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Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foliar application of Atonik (sodium nitrophenolate) at crop critical growth stages is expected to improve crop physiology, morphology, and productivity. The present field study was conducted at the University of Agriculture, Faisalabad in autumn season of 2018 and 2019. Water deficit conditions were imposed by skip irrigation method. Plants were treated with foliar application of Atonik 10 (mg L−1) to evaluate the physiological, morphological, yield, and yield causative attributes of maize grown under deficit irrigation treatments. Randomized complete block design (RCBD) with split plots arrangement was used to layout the experiment having three replications. It was revealed that application of Atonik improved the crop's physiological attributes: relative leaf water contents (RLWC by 10%), chlorophyll contents (14%), and carotenoids content (15%) under water deficit conditions. Similarly, Atonik application augmented the leaf length at maturity, the number of green leaves at harvesting, and the number of grains row−1 of maize by 7%, 20% and 12%, respectively. Moreover, the application of Atonik amended the 100-grains weight, grain yield, and biological yield by 8%, 9% and 20%, respectively. In crux, application of Atonik is an excellent strategy to alleviate the detrimental influence of water deficit on physiological, morphological, and yield causative attributes of maize. [ABSTRACT FROM AUTHOR]

Alternate wetting and drying (AWD) has been recognized as a water‐saving technology in rice production systems; however, pre‐ and post‐flowering AWD could induce changes in yield, quality and aroma biosynthesis in fragrant rice. In the present study, two fragrant rice cultivars (Guixiangzhan and Nongxiang‐18) were subjected to AWD till soil water potential reached −25 to −30 kPa during vegetative stage (VS), reproductive stage (RS), and both stages (VS + RS). The AWD did not affect net photosynthesis and gas exchange significantly, while malondialdehyde (MDA), H2O2 and electrolyte leakage (EL) were higher than in control plants. The AWD treatments variably affected soluble sugars, proline and protein accumulation as well as the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and reduced glutathione (GSH) contents. Moreover, filled grain percentage and 1000‐grain weight in AWD treatments were found to be statistically similar (p > 0.05) to control, except grains panicle−1 under AWD‐VS + RS that was reduced by 11% and 14% for Guixiangzhan and Nongxiang‐18, respectively. On average, yield and related attributes in Guixiangzhan remained higher than in Nongxiang‐18. In addition, the grain aroma volatile (2‐acetyl‐1‐pyrroline, 2‐AP) content increased by 8.79%, 14.45%, and 6.87% and 7.95%, 14.02%, and 5.04% under AWD‐VS, AWD‐RS, and AWD‐VS + RS treatments, for Guixiangzhan and Nongxiang‐18, respectively. Overall, AWD treatments, either at VS or RS, could promote rice aroma in terms of accumulation of 2AP, which might be linked with enhanced endogenous proline contents (a precursor for 2AP biosynthesis) without any severe consequences on rice yield and quality. [ABSTRACT FROM AUTHOR]

Gamma-aminobutyric acid (GABA) is a non-protein amino acid and has a multi-functional role in abiotic stress tolerance. A pot experiment was conducted to assess the role of exogenous gamma-aminobutyric acid (GABA) application to modulate the growth, yield, and related physio-biochemical mechanisms in two aromatic rice cultivars, that is, Guixiangzhan (GXZ) and Nongxiang 18 (NX-18), under Pb toxic and normal conditions. The experimental treatments were comprised of Ck: without Pb and GABA (control), GABA: 1mM GABA is applied under normal conditions (without Pb), Pb + GABA: 1mM GABA is applied under Pb toxicity (800mg kg-1 of soil), and Pb= only Pb (800mg kg-1 of soil) is applied (no GABA). The required concentrations of GABA were applied as a foliar spray. Results revealed that Pb stress induced oxidative damage in terms of enhanced malondialdehyde (MDA), electrolyte leakage (EL), and H2O2 contents, while exogenous GABA application improved leaf chlorophyll, proline, protein and GABA contents, photosynthesis and gas exchange, and antioxidant defense under Pb toxicity in both rice cultivars. Moreover, glutamine synthetase (GS) and nitrate reductase (NR) activities were variably affected due to GABA application under Pb stress. The yield and related traits, that is, productive tillers/pot, grains/panicle, filled grain %, 1,000-grain weight, and grain yield were 13.64 and 10.29, 0.37%and 2.26%, 3.89 and 19.06%, 7.35 and 12.84%, and 17.92 and 40.56 lower under Pb treatment than Pb + GABA for GXZ and NX-18, respectively. Furthermore, exogenous GABA application in rice reduced Pb contents in shoot, leaves, panicle, and grains compared with Pb-exposed plants without GABA. Overall, GXZ performed better than NX-18 under Pb toxic conditions. [ABSTRACT FROM AUTHOR]

