scholarly journals Can Superabsorbent Polymers Improve Plants Production in Arid Regions?

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mohsen Jahan ◽  
Mehdi Nassiri Mahallati

Superabsorbent polymers (SAPs) have shown to be quite effective and useful in acting as a reservoir for water and some nutrients in arid and semiarid regions. There are many studies in Iran that have been performed in relation to SAPs and their useful application in agriculture; however, there is still a lack of its applied definition in arid regions. Therefore, this study was conducted with the aim of doing a meta-analysis of the results of studies conducted in Iran and answering a general question about whether the application of SAPs has been effective in enhancing the production or not, and if so, how much of SAP is recommended. To conduct this research, articles published during 2006–2016 on the subject of the effects of different rates of SAP application on yield and yield components of crops (including cereals, legumes, and medicinal and grassland plants) were investigated. The results of the meta-analysis showed that the mean consumption rate of SAPs for cereals, legumes, and medicinal and grassland plants was 83, 322, 1031, and 210 kg ha−1, respectively, and that, at these SAP application rates, the mean seed yield in cereals, medicinal plants, and legumes increased by 15.2, 12.6, and 38% (equivalent to 1059, 345, and 452 kg ha−1), respectively, compared with the control. Dry matter response to superabsorbent application was slower compared with the seed yield response. The mean consumption of 83 kg ha−1 of superabsorbent for cereals increased seed yield by 15.2% on average. According to the results, it seems that the application of 100 kg SAP ha−1 is the most appropriate rate for increasing seed and dry matter yields and satisfying economic aspects. These study findings may shed light on the environment and socioeconomic concerns and improve efficacy and reduction of costs.

1984 ◽  
Vol 35 (4) ◽  
pp. 511 ◽  
Author(s):  
RW Downes ◽  
JS Gladstones

Plants of Lupinus angustifolius cv. Unicrop were raised at 27/22 or 21/16�C dayhight temperatures until flowering. They were then either grown on to maturity at these conditions or moved to the other regime. Branches were removed as they started to develop and leaves were removed at the start of flowering so that 0, 3, 6, 9, 12 upper leaves or all 21 leaves were retained. Conditions before flowering determined potential pod number. Defoliation treatments revealed that under favourably cool conditions all leaves contributed to seed yield but in treatments involving 27/22'C there was no seed yield response to more than about six leaves, emphasizing the significance of environmental conditions rather than current assimilate on pod set and other yield components. In another experiment, plants were raised to flowering at 27/22, 21/16 or 15/10�C before flowering, when all were moved to 21/16�C. Half the plants were allowed to develop branches and on the remainder branch buds were removed. Branch and stem growth appeared to provide severe competition for the development of the primary inflorescence. Though branching was much more pronounced in plants at 15/10�C before flowering than in other treatments, vegetative development exceeded reproductive investment and harvest index was low under these conditions. It was suggested that there appears to be a need to develop and evaluate unbranched or less-branched lupin genotypes.


1977 ◽  
Vol 88 (3) ◽  
pp. 605-614 ◽  
Author(s):  
P. D. Hebblethwaite

SUMMARYThe effects of irrigation and nitrogen on S. 23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1972 to 1974. Irrigation significantly increased seed yield by 16% in 1972 and 52% in 1974 but had no effect in the wet year of 1973. In 1972 maximum deficit reached 110 mm at the end of July and coincided with anthesis. Consequently the yield response was due to an increase in number of seeds per unit area and no other seed yield component was affected. In 1974 peak deficit also reached about 100 mm but started to build up rapidly very early in the season and had reached 80 mm by the time that the first ears emerged. Consequently the yield response was due to increases in number of fertile tillers, number of seeds per unit area and 1000-seed weight.Irrigation had no significant effect on number of florets or seeds, except in 1974 when percentage of florets which produced seed was increased by 2%.Irrigation had some effect on threshed straw yields, total dry matter, harvest index and total number of tillers but where this occurred the response was much smaller than that of seed yield which indicates that irrigation had greater effects on the reproductive development of the crop than on yield of dry matter and tillering patterns. Increasing the quantity of nitrogen from 0 to 80 kg/ha increased seed yields, all seed yield components except 1000-seed weight, threshed straw yields and total dry matter and number of tillers at most sampling dates. Increasing the quantity of nitrogen from 80 to 160 kg/ha had little further effect on the above components except in 1972 where seed yields were significantly decreased.In 1972 number of florets was increased and percentage of florets which produced seed decreased with increasing quantities of nitrogen.


