Increase In Number Of Ears Research Articles

Improving crop productivity by optimizing straw returning patterns to delay senescence of wheat leaves

Early senescence in the conventional pattern of wheat production is widespread, leading to decline in potential for increased and stabilized yield. Straw returning could effectively improve soil quality and extend the growth period of wheat. However, the response mechanism of straw returning in delaying leaves senescence and increasing crop productivity by regulating the internal physiological and biochemical processes of leaves is not clear. A field experiment was conducted in northwest China in 2013 (the data used in the text from 2021–2023) with four straw returning patterns: no tillage with straw mulching (NTSM), no tillage with straw standing (NTSS), conventional tillage with straw returning (CTS), and conventional tillage with straw removing (CT, the control). The antioxidant enzyme activities, cellular osmotic contents, endogenous hormones contents, stay-green capability of wheat leaves, photosynthetic source, and crop yield were investigated and analyzed. We found that no tillage with straw mulching (NTSM and NTSS) could effectively enhance the antioxidant and cell osmoregulation capabilities of wheat leaves during the grain filling process. Compared to CT, the SOD activity of NTSM and NTSS increased by 24.9–28.2 % and 18.6–20.4 %, respectively. Soluble protein content increased by 37.3–43.2 % and 25.2–57.1 %, and proline content increased by 37.3–78.4 % and 26.5–31.4 %. However, malondialdehyde content decreased by 20.3–21.4 % and 19.2–23.2 %. It was evident that the NTSM treatment provided a solid physiological foundation for delaying leaves senescence. NTSM could also help to maintain the homeostasis of endogenous hormones in wheat leaves during the grain filling period. Compared to CT, the contents of zeatin, salicylic acid, and jasmonic acid of NTSM increased by 23.3–27.2 %, 18.5–22.0 %, and 15.2–15.3 %, while abscisic acid content of NTSM decreased by 9.4–10.2 %. Based on physiological changes within the leaves, NTSM and NTSS reduced stay-green of leaves before 45 d post-emergence by 20.6–20.9 % and 17.5–17.8 % compared to CT. After 45 d post-emergence, NTSM and NTSS increased stay-green of leaves by 21.9–23.0 % and 17.0–19.1 % over CT. Thus, the grain yield of NTSM was 15.0–22.2 % and 9.0–11.3 % higher than that with CT and CTS, primarily due to the synchronous increase in ear number and thousand grain weight. Therefore, no tillage with straw mulching promoted the mobilization of antioxidant and cellular osmoregulatory responses, optimized endogenous hormones signaling, and maintained higher photosynthesis source and stay-green during the grain filling stage, thus delaying leaves senescence and increasing crop productivity in arid irrigated areas.

Soybean Crops Penalize Subsequent Wheat Yield During Drought in the North China Plain.

Contemporary wisdom suggests that inclusion of legumes into crop rotations benefit subsequent cereal crop yields. To investigate whether this maxim was generically scalable, we contrast summer soybean–winter wheat (SW) with summer maize–winter wheat (MW) rotation systems in an extensive field campaign in the North China Plain (NCP). We identify heretofore unseen interactions between crop rotation, synthetic N fertilizer application, and stored soil water. In the year with typical rainfall, inclusion of soybean within rotation had no effect on wheat ear number and yield, while N fertilization penalized wheat yields by 6–8%, mainly due to lower dry matter accumulation after anthesis. In contrast, in dry years prior crops of soybean reduced the rate and number of effective ears in wheat by 5–27 and 14–17%, respectively, leading to 7–23% reduction in wheat yield. Although N fertilization increased the stem number before anthesis in dry years, there was no corresponding increase in ear number and yield of wheat in such years, indicating compensating reduction in yield components. We also showed that N fertilization increased wheat yield in MW rather than SW as the former better facilitated higher dry matter accumulation after flowering in dry years. Taken together, our results suggest that soybean inclusion reduced soil available water for subsequent wheat growth, causing yield penalty of subsequent wheat under drought conditions. We call for more research into factors influencing crop soil water, including initial state, crop water requirement, and seasonal climate forecasts, when considering legumes into rotation systems. Graphical Response of wheat population and yield to soybean inclusion under limited-irrigation.