Mepiquat chloride (MC) is a plant growth regulator used to manage the rampant vegetative growth of cotton. A two-year field experiment was conducted at the Postgraduate Agricultural Research Station, University of Agriculture, Faisalabad, Pakistan, during 2017 and 2018 to investigate the influence of MC applied at different times on phenology, morphology, lint yield and quality of cotton cultivated using different sowing techniques. MC was applied 50 days after sowing (DAS), 60 DAS and 70 DAS to cotton planted in flat fields (flat sowing), ridges (ridge sowing) and beds (bed sowing). The interactive effect of MC application time and sowing technique did not influence crop phenology, morphology, and lint yield and quality. It was revealed that the crop planted on beds took fewer days to flower (10%) as compared to that on the flat field, and the bed-sown crop produced a higher number of opened bolls (60%) and was characterized by a higher boll weight (32%) and seed cotton yield (50%) in comparison to the flat-sown crop. A late application of MC (at 70 DAS) caused a significant reduction in the time to flowering (8%), with a simultaneous increase in the number of opened bolls (60%), boll weight (32%), ginning out turn (8%) and lint yield (27%) as compared to MC application at 50 DAS. In terms of lint quality, cotton planted on beds had better fiber uniformity (8%) compared to that on the flat field, while MC applied at 70 DAS produced better fiber fineness by 27% in comparison to MC applied earlier. Overall, cotton planting on beds and MC application at 70 DAS may help improve cotton yield and fiber quality and may help in the mechanical picking of cotton. [ABSTRACT FROM AUTHOR]

The conventional rice production system of Pakistan is escalating due to the higher level of labor involved, shortage of water and higher cost of production due to the rapidly increasing cost of energy resources. Dry direct seeded aerobic rice (DDSAR) is a valuable option to ease the problem of labor, water, and energy resources. In this study, screening of four rice varieties of conventional transplanted rice was evaluated under DDSAR in terms of yield, milling recoveries, grain and cooking quality. Four rice cultivars, viz; Super Basmati; Basmati 2000; Basmati 515 and PS-2 were sown at the Research Station of the Engro Fertilizers, Sheikhupura, Pakistan during three consecutive summer seasons (2016 to 2018). The sowing was accomplished in well prepared dry fields. Each variety performed well in terms of yield and quality traits in DDSAR but in terms of yield, Basmati-515 outperformed the other varieties and showed consistency in yield for three consecutive years of cultivation. PS-2 also gave yield statistically similar to Basmati-515 but maximum cooked grain length (17.1-17.5 mm) and grain elongation ratio (1.69-1.7) was recorded for PS-2. In contrast to other varieties, the minimum head rice percentage (40.5-43.5%) was recorded in PS-2 cultivar besides having the second-highest total milled rice percentage (50.5-73.4%) after Basmati-515 (81.0-82.8%). DDSAR did not affect the cooking quality of rice except bursting. In crux, the cultivation of low land rice cultivars under DDSAR not only maintained or increased the grain yield but also the grain and cooking quality of rice. [ABSTRACT FROM AUTHOR]

