Late Planting Date Research Articles

Irrigation Scheduling Impacts Vegetative Growth, Seed Yield, and Fungal Diseases of Spinach Seed Crops in a Maritime Mediterranean Climate

Although irrigation scheduling has been studied for diverse vegetable crops, much less attention has been given to irrigation scheduling for the seed crops on which these production systems rely. In spinach, for which irrigation scheduling needs are likely to vary greatly between seed and leaf production, this leaves seed producers without adequate resources to make irrigation scheduling decisions. Our research sought to fill this gap by evaluating two alternative irrigation scheduling strategies (a publicly available decision-support tool and soil moisture sensors) and four soil moisture thresholds for irrigation for their impacts on vegetative growth, marketable seed yield, seed quality, and the severity of Stemphylium leaf spot (caused by Stemphylium vesicarium and Stemphylium beticola), a common foliar disease of spinach, under sprinkler irrigation. We found that in all 3 years of the study, earlier and more frequent irrigation increased vegetative growth. However, marketable seed yield only increased relative to the control treatment based on farmers’ standard irrigation practices in 1 of the 3 years—a year with an abnormally late planting date. This indicates that vegetative growth is more responsive than seed yield to earlier and more frequent irrigation, and that increases in vegetative growth do not translate directly to increased marketable seed yield. Contrary to the expected increase in Stemphylium leaf spot severity with increasing irrigation, the severity decreased in both years it was measured, likely as a result of the small stature of the spinach seed parent lines used in our study and opportunistic pathogenicity on moisture-stressed plants. These results provide a useful foundation from which spinach seed producers can make irrigation management decisions for their crops that underpin a valuable global industry.

Studying the cumulative vigor response index of morpho-physiological, quality, and yield-related traits of wheat cultivars using planting dates

Wheat (Triticum aestivum L) is one of the major staple food crops consumed globally. Nonetheless, the cultivation of wheat is influenced by various environmental factors, with the planting date being significantly impacted by the effects of climate change. Addressing these changes could involve evaluating wheat genotypes to identify appropriate planting dates. A phenotypic screening experiment was conducted in the field crop station of Agriculture College of Tikrit University to determine the suitable planting time for wheat cultivars under local environmental conditions during 2022-23. Several morpho-physiological, quality, and yield traits were measured. Factorial experiment using spilt plot through randomized completely block design (RCBD). was used with three replications. The five planting dates (5-10, 25-10, 15-11, 5-12, and 25-12) were considered as the main plot, and the eight wheat cultivars (Ipaa99, Al-Rasheed, Al-Baraka, Sham6, Tammuz2, Al-Hashimiya, Al-Noor, and Al-Adnanieh) as sub-main plot. Data were used to calculate the Individual, Cumulative, and Total Vigor Response Indices (IRI, CRI & TRI). Cultivars were classified into different categories using total cumulative early or late planting date vigor response index values (TRI-e) or (TRI-l) and standard deviation (SD). The (TRI-e) values ranged from 36.07 (sensitive) for the cultivar Al-Baraka to 39.13 (tolerant) for the cultivar Al-Hashimiya. However, the (TRI-l) values ranged from 36.59 (sensitive) for the cultivar Al-Noor to 39.52 (tolerant) for the cultivar Al-Hashimiya. The correlation coefficient (r2) between the (TRI-e) and cumulative very early/early planting date vigor response index was positively correlated (r2 = 0.70 for very early planting date (5-Oct) and r2 = 0.60 for early planting date (25-Oct). Furthermore, 76% of the total variation in the (TRI-l) was explained by the cumulative very late planting date vigor response index (CRI-vl) while just 49% of the total variation was explained by the cumulative late planting date vigor response index (CRI-l). Based on those results, wheat producers could select either tolerant cultivars for early planting or tolerant cultivars for late planting to maximize wheat production in their specific growing environments including planting dates.

