Microclimate modification and insect pest exclusion using agronet improve pod yield and quality of french bean

French bean [Phaseolus vulgaris (L.)] is among the leading export vegetable in Africa, mostly produced by small-scale farmers. Unfavorable environmental conditions and heavy infestations by insect pests are among the major constraints limiting production of the crop. Most French bean producers grow their crop in open fields outdoors subject to harsh environmental conditions and repeatedly spray insecticides in a bid to realize high yield. This has led to rejection of some of the produce at the export market as a result of stringent limits on maximum residue levels. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya, to evaluate the potential of using agricultural nets (herein referred to as agronets) to improve the microclimate, reduce pest infestation, and increase the yield and quality of French bean. A randomized complete block design with five replications was used. French bean seeds were direct-seeded, sprayed with an alpha-cypermethrin-based insecticide (control), covered with a treated agronet (0.9 mm 3 0.7 mm average pore size made of 100 denier yarn knitted into a mesh impregnated with alpha-cypermethrin), or covered with an untreated-agronet (0.9 mm 3 0.7 mm average pore size made of 100 denier yarn knitted into a mesh not impregnated with insecticide). Alpha-cypermethrin and agronets were manufactured by Tagros Chemicals (India) and A to Z Textile Mills (Tanzania), respectively. Covering French bean with the agronets modified the microclimate of the growing crop with air temperature increased by '10%, relative humidity by 4%, and soil moisture by 20%, whereas photosynthetic active radiation (PAR) and daily light integral (DLI) were decreased by '1% and 11.5%, respectively. Populations of silverleaf whitefly [Bemisia tabaci (Gennadius)] and black bean aphids [Aphis fabae (Scopoli)] were reduced under agronet covers as contrasted with control plots. Furthermore, populations of both pests were reduced on French bean grown under impregnated agronets compared with untreated agronets, but only on three of the five sampling dates [30, 44, and 72 days after planting (DAP)] for silver leaf whitefly or at only one of the five sampling dates (30 DAP) for black bean aphid. Covering French bean with agronets advanced seedling emergence by 2 days and increased seedling emergence over 90% compared with control plots. French bean plants covered with both agronet treatments had faster development, better pod yield, and quality compared with the uncovered plants. These findings demonstrate the potential of agronets in improving French bean performance while minimizing the number of insecticide sprays within the crop cycle, which could lead to less rejection of produce in the export market and improved environmental quality. (Résumé d'auteur

Farmer's perceptions of Eco-friendly nets adapted to vegetable production in Benin

City food supplies are a rising concern for food security in an urbanizing context as productivity and yields are expected to increase to meet the growing needs of urban dwellers. Domestic food supplies will not only require increased food production but face a series of constraints related to quality. Some of such constraints are the restrictions on insecticide residues. Eco-friendly nets contribute to improve food production with both reducing insecticide residues and improving product quality. Eco-friendly nets proved to be a viable alternative to harmful and unsustainable insecticide application practices in tropical countries. However, this technology needs to be adapted to the social and economic context in which small-scale farmers evolve. To this end, we investigated a cross-section study of 115 farmers involved in vegetable production and evenly distributed between adopters and non adopters in the Mono and Couffo divisions of Benin. We identified the various factors that govern their preferences. We performed a summary and partial analysis using Likert's scale measurement, W-test of Kendall as well as a multiple regression model. Results show that insecticides were still adopted by 70% of the sample either exclusively or in conjunction with eco-friendly nets. Farmer's preferences expressed for insect control revealed that speed of action and spectrum activity were the first two factors influencing the adoption of a insect control technology. These results were in concordance with preferences expressed by farmers for eco-friendly nets as speed of action and spectrum activity were considered as positive factors. However, costs were considered as negative factors (labor costs, fixed costs and depreciation). The model stated that level of income, knowledge about net use, access to credit and level of education positively correlate with the level of satisfaction for eco-friendly net use in its initial stages of adoption. (Résumé d'auteur

Farmers' preferences for eco-friendly nets as an alternative to insecticides in Africa

Vegetable production in Africa is highly dependent on pesticides with a large proportion of the population involved in farming. We investigate if eco-friendly nets (EFNs) are a viable and accepted alternative to farmer's current practice of extreme use of insecticides in vegetable production. Using a choice experiment, we found that farmers in Benin preferred all of the characteristics of EFNs except the higher labor requirements. The break-even point can vary with the lifespan of EFNs, their purchase price and potential health benefits from avoiding large quantities of insecticides. To break even the nets need to be used for at least two production cycles. To overcome risk-averse farmer's reluctance to adopt EFNs we propose a credit and warranty scheme along with the purchase of the nets. The study's findings can guide the implementation of EFNs in other African countries as part of integrated pest management with global benefits for the environment and health by reducing the use of pesticides. (Résumé d'auteur

