Effects of a Dehydrating Agent on Dry Matter Accumulation and Nutritional Quality of Different Maize Varieties

The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.

Effects of Calcium Application Rate on Dry Matter Accumulation and Yield of Peanut

The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results showed that number of full fruit,dry weight per plant,kernel yield,and pod yield all increased with calcium application increased,and they decreased when calcium application rate was more than150 kg/ha. Both the height of main stem and the length of side shoot decreased with calcium application increased. Therefore,to obtain the optimal agronomic character index and the highest yield benefit,the suggested calcium application rate would be 150 kg/ha for peanut.

Pattern of Growth and Dry Matter Accumulation in Some Improved Cowpea Varieties (<i>Vigna unguiculata</i>) Exposed to Alpha Nano Spin

Ten (10) cowpea varieties exposed to alpha nano spin were evaluated during the 2019 cropping season to access the role of alpha nano spin in their growth and dry matter accumulation at the Botanical garden of Federal University, Lafia. A Randomized Complete Block Design (RCBD) with four replications was used. The fourth replication was used for the destructive sampling over time. The seed was exposed to alpha nano spin before planting at 0, 20, 40 and 60 minutes respectively. Results of the study showed that the varieties differed significantly with respect to morphological traits studied (P < 0.05) as exposed to the alpha nanoparticles. Morphological traits such as vine length, number of leaves and above ground stems were significantly influenced by alpha nano spin bombardment. 40 mins alpha nano spin resulted in maximum accumulation of dry matter, leaf area and leaf area index. The traits evaluated were stable under alpha nano spin exposure, suggesting that they could be useful indices in creating genetic variability in each of the varieties.

Dynamics of physiological characteristics and dry matter accumulation under rain-water storage irrigation

Photosynthesis is related to dry matter accumulation in aboveground part of rice plant,which is the direct factor of production.This study carried out research on physiological indicators and the relationship between photosynthesis and dry matter accumulation under different water management in paddy field.In general,the photosynthetic and physiological indicators showed the trend of increasing and then decreasing with the growth stage of rice.Experimental results showed that,chlorophyll content and leaf area index of rice leaves showed a quadratic curve positive correlation.Canopy light transmission reached the maximum at heading-flowering stage,and it had quadratic relationship with leaf area index,while it showed extremely positive correlation under rain-water storage irrigation mode.Photosynthetic rate(Pn)and transpiration rate(Tr)had quadratic curve positive correlation with chlorophyll content.The water condition under rain-water storage was favorable for dry matter accumulation in panicle.After multiple regression and main factor analysis,canopy light transmission,light transmission coefficient and Pn were main factors related to dry matter accumulation.The conclusions in this article were helpful for promoting rice yield in practice.

Effect of different film color mulching on dry matter and grain yield of oil flax in dry-land

Mulching can effectively maintain soil moisture;color of mulching film affects soil water storage capacity and further promote crop growth to improve grain yield.Field experiment was conducted to study effects of different film colors on dry matter accumulation(DMA)and grain yield of oil flax.Results showed that white plastic film mulching could increase leaf area,chlorophyll content and DMA.DMA of white film mulching and micro-ridge with soil covering was 53.0%higher than that of CK,and 7.8%higher than that of black film mulching.Mulching method also influenced DMA.Micro-ridge alone increased it by 13.7%than flat cultivation and soil covering improved another 7.6%under white film mulching.Both white and black film mulching with microridge could significantly improve grain yield.Black film mulching with micro-ridge and soil covering,white film mulching with micro-ridge and no soil covering significantly increased capsule number per plant,1,000-grain weight and grain yield of oil flax,compared with CK.Grain yield increased 29.0%and 28.9%respectively.These results indicated that the above mulching methods were suitable for high yield cropping pattern in dry-farming regions.