Integrated management of cheat (Bromus secalinus L.) and downy brome (Bromus tectorum L.) in Oklahoma grain-only winter wheat

Abstract In Oklahoma, downy brome and cheat are difficult-to-control winter annual grasses. In the past, cheat infested most of the winter wheat hectares harvested in Oklahoma. Biotypes that are cross-resistant to acetolactate synthase–inhibiting herbicides have left growers with minimal management options for conventional and herbicide-tolerant systems. Field trials near Lahoma, Oklahoma, in 2019–2020 and 2020–2021 evaluated integrated management of cheat and downy brome using three strategies: planting date (optimal, delayed, and late), cultivar selection (high and low competitiveness), and herbicide choice (no herbicide, sulfosulfuron at 35.2 g ai ha−1 and pyroxsulam at 18.4 g ai ha−1). Visual control, weed species present, wheat biomass at heading, and grain yield data were collected. In 2019–2020, 8 to 9 wk after treatment, visual control increased by 15% with the delayed planting compared with the optimal planting date and 14% with the late planting date. In 2020–2021, similar control (∼99%) was recorded for delayed and late plantings with 23% greater control than the optimal timing. Due to a lack of weed coverage, weed biomass in 2019–2020 had no response to planting date, cultivar, or herbicide treatment. Downy brome biomass during 2020–2021 was approximately 90% lower with delayed to late planting dates than the optimal planting date. In the same year, downy brome and cheat biomass were low (≤0.4 and 0.2 g m−2) and 98% less after an herbicide application than a nontreated area. Wheat grain yield at the optimal planting date was greater than yields from delayed and late plantings in 2019–2020. A delay in planting from the optimal date to delayed or late timings decreased wheat yield by 14% and 21%, respectively. In 2020–2021, wheat yield from the late planting was reduced by 57% compared with the optimal planting yield. Delaying the planting date and the use of a common herbicide can suppress cheat and downy brome, but a decline in wheat yield may occur.

Unveiling the resilience of smallholder farmers in Senegal amidst extreme climate conditions

AbstractIn Senegal, agriculture is an important sector underpinning the socioeconomic fabric of the populace. Notably, the agricultural production in this region exhibits heightened sensitivity to climatic perturbations, particularly droughts and heat waves. This study aims to determine the resilience of different agronomic interventions for farmers practicing mixed farming that produce both crops (i.e., groundnut (Arachis hypogaea L.) and pearl millet (Pennisetum glaucum (L.) R. Br.)) and raise animals in the Groundnut Basin in Senegal, which holds historical and socioeconomic significance. To understand the current situation regarding demographics, economics, consumption behavior, and farm operations for smallholder farmers, data were comprehensively collected from government and nongovernment organizations (NGO) reports, scientific papers, organization databases, and surveys. Additionally, the Agricultural Production Systems sIMulator (APSIM) was used to understand how combinations of three planting dates, three plant densities, and six urea nitrogen (N) fertilizer rates affected the yield of pearl millet, which were used as the alternative scenarios to the baseline in the farm modeling and analyses. All the collected and generated data were used as inputs into the Farm Simulation Model (FARMSIM) to generate economic, nutritional, and risk data associated with mixed farming systems. The generated data were then used to determine the resilience of the alternative scenarios against the baseline. Initially, a multi‐objective optimization was employed to meet nutritional needs while maintaining a healthy diet at the lowest cost. Then, the scenarios that met the population's nutritional requirements were evaluated based on four economic indicators: net cash farm income (NCFI), ending cash reserves (EC), net present value (NPV), and internal rate of return (IRR). Lastly, those that passed the economic feasibility test were ranked based on risk criteria certainty equivalent (CE) and risk premium (RP). The analyses found N fertilizer rates of 0, 20, and 100 kg N ha−1 were generally economically not feasible. Additionally, medium (early‐July to late‐August) and late (late‐July to mid‐September) planting dates generally performed better than early (early‐June to late‐July) planting dates, while plant densities of 3.3 and 6.6 pL m−2 performed better than 1.1. The robust resilience approach introduced in this study is easily transferable to other regions.

Impact of Variety and At-Planting Insecticides on Thrips (Thysanoptera: Thripidae) Management in Peanut

Tobacco thrips are one of the most prevalent early season insect pests in peanut production systems. Experiments were conducted in 2018 and 2019 in Stoneville Mississippi to evaluate integrated pest management approaches to mitigate negative effects of thrips. Experimental treatments included a normal and late planting date, varieties Georgia-06G and QR-14, and in-furrow insecticide treatments consisting of a non-treated control, phorate, and imidacloprid. Measurements included early and final plant stands, immature and adults thrips counts, and pod yield. In-furrow insecticide had a strong effect on number of thrips per plant with treatment thrips ranking of: phorate < imidacloprid < non-treated control. However, in-furrow insecticide had no interaction with variety or plating date. Although phorate provided greater thrips control than imidacloprid, pod yield for the two treatments was similar, and both in-furrow treatments had greater yield than the non-treated control. The variety QR-14 had greater pod yield than Georgia-06G when planted late. Overall, these results confirm that in-furrow insecticide applications of either imidacloprid or phorate are adequate in protecting against yield loss from thrips within a midsouthern peanut production environment.