Enhancing cabbage (Brassica oleraceae Var capitata) yields and quality through microclimate modification and physiological improvement using agronet covers

Adverse environmental conditions have contributed to perpetual poor cabbage (Brassica oleraceae var. capitata) yields in sub-Saharan Africa. Elsewhere, net covers have been reported to provide a low-cost technology with the potential of modifying the microclimate around a crop for better performance. Two experiments were therefore conducted over a span of two seasons to determine the effects of agronet covers on microclimate modification and subsequent cabbage yield and quality. The treatments comprised cabbage plants grown under either fine mesh (0.4 mm pore diameter) or large mesh (0.9 mm pore diameter) agronet covers maintained permanently closed, or opened thrice weekly from 9 am to 3 pm and a control treatment where cabbage was grown in the open field. Net covering generally modified the microclimate by raising temperatures, relative humidity and volumetric water content but lowering photosynthetic active radiation and diurnal temperature range compared to control. The use of agronet covers resulted in better cabbage performance. The large mesh (0.9 mm) enhanced leaf stomatal conductance and chlorophyll content, and improved fresh and dry weight as well as head quality. Results of this study present the use of agronet covers as a potentially effective technology for use by small-scale farmers in protected cabbage culture in sub-Saharan Africa. (Résumé d'auteur

The assessment of the use of eco-friendly nets to ensure sustainable cabbage seedling production in Africa

High seed cost accompanied by poor germination and seedling performance renders cabbage nursery and field production enterprises unsustainable to many small-scale growers in tropical and sub-tropical countries. In most nurseries, adverse ecological conditions and pest damage are among the major factors responsible for poor seedling performance. The objective of this study was to test the potential use of eco-friendly net (EFN) covers as a low cost technology for sustainable cabbage seedling production. The study was a two-season experiment conducted using a randomized complete block design with five replications and two treatments. Treatments were: the standard open field transplant production (control) and transplant production under 0.4 mm mesh polyethylene net covering. EFN covering increased both temperature and relative humidity, enhanced seedling growth and reduced insect pest damage. Seed germination and seedling emergence were under the net covering earlier. Higher seed germination and seedling survival were recorded under the EFN treatment, indicating a potential for reducing the seed requirement per unit area of cabbage production. Seedlings grown under the nets had higher stomatal conductance and leaf chlorophyll content; furthermore, they grew taller, with more leaves within a shorter period of time compared to the control seedlings. The use of EFN in cabbage nurseries offers a sustainable technology for enhancing seedling performance by reducing pest infestation, thereby lowering production cost and improving the grower's income. (Résumé d'auteur

Intensification de la culture de tomate sous abri couvert de filet anti-insectes en région chaude et humide du Sud-Bénin

Dans le but de diversifier le système de production de la tomate et réduire l'utilisation des pesticides au Sud Bénin, trois modalités d'intensification à savoir : " Avec taille en plein champ ", " Sans taille sous AgroNet " et " Avec taille sous AgroNet " ont été comparées à un témoin " Sans Taille en plein champ ". L'effet du filet " AgroNet " et de la taille sur la croissance et le développement des plants, l'efficacité du filet vis-à-vis des ravageurs et maladies, l'incidence des oiseaux, les niveaux de rendements, la modification du microclimat et la rentabilité financière de ces systèmes ont été évalués. Les résultats indiquent que l'intensification de la production agricole sous abri AgroNet augmente certes la température (de 4 à 6°C) et l'humidité relative (entre 70 % et 80 %). mais n'impacte pas négativement la croissance et le développement des plants de tomate. L'utilisation du filet a permis de réduire significativement l'incidence des oiseaux. Des rendements commercialisables de l'ordre de 50 à 57 t/ha ont été obtenus sous filet. Les marges nettes dégagées sous filet sont plus élevées sur un marché bio (407 F CFA / Kg) que sur un marché conventionnel (7 F CFA / Kg). L'étude a permis de produire des tomates saines, sans risque de résidus de pesticide. (Résumé d'auteur

Microclimate modification using eco-friendly nets and floating row covers improves tomato (Lycopersicon esculentum) yield and quality for small holder farmers in East Africa

Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, min- erals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations espe- cially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (ag- ronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A ran- domized complete block design with five repli- cations was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were main- tained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open con- trol treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated con- trol). The use of EFN or FRC modified the micro- climate with higher temperatures, lower diurnal temperature ranges, and higher volumetric wa- ter content recorded compared with the controls. On the other hand, light quantity and photo- synthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield com- pared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These find- ings demonstrate the potential of EFN and FRC in modifying microclimate conditions and im- proving yields and quality of tomato under tropi- cal field conditions. (Résumé d'auteur

Repellent effect of alphacypermethrin-treated netting against Bemisia tabaci (Hemiptera: Aleyrodidae)

For _20 yr, Bemisia tabaci Gennadius persists as a begomovirus vector and is a serious problem in tomato production in many parts of the world. In tropical countries, the use of netting to protect horticultural crops has proven to be an effective and sustainable tool against Lepidoptera but not against small insects. This study evaluated the repellent effect of AgroNet 0.9T, a 0.9-mm pore diameter and 40-mesh size netting treated with alphacypermethrin insecticide against B. tabaci. This pyrethroid insecticide is known to have toxic and repellent effects against mosquitoes and has been used for treatment of mosquito nets. Two nontreated netting materials were used as control: AgroNet 0.9NT with 0.9-mm pore diameter and 40-mesh size and AgroNet 0.4NT with 0.4-mm pore diameter and 80-mesh size. The behavior of B. tabaci and its parasitoid Encarsia formosa Gahan as they progressed through the treated netting was studied in the laboratory in choice and no-choice tests. The development of wild B. tabaci population on tomato plants protected by the same nets was followed in two Þeld trials implemented in Njoro, Kenya. Results obtained with the no-choice tests showed a signiÞcant reduction of movement on the treated net with 40-mesh (19%) compared with nontreated netting (35 and 46% with 80- and 40-mesh, respectively). The mortality of B. tabaci was signiÞcantly higher (two-fold) in the test tube containing only the treated netting compared with the nontreated one. The repellent effect of the treated netting was also demonstrated against E. formosa, but it did not have this toxic effect. Unlike for B. tabaci, the treated and nontreated nets appeared to have a similar repellent effect on E. formosa in the choice test, which suggests a learning behavior of the parasitoid. In both Þeld tests, B. tabaci population was signiÞcantly lower on tomato protected by the treated net compared with the same nontreated net. However there was no signiÞcant difference in B. tabaci population between the treated 0.9-pore diameter and the nontreated 0.4-pore diameter. We discussed these Þndings and their implications for the use of repellent netting in integrated pest management in horticulture and more specifically in vegetable production. (Résumé d'auteur

A Systematic Review Including an Additional Pediatric Case Report: Pediatric Cases of Mammary Analogue Secretory Carcinoma

Importance Mammary Analogue Secretory Carcinoma (MASC) is a newly characterized salivary gland carcinoma resembling secretory carcinoma of the breast. Prior to being described, MASC was most commonly misdiagnosed as Acinic Cell Carcinoma. Though MASC is predominantly an adult neoplasm, cases have been reported in the pediatric population. Reporting and summarizing of known cases is imperative to understand the prognosis and clinical behavior of MASC. Objective (1) Report a rare case of pediatric MASC. (2) Review and consolidate the existing literature on MASC in the pediatric population. Evidence review Web of Science, Medline, EMBASE, and The Cochrane Library were searched for studies that included pediatric cases of MASC. Data on clinical presentation, diagnosis and management, and pathology were collected from all pediatric cases. Findings Case Report 14 year old with left-sided parotid mass diagnosed as MASC based on histology and immunohistochemistry. He was managed surgically with left superficial parotidectomy with selective neck dissection. Literature review The majority of MASC cases have been identified via retrospective reclassification of previously misclassified salivary gland tumors. Of all the pediatric cases (N=11) of MASC, the female-to-male ratio is 1:1.2 with an age range of 10-17 years old. The most common clinical presentation was a slowly growing, fixed, and painless mass of the parotid gland, often detected incidentally on physical examination. Common pathological features include eosinophilic vacuolated cytoplasm within cystic, tubular, and/or papillary architecture. Immunohistochemistry showed positivity for S100, mammaglobin, cytokeratin 19, and vimentin. The diagnosis was confirmed by the detection of the characteristic ETV6-NTRK6 fusion gene via fluorescent in-situ hybridization (FISH). Only 4 cases discussed treatment. Each of these underwent successful surgical resection alone with or without lymph node dissection. Conclusions and relevance Since the first case of MASC in the pediatric population was described in 2011, only 12 cases, including this one, have been described in the literature. With this paucity of information, much remains unknown regarding this new pathologic diagnosis. The collection of clinical outcomes data of children with MASC is needed to better understand the behavior of this malignancy as well as determine optimal treatment regimens