Effect of Cl- and Na+ ratios in nutrient solutions on tomato (Solanum lycopersicum L.) yield in a hydroponic system

Intensive tomato (Solanum lycopersicum L.) production in coastal areas of Sinaloa is exposed to significant amounts of Cl and Na deposited by sea breezes and irrigation water, which affects the yield of this vegetable. The aim of this study was to evaluate three percentage ratios of Cl-/anions (25/100, 50/100 and 75/100) and three percentage ratios of Na+/cations (25/100, 50/100 and 75/100) in the nutrient solution on mineral composition, dry matter production and yield of tomato. The experimental design was completely randomized with a 32 factorial arrangement and four replications. Analysis of variance and mean comparisons were performed (Tukey, P ≤ 0.05). Cl and Na concentrations in tomato leaves, stems and fruits increased significantly with increasing ratios of Cl-/anions and Na+/cations in the nutrient solution. The 75/100 Cl-/anions ratio reduced (P ≤ 0.05) the Ca concentration in leaves, while the 75/100 Na+/cations ratio decreased (P ≤ 0.05) K concentrations in leaves and stems. Both ratios reduced aerial dry biomass (48 and 25.8 %, respectively) and tomato yield (50.8 and 45.7 %, respectively). The results indicate that tomato plants grown with the 75/100 percentage ratio of Cl-/anions or the 75/100 percentage ratio of Na+/ cations absorb excessive amounts of Cl or Na, which causes ionic imbalance (especially of K+ and Ca2+) and affects dry matter production and yield.

Effect of Smashing Ridge Tillage Depth on Soil Water, Salinity, and Yield in Saline Cotton Fields in South Xinjiang, China

To explore the potential of smashing ridge tillage irrigation, it is necessary to investigate how smashing ridge tillage technology with mulched drip irrigation affects soil water, salinity, and cotton yield in saline fields. We conducted a two-year (2020–2021) field experiment to study the effects of different smashing ridge tillage depths on soil bulk density, moisture, salinity, dry matter production, yield, and its constituents (effective bolls, 100-bell weight). There were three smashing ridge tillage depths: A (20 cm), B (40 cm), and C (60 cm), with traditional tillage as the CT. The results showed that all of the smashing ridge tillage could reduce soil bulk density, improve the utilization and uptake of deep soil water during the rapid growth period, and reduce the soil salt content. Compared with the CT treatment, the average soil bulk density of the 0–60 cm soil layer in treatments A, B, and C in 2020 and 2021 decreased by 3.05%, 5.87%, 10.09%, and 1.65%, 4.48%, and 8.49%, respectively. The average soil water content in the 0–120 cm soil layer at the flowering and boll stage decreased by 3.68%, 6.28%, 9.04%, and 3.59%, 6.52%, and 9.98%, respectively; the soil salt content in the 0–120 cm soil layer at the boll opening stage decreased by 4.21%, 6.75%, 11.95%, and 5.47%, 24.25%, and 54.13%, respectively. Cotton dry matter production and yield tended to increase with an increasing depth of smash ridge tillage. Treatment C obtained the maximum dry matter production, seed cotton yield, effective bolls, and 100-boll weight. The dry matter production at the boll opening stage was significantly increased by 17.16% and 15.91%, and the yield was significantly increased by 65.24% and 84.14% in treatments C in 2020 and 2021, respectively, compared to CT. The smashing ridge tillage of 60 cm can optimize the structure of the soil tillage layer and also reduce soil salinity and increase yield, which is the suitable depth of smashing ridge tillage for saline cotton fields in the south of Xinjiang. The findings of the study can provide some theoretical basis and practical experience for the improvement of saline soils and sustainable agricultural development in South Xinjiang, China.

