Quantification of direct and indirect damage caused by Diceroprocta bulgara (Distant) (Hemiptera: Cicadidae) in lime

Objective: To quantify the direct and indirect damage caused by Diceroprocta bulgara in the cultivars of Persian lemon, Mexican with and without thorn, Colimex and Lise, in the Oaxaca Coast. Design/methodology/approach: The damage caused by D. bulgara was recorded their nests in each tree. In each plot, 15 trees were randomly selected to evaluate tree height, crown diameter, number of damaged vegetative growth flows, diameter of the first three flows, length of damage and oviposited eggs. In three planting densities of Lise and Colimex, the loss of fruit was estimated due to the indirect effect of the insect (kg ha-1). Results: The incidence of damage was from 79% (Mexican without spines) to 95% (Colimex). A slight correlation between tree size and damage was observed, larger trees showed a higher percentage of affected flows. The flow with the highest frequency of damage was the second (31.99%) and the first with the lowest (17.33%). The lowest number of eggs oviposited was 26 on the flow 1 in the Mexican lemon, and the maximum of 171 in the spineless one. The higher number of eggs was recorded in Persian lemon (371). A significant relationship was determined between the number of eggs with the length of damage and flow diameter (<0.05). The highest number of mummified fruits (15.6) was observed in Colimex (density 312 trees ha-1), estimating that up to 146 kg of fruit could be lost. Findings/conclusions: In the present work, the direct and indirect damage caused by the cicada D. bulgara was quantified for the first time, which represents a loss of fruit in productive trees. Studies on the biology of the insect are suggested for future integrated management plans.Objective: To quantify the direct and indirect damage caused by Diceroprocta bulgara in lime cultivars: Persian, Mexican with and without thorns, Colimex and Lise; on the Coast of Oaxaca, Mexico. Design/Methodology/Approach: The damage caused by D. bulgara was calculated by counting nests in trees of five lime cultivars (Persian, Mexican with thorns, Mexican without thorns, Colimex and Lise). In each plot, 15 trees were selected randomly to evaluate the variables: height, crown diameter, damaged growth flows, damaged growth diameter, damage length, and number of eggs. The loss of fruit from the indirect effect (kg ha-1), was estimated in three densities of Colimex and Lise. Results: The damage ranged between 78.6% (Mexican without thorns) and 94% (Colimex). The trees of largest size showed a higher percentage of affected flows. The second flow showed the highest frequency of damage (32%), while the lowest frequency was obtained in the first flow (17.3%). The lowest number of eggs was 26 in flow one in Mexican lime without thorns, while the highest was 171 in Mexican lime without thorns. The greatest number of eggs was observed in Persian lime (371). A significant relationship was determined between the number of eggs and the damage length and flow diameter (<0.05). The highest number of mummified fruits (15.6) was observed in Colimex (density of 312 trees ha-1) and the estimation that up to 146 kg of fruit could be lost. Findings/Conclusions: This study quantifies for the first time the direct and indirect damage caused by oviposition of the cicada D. bulgara, which represents a loss of fruit in productive trees. Studies on the insect’s biology are suggested for integral management plans

Caracterización de genotipos élite de Coffea canephora por su tolerancia a sequía.

El objetivo del presente trabajo fue identificar el grado de tolerancia a sequía en diferentes genotipos élite de Coffea canephora P. var. Robusta. El estudio se realizó del 2013 al 2015 en Tuxtla Chico, Chiapas, México. De cada genotipo (INIFAP P9, INIFAP P4, INIFAP P5, INIFAP P7, INIFAP P8) se utilizaron veinte plantas, excepto para el INIFAP P9 con doce; un grupo con la mitad de plantas de cada genotipo se mantuvo en condiciones de capacidad de campo (CC) y la otra mitad en punto de marchitez permanente (PMP). Al nalizar la etapa de estrés y después del riego de recuperación, se evaluaron variables morfológicas y siológicas, tales como parámetros de crecimiento, contenido relativo de agua, acumulación de prolina, índice y densidad estomática e índice de tolerancia a sequía. Los genotipos de C. canephora presentaron entre ellos diferente grado de tolerancia al déficit hídrico, pero compartieron entre sí la detención de sus funciones y activación de diferentes rutas para tolerar la sequía, como disminución en el contenido relativo de agua y aumento de prolina durante el periodo de estrés. Al determinar el índice de tolerancia a sequía, el genotipo más tolerante fue el INIFAP P5 de acuerdo con las variables número de hojas retenidas y totales, tasa de crecimiento relativo, número de pares de ramas plagiotrópicas y nudos totales; mientras que el INIFAP P4 se identificó como uno de los más susceptibles de acuerdo con la tasa de crecimiento relativo y el número de nudos totales, en las cuales presentó los valores más bajos.