Chapter 16 - Solanum nigrum and Solanum physalifolium

Abstract

Solanum nigrum L. and Solanum physalifolium Rusby are two important weeds from Solanaceae family. However, S. nigrum is found as a more widespread weed than S. physalifolium worldwide. Because of this, S. nigrum has been in the subject of many studies, whereas there is limited information on S. physalifolium. Therefore the information in this chapter is centered on S. nigrum. Both species cause a substantial reduction in crop quantity and quality if they are not controlled. Information on the biology and life cycle of these species is of vital value to control the weeds efficiently. Seeds of both species have primary dormancy that can be reduced by cold stratification. Buried seeds of both species are shown to undergo seasonal dormancy cycle, with dormancy reduction during autumn and winter, seed germination and seedling emergences in spring, and dormancy induction during summer. They therefore appear as summer annual weeds in different crops and usually complete their life cycle by late summer to early autumn. Herbicides are efficient means of weed control and have been used extensively to control Solanum as well as other weeds. However, there is an increasing desire to reduce herbicide usage in agricultural systems due to the development of herbicide-resistant biotypes and environmental contamination. Several weed control measures are seen as promising ways to control Solanum weed species including herbicides, interrow mechanical weed control, sowing date, plant density, cover crop, crop rotation, soil disturbances, mulching, and preventive and site-specific weed control options. To achieve sustainable weed control, an integrated management strategy need to be designed using combination of various weed control measures. To do so, feasibility of adapting early and late season control measures under local conditions should also be considered.