Effects of Nipping and Micronutrient Foliar Application on Dry Matter Production, Yield, Agronomic Efficiency and Nutrient Uptake of Short Duration Pigeonpea (Cajanus Cajan L.) Co(Rg)- 7

Background The productivity of pulse crop is low due to cultivation on agriculturally marginal and sub marginal lands under poor management. So, it needs earnest attention in adaption of desirable production technologies to exploit the yield potential of the pulses and it can be possible by application of fertilizers, nipping and foliar application of nutrients.In this view, aresearch was conducted to studyyield maximization, agronomic efficiency and nutrient uptake pattern with nipping and nutrient management practices in irrigated pigeonpea.Methods Field experiment was conducted at farmer’s field, Palacode, Palacode Taluk, Dharmapuri District.The pigeonpea seeds were sown by adapting a spacing of 45 × 30 cm. Entire dose of N, P2O5 and K2O (25: 50: 25 kg)were applied basally and the foliar spraying of 0.5 per cent Micronutrient mixture was done as per treatment schedule on 30th& 45th days after sowing using Knapsack Sprayer with the spray fluid of 500 lit. ha-1.Results The results revealed that the application of T9 (125% RDF + Nipping + Micronutrient) recorded significantly higher dry matter production, yield and nutrient uptake.The least values were recorded under the treatment T1 (Control).

Alternate Wetting and Drying (AWD) Mitigates the Decline in Grain Filling of Basmati 370 Due to Low Temperature in Tropical Highlands

In the rice growing area of Kenya’s highlands, the development of a water-saving rice cultivation system is a key strategy because the shortage of irrigation water is a frequently occurring problem. The purpose of this study was to investigate the effect of alternate wetting and drying (AWD) on the growth and yield of rice under the unique cultivation environment of tropical highlands. Field experiments were performed over a period of four years (2014–2017) in a paddy field. Dry matter production of a lowland variety, Basmati 370, was greater under continuous flooding (CF) than under AWD. In years with low minimum temperature (less than 15 °C) during the reproductive and ripening stages, filled grain ratios were significantly higher under AWD than under CF. Accordingly, higher dry matter production under CF did not contribute to grain yield. In the years when rice was not exposed to low minimum temperature during the reproductive and ripening stages, filled grain ratio did not decrease even under CF. Therefore, there was no difference between filled grain ratio under AWD and CF. Our results indicated that AWD could mitigate the decline in grain filling, induced by low minimum temperature during the reproductive and ripening stages in Basmati 370, under the cultivation conditions in tropical highlands. Although AWD may reduce the above-ground biomass, its mitigation effect on grain filling could outweigh this drawback and can still be beneficial to rice farmers in the tropical highlands.

Impact of Reduced Rainfall on Above Ground Dry Matter Production of Semi-natural Grassland in South Gloucestershire, UK: A Rainfall Manipulation Study

In the United Kingdom, agricultural grasslands cover 40% of the land area, make up 89% of the total agricultural area and are an important land use for ecosystem services and food security. Climate change predictions suggest that the United Kingdom will experience more frequent and severe periods of drought that may impact these grasslands. As part of the Drought Risk and You (DRY) project, a field experiment in which rain shelters reduced precipitation reaching the vegetation by approximately 50%, was set up in the South West of England. The experiment ran for 3 years, from October 2015 to October 2018. The study was carried out at two locations in the catchment of the Bristol River Frome. Both sites were species-rich semi-natural pastures that had received no inputs of fertilizer or herbicide for many years. Automatic weather stations recorded environmental conditions, especially rainfall, within the experimental area. The existing agricultural management regimes were approximated by cutting the vegetation in the plots, by hand, at the appropriate times of year. The effect of rainfall reduction on plant growth was assessed by biomass sampling. At both sites, the rainfall reduction treatment had only small effects on total above ground dry matter production (biomass). These effects were much smaller than the year-to-year variation in total biomass. Our results suggested that well-established permanent pastures in the South West of England were able to tolerate a 3-year period of reduced water supply. The observed year-to-year variation in biomass demonstrated how important the timing of dry weather is for biomass production, and this will be reflected in effects on yield and quality of hay.