Quantile function modeling with application to salinity tolerance analysis of plant data

BackgroundIn plant science, the study of salinity tolerance is crucial to improving plant growth and productivity under saline conditions. Since quantile regression is a more robust, comprehensive and flexible method of statistical analysis than the commonly used mean regression methods, we applied a set of quantile analysis methods to barley field data. We use univariate and bivariate quantile analysis methods to study the effect of plant traits on yield and salinity tolerance at different quantiles.ResultsWe evaluate the performance of barley accessions under fresh and saline water using quantile regression with covariates such as flowering time, ear number per plant, and grain number per ear. We identify the traits affecting the accessions with high yields, such as late flowering time has a negative impact on yield. Salinity tolerance indices evaluate plant performance under saline conditions relative to control conditions, so we identify the traits affecting the accessions with high values of indices using quantile regression. It was observed that an increase in ear number per plant and grain number per ear in saline conditions increases the salinity tolerance of plants. In the case of grain number per ear, the rate of increase being higher for plants with high yield than plants with average yield. Bivariate quantile analysis methods were used to link the salinity tolerance index with plant traits, and it was observed that the index remains stable for earlier flowering times but declines as the flowering time decreases.ConclusionsThis analysis has revealed new dimensions of plant responses to salinity that could be relevant to salinity tolerance. Use of univariate quantile analyses for quantifying yield under both conditions facilitates the identification of traits affecting salinity tolerance and is more informative than mean regression. The bivariate quantile analyses allow linking plant traits to salinity tolerance index directly by predicting the joint distribution of yield and it also allows a nonlinear relationship between the yield and plant traits.

Effect of continuous ethephon application on culm length, sugar content and yield in spring wheats.

Three varieties of spring wheat, tall Haruhikari, semi-dwarf Haruyutaka and tall late Selpek, were grown in a 5 cm equidistant square pattern (400 plants/m2) and the 100 ppm of ethephon was applied four and six times at four days interval during the period from double ridge stage to flag leaf emergence (DR treatment) and from flag leaf emergence to anthesis (CE treatment), respectively. The ethephone treatments did not influence the phenological events (Table 1), but inhibited culm elongation (Fig. 1), especially the lower internodes in DR treatment and the upper internodes in CE treatment (Table 2). The effect of shortening in culm length was more in CE treatment and in tall varieties than in DR treatment and in semi-dwarf variety. The water soluble sugar content in culm changed higher in CE treatment (Fig. 2), indicating a highly negative correlation with culm length at milk-ripe stage regardless of the treatments and varieties (Fig. 3). The grain yield in DR treatment was higher in all varieties than those in controls, though not significant, mainly due to the increase in number of ears and grain number per ear (Table 4).

The influence of spatial arrangement on grain yield of wheat

In four experiments, conducted over three contrasting seasons on the central western slopes of New South Wales, the grain yields of three wheat cultivars (Condor, Durati and Phoenix) sown in rhomboidal, square and rectangular patterns were compared with yields from traditionally sown (Poisson distribution along rows 180 mm apart) and broadcast arrangements. Square sowing resulted in significant (P < 0.05) yield increases (due to an increase in ear number) over rectangular arrangements in one experiment at three sowing densities 75,150 and 200 plants m-2. In two drier years there was no significant effect of arrangement at any density (40-400 plants m-2) in any one experiment. There was, however, a consistent significant (P < 0.05) trend over all experiments over 3 years, described by a response surface, of decreasing yield with increasing rectangularity as density was decreased. It is postulated that this was due to reduced ability of the plants to utilize available space. Traditional (sown in three seasons) and broadcast (sown in one season) arrangements produced yields which were not significantly (P > 0.05) different from the highest yielding treatments. It was concluded that there is no advantage in changing from the traditional sowing pattern to any precise geometric pattern. However, in precision sowing, rectangular patterns will result in lower yields than square patterns as density decreases from 200 plants m-2.