A considerable amount of rice stubbles (7-10 ton ha-1) are produced yearly in rice-wheat cropping system. Suitable management of these crop stubbles maintains soil health and natural balance of the cropping systems. Rice stubbles management requires number of tillage operations to prepare the seedbed which ultimately delayed the wheat sowing process. Consecutive two-year trail was conducted at Agriculture Extension and Adaptive Research Farm, Gujranwala, Pakistan i.e. 2012-13 and 2013-14, with the objectives to determine the most profitable economical rice residues management technique for this system. Trail was comprised of seven tillage methods; turbo seeder (TS), happy seeder (HS), zone disc tiller drill (ZDT), zero tillage drill (ZTD), ZTD after physical elimination of rice stubbles, ZTD after straw burning, conventional tillage and three nitrogen application timings; all N application at sowing time; 0.5 N at as basal dose + 0.5 N at first irrigation; 0.5 N at first irrigation + 0.5 N at second irrigation. Statistically, higher plant height was noted in turbo and happy seeded wheat as compare to other wheat sowing methods while nitrogen application timings gave maximum plant height where N fertilization was done, 0.5 N during seed bed preparation and 0.5 N at first irrigation. Turbo seeded treatment gave 265.33 fertile tillers m² that were 5%, 7%, 12%, 11%, 6% and 4 % more than HS, ZDT drill, ZTD, conventional ZTD after rice straw removal manually, conventional ZTD after rice straw burning and conventional wheat sowing, respectively. Turbo seeded wheat produced substantial higher spike length compared to other ZT methods. Statistically, maximum grains per spike were recorded in experimental units where wheat cultivation was done with turbo seeder followed by conventional tillage method of wheat sowing. Among nitrogen application timings higher grains per spike were calculated where N fertilizer was applied, 0.5 N during seedbed preparation and 0.5 N at primary watering. Uppermost thousand grain weight (TGW) was recorded in conventional sowing method and it was similar with TS, HS, ZTD, ZTD after physical elimination of rice stubbles and ZTD after straw blazing while, in case of N application timings, utmost TWG was obtained when N fertilization was done half N as basal dose and half at the time of primary irrigation. Turbo seeder treatment gave substantially highest total crop biomass as compared with other sowing methods. Wheat sown with turbo seeder gave 5.69%, 14.95%, 12.18%, 9.33%, 5.1% and 1.99% higher yield than HS, ZDT, zero tillage drill, ZTD after physical elimination of rice stubbles ZTD after straw blazing and conventional method of wheat sowing, respectively. Among nitrogen application timings, higher grain yield was obtained where N fertilization was done with 0.5 N at sowing and 0.5 N at time of primary irrigation. During both year of experimentation, LAI and crop growth rate (CGR) at 75 days after sowing (DAS) and total dry matter (TDM) and leaf area duration (LAD) at 120 DAS was maximum in turbo seeded wheat when N was added 0.5 N dose as a basal and 0.5 N at the time of primary irrigation. Net assimilation rate was higher in turbo seeded wheat when N was added 0.5 N during seedbed preparation and 0.5 N at primary watering. Moreover, highest grain protein contents (12.95%), fat contents (0.85%), and fiber contents (0.14%) were observed in TS experimental unit. Among different zero tillage sowing methods turbo seeder gave better returns and in case of nitrogen application timing the treatment gave better returns when half nitrogen was applied at sowing time and half nitrogen was applied at first irrigation. [ABSTRACT FROM AUTHOR]

Weed infestation is a major problem in direct seeded rice because weeds reduce yield as well as quality of rice. Manual weeding in direct seeded rice is very tedious, time consuming and mostly weather dependent operation. A field experiment was conducted in summer season 2018 to study the comparative efficacy of different pre and post-emergence herbicides in direct seeded rice to control weeds. The experiment was comprised of ten treatments with eight herbicides application viz. pendimethalin at 1137.5 g a.i. ha-1, oxadiargyl 80 g a.i. ha-1, triafaman+ ethoxy sulfuran ethyl 56.25 g a.i. ha-1, pyriftalid+ bensulfuron ethyl 220.32 ml a.i. ha-1, bispyribac sodium+bensulfuran 75 g a.i. ha-1, phenoxaprop 431.25 ml a.i. ha-1, pendimethalin 1137.5 g FB ethoxy sulfuran ethyl 7.5 g a.i. ha-1, oxadiargyl 80 g a.i. ha-1 FB ethoxy sulfuran ethyl 7.5 g a.i. ha-1 and there were two control treatments viz. hand weeding and weedy check. The experiment was laid out in randomized complete block design (RCBD) with three replications. The data related to weed growth, weed dominance analyses and yield parameters were recorded and calculated by following the standard procedures. The results showed that triafaman+ ethoxy sulfuran ethyl gave effective weed control for about 50 days after sowing as compared to other herbicides. Also all the yield related parameters rice were recorded maximum in hand weeding and triafaman+ ethoxy sulfuran ethyl applied treatment. As hand weeding is a very tough operation, application of triafaman+ ethoxy sulfuran ethyl 56.25 g a.i ha-1 as preemergence herbicide is recommended to get effective control of weeds and higher paddy yield in direct seeded rice. [ABSTRACT FROM AUTHOR]