2017 ◽  
Vol 9 (4) ◽  
pp. 21 ◽  
Author(s):  
Everton Dezordi Sartori ◽  
Maria Eugênia Andrighetto Canozzi ◽  
Daniele Zago ◽  
Ênio Rosa Prates ◽  
João Pedro Velho ◽  
...  

This meta-analysis evaluates the effects of yeast supplementation (Saccharomyces cerevisiae) on dry matter intake (DMI) and average daily gain (ADG) in beef cattle. The inclusion criteria were complete and randomized trials and supplementation with yeast S. cerevisiae versus no supplementation to measure DMI or ADG. Data were extracted from relevant papers via pre-defined protocols. A meta-analysis of random effects was conducted for each indicator separately including the mean of the control and treated groups. The results were presented with the pooled mean difference (MD), 95% of confidence interval, and I² (percentage of total variation between studies that is due to heterogeneity rather than chance). A total of 12 publications reporting 22 trials conducted in 1,161 cattle were analysed. The heterogeneity between studies was high and ranged from 92 to 99%. No effects were observed in ADG with the inclusion of yeast in the diet (MD = -2.849 g/day, p = 0.492). However, there was a reduction in the DMI (MD = -0.885 kg/day; p = 0.023) despite the high heterogeneity among studies (I2 = 92.4%; p < 0.001). The ADG increased when the forage level in the diet was between 30 and 50% (MD = 641.08 g/day; p = 0.001) and decreased when the level range from 51 to 75% (MD = -2.90 g/day; p < 0.001). In over 60% of the Neutral Detergent Fibre, the use of yeast in the diet decreased the ADG by 406.94 g/day (p = 0.034). Feedlot animals showed a reduction in the DMI (MD = -0.97 kg/day; p = 0.019) if supplemented with yeast. Supplementation with S. cerevisiae in the diet of beef cattle had no effect on ADG; however, it does improve the feed conversion due to the reduction in DMI.


HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Simone da Costa Mello ◽  
Francis J. Pierce ◽  
Rachel Tonhati ◽  
Guilherme Silva Almeida ◽  
Durval Dourado Neto ◽  
...  

Polyhalite (PH) is a hydrated sulfate evaporite mineral containing potassium, calcium, magnesium, and sulfur, nutrients all required in significant quantities by crops, but has limited evaluation as a fertilizer for potato (Solanum tuberosum L.). Fertilizer source and application rate field trials were conducted to evaluate PH as a fertilizer for potato production in the weathered tropical soils in Brazil. We selected two locations in the potato producing region of Southeast Brazil in 2015–16, one trial was conducted during the wet season at Tapira in São Paulo and the other during the winter season at Casa Branca in Minas Gerais. A common blend, 4–14–8, was made with either muriate of potash (MOP), sulfate of potash (SOP), or PH as the K source; with kieserite and gypsum added to the SOP to make a synthetic PH with similar composition; P either as single super phosphate (SSP) for the MOP blend or mono ammonium phosphate (MAP) for the PH and SOP blends; and N as urea adjusted for the N in MAP. All blends were applied at four application rates of 62, 125, 187, and 249 kg K/ha. A control was also included consisting of N and P as urea and MAP but no K, Ca, Mg, or S. Total and marketable yields as well as potato quality including dry matter, starch, soluble solids, hardness, and crunchiness were measured at harvest using standard techniques. At Tapira, potato yields increased linearly with increasing K application rate from 22.4 t·ha−1 for the control to the highest yield of 29.2 t·ha−1 and were higher for PH and SOP than MOP (28.8, 29.2, and 25.3 t·ha−1, respectively). At Casa Branca, yields increased from 31.5 t·ha−1 for the control to 42.4 kg·ha−1 at the 62 kg K/ha application rate with no further increases at higher rates and no differences among fertilizer blends at any application rate. Polyhalite blend increased dry matter and starch at the higher application rates compared with MOP and SOP at Tapira and increased potato hardness and crunchiness at the optimum 62 kg K/ha application rate at Casa Branca. Yield response was similar for PH and SOP but quality differences between these two fertilizer blends were observed even though they were similar in composition. Differences between PH and MOP may be related either to Cl or lack of Mg in the MOP blend. PH performed well as a fertilizer for potatoes as it produced equal or higher yields and provided benefits to potato quality when compared with MOP or SOP as a K source in a common fertilizer blend.


