Silicon impedes stalk penetration by the borer Eldana saccharina in sugarcane

Abstract

Many plants grown in soils amended with silicon (Si) display increased levels of resistance to attack by insect herbivores. This study aimed to determine if Si treatment impeded Eldana saccharina Walker (Lepidoptera: Pyralidae) stalk penetration and subsequent damage, as well as borer mass gain, on the node and internode of a susceptible (N11) and a resistant (N33) sugarcane cultivar. Sugarcane [Saccharum spp. (Poaceae)] cultivars were grown in a pot trial in Si‐deficient river sand, with (Si+) and without (Si–) calcium silicate. Sugarcane was infested with 2‐week‐old E. saccharina larvae and harvested at four times, 24, 48, 72, and 96 h after infestation. Silicon‐treated plants showed significant increases in Si content compared to controls, and the external rind was significantly harder for Si+ cane than Si– cane. Silicon treatment significantly decreased borer penetration, stalk damage, and larval mass gain. The results are consistent with the hypothesis that Si contributes to sugarcane stalk borer resistance by impeding larval penetration. Silicon appears to contribute to the suppression of E. saccharina directly through reduced larval growth and feeding damage to the crop, and indirectly by delaying stalk penetration, resulting most likely in increased exposure time of young larvae to natural enemies, adverse climatic factors, or control measures that target young larvae (e.g., insecticides).

Effect of Organic and Inorganic Sources of Silicon against Yellow Stem Borer (Scirpophaga incertulas Walker) of Rice in Odisha, India

“…This higher accumulation of silicon is the reason for low borer damage in plots receiving higher doses of DAE. It has been hypothesized that "Si" deposited on the tissue surface acts as a physical barrier and it prevents physical penetration and / or makes the plant cells less susceptible to enzymatic degradation by insect pests (Salim and Saxena 1992) and (Kvedaras and Keeping, 2007). This mechanism is supported by the positive correlation between the Si content and the degree of suppression of insect pests which is well established through this investigation (Table 3).…”

Ecological fitness of brown planthopper, Nilaparvata lugens (Stål), to rice nutrient management

“…Some reports showed that N is essential for insects mainly for its role in amino acid production and protein synthesis (Sterner and Elser 2002;Schoonhoven et al 2005). On the other hand, many studies have shown that Si could enhance plant resistance to herbivores (Kvedaras and Keeping 2007;Reynolds et al 2009;Kvedaras et al 2010;Han et al 2015;Nikpay et al 2015). Furthermore, regression analysis in the present study clearly indicated that survival of BPH was correlated positively with plant tissue content of N, total free sugar (TFS), and SP but negatively with Si.…”

Priming of jasmonate-mediated antiherbivore defense responses in rice by silicon

“…The results obtained in this study also strongly suggest a role for Si in the priming of JA-mediated inducible defense responses, in addition to the potential of Si to act as an insect antifeedant or as a component of physical barriers inhibitory to feeding (2,5,8). The analysis of JA-dependant defense-associated enzymes and genes (Figs.…”

“…An increased physical barrier produced by the deposition of Si beneath the leaf cuticles has long been considered to represent a major component underlying Si-mediated plant resistance to insect pests (5,8). Si deposition, occurring mainly as opaline phytoliths, is associated with increased rigidity and abrasiveness of plant tissues, thereby reducing their digestibility to herbivores.…”