types of organic management (ORG1—cattle manure and ORG2—green manure), in terms of production, grape quality, pest susceptibility, and soil nutrient availability. The results, after the fifth, sixth, and seventh year of testing, showed that organic management obtained a yield and vegetative features comparable to INT. Grape quality also did not show considerable overall differences between the theses in the must properties, despite the higher total sugar content and lower yeast available in ORG1. In the three-year period, the management of downy mildew, powdery mildew, and rot, as well as the soil fertilization, with the products available in organic farming proved to be comparable to the INT method. The application of cattle manure contributed by enriching the soil in K and P, while a balanced green manure mix has proven to be the best agronomic practice in terms of the release of mineral N during the phenological stages of greatest need of the vine. Organic management appears as an agronomic strategy able quantitatively and qualitatively support the vineyard system.

Metarhizium anisopliae is a valuable grist for biocontrol in beta‐cypermethrin‐resistant Blattella germanica (L.)

The widespread use of chemical insecticides has resulted in the development of resistance in German cockroaches worldwide, and biopesticides based on entomopathogenic fungi as active ingredients have become a promising alternative strategy. Resistance can change many of the physiological and biochemical characteristics of insect pests, such as cuticle thickness, detoxification enzyme activity, and even intestinal flora composition. Thus, potential interactions between pathogenic fungi and insecticide resistance may lead to unpredictable changes in pest susceptibility to fungi. Beta-cypermethrin-resistant German cockroaches were more susceptible to infection with the fungus Metarhizium anisopliae regardless of age and sex. Histopathological results showed that the infection of resistant strains (R) by M. anisopliae was visibly faster than that of susceptible strains (S). The gut microbiota of the S strain indicated a stronger ability to inhibit fungi in vitro. The abundance of Parabacteroides, Lachnoclostridium, and Tyzzerella_3 decreased significantly in the R strain, and most demonstrated the ability to regulate glucose and lipid metabolism, and antifungal infections. The expression levels of Akirin, BgTPS, and BgPo genes in the R strain were significantly lower than those in the S strain, while BgChi and CYP4G19 gene expression were significantly higher. The mortality of cockroaches infected with M. anisopliae decreased to varying degrees after RNA interference, reflecting the role of these genes in antifungal infection. Results confirmed that insecticide resistance may enhance cockroach susceptibility to fungi by altering intestinal flora and gene expression. Fungal biopesticides have high utilization value in pest control and insecticide resistance management strategies. © 2021 Society of Chemical Industry.

Occurrence and insecticide susceptibility of the grain aphid Sitobion avenae in northern Mongolia

A survey was carried out to determine the prevalence of Sitobion avenae (S. avenae) in the central agriculture zone of northern Mongolia (including Darkhan-Uul, Selenge, Tuv, and Erdenet aimags). Bioassays were used to assess the pest's susceptibility to three regularly used insecticides (deltamethrin, fenvalerate, and imidacloprid). DNA sequencing was used to look into the genotypes of codons 918 and 1014 of the Voltage-gated sodium channel (VGSC) gene in S. avenae. The findings revealed that in 2019, the population density of S. avenae was low in 159 fields and medium in 31, and the infestation rate was low in 73 fields, medium in 117 fields. Even at a concentration of 0.005%, high mortality rates (>84 per cent) of S. avenae nymphs were detected after 72 hours of exposure to the three insecticides, indicating that this pest was susceptible to all three insecticides tested. In our grain aphid samples, the pyrethroid resistance-causing mutations (M918L and L1014F) in the voltage-gated sodium channel were not detected.

Morphological and biochemical basis of resistance to pod borer <i>Helicoverpa armigera</i> in pigeonpea

This study evaluates sources of resistance to the pod borer Helicoverpa armigera (Hubner) in 15 long duration pigeonpea genotypes with experiments done during 2017-19. Association of morphological and biochemical traits was also evaluated. The results revealed that the least pod damage was attributed to high phenol content in pods (-0.668**), seeds (-0.719**) and high trichomes density (-0.637*). The susceptibility of genotypes (IVT-1-903, IVT-12-904, IVT-703) was indicated by their high pest susceptibility rating (PSR), and due to greater pod length (0.563*) and width (0.603**). The activity of protein, reducing sugars, chlorophyll, carbohydrates, pod wall thickness and number of seeds/ pod was also studied. Genotypes IVT-705, IVT-706 and IVT-1-901 emerged out to be the least susceptible (PSR = 4). Role of these traits are discussed to identify basis of resistance.

