Further studies are necessary to evaluate not only the effectiveness of preemergent herbicides for weed control and selectivity in soybeans but also the potential carryover damage to crops planted in succession, such as sorghum and maize. This study aimed to assess the efficacy of preemergent herbicides in controlling L. and L., as well as their selectivity in soybeans ( L.) and the residual effects on crops sown in succession, including maize ( L.) and sorghum ( (L.) Moench). Two field experiments were conducted with soybean, both in a randomized block design, consisting of the following treatments: sulfentrazone + diuron, flumioxazin + imazethapyr, diclosulam, sulfentrazone, s-metolachlor and flumioxazin, in addition to weeded controls and without weeding, with four replicates. Subsequently, the sowing of maize and sorghum was performed. Visual evaluations of weed control were performed at 14, 21, 28, 35 and 42 days after application of the treatments (DAA) and of phytotoxicity in soybean, sorghum and maize at 14, 21, 28, 35 and 42 days after planting emergence (DAE), and at the end, yield estimate. It was found that the sulfentrazone, sulfentrazone + diuron and imazethapyr + flumioxazin treatments were effective in controlling and up to 42 DAA. For sorghum and maize, no significant injury levels were observed for any treatment, with the exception of sulfentrazone alone, which provided significant reductions in productivity.
People have known that El Niño events are associated with low rainfall in Southern Africa for a century, and seasonal rainfall forecasts are now available in agricultural advisories for farmers. While there is abundant theory as to how farmers might (or should) use seasonal rainfall information on their farms, little is known about whether this information has been widely used or has had widespread benefit. In this study, we use subnational data on cropping area and yield to see if we can detect any macro-level patterns in agricultural choices or outcomes that are related to knowledge of the El Niño Southern Oscillation or seasonal forecast information in Southern Africa.
Aerosol-producing global catastrophes such as nuclear war, super-volcano eruption, or asteroid strike, although rare, pose a serious threat to human survival. Light-absorbing aerosols would sharply reduce temperature and solar radiation reaching the earth's surface, decreasing crop productivity including for locally adapted traditional crop varieties, i.e.
Heat stress affects various components of photosynthetic machinery of which Rubisco activation inhibition due to heat sensitive Rubisco activase (RCA) is the most prominent. Detailed comparison of RCA coding genes identified a tandem duplication event in the grass family lineage where the duplicated genes showed very different evolutionary pattern. One of the two genes showed high level of sequence conservation whereas the second copy, although present only 1.
Global demand for food may rise by 60% mid-century. A central challenge is to meet this need using less land in a changing climate. Nearly all crop carbon is assimilated through Rubisco, which is catalytically slow, reactive with oxygen, and a major component of leaf nitrogen.
