English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The bean crop is of great importance for human consumption as a source of protein. One of the most limiting insect pests of this crop in Colombia is the whitefly, Trialeurodes vaporariorum (Westwood). Currently, various nonchemical pest control alternatives for cleaner production are being sought. This study aimed to determine the influence of kaolin on the development of populations of whitefly in greenhouses, and its effect on the physiological characteristics of the bean crop [Phaseolus vulgaris (L.)]. This work was conducted in the greenhouses of the Universidad Nacional de Colombia, in Bogot a. Three experiments were carried out and four treatments were evaluated: 1) control (without any insecticide), 2) synthetic chemical insecticides, and foliar applications of kaolin at 3) 2.5%, and 4) 5% (W/V). Generally, the results showed a high percentage of efficacy (’91%) on whitefly control in plants treated with 5% kaolin, compared with the plants not treated with insecticides in the three different experiments. In addition, foliar applications of kaolin decreased transpiration by 40% and enhanced by 43% the contents of leaf chlorophyll without affecting bean yield. In conclusion, the use of kaolin particle can be considered as an alternative tool in a program of agricultural management on the bean crop since it can control a high percentage of whitefly and it may help the plant physiology, especially under conditions of abiotic stress such as drought stress. The bean (P. vulgaris) is considered a principal component of the diet in many countries; it is a source of protein and some essential minerals. It is arguably the most important grain legume for direct human consumption (Islam et al., 2002). In Colombia, bean crops occupied 39,822 ha with an average yield of 2 tons/ha in 2012 (DANE, 2013). Bean crops can have a high incidence of pests and diseases, causing extensive use of products of chemical synthesis for crop protection to control them. This can lead to an increase in production costs, decreasing the profitability and competitiveness of this crop (Pastor-Corrales and Schwartz, 1994; Singh, 1990). One of the most important pests in this crop is the greenhouse whitefly, T. vaporariorum (Westwood) (Hemiptera: Aleyrodidae) that can cause yield losses up to 50% and is one of the most prevalent pests in the Andean region in the bean crop (Manzano and van Lenteren, 2009; Rend on et al., 2001).The damage this pest generates can be caused by both nymphal instars and adults alike, as they feed on the phloem of plants. Furthermore, T. vaporariorum can also act as a viral diseases vector (Jones, 2003). At the moment, crop protection is focused on decreasing the use of conventional pesticides and the development of new strategies that can be included in programs of integrated pest management (IPM). From this viewpoint, studies with inert particles such as kaolin have been developed (aluminosilicate clay) to become an alternative for the control of arthropods (Glenn et al., 1999). It has been found that foliar applications of kaolin have a positive effect on Hemiptera control such as Agonoscena targionii (Psyllidae) in pistachio (Saour, 2005), Diaphorina citri (Liviidae) in citrus (Hall et al., 2007) and Cacopsylla pyri (Psyllidae) in pears (Saour et al., 2010). In addition, use of kaolin can have positive effects on the plant physiology (Glenn and Puterka, 2002). It has also been stated that leaf temperature and/or fruit decreased (W€unsche et al., 2004) and the chlorophyll content increasedwith kaolin particle film (Segura-Monroy et al., 2015). Furthermore, kaolin helps to regulate plant water relations and promotes water use efficiency (Glenn et al., 2010; Jifon and Syvertsen, 2003). Studies in temperate regions have shown that kaolin foliar sprays can exert an insecticidal activity. However, this type of research in tropical areas, specifically in Andean regions is virtually nonexistent. This study may provide alternatives for IPM programs in horticultural crops. The aim was to compare the effect of using kaolin and synthetic chemical insecticides on the population dynamics of whitefly T. vaporariorum (Westwood) in beans and the influence of the particle film on leaf transpiration, chlorophyll content, and yield components. Materials and Methods Growing conditions Three experiments were carried out at greenhouses of the Faculty of Agricultural Sciences at Universidad Nacional de Colombia, Bogot a (with geographical coordinates 4 38#17.59## N, 74 5#3.65## O) with an average altitude of 2640 m above sea level. In general, the three experiments lasted 120 d. Cultivar used was ICA-Cerinza, widely planted by bean farmers in the Colombian Andes. The planting pattern was 1 m between rows and 0.33 m between plants by placing one seed per site. Guard rows were established between treatments to avoid drifting. Total planted area was of 120 m and plot size was 15 plants. Each plant was watered with 750 mL of water per week throughout the crop cycle using a watering can. The irrigation frequency was three times per week. The volume of irrigation in each frequency was 250mL. The soil characteristics were texture sandy loam soil, pH 5.5, cation exchange capacity = 17.5 meq/100 g, N = 0.45%, Ca = 14.8 meq/100 g, K = 0.79 meq/100 g, Mg = 1.26 meq/100 g, Na = 1.48 meq/100 g, P = 81.3 mg/kg, Cu = 1.40 mg/kg, Fe = 88.5 mg/kg, Mn = 6.69 mg/kg, Zn = 9.93 mg/kg, B = 1.11 mg/kg. In all experiments, plants were fertilized with 25 g of N–P–K compound fertilizer (15–15–15; Precisagro, Colombia) at 21 and 84 d after sowing (DAS). In addition, bean plants were treated with a foliar fertilizer (Wuxal ; Bayer, Colombia) at 1 mL/L (v/v) to supply microelements at 42 and 105 DAS between 800 HR and 1000 HR in all cases.Weed control was manual and disease control was carried out as necessary following recommendations by Pastor-Corrales and Schwartz (1994). In all experiments, greenhouse was at 20 ± 3 C, 60% to 90% relative humidity, and a natural photoperiod of 12 h. Experiments were conducted on the following dates: 1) first experiment (E1) between 30 Sept. 2011 and 30 Jan. 2012, 2) second experiment (E2) between 23 Feb. and 28 June 2012, and 3) third experiment (E3) between 24 Aug. and 21 Dec. 2012. Received for publication 20 Mar. 2015. Accepted for publication 7 Aug. 2015. We thankGustavo Ligarreto for his help during this work. Corresponding author. E-mail: hrestrepod@unal. edu.co. HORTSCIENCE VOL. 50(10) OCTOBER 2015 1503 DISEASE AND PEST MANAGEMENT

hortscience

Impact of Kaolin Particle Film and Synthetic Insecticide Applications on Whitefly Populations Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) and Physiological Attributes in Bean (Phaseolus vulgaris) Crop