1989 ◽  
Vol 40 (4) ◽  
pp. 817 ◽  
Author(s):  
JD McFarlane

Three cultivars of subterranean clover (Trifolium subterraneum L. cvv. Woogenellup, Nungarin; Trifolium yanninicum cv. Trikkala) were grown on three copper-deficient soil types at seven rates of copper, applied at sowing, to determine their vegetative and seed yield response to copper fertilizer.On two soil types, symptoms of copper deficiency were apparent where no copper was supplied. On the third, symptoms appeared only in one season, after the site was waterlogged. On the three soil types, the symptoms disappeared when 0.125 kg Cu/ha was applied at sowing. although at this rate vegetative and seed yields were reduced by as much as 44% and 59% respectively.The proposed critical concentration range in youngest open leaf tissue for both diagnosing maximum vegetative dry matter and predicting maximum seed yield is 3.0-4.5 mg Cu/kg for Woogenellup and Nungarin subterranean clover. Trikkala subterranean clover had higher critical concentration ranges for diagnosing maximum vegetative dry matter (4.0-6.0 mg Culkg) and predicting maximum seed yield (4.5-7.0 mg Cu/kg). It was not clear whether this difference was due to a higher internal requirement for copper of Trikkala or overlying environmental conditions affecting the external copper supply at the time of sampling.For whole top tissue (WT), there was no difference in the critical concentration range between the three cultivars for diagnosing maximum vegetative yield (3.0-4.0 mg Cu/kg). However, the critical concentration in WT for predicting maximum seed yield was higher for Trikkala (5.0-6.0 mg Cu/kg) than Woogenellup and Nungarin (3.5-4.5 mg Cu/kg). In the pasture situation, a critical concentration of 5.0-6.0 mg Cu/kg in the WT should be adopted when animal requirement is considered.Seed copper concentration for predicting maximum seed or vegetative yield was not a reliable indicator of copper status of subterranean clover.


Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2505-2511
Author(s):  
Leandro G. Cordova ◽  
Felipe Dalla Lana ◽  
Pierce A. Paul ◽  
Natalia A. Peres

Botrytis fruit rot (BFR) is a major disease that affects strawberry production in Florida and worldwide. BFR management relies on frequent fungicide applications. A meta-analysis was conducted on the outcomes from nine field trials to evaluate the efficacy and profitability of conventional and biological fungicides compared with a nontreated control (NTC). All trials were conducted in Florida between the 2005/06 and 2016/17 growing seasons. Fungicide treatments were applied weekly, and plots were harvested twice a week for yield and BFR incidence quantification. Treatments were grouped into four categories: NTC, multisite only (Thiram), Standard (captan alternated with fludioxonil + cyprodinil), and Bacillus. Following primary analyses, a random effects network meta-analytical model was fitted to estimate the mean yield and BFR incidence responses for each treatment group and to compare means between pairs of groups. The Thiram and the Standard treatment groups increased yield by 378.8 and 502.2 kg/ha/week, respectively, compared with the NTC. The yield difference between Bacillus and NTC was not statistically significant. Besides increasing yield, Thiram and Standard also reduced BFR incidence by approximately 10% compared with the NTC. The mean yield responses and among-study variability from the meta-analysis were used to estimate the probability of a given yield response in a new future trial. The Standard and Thiram treatment groups showed higher estimated probabilities of increasing yield and resulting in a profitable return on application investments than the Bacillus group of treatments. The results from this study provide growers with information that will aid their decision-making process regarding BFR management.