Night warming increases wheat yield by improving pre-anthesis plant growth and post-anthesis grain starch biosynthesis

Global climate change is characterized by asymmetric warming,i.e.,greater temperature increases in winter,spring,and nighttime than in summer,autumn,and daytime.Field experiments were conducted using four wheat cultivars,namely‘Yangmai 18’(YM18),‘Sumai 188’(SM188),‘Yannong 19’(YN19),and‘Annong 0711’(AN0711),in the two growing seasons of 2019-2020 and 2020-2021,with passive night warming during different periods in the early growth stage.The treatments were night warming during the tillering-jointing(NW_(T-J)),jointing-booting(NWJ-B),and booting-anthesis(NWB-A)stages,with ambient temperature(NN)as the control.The effects of night warming during different stages on wheat yield formation were investigated by determining the characteristics of dry matter accumulation and translocation,as well as sucrose and starch accumulation in wheat grains.The wheat yields of all four cultivars were significantly higher in NW_(T-J)than in NN in the 2-year experiment.The yield increases of semi-winter cultivars YN19 and AN0711 were greater than those of spring cultivars YM18 and SM188.Treatment NW_(T-J)increased wheat yield mainly by increasing the 1,000-grain weight and the number of fertile spikelets,and it increased dry matter accumulation in various organs of wheat at the anthesis and maturity stages by increasing the growth rate at the vegetative growth stage.The flag leaf and spike showed the largest increases in dry matter accumulation.NW_(T-J)also increased the grain sucrose and starch contents in the early and middle grain-filling stages,promoting yield formation.Overall,night warming between the tillering and jointing stages increased the pre-anthesis growth rate,and thus,wheat dry matter production,which contributed to an increase in wheat yield.

Morpho-Physiological Response of Oryza glaberrima to Gradual Soil Drying

Soil drought occurrence during dry season has been the main constraint, besides prolonged flooding during rainy season, in increasing cropping intensity and rice productivity in tropical riparian wetland. Use of drought tolerant rice genotype might be a suitable option for overcoming such problem. This study focused on the effects of gradual soil drying during early vegetative growth stage on morphological and physiological traits of five Oryza glaberrima genotypes, namely RAM12, RAM14, RAM59, RAM97 and RAM101, and two Oryza sativa subsp japonica genotypes, i.e. Koshihikari and Minamihatamochi. The plants were subjected to 6 d of gradual soil drying condition from 15 days after transplanting(DAT) to 20 DAT, and were allowed to recover until 22 DAT. Gradual soil drying reduced plant growth as indicated by dry mass accumulation. Drought reduced stomatal conductance and increased leaf rolling score of all the genotypes. All the genotypes showed comparable response on stomatal conductance, but O. glaberrima genotypes performed higher in leaf rolling recovery. Meanwhile, O. sativa genotypes decreased total leaf area and specific leaf area, but increased specific leaf weight in order to avoid further damages due to drought stress. Drought tolerance mechanisms in RAM101, RAM12, RAM59 and RAM14 were associated with leaf morpho-physiological responses, root traits and dry biomass accumulation.

Combined effects of high temperature and waterlogging on yield and stem development of summer maize

The purpose of this study was to identify the physiological mechanism underlying the effects of high temperature and waterlogging on summer maize.The stem development and yield of the maize hybrid Denghai 605 in response to high-temperature stress,waterlogging stress,and their combination applied for six days at the third-leaf,sixth-leaf,and tasseling stages were recorded.The combined stresses reduced lignin biosynthetic enzyme activity and lignin accumulation,leading to abnormal stem development.Reduction of the area and number of vascular bundles in stems led to reduced dry matter accumulation and allocation.Decreased grain dry weight at all three stages reduced grain yield relative to a control.In summary,high temperature,waterlogging,and their combined stress impaired stem development and grain yield of summer maize.The combined stresses were more damaging than either stress alone.

Late spring cold reduces grain number at various spike positions by regulating spike growth and assimilate distribution in winter wheat

Late spring cold(LSC) occurred in the reproductive period of wheat impairs spike and floret differentiation during the reproductive period,when young spikelets are very cold-sensitive.However,under LSC,the responses of wheat spikelets at various positions,leaves,and stems and the interactions between them at physiological levels remain unclear.In the present study,two-year treatments at terminal spikelet stage under two temperatures(2 C,-2 C) and durations(1,2,and 3 days) were imposed in an artificial climate chamber to compare the effects of LSC on grain number and yield in the wheat cultivars Yannong 19(YN19,cold-tolerant) and Xinmai 26(XM26,cold-sensitive).The night temperature regimes were designed to reproduce natural temperature variation.LSC delayed plant growth and inhibited spike and floret differentiation,leading to high yield losses in both cultivars.LSC reduced dry matter accumulation(DMA,g) in spikes,stems,and leaves,reducing the DMA ratios of the spike to leaf and spike to stem.Plant cell wall invertase(CWINV) activity increased in upper and basal spikelets in YN19,whereas CWINV increased in middle spikelets in XM26.Under LSC,soluble sugar and glucose were transported and distributed mainly in upper and basal spikelets for glume and rachis development,so that spike development was relatively complete in YN19,whereas the upper and basal spikelets were severely damaged and most of the glumes in middle spikelets were relatively completely developed in XM26,resulting in pollen abortion mainly in upper and basal spikelets.The development of glumes and rachides was influenced and grain number per spike was decreased after LSC,with kernels present mainly in middle spikelets.Overall,reduced total DMA and dry matter partitioning to spikes under LSC results in poor spikelet development,leading to high losses of grain yield.

