Optimization of irrigation and nutrient concentration based on economic returns,substrate salt accumulation and water use efficiency for tomato in greenhouse

To evaluate the effects of different irrigation and nutrient concentration strategy on growth, yield, water use efficiency (WUE), fruit quality and substrate salt accumulation, tomatoes were grown with five different levels of water (W: 50%, 75%, 100%, 125% and 150%) and nutrient concentrations (N: 0.5, 0.75, 1.0, 1.5 and 2.0 times of Hoagland strength(X)). Fruit quality index was determined by normalization of fruit quality parameters. Deficit irrigation at standard concentration of nutrients reduced yields by 17.43% and 15.52% for T₇ (W_75%-N_1.0x) and 49.54%–51.99% for T₈ (W_50%-N_1.0x) during spring-summer (SS) and fall-winter (FW) seasons, respectively. Contents of total soluble solids (TSS), titrable acidity (TA) and sugar acid ratio (SAR) were all increased in water-deficit treatments. T₈ was found to be highest in TSS, TA and SAR except SAR in FW. Over-irrigation with excessive and standard Hoagland nutrient concentration caused non-significant reduction in yield except T₆ (W_125%-N_1.0x) in SS. T₂ (W_100%-N_2.0x) and T₄ (W_100%-N_1.5x) caused more substrate salt accumulation which resulted in significant decrease in yield and WUE. Through economic analysis, over-watering along with excessive nutrients caused profit reductions. Considering water saving, yield and fruit quality through economic analysis, T₇ found to be optimal strategy.     

Appraisal for site specific plant nutrient management through spatial variability and mapping in hilly areas of northern Pakistan

Purpose

The main purpose of this research work was to assess soil nutrient, spatial variability, and their mapping through GIS for better fertilizer recommendation and management.

Materials and methods

Soil samples (0–20-cm depth) were collected from major crop areas of district Chitral, northern Pakistan during April 2014. The crops areas were divided into eight main sampling units. Each sampling location was recorded through GPS point. The samples were then brought to laboratory of Soil and Environmental Sciences, for further analysis.

Results and discussion

The overall results showed that Zn content was the most deficient nutrient followed by K with 86 and 64% of samples, respectively. These results are different from other plain and agricultural areas which are dominantly deficient in order of N > P > K that could be associated to steep topography, climatic condition, and parent materials. The analyzed nutrients varied independently as indicated by their lower correlation values but showed stronger spatial patterns. Gaussian, linear, and exponential models were used depending on mean prediction error (MPE), root mean square standardize prediction error (RMSSPE), and nugget values for semivariogram analysis and consequent mapping of different nutrients through GIS.

Conclusions

The N and P were weakly distributed, while K and all micronutrients had strong spatial pattern suggesting that only N and P were managed during farming practices and that varied irregularly in the sampled area. In contrast to other plain agricultural areas of the country, the Zn and K were the most deficient elements and should be applied with suitable Zn and K fertilizers for optimum crop production in the area. This low Zn and K contents would be associated to the parent materials, low pH, and high organic matter contents especially in high altitude and comparatively high P content in the soil. The prepared maps can help on site-specific recommendation of fertilizers for farmers, researcher, and planners.

     

Chemical constituents of Stereospermum acuminatissimum and their urease and α-chymotrypsin inhibitions

Phytochemical investigation of the stem bark of Stereospermum acuminatissimum K. Schum. resulted in the isolation of 21 compounds, including two new guanine derivatives, 1,3,7-trimethylguanin-1/3-ium (1) and 3,7-dimethylguanin-1/3-ium (2), and one new phenolic long chain ester, 2-(4-hydroxyphenyl)ethyl hentriacontanoate (3). The known compounds were identified as sterequinones A, F, and H (4, 5, and 6), zenkequinones A-B (7-8), p-coumaric acid (9), methyl caffeate (10), caffeic acid (11), psilalic acid (12), syringaldehyde (13), norviburtinal (14), specioside (15), verminoside (16), tyrosol (17), eutigoside A (18), ellagic acid (19), atranorin (20), and ursolic acid (21). The metabolites were screened for their potential against urease and α-chymotrypsin enzymes, as urease is targeted in peptic ulcer while α-chymotrypsin is used to remove protein debris in ulcer. Compound 20 was found to be excellent urease inhibitor with IC₅₀ value of 18.2 ± 0.03 μM. Compounds 13 and 18-20 are reported for the first time from the genus Stereospermum. The chemotaxonomic significance of the isolated compounds was also described.     

