Biostimulants are innovative organic tools, which promote the growth, plant development, production, and quality of various crops without harming the environment; however, the effects of biostimulants on the production of tomato needed to be explored further under open field conditions. Based on this view, this study’s objective was to assess the impact of Kendal Root, a biostimulant-containing seaweed, Ascophyllum nodosum, and plant extracts on the phytomorpho-physiological, yield, and quality of tomato. Three doses of Kendal Root (2.5, 5.0, and 10 L ha⁻¹) were given as soil drenching, and the results were compared with control. Generally, the Kendal Root treatments positively improved the growth, physiological, yield, and quality attributes of tomato. However, among the three different concentrations, Kendal Root 5.0 L ha⁻¹ significantly improved the plant growth and physiological aspects of tomato, such as plant height, leaf area, shoot and root dry weight, SPAD value, and gas exchange parameters. Considering the yield traits, the Kendal Root 5.0 L ha⁻¹ application significantly improved the tomato fruit number, yield per plant, and yield per hectare. Conversely, flower number per plant and average fruit weight was not remarkably improved by Kendal Root 5.0 L ha⁻¹. Moreover, Kendal Root 5.0 L ha⁻¹ positively improved the quality traits of tomato, including total soluble solids, ascorbic acid content, lycopene, and total sugars than the titratable acidity content of tomato fruits. Hence, the integration of Kendal Root biostimulant in tomato production could be an effective way to boost plant growth, production, and quality of tomato.

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.

In recent days, liquid formulations of brown seaweed extract, Ascophyllum nodosum used as a biostimulant in agriculture. Various studies suggest that A. nodosum enhanced the growth and yield of agriculturally important crops, but still, there is a lack of information about the biostimulation effects on photosynthesis, flowering and fruit setting of tomato. Hence, the present study aimed to know the effect of foliar application of A. nodosum on photosynthesis, flowering, fruit setting, yield and quality of tomato. A biostimulant product, MC Set with A. nodosum extract applied to tomato as a foliar spray at rates of three different concentrations such as 1.0 L ha−1 (MS 1), 2.0 L ha−1 (MS 2), 3.0 L ha−1 (MS 3) for six times during flowering of 2nd (30 Days after transplanting – DAT), 3rd (40 DAT) and 4th (50 DAT) cluster and fruit setting of 2nd (60 DAT), 3rd (70 DAT) and 4th (80 DAT) cluster respectively. The MC Set treatments enhanced the plant photosynthesis, flower number and fruit number per cluster, yield and quality traits of tomato. However, the middle concentration MS 2 showed highest photosynthetic rate, stomatal conductance, SPAD value, flower and fruit in 2nd, 3rd and 4th cluster. It also had better average fruit weight and yield per plant and hectare and enhanced the quality parameters such as total soluble solids, ascorbic acid content, lycopene and total sugars compared to control and other two concentrations of MS Set. Hence, using A. nodosum extract on tomato growth could be a better sustainable crop production method.

As climate change intensifies, drought stress presents a critical challenge for horticultural crops like okra (Abelmoschus esculentus). The effectiveness of melatonin in reducing drought stress is investigated in this study. The treatments include: Absolute control (fully irrigated), control (drought), drought and seed treatment with 100 µM melatonin, drought and foliar spray of 100 µM melatonin, and drought stress with combined effect of seed treatment and foliar spray of 100 µM melatonin. Physiological parameters such as photosynthetic rate, stomatal conductance, transpiration rate, Fv/Fm ratio, and chlorophyll index were evaluated, alongside biochemical parameters including malondialdehyde, proline content, membrane stability index and antioxidant enzyme activities such as catalase and ascorbate peroxidase were quantified. Melatonin supplemented as seed treatment and foliar spray enhanced both physiological and biochemical parameters including antioxidant activity compared to drought control. Metabolite profiling identified bioactive compounds (mainly carbohydrates and amino acids) contributing to drought tolerance in okra. The results highlight that application of 100 µM melatonin via seed treatment and foliar spray enhances drought tolerance in okra, suggesting its potential to enhance crop resilience under water-deficit conditions.

Cotton is one of the most important fiber and cash crops, which plays a dominant role in the industrial and agricultural economics of the world. Most cotton cultivars produce excessive foliage even at crop maturity due to their indeterminate growth habit, which delays boll opening and results in unsynchronized maturation. Due to this, the multiple pickings in cotton require more labour and is also time-consuming process. These problems can be overcome by the practice of mechanical picking in cotton cultivation. For mechanical picking, it is necessary to defoliate the leaves artificially through application of chemicals which will also synchronize the boll opening, finally yield. To address this, we evaluate the various chemicals on morpho-physiological traits, the nutrio- hormonal changes for efficiency in defoliation, boll opening percentage, and synchronization of the entire yield in cotton. The results show that chemical defoliation makes a significant contribution in the improvement in leaf abscission, decreases green leaf retention, and hastens boll opening, allowing for a more even harvest. Among the chemicals, the application of thidiazuron + diuron exhibited the greatest defoliation percentage (96%) and boll opening rate (84%), resulting in enhanced the synchronized boll opening of harvesting efficiency and fiber quality. Overall, this research offers important information for cotton producers seeking to maximize the defoliant application for efficient mechanized harvesting.

Background: In rice belts, cultivation of rice under aerobic conditions provides an alternative way to reduce the enormous amounts of water usage, by using 50 percent of the water when compared to traditional cultivation. However, micronutrient deficiencies are more common in aerobic rice during its early stages of growth. Mycorrhizal fungi were found to be efficient in mobilizing the nutrients under aerobic situations. Methods: The field experiment was conducted in Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore. The experiment consisted of thirteen treatments which includes different recommended doses of VAM 50, 62.5 and 75kg ha-1 along with different combinations of foliar application of 0.5% urea, 0.5% ZnSO4 and 1% FeSO4. Result: The study revealed that combined application of 150 % of recommended dose of VAM and foliar application of 0.5% urea + 0.5% ZnSO4 + 1% FeSO4 at 25 and 45 DAS significantly increased the VAM colonization area, photosynthetic pigments and growth parameters such as plant height, shoot and root weight, root growth, leaf area index and yield attributes and it was found to be a better optionin rice cultivation to overcome the micronutrient deficiencies in its earlier stages under aerobic conditions.