Pea leaf weevil herbivory on pea seedlings: effects on growth response and yield

Abstract

Field experiments were conducted to determine growth and yield responses of Pisum sativum L. to defoliation by adult Sitona lineatus (L.). Seedlings grown under conventional (moldboard plowed) and conservation (chisel plowed) tillage treatments were infested for a 1‐week period with 0, 1 and 8 weevils per plant at two times: at 75% field emergence and 1 week later. After the early infestation, defoliation for the control, low and high weevil densities was about 0, 15 and 50%, respectively, while defoliation after the late infestation was about 0, 10 and 35%. An undercompensatory growth response was observed in one experiment after seedlings were subjected to moderate levels of early defoliation. Exact compensation was observed in two experiments after early infestations of low and high Sitona densities. Sitona defoliation reduced the number of pods per plant and pod length in two experiments. However, seed biomass was never significantly reduced. Averaged over all experiments, reduction in seed biomass due to high Sitona densities was 10 and 5% for early and late infestations, respectively. Tillage treatments did not affect Pisum compensatory growth response, although yield components were sometimes greater in conservation tillage than in conventional tillage, possibly due to slightly greater soil moisture in the conservation tillage plots.

Differences between the effects of insecticidal seed and foliar treatments on pea leaf weevils (Sitona lineatus L.) in the field pea (Pisum sativum L.)

“…A single effect of S. lineatus on seed yield and yield factors is not easy to determine. According to Williams et al (1995), by pea leaf weevils caused defoliation can reduce the number of pods per plant and pod length although seed yield was never significantly reduced. Experiments carried out by Cantot (1989) show the effect of the larvae on productivity factors in the peas at a threshold of 10 eggs per plant.…”

“…The pea leaf weevil, Sitona lineatus (L.) is a serious pest of the field pea, Pisum sativum L., in Europe and in the Pacific Northwest (Landon et al 1995;Williams et al 1995;Wnuk & Wiech 1996;.…”

Modeling Embryonic Development in <I>Sitona lineatus</I> (Coleoptera: Curculionidae) in Fluctuating Temperatures

“…This is not the case when pea is grown as a winter crop (Doré and Bouthier 1991). Adults make notches on the leaves, or stipules in leaßess types, but apparently have no effect on yield (Williams et al 1995). At 25ЊC, females can lay up to 40 eggs daily (J.L., unpublished data), and these are deposited directly on the ground or on leaves from which they fall shortly thereafter.…”

Molecular and functional characterization ofcry1Actransgenic pea lines

“…Sharma et al, 2010 In pea, 10 to 70 % yield losses can be incurred depending on the insect pests. Schroeder et al, 1995;Clement, Hardie, Elberson 2002;Legowski, Gould 1960;Williams, Schotzko, Okeeffe 1995;Biddle, Cattlin 2001;Korth 2008 When a desired trait is not available in a given gene pool, one way to complement conventional breeding is to apply biotechnological techniques to access and transfer genes for novel traits from other sources. This approach has been used to develop not only varieties resistant to production constraints (such as insect and diseases) but also to improve the nutritional value of different crops.…”