The Performance of Representative Asian Vegetables in Different Production Systems in Texas

Demand for Asian vegetables is rising rapidly due to changing demographics and increasing consumer awareness of their health benefits. However, growers are not familiar with growing these “foreign” crops due to insufficient technical information regarding suitable cultivars for different regions, production schedules, disease and pest susceptibility, and postharvest management. The objective of this study was to conduct trials in different production systems and climate regions to demonstrate the potential of growing Asian vegetables in Texas. We conducted preliminary trials of nine leafy greens in the open field, high tunnel, and greenhouse (container and hydroponic production) to explore the suitability and potential for year-round production. We also conducted field trials for warm season crops in the open field in different climate zones. Results indicated that for cool season leafy greens, open field production has a limited growing season, high tunnel has the potential to extend the growing season, while greenhouse may provide year-round production using soilless substrate container culture or hydroponic system. For warm season crops, early planting is recommended for high yield. Additional research is warranted in different regions to test more species and cultivars and optimize the production system of high-performing cultivars to maximize production and profitability.

Nonlinear Model Selection for Fruit and Kernel Development as a Function of Heat in Pistachio

Knowing a tree crop’s seasonal growth and development as a function of heat accumulation can facilitate scheduling of irrigation, pesticide applications, and harvest. Our objective was to compare the goodness of fit of applied models and determine which provides the best description of pistachio nut growth as a function of thermal unit accumulation. Three fruit growth traits of pistachio—pericarp (hull) + endocarp (shell) size, endocarp thickening and hardening, and embryo (kernel) size—exhibited clear nonlinear dependence on heat accumulation. We tested three nonlinear models—Michaelis–Menten, three-parameter logistic, and Gompertz—fitted to fruit development data to create a tool to forecast pest susceptibility and harvest timing. Observation of development began at full bloom and ended at harvest. Data were collected from six pistachio cultivars in one experimental and eight commercial orchards over 3 years. Analyses of residual distribution, parameter standard errors, coefficient of determination (R2) and the Akaike information criterion (AIC) all demonstrated the Gompertz function was the best model. Cultivars differed significantly in all the three parameters (Asym, b, and c) for all three traits with the Gompertz model, demonstrating the Gompertz model can adjust to incorporate cultivar differences. The growth curve of the three traits together provided integrated information on nut biomass accumulation that facilitates predicting the critical timing for multiple orchard management practices.

Delving into possible missing links for attainment of food security in Central Malawi: farmers’ perceptions and long term dynamics in maize (Zea mays L.) production

Globally, maize is one of the major cereal crops contributing 30% of food calories to about 4.6 billion people. The crop is considered staple in 125 developing countries where majority of producers are smallholder farmers. From 1960s to present, production and area for maize have increased but yield has remained questionable in most developing countries. Limited knowledge, poor linkages among service providers, climate change, land degradation, input costs are some of the challenges limiting maize production at world level. In Malawi maize production has always been associated with several challenges such as expensiveness of improved seed, climate change, unproductive soils and variations in variety preferences. Assessments on maize production has concentrated on short-term (1–5 years) and rarely consider farmer perceptions. This has caused mixed reactions on the dynamics of maize production. In this study, maize production, area and yield dynamics were assessed based on production data from 2004/05–2018/19 and farmer perceptions using Focus Group Discussions (FGD) in Salima, Central Malawi. A total of 2,400 households (36,000 in 15 years) were sampled each season to estimate the annual maize production dynamics for the district. The FGD was adequately represented by 15 farmers from all the geographical, social and maize production realms of the district. The maize production data was analysed in R Statistical Software Version 3.6.2 while that of FGD by Constructivism epistemology. The results showed that farmers used 17, six and two varieties for hybrid, Open-pollinated varieties (OPV) and local maize respectively. Farmers sourced hybrid and OPV maize seed from Private Agro dealers while local maize was own-sourced. Farmers preferred local maize for being cheap, good taste, low storage costs, and pest resistance although low yielding. They preferred hybrid and OPV maize for high yielding and early maturing despite demanding high storage costs, pest susceptibility, and low flour. From 2004/05–2018/19, the area under local and OPV maize reduced by 61% (21,619–8,331 ha) and 12% (12,913–11,309 ha) respectively, while that of hybrid maize increased by 49% (9,811–19,379 ha). A synthesis of the recent five years (2014/15–2018/19) showed a consistent decrease in area for hybrid and OPV and a significant increase of that of local maize. This may signal a catastrophic maize production in the region. Further elucidation for the next seven years (2019/20–2025/26), showed that the production of all maize was projected at 44,172 tons by 2025/26, representing a 1.6% increase from the base year 2019/20. This increase will be due to favorable climatic conditions and not increase in area or yield. If maize yield were improved by 30% in 2019/20, production would increase to 110,430 tons representing 67% of the food requirement in the study area. The current maize production trend in Salima does not guarantee food security prospects. Therefore, policymakers should consider reviewing the past interventions (input pricing, promotion strategies, sustainable practices, policies) in the maize subsector to enhance maize productivity.