2021 ◽  
Vol 9 (1) ◽  
pp. 27-36
Author(s):  
Abere Mnalku Ygrem ◽  
Getahun Mitiku Benti

Field and green house experiments were conducted on faba bean and chickpea during 2016-2017 to investigate the effect of fungicides and rhizobial inoculant interaction on nodulation and biomass accumulation of chickpea under Vertisol condition and (ii) faba bean under Nitisol condition. Chickpea seed was treated with Apron Star, Imidalm and both, and co-dressed with EAL-029 rhizobia simultaneously or a week later. Likewise, in one of the two sets, faba bean seed was treated with Apron Star and simultaneously dressed with FB-1017 or FB-1035 rhizobial strain. The other set had the same strains as pre inoculant and sprayed with Mancozeb at 30th day after sowing. Sole inoculants and N (faba bean) were used as check. The application rates of Apron Star, Imidalm, and inoculant were 2.5, 0.75, and 3.12 g kg-1 of seed while for Mancozeb is 2.5kg/ha. All treatments were replicated 4x and laid in RCB design. The result generally depicted that Apron Star application was compatible to EAL-029 rhizobia on chickpea. Staggered dressing of Apron Star and EAL-029 had better chickpea shoot dry matter accumulation. With regards to faba bean, co-dressing of Apron Star with FB-1017 or FB-1035 produced the highest nodulation. This confirmed the synergy of Apron Star with FB-1017 on Nitisol of central high land of Ethiopia. Moreover, spraying mancozeb on the 30th day after sowing to FB-1017 or FB-1035 preinoculated faba bean plant showed enhanced seed yield on Nitisol.


1969 ◽  
Vol 62 (1) ◽  
pp. 10-28
Author(s):  
Modesto Capiel ◽  
Eduardo Brenes ◽  
M. A. Lugo-López ◽  
Paul G. Schoch ◽  
Víctor L. Guzmán

An ecologic study was conducted to evaluate the dry matter yield response and the mean daily growth and water consumption rates of grain sorghum at four climatic sites in the tropics and subtropics. BR-54 seeds of this crop were grown in pots watered by capillarity with a specially-devised fiberglass wick-tin can reservoir technique which permitted water use measurements and drainage through the same wick. Seven weekly harvests were made of shoots and roots separately over a 52-day growth period centered on the March 22 vernal equinox . Climatic sites had a marked effect on dry matter yields (weight of the shoot). The yield response is directly related to the amount of water consumed which, at the same time, is closely related to the leaf area. However, an analysis of variance indicates that the relative growth rate, unit leaf area, water use rate, and other related indices did not significantly differ with climatic sites. As a result, it was found that there existed highly significant quadratic relationships of the relative growth rates and water use rates as a function of days after emergence when the four climatic sites were included together in regression analysis. Linear regression analysis showed also a significant relationship of unit leaf rate and water use rate on the mean daily values of solar radiation intensity and, to a lesser extent, to the open-pan evaporation.


2016 ◽  
Vol 11 (1) ◽  
pp. 333-337 ◽  
Author(s):  
Arvind Kunapara ◽  
R Subbaiah ◽  
Girish Prajapati ◽  
Jaydip Makwana

Cumin is one of the important spice crops grown in arid and semi arid regions of India and is being adopted to cure some of the dreaded diseases. Determination of optimum water requirement which is function of soil crop and atmosphere is needed for achieving more profit and higher productivity per unit of water. Keeping in view, a field experiment was undertaken to access the conjugate impact of three irrigation regimes (0.6IW/ETc, 0.8IW/ETc and1.0IW/ETc) and three lateral spacing (0.60m, 0.70m and 0.80m) on productivity of cumin. Split plot design with three treatment replications was adopted. Drip irrigation with 0.8 IW/ETc resulted higher seed yield, plant height and dry matter of 1344.17 kg/ha, 36.42 cm and 2365 kg/ha respectively at 0.8 IW/ETc with lateral spacing 0.6 m as compared to other treatments. Highest water use efficiency (5.58 kg/ha.mm) was observed at 0.6 IW/ETc with 0.60 m lateral spacing. Highest B:C ratio (2.27) observed at 0.8 IW/ETcwith lateral spacing 0.6m as compared to other treatments.


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