Barley grain-based diet treated with lactic acid and heat modulated plasma metabolites and acute phase response in dairy cows

This study investigated the effects of feeding barley grain treated with lactic acid (LA) and heat on the profile of plasma metabolites related to carbohydrate and lipid metabolism and variables related to rumen health and acute phase response. Eight primiparous rumen-fistulated lactating Holstein cows were randomly assigned, in a crossover design, to 1 of the 2 dietary treatments consisting of 32% (DM basis) rolled barley grain steeped in an equal quantity of either tap water alone (CTR) or a 1.0% LA solution and heated at 55°C for 48 h (LAH). Each experimental period was 21 d, with the last 10 d used for measurements. Blood samples were collected on d 1, 3, 5, 7, 9, and 11 before the morning feeding and on the last day of each period at 0, 2, 4, 6, 8, 10, and 12 h postfeeding to measure glucose, lactate, cholesterol, beta-hydroxybutyrate (BHBA), NEFA, haptoglobin (Hp), serum amyloid A (SAA), and tumor necrosis factor-alpha (TNF-α). Also, rumen samples were collected on d 1, 5, and 11 as well as at 0, 4, 8, and 12 h postfeeding on the last day of each period for measuring the concentration of rumen endotoxin. Results of the day-to-day analysis indicated that cows fed the LAH diet had reduced preprandial concentrations of rumen endotoxin (472 vs. 793 ng/mL; P < 0.01) and cholesterol and greater lactate in the plasma; however, treatment had no effect on plasma Hp and TNF-α (P > 0.10). Postprandial responses showed that the LAH diet tended to decrease the concentration of SAA (4.67 vs. 8.50 μg/mL; P = 0.06). Also, there was a treatment by time interaction for rumen endotoxin (P < 0.01), suggesting a role for both the treatment and the time of sampling on this variable. Furthermore, greater concentration of BHBA and a tendency for greater NEFA and reduced concentrations of plasma glucose were observed in cows fed the LAH diet. In conclusion, results indicated that feeding dairy cows barley grain steeped in 1.0% LA and treated with heat modulated the profile of plasma metabolites and acute phase response.     

Effect of varying dietary energy levels during the last trimester of pregnancy on subsequent first lactation performance in Sahiwal heifers

The aim of the study was to determine optimum dietary energy level during the last trimester of pregnancy for Sahiwal heifers in subtropical Pakistan. Sixteen Sahiwal heifers, 5–6 months pregnant, were assigned to four dietary treatments with four heifers on each treatment. Isonitrogenous (CP = 14.1%) diets having varying energy, namely, ME 88%, ME 100% (Control), ME 112% and ME 124% of NRC recommended level for pregnant heifers, were fed until calving. All were fed a similar diet after calving. Precalving weight gain was highest (P < 0.05) in heifers fed ME 112 and 124% (486 ± 13 and 497 ± 5 g/day, respectively) followed by ME 100% (444 ± 7 g/day), and the lowest weight gain was recorded for ME 88% (397 ± 8 g/day). A similar trend was observed for feed efficiency. Body condition score at calving in groups ME 124% and ME 112% was higher than ME 88% and ME 100%. Nutrient digestibility, birth weight of calves and milk composition except fat content were not influenced by energy levels. The highest daily milk yield was observed in heifers fed ME 100% followed by ME 112, 124, and 88%. We conclude that the NRC recommendation is applicable to the subtropical region.     