Effect of Different Chickpea Genotypes and Its Biochemical Constituents on Biological Attributes of Helicoverpa armigera (Hubner)

Background: Chickpea (Cicer arietinum L.) is the third most important pulse crop grown all over the world. Chickpea is infested by an average of about 60 insect-pests, of which gram pod borer, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is known to be the key pest. The migratory nature, polyphagous, short life cycle, multivoltine and resistance to insecticides makes H. armigera very difficult to control. In order to develop the resistance chickpea genotypes against H. armigera it is very important to understand the interrelation between the chickpea biochemical constituents and their effect on insect growth and development.Methods: The biological performance of H. armigera on different chickpea genotypes was studied using detached leaf method and the test genotypes were also evaluated for field level resistance to H. armigera under natural conditions. Different biochemical constituents viz., reducing sugar, protein, total phenol and tannins content in chickpea genotypes were estimated at 30 days after sowing. The relationship between biological attributes of H. armigera reared on different chickpea genotypes and biochemical constituents of chickpea genotypes was computed using simple correlation co-efficient.Result: Among the test genotypes, the lowest larval weight, prolonged larval duration and pupal duration were observed in GL-13042. The lowest pupal weight and percent of adult emergence was observed in NBeG-786 while the lowest fecundity was observed in GL-13001. The percent pod damage, pest susceptibility/ resistance per cent and PRSR on different chickpea genotypes in the field condition varied from 25.9 to 47.84%, 12.91 to 45.86 and from 4 to 5. In the biochemical constituents, the highest total phenol and tannin content were observed in NBeG-786 whereas the lowest protein and reducing sugar content were observed in GL-13042. Relationship between biological attributes of H. armigera and biochemical constituents in different chickpea genotypes revealed that reducing sugars, protein, total phenols and tannins content showed negative association with biological attributes of H. armigera reared on chickpea genotypes.

Performance evaluation of seventeen common fig (Ficus carica L.) cultivars introduced to a tropical climate

Common fig (Ficus carica L.), an economically-important fruit species widely cultivated in the Mediterranean Basin, is gaining increasing interest in the tropical and subtropical regions. A vast genetic diversity of common fig is available; however, systematic studies of cultivar performance in a particular new environment are scarce. The objective of this study was to evaluate the performance of 17 common fig cultivars grown under the Malaysian tropical climate. Evaluation was based on 15 parameters relevant to fruit yield, fruit quality and pest susceptibility. The results showed variable performance among the cultivars tested; 10 cultivars performed well for orchard establishment. Cultivar ‘A134’ produced the highest fruit yield per plant (3410 g) compared to the average yield of the cultivars studied (2500 g). Cultivars ‘Fen Chan Huang’ and ‘Wuhan’ produced the highest number of fruits per plant, 119 and 82 fruits, respectively. Mealybug infestation and ostiole-end splitting are major limitations to fig cultivation in Malaysia. Cultivar ‘Longue d’Aout’ was the most susceptible to mealybug infestation; whereas cultivar ‘B110’ was the most resistant. Above 60% of the fruits of cvs. ‘Brunswick’ and ‘Qing Pi’ had split ostiole; however, this was less than 20% in cvs. ‘Longue d’Aout’ and ‘Alma’. This study facilitates successful farming of figs in Malaysia and provides insights for future development programs.