The Effects of Benomyl on the Growth and Development of Wheat1

Wheat crops treated with benzimidazole‐containing fungicides have often shown small increases in yield in the absence of any detectable disease. This project was designed to test the possibility that direct physiological effects of the fungicide were responsible. The major effect of benomyl, at concentrations in the range 200–5000 ppm was to increase the development of tillers. Spraying at any one of several stages of development caused an increase in the number of tillers detected about 6 weeks later. This was found to be due to a more rapid initiation of tillers and not to more rapid growth following initiation. Associated with this earlier initiation was an increase in the incorporation of C14‐labelled assimilates into newly initiated tiller buds, but not into older ones. These responses resemble those reported for the effects of cytokinin applications to cereals. In field experiments, the increase in tiller production caused an increase in ear number only when plants were widely spaced. The decrease in tiller number as plant density increased was more rapid in treated plants than in controls, so that both treatments produced similar ear densities at around optimum plant density.

EFFECTS OF SLITTED POLYETHYLENE MULCHES ON SOIL TEMPERATURE AND YIELD OF SWEET CORN

During 1974 and 1975, experiments using slitted polyethylene mulch were conducted with sweet corn on a Charlton loam soil in Madbury, New Hampshire. Temperatures under slitted clear polyethylene mulch were higher than black mulch or bare soil during the early growing season; differences in soil temperature among mulch treatments decreased as the plant canopy increased. Early growth and subsequent maturity were promoted with clear but not with slitted black polyethylene mulch. Yield increased with slitted clear polyethylene mulch compared with black mulch or bare soil in 1974 due to an increase in number of ears per plant; percent stand was similar among mulch treatments. In 1975, yield increased with slitted clear polyethylene mulch compared with black mulch or bare soil of the 2 May planting due to increased percent stand; no differences in yield occurred among mulch treatments of the 23 May planting when percent stand was similar. At maturity, total accumulation of N, P, and K in the plants was higher under mulches compared to bare soil; no significant differences occurred between slitted black and clear polyethylene mulches.

Defoliation studies in hybrid maize: II. Dry-matter accumulation, LAI, silking and yield components

SUMMARYData are presented from an experiment made in two crop seasons, to examine the effects of plant density and degree of defoliation at different stages of growth in maize at Pantnagar, India, on the dry-matter accumulation in different plant parts, leaf area index (LAI), time of silking and grain yield components.Different patterns of dry-matter accumulation in various plant parts was observed. Silking was delayed by increasing plant density. Defoliation (even partial) at the 16th fully expanded leaf stage resulted in substantial reduction in LAI and such yield components as number of ears, ear length, ear diameter and 1000-grain weight. On the other hand, partial defoliation done at the 10th fully expanded leaf stage to simulate an ‘erectophile canopy’ led to yield increases even under high plant density (90000 plants/ha) in the Kharif (rainy season), mainly through an increase in number of ears, 1000-grain weight and grain to stover ratio coupled with a reduction in barrenness and percentage of lodging. It is suggested that an increase in the photosynthetic efficiency per unit area of leaf resulting from the ‘erectophile canopy’ is the reason for these effects.

The effect of applying a nitrogenous fertiliser to wheat at different stages of growth

The effect of applying a nitrogenous fertiliser to wheat at seven different times and three rates, was studied in pot culture. It was found that the later the time of application the smaller was the increase in the yield of total dry matter and of straw. The increase in the yield of grain, on the other hand, was constant for the first six times of application, the last of which was made on May 25, but a later application made after ear emergence produced no increase.Analysis of the grain yield showed that early application produced its effect by increasing the number of ears per plant. Later applications caused a smaller increase in ear number, but also increased the number of grains per ear and 1000-corn weight. There was no evidence of a critical time for tiller formation such as has been postulated by Doughty and Engledow.The increase in total nitrogen uptake was equal for all times of application, but the ratio of nitrogen in grain to nitrogen in straw and chaff was greater, the later the time of application.The writer wishes to thank Messrs A. M. S. Clarke, G. T. Detlefsen and S. A. W. French for much help with the experimental work, and Mr R. G. Warren for making the nitrogen determinations.