Effects of post-silking water deficit on the leaf photosynthesis and senescence of waxy maize

Waxy maize is widely cultivated under rainfed conditions and frequently suffers water shortage during the late growth stage.In this study,a pot trial was conducted to examine the effects of post-silking drought on leaf photosynthesis and senescence and its influence on grain yield.Two waxy maize hybrids,Suyunuo 5(SYN5)and Yunuo 7(YN7),were grown under the control and drought(soil moisture content was 70–80%and 50–60%,respectively)conditions after silking in 2016 and 2017.The decrease in yield was 11.1 and 15.4%for YN7 and SYN5,respectively,owing to the decreased grain weight and number.Post-silking dry matter accumulation was reduced by 27.2%in YN7 and 26.3%in SYN5.The contribution rate of pre-silking photoassimilates transferred to grain yield was increased by 15.6%in YN7 and 10.2%in SYN5,respectively.Post-silking drought increased the malondialdehyde content,but decreased the contents of water,soluble protein,chlorophyll,and carotenoid in the leaves.The weakened activities of enzymes involved in photosynthesis(ribulose-1,5-bisphosphate carboxylase and phosphoenolpyruvate carboxylase)and antioxidant system(catalase,superoxide dismutase and peroxidase)reduced the photosynthetic rate(Pn)and accelerated leaf senescence.The correlation results indicated that reduced Pn and catalase activity and increased malondialdehyde content under drought conditions induced the decrease of post-silking photoassimilates deposition,ultimately resulted in the grain yield loss.

Effects of Irrigation Schedules on Photosynthetic Carbon Assimilation of Winter Wheat (Triticum aestivum L.) in North China Plain:from Leaf to Population

A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation (W0), irrigation once at jointing (W1j) or at booting (W1b), irrigation twice at jointing and booting (W2), and irrigation three times at jointing, booting and grain-filling (W3) and three planting densities, such as 180 (D1), 300 (D2) and 450 (D3) seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis (resulting from more irrigation time/volume) were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.

Effects of water,fertilizer,dissolved oxygen and temperature coupling on the photosynthesis,quality and yield of lettuce

With the increased demand for vegetables of nutritional value,enhancing vegetable quality while pursuing high yield has become a goal of many investigators.In the present study,the effects of irrigation quota(A),fertilizer amount(B),dissolved oxygen(DO,C),and temperature in the climate chamber(D)applied in combination with the quality and yield of lettuce were investigated.Four-factor and three-level orthogonal designs were used to determine the single-factor trend,the sequence of primary and secondary influencing factors,and optimal regulatory measures concerning the lettuce.The order of the primary and secondary effects on the plant height,net photosynthesis rate(P_(n)),transpiration rate(E),vitamin C content(V_(c)),soluble protein content(S_(p)),dry matter accumulation(Dm),yield,irrigation water use efficiency(IWUE)of the lettuce plants followed the order A>B>D>C.In addition,the order of the primary and secondary effects on the intercellular carbon dioxide concentration(C_(i)),chlorophyll content,and nitrate content followed the order A>D>B>C.The optimum scheme for lettuce was A3B2C1D3(irrigation quota of 69 mm;fertilizer amount of 1.30 g/pot;DO of 6.5 mg/L;and temperature in the climate chamber of 20℃).Under the coordinated regulation of water,fertilizer,air,and temperature,the quality and yield of lettuce have been significantly improved.This study had important reference significance for the comprehensive regulation of water,fertilizer,air,and temperature facilities for vegetables.