Chemical Control of the Pine Shoot Moth, Rhyacionia buoliana (Denis and SchiffermUller) (Lepidoptera: Tortricidae) in Seed Orchards in Britain

In 1970 and 1971 a high population of Rhyacionia buoliana (Denisand SchiffermÜller), the Pine shoot moth, appeared in aseed orchard of Pinus contorta Douglas ex Loud, in Wiltshire.The opportunity was taken to compare several alternative insecticideswith DDT. Field trials in March and August showed that fenitrothioncan be used as an alternative to DDT to control the Pine shootmoth.     

Diurnal changes in acetylene reduction in field-grown cowpeas and soybeans

The effects of five environmental factors on variation in the rate of C₂H₂ reduction in two cowpea (Vigna unguiculata L. Walp.) and two soybean (Glycine max L. Merrill) cultivars were examined at two stages of growth in the field. Diurnal changes in C₂H₂ reduction, estimated as μmoles C₂H₄ produced·g^?1 nodules·h^?1, over a 30 h period were compared with changes in soil, canopy and air temperatures, global radiation, and vapour pressure deficit. Although the environmental factors showed one maximum and one minimum during a diurnal cycle, the C₂H₂ reduction rate in nodulated cowpea roots showed two peaks: one between 0600–1200 and another between 1800–2400 and two minima: one between 1200–1600 and another between 2400–0600. Variation in C₂H₂ reduction in soybean nodules did not show any definite pattern. Vapour pressure deficit appeared the most likely factor influencing the decline in C₂H₂ reduction between 1200–1600.The rate of C₂H₂ reduction in cowpeas was greater at the pre-flower than at the early pod-fill period; the rate in soybeans was not greatly different at early flower or early pod-fill.