Pb fractionation and redistribution as affected by applied inorganic amendments under different soil moisture regimes and incubation time in saline–sodic Pb-polluted paddy soil

Bioavailability and mobility of lead (Pb) in soils depend upon their partitioning between solution-solid phases and their further fractionation and redistribution among different solid-phase components. However, the dynamics of Pb in salt-affected (saline–sodic) Pb-contaminated (polluted) paddy soil need more exploration particularly under the influence of application of amendments at varying hydrological regimes and residence time. In this context, an incubation study was conducted to investigate the effect of application of three inorganic amendments (gypsum, rock phosphate and diammonium phosphate) on Pb fractions at two soil moisture regimes (flooding regime and 75% field capacity) and two incubation times (after 2 and 30 days) successively in non-saline/sodic and saline–sodic Pb-polluted paddy soils. After applied treatments, the concentration of Pb in five, i.e., exchangeable (F1), carbonate (F2), Fe–Mn oxide (F3), organic matter and sulfide bound (F4) and residual (F5) fractions, was assessed by sequential extraction. The results showed that the Pb spiked in the soils was significantly (P?≤?0.05) transformed from easily extractable (exchangeable and carbonate) fractions into less labile (Fe–Mn oxide, OM–S bound and residual) fractions. Among tested amendments, gypsum performed better in reducing the lability of Pb followed by DAP.     

Appraisal of Biofertilizers in Rice: To Supplement Inorganic Chemical Fertilizer

A field experiment was carried out to evaluate the feasibility of inoculating rice seedlings with biofertilizers (Azospirillum and Trichoderma) in order to reduce the use of chemical inorganic nitrogen (N) fertilizer on rice variety BU Dhan 1. The plant performances were better when 25% less inorganic N was applied with Trichoderma and combined application of Trichoderma and Azospirillum. Plants contained the highest chlorophyll concentrations when they were treated with 75% N + Trichoderma. Considering the yield attributes, 75% N + Trichoderma and 75% N + Trichoderma + Azospirillum performed similar to the control. The grain yield of rice was similar to the recommended dose even with 25% less N application. Application of Trichoderma resulted higher yield, followed by combined application with Azospirillum. Results revealed the greater scope of applying biofertilizer (Trichoderma) to supplement chemical N fertilizer with optimum yield of rice.     

Effect of matrix depleting agents on the expression of chondrocyte metabolism by equine chondrocytes

This study was carried out to investigate the effect of two enzymes (collagenase and chondroitinase) and two cytokines/metabolites (interleukin-1beta and retinoic acid) of known catabolic activity on the expression of cartilage metabolism/phenotype in equine articular cartilage. Articular cartilage explants from 11 horses (5-13 years old) were treated for 48 h and assayed for total sulphated glycosaminoglycan (GAG), the incorporation of 35S-sulphate, collagen degradation and mRNA expression of the proteoglycans collagen II, collagen IIA, collagen III, collagen IX, collagen X, collagen XI and glyceraldehyde-3-phosphate (GAPDH). Purified collagenase and retinoic acid were responsible for increased GAG loss from the tissues. Chondroitinase, responsible for catalysing the elimination of glucuronate residues from chondroitin A, B and C (Chondroitinase ABC) and retinoic acid treatment induced an inhibition of proteoglycan synthesis, whereas collagenase treatment did not. Collagenase activity was correlated with increased appearance of the CB11B epitope and type II collagen denaturation. By RT-PCR there was evidence of expression of altered collagen type IIA in purified collagenase treated tissues.     

Sennoside content and yield attributes of Cassia angustifolia Vahl. as affected by NaCl and CaCl2

Pot culture experiments were conducted to assess the extent of growth, photosynthetic capacity, sennoside concentration and yield attributes of Senna plant under the individual as well as combined influence of NaCl and CaCl₂. Six treatments, i.e. NaCl (80 and 160 mM), CaCl₂ (5 and 10 mM) alone and a combination of NaCl + CaCl₂ (80 + 10 and 160 + 10 mM) were given to the growing Senna plants at pre-flowering (45 DAS), flowering (75 DAS) and post-flowering (90 DAS) stages. Significant reductions were observed in pod biomass, leaf area, stomatal conductance, photosynthetic rate and sennoside concentration and yield, with each NaCl treatment. On the contrary, individual CaCl₂ treatments had a favourable effect. Under the effect of combination treatments, although these parameters were reduced, the extent of reduction was much less than one caused by NaCl treatments. The combined treatments thus mitigated the adverse effects caused by NaCl.