Salinity effects on rice, rice weeds, and strategies to secure crop productivity and effective weed control. A review

Abstract

This study is the first one that examines simultaneously the direct and indirect effects of soil salinity on rice and rice weeds and suggests solutions to secure both rice production and effective weed control. Salinity negatively impairs growth, reproduction, and rice grain yield. Several studies have addressed the effects of salinity on rice yield when plants are exposed to salinity stress either at the vegetative or reproductive stage. However, rice response to salt stress is a quantitative trait that is influenced by several other factors including genotype, severity and extent of stress, type of tissue, and the stage of growth at which the stress occurs. It is therefore important to exploit holistically the effects of salinity on rice in order to utilize effective short- and long-term strategies to alleviate the negative effects of salinity on the crop. The complexity of this important and growing problem becomes even more acute when the effects of rice weeds that coexist with the crop at saline conditions are taken into consideration. Although the response of rice to salt stress has been investigated in-depth, knowledge of the salinity effects on the weed community is limited. Furthermore, the synergistic options for both salinity and weed management are inadequate. Here, we suggest strategies that address both issues. The use of salt-tolerant rice cultivars, transplanting systems, and seed priming can be adequately employed for both salinity adaptation and effective weed control. Other strategies such as double rice cropping systems, fertilization management, use of soil amendments, water management, exogenous application of phytoprotectants, or inoculation with growth-promoting bacteria require more research and thorough consideration before their adoption because it is likely that such practices could benefit the crop as well as the weeds.