Copyright of Agrociencia is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat stress at reproductive stages of cotton is a leading encumbrance to accomplish yield potential. An experiment was conducted to alleviate adversities of terminal heat stress on cotton. Experiment was conducted at University of Agriculture Faisalabad, Pakistan during 2013 and repeated in 2014 using Randomized Complete Block Design (RCBD) with split arrangement. Treatments were comprised of heat stress in main plots, viz., H0 = no heat imposition, H1 = heat imposition at squaring, and H2 = heat imposition at flowering. Selenium was foliar applied in split plot, viz., Se0 = 0, Se50 = 50, Se100 = 100, and Se150 = 150 mg L−1. Cell membrane thermostability, soluble proteins, and total phenolics were reduced significantly under heat stress leading to reduced cotton yield and related components. Maximum membrane thermostability, total phenolics, soluble proteins, opened bolls, boll weight, sympodial branches, and seed cotton yield were recorded with the application 150 mg Se L−1. [ABSTRACT FROM AUTHOR]

Rice cultivation in lead (Pb) polluted soils often leads to high Pb contents in rice grains. The present study investigated the dynamics of Pb uptake under different water regimes in two fragrant rice cultivars i.e., Guixiangzhan and Nongxiang-18. Results revealed that water dynamics regulated the antioxidant activities in both rice cultivars under Pb toxicity. Compared to continuous ponding (CP), taken as control, alternate wetting and drying (AWD) reduced the Pb contents in roots, stems, leaves, and grains up to 17%, 41%, 22%, and 52% in Guixiangzhan and 23%, 19%, 17%, and 37% in Nongxiang-18, respectively. Furthermore, AWD-treatments reduced paddy yield from 11% to 21% in Guixiangzhan and 11–33% in Nongxiang-18 under Pb toxicity. In conclusion, Pb loadings in fragrant rice can be regulated by effective water management and/or by controlling irrigation water at different growth stages. Special control measures or management is required to cultivate the rice in metal(loid)s polluted soils. [ABSTRACT FROM AUTHOR]

Zinc and Boron dearth is an imperative soil constraint in Pakistan. Zinc (Zn) and boron (B) deficiency in soil is primary hindrance to achieve yield potential of maize. An experiment was conducted with the objectives to optimize methods of B and Zn application in maize and ultimately enhance profitability. The experiment was laid out in randomized complete block design with factorial arrangement during autumn 2015. Treatments were replicated three times. The treatments were comprised of C = no Zn and B (Control); Zn (S) = soil application of Zn @ of 12 kg ha-1; B (S): soil application of B @ 3 kg ha-1; Zn (F) = foliar application of 1% Zn at 9th leaf stage; B (F) = foliar application of 0.5% B at 9th leaf stage; Zn (S) + B (S) = soil application of Zn @ 12 kg ha-1 + B @ of 3 kg ha-1 and Zn (F) + B (F) = foliar application of 1% Zn + 0.5% B at 9 leaf stage. Foliar application of Zn and B produced more plant height, cob length, girth, stem girth, shelling percentage, number of grains per cob, 1000-grain weight, harvest index, grain and biological yield. Maximum marginal rate of return was obtained with foliar application of both Zn and B and using foliar Zn alone. Integrated B and Zn application produced more marginal rate of returns both in soil and foliar applications. Use of foliar Zn application also depicted promising results while foliar or soil B application without using Zn enhanced cost of production. [ABSTRACT FROM AUTHOR]