Foliar Nutrition with Water Soluble Macro and Micro Nutrient Fertilizers for Yield Maximization in Bush Vegetable Cowpea

Background: Cowpea is a leguminous crop of indeterminate growth habit and continues to produce flowers throughout its life cycle. In order to realize the genetic yield potential of cowpea, nutrient requirements of later formed flushes also needs to be met. Hence the present study was formulated to assess the effect of foliar application of water-soluble macro nutrient fertilizers viz., NPK 19:19:19 and potassium nitrate and micronutrient fertilizers viz. zinc sulphate and solubor for yield maximization in bush vegetable cowpea. Methods: The field experiment was conducted at Coconut Research Station, Balaramapuram, during Rabi 2020-21. The experiment was laid out in randomized block design with 13 treatments in three replications. The treatments comprised of recommended dose of conventional fertilizers (RDF) NPK 20:30:10 kg ha-1 as control and RDF + foliar application of water-soluble fertilizers 19:19:19 (0.5%) and potassium nitrate (0.5%) with zinc sulphate (0.05%) and solubor (0.025%) in twelve different combinations. Result: Results revealed that compared to RDF alone, RDF + foliar application of water-soluble macro and micro nutrient fertilizers at 45 DAS significantly improved the dry matter production, number of pods per plant and pod weight and recorded a yield enhancement of 22 to 55 per cent. Among the treatments, RDF + foliar application of 19:19:19 (0.5%) and solubor (0.025%) at 45 DAS recorded the highest dry matter production per plant (39.51 g), pods per plant (30.88 no.), pod yield (7410 kg ha-1), net return (82651 Rs ha-1) and B:C ratio (2.26). The treatments, RDF + foliar application of 19:19:19 (0.5%) at 45 DAS; RDF + foliar application of 19:19:19 (0.5%), zinc sulphate (0.05%) and solubor (0.025%) at 45 DAS; and RDF + foliar application of potassium nitrate (0.5%) and solubor (0.025%) at 45 DAS also recorded comparable number of pods per plant, green pod yield, net return and B:C ratio. Considering the highest green pod yield, net return and B:C ratio, RDF + foliar application of NPK 19:19:19 (0.5%) and solubor (0.025%) at 45 DAS could be recommended for yield maximization in bush type vegetable cowpea.

Water deficit modifies C:N:P stoichiometry affecting sugarcane and energy cane yield and its relationships with silicon supply

Climate change has increased the occurrence of water deficit in regions where sugarcane and energy cane are cultivated, jeopardizing dry matter production of stems. It was hypothesized that the reasons behind this fact relate to C:N:P stoichiometric modifications in these species that impair the conversion rates of accumulated nutrients in the stems, which could be attenuated by supplying silicon (Si) to the crops. Thus, the aims of this study were to evaluate the effects of water deficit in sugarcane and energy cane ratoons in the presence and absence of Si, in the C:N:P stoichiometry of stems, in the use efficiency of these nutrients and in the accumulation of dry matter in stems. Two experiments were carried out, using sugarcane (Saccharum officinarum) and energy cane (S. spontaneum), cultivated in pots filled with a Typic Quartzipisamment. The treatments for both experiments were arranged in a factorial scheme 2 × 2, without (70% of the soil’s water retention capacity) and with (30% of the capacity) water deficit, without and with the application of Si via fertirrigation, associated with foliar pulverization, both at a concentration of 2.5 mmol L−1, arranged in randomized blocks. The reduction in dry matter production of stems in both species caused by water deficit was due to modifications of the C, N and P stoichiometric homeostasis, but the benefit of Si in these plants when increasing dry matter production was not a reflection of the change in homeostasis, thus it may be involved in other mechanisms that remain unknown and should be further studied.

Simulation of Total Dry Matter Production of Glycine Max L Merrill Under Weed Management Practices

An investigation on “Weed Management and Crop Growth Modeling in Soybean” was carry out on red sandy loam soil at UAS, Main Research Station, Hebbal, Bangalore during Rabi 2010 (September to December). The weed control practices included in the study were i) Pendimethalin 30 EC 1.0 kg a.i./ha – 3 days after sowing, ii) Imazethapyr 10 SL 100 g a.i./ha – 20 days after sowing, iii) Quizalofop-p-ethyl 5 EC 50 g a.i./ha – 20 days after sowing, iv) Chlorimuron ethyl 25 WP 6 g a.i./ha – 20 days after sowing, v) Hand weeding (20 & 40 DAS) and vi) un-weeded control. The experiment was designed as RCBD with four replications. Growth models – Richards, Logistic, Cubic polynomial and Quadratic polynomial simulated the course of dry matter production/plant by >97per cent under all weed management practices, indicating that weed competition did not alter the pattern of crop growth, but affected the total production substantially.