RESUMO
The foliar application of nutrients and plant growth regulators (PGRs) at critical crop growth periods can improve the yield of field crops. Hence, the present study was conducted to quantify the effects of the combined application of nutrients and PGRs (crop-specific formulation) on maize, blackgram, greengram, groundnut, cotton, sugarcane, and coconut yield. In all the crops except coconut, the treatments included (i) a foliar spray of crop-specific nutrients and PGR combinations and (ii) an unsprayed control. In coconut, the treatments included (i) the root feeding of coconut-specific nutrients and PGR combinations and (ii) an untreated control. Crop-specific nutrient and PGR formulations were sprayed, namely, Tamil Nadu Agricultural University (TNAU) maize maxim 1.5% at the tassel initiation and grain-filling stages of maize, TNAU pulse wonder 1.0% at the peak flowering stage of green gram and black gram, TNAU groundnut-rich 1.0% at the flowering and pod-filling stages of groundnut, TNAU cotton plus 1.25% at the flowering and boll development stages of cotton, and TNAU sugarcane booster 0.5% at 45 days after planting (DAP), 0.75% at 60 DAP, and 1.0% at 75 DAP of sugarcane. The results showed that the foliar application of TNAU maize maxim, TNAU pulse wonder, TNAU groundnut-rich, TNAU cotton plus and TNAU sugarcane booster and the root feeding of TNAU coconut tonic increased the yield of maize, pulses, groundnut, cotton, sugarcane, and coconut, resulting in higher economic returns.
RESUMO
Calcineurin B-like proteins (CBL) and CBL-interacting protein kinases (CIPK) mediate plant responses to a variety of external stresses. Here we report that Arabidopsis CIPK6 is also required for the growth and development of plants. Phenotype of tobacco plants ectopically expressing a homologous gene (CaCIPK6) from the leguminous plant chickpea (Cicer arietinum) indicated its functional conservation. A lesion inAtCIPK6 significantly reduced shoot-to-root and root basipetal auxin transport, and the plants exhibited developmental defects such as fused cotyledons, swollen hypocotyls and compromised lateral root formation, in conjunction with reduced expression of a number of genes involved in auxin transport and abiotic stress response. The Arabidopsis mutant was more sensitive to salt stress compared to wild-type, while overexpression of a constitutively active mutant of CaCIPK6 promoted salt tolerance in transgenic tobacco. Furthermore, tobacco seedlings expressing the constitutively active mutant of CaCIPK6 showed a developed root system, increased basipetal auxin transport and hypersensitivity to auxin. Our results provide evidence for involvement of a CIPK in auxin transport and consequently in root development, as well as in the salt-stress response, by regulating the expression of genes.