Water deficit is an environmental constraint restricting plant growth and productivity, and is further worsened by reduced soil fertility. Plant growth-regulating substances ameliorate damaging effects of abiotic stresses, and their efficacy is improved by application of adequate nutrients. An experiment was undertaken to investigate the influence of foliar-applied nutrients (nitrogen, phosphorus, potassium: NPK) and 5-aminolevulinic acid (ALA) alone and in combination on morpho-physiological indices of the perennial grass Leymus chinensis (Trin.) Tzvel under drought and well-watered conditions. Drought stress caused a reduction in growth and photosynthetic pigments while increasing the accumulation of malondialdehyde (MDA) and osmolytes compared with well-watered conditions. However, application of NPK and ALA improved plant height, fresh and dry weights, and chlorophyll content. Production of soluble proteins and sugars, proline content, and antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and glutathione reductase) were increased and MDA accumulation was lowered by application of NPK and ALA relative to the control (no application). Combined application of NPK and ALA proved more advantageous than NPK or ALA alone in exerting ameliorative effect on L. chinensis under drought-stressed conditions. The results suggest that combined application of NPK and ALA improves the growth and development of L. chinensis by modulating physiological processes and aids in sustaining drought. [ABSTRACT FROM AUTHOR]

Water and labour scarcity pushes researchers to explore alternate sowing methods for rice like aerobic direct seeding but weed infestation is the major hindrance to adapt this production system. In our study, mechanical, chemical and cultural approaches were employed as weed control measures. Weed dynamics and yield parameters were recorded and economic analysis was performed. All weed control measures significantly reduced the weed density and weed dry weight as compared to control and improved harvest index. Maximum control in total weed density and total weed dry weight was achieved by hoeing followed by chemical control. The order of treatment groups in decreasing total density, total weed dry matter production and increment in harvest index was as cultural, chemical and mechanical. However, substantially highest net returns (PKR 44,049/) and highest benefit cost ratio (BCR) (1.53) were obtained by post emergence application of Penuxsulam at the rate of 15 g a.i ha-1 followed by hoeing. Inter-culture, mulching technique and Sesbania drummondi intercropping scored 1.19, 1.13 and 1.21 BCR, respectively. Thus, hoeing with hoe (25 and 45 days after sowing) and post emergence application of Penoxsulamat the rate of 15 g a.i ha-1 were most effective, profitable and economical weed control options. [ABSTRACT FROM AUTHOR]

Crop growth and productivity may differ under different sowing methods and planting densities. A field experiment was conducted to evaluate the influence of different sowing methods and planting densities on growth, yield, quality and economic returns of cotton. Sowing methods included pit planting (1 m × 1 m pits), bed planting (75 cm apart beds), ridge planting (75 cm apart ridges) and line sowing with varied inter row spacing (25, 50 and 75 cm). Sowing methods significantly affected growth and yield of cotton. Pit planting imposed maximum increase in plant height (152 cm), number of monopodial branches (4.7) and sympodial branches (22.6) per plant, number of unopened (9.4) and opened bolls (41.1) per plant, and average boll weight (3.0 g) of cotton. However, highest seed cotton yield (2944.5 kg ha-1) was obtained by flat sowing on 25 cm apart rows owing to highest planting density per unit area. Maximum ginning out turn (GOT) (41.6%) was noticed in pit planting of cotton, while, fiber quality was not affected significantly by sowing methods. Economic analysis showed that economic returns and benefit cost ratio (BCR) (1.52) was elevated by flat sowing on 25 cm apart rows. In conclusion, maximum seed cotton yield and economic returns can be acquired by flat sowing with 25 cm apart rows, while, fiber quality is independent of sowing methods. [ABSTRACT FROM AUTHOR]

Accumulation and soil enrichment with non-essential heavy metals like chromium (Cr) above threshold levels results in Cr toxicity in plants. In order to study the effect of varying Cr stress levels on maize growth, photosynthesis and gas exchange capacities and yield responses, two maize hybrids i.e., Wan Dan 13 and Run Nong 35 were grown in soil contained pots contaminated with different concentrations of Cr (0 µM, 30 µM, 60 µM, 90 µM, 120 µM and 150 µM). Cr toxicity substantially reduced total chlorophyll contents, net photosynthesis, transpiration rate, inter-cellular CO2, stomatal conductance, water use efficiency and intrinsic water use efficiency. It further haltered growth (plant height, number of leaves/plant, leaf area, stem diameter, shoot fresh and dry weight) and yield and related attributes (ears/plant, number of kernels/row, 100-kernels weight, grain yield/plant, biological yield/plant) as well as harvest index both maize hybrids but the effects were more conspicuous in Run Nong 35 than Wan Dan 13. The overall toxicity of Cr to both maize hybrids were recorded as: 150µM > 120µM > 90µM > 60µM > 30µM > 0µM. In sum, Cr contamination negatively influenced on maize, however, Wan Dan 13 was better able to resist Cr-stress than Run Nong 35. [ABSTRACT FROM AUTHOR]

Insufficient mobilization of pre-anthesis photosynthates from vegetative sources to reproductive sinks during achene growth and development plays a key role in reduced productivity of sunflower. Among different essential plant nutrients, a micronutrient boron (B) is known to have a prominent role in the mobilization of pre-anthesis reserves. A field experiment was carried out to investigate the role of soil applied boron in the mobilization and partitioning of pre-anthesis photoassimilates in early and late sown sunflower hybrid. Treatments were comprised of sowing dates (S) randomized in main plots and different rates of boron (B) randomized in sub plots. Treatments were S1= Normal sowing (Mid-February); S2= Late sowing (1st week of March) and B1= Control; B2= Water spray; B3= 1.5 kg B ha-1 at button stage; B4= 2 kg B ha-1 at button stage; B5= 2.5 kg B ha-1 at button stage; B6= 1.5 kg B ha-1 at ray floret stage; B7= 2 kg B ha-1 at ray floret stage; B8= 2.5 kg B ha-1at ray floret stage. Soil applied boron significantly improved the dry matter accumulation (fresh and dry weight of leaf, stem, head and whole plant) and mobilization of photosynthates, capitulum diameter, number of achenes per head, 1000-achene weight, achene and biological yield. Moreover, achene oil and protein contents also increased by the soil application of boron. Normal sowing date was more effective for mobilization of reserves. However, application of B (2-2.5 kg ha-1) mitigated the adverse effects of late sowing to a considerable extent. [ABSTRACT FROM AUTHOR]

Six advance lines IR1, IR2, IR3, RF1, RF2 and RF3 and four cultivars Pirsabak-08 (PS08), Janbaz (JZ), Zam-04 (ZM04) and Kohat-10 (KT10) were crossed in line × testers fashion in spring 2011 to produce F1 hybrids. The experimental material consisting of 34 genotypes (10 parents and 24 F1 hybrids) were evaluated under irrigated conditions in triplicated randomized complete block design at Cereal Crops Research Institute (CCRI), Pirsabak, Nowshera, Pakistan during 2011-12. Data were recorded on tillers plant-1, spike length, grains spike-1, 1000-grain weight, biological and grain yield plant-1. Mean of 24 F1 hybrids was greater than mean of 10 parents for all traits studied. Among lines RF3 and testers ZM-04 were good general combiners for most of the yield traits including grain yield plant-1. Cross combination RF3 × PS08 proved as good specific combiner showing positive SCA effects for all traits including grain yield plant-1. Crosses viz. IR1 × JZ, RF2 × ZM04 and RF2 × KT10 proved as good specific combiners for all traits except 1000-grain weight. Another three set of crosses viz. IR2 × JZ, RF1 × KT10 and RF1× JZ proved as good specific combiners for all traits except grains spike-1, biological yield and grain yield plant-1, respectively. All aforementioned crosses expected to yield transgressive segregants with more grain yield compared to their parents as these cross combinations had positive SCA effects for grain yield plant-1. GCA to SCA variances ratio revealed predominantly non-additive gene effects in the inheritance of all traits in wheat. Development of high yielding varieties with improved traits is therefore suggested through selection in late segregating generations. [ABSTRACT FROM AUTHOR]