Paclobutrazol Application Improves Growth and Physiological Traits of Wheat Cultivars Under Heat Stress Imposed by Late Planting Date

Paclobutrazol Application Improves Growth and Physiological Traits of Wheat Cultivars Under Heat Stress Imposed by Late Planting Date

Mapping of Evapotranspiration and Determination of the Water Footprint of a Potato Crop Grown in Hyper-Arid Regions in Saudi Arabia

Seasonal quantification of a crop’s evapotranspiration (ET) and water footprint (WF) is essential for sustainable agriculture. Therefore, this study was conducted to estimate the ET and WF of an irrigated potato crop using satellite imagery of Landsat and Sentinel-2 sensors. The Simplified Surface Energy Balance (SSEB) algorithm was used to evaluate the crop water use (ETa) for potato fields belonging to the Saudi Agricultural Development Company, located in the Wadi-Ad-Dawasir region, Saudi Arabia. Normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and land surface temperature (LSD) were computed for Landsat and Sentinel-2 datasets, which were used as inputs for mapping the potato tuber yield and, subsequently, the WF. The results indicated that the NDVI showed the best accuracy for the prediction of the potato tuber yield (R2 = 0.72, P > F = 0.021) followed by the SAVI (R2 = 0.64, P > F = 0.018), compared to the field harvested actual yield (YA). A comparison between the satellite-based ETa and the actual amount of water applied (WA) for irrigation showed a good correlation (R2 = 0.89, RMSE = 4.4%, MBE = 12.9%). The WF of the potatoes in the study area was estimated at values between 475 and 357 m3 t−1 for the early (September–December) and late (December–April) growing periods, respectively. A major portion (99.2%) of the WF was accounted for from irrigation with variations of 18.5% and 3.5% for early- and late-planted potatoes, respectively, compared to the baseline (crop planted in season). In conclusion, the results showed the possibility of satisfactorily estimating the WF using the SSEB algorithm by integrating the Landsat-8 and Sentinel-2 datasets. In general, the high rates of ET in the early planting season led to higher WF values compared to the in-season and late planting dates; this will help in selecting suitable planting dates for potato crops in the study area and areas with similar environments, which enhances the opportunities for sustainable management of irrigation water.

Variable Yield Responses among Grafted and Nongrafted Late blight–resistant Tomato (Solanum lycopersicum L.) Hybrids in North Carolina

Host resistance is an environmentally and economically sustainable disease management strategy that may be especially beneficial to small-scale and organic growers for whom other management tools such as synthetic pesticides are too costly or not permitted. In western North Carolina, the demand for vine-ripened tomatoes (Solanum lycopersicum L.) from local and organic farms has led to the development of cultivars bred for resistance to geographically relevant diseases, including late blight of tomato, which causes rapid defoliation and lesions on fruit. Grafting tomato plants has the potential to increase plant vigor and yield; however, this effect is known to be dependent on multiple factors, including scion and geographic location. In this study, we evaluated the yield response of one determinate (‘Mountain Gem’) and four indeterminate (‘Mountain Heritage’, ‘Mountain Girl’, ‘Mountain Rouge’, and ‘NC10291’) late blight–resistant tomato cultivars, grafted on tomato rootstock ‘Maxifort’ or nongrafted, on a commercial farm and at two research facilities in western North Carolina. Yield of marketable fruit from grafted plants was greater than that from nongrafted plants at one location (P = 0.008); however, yield response of each cultivar, grafted or not grafted, differed by location. Yield was consistently greater from ‘Mountain Gem’ plants than other cultivars, and grafted ‘Mountain Gem’ plants had greater yields later in the season at two locations than nongrafted plants. Because of the late planting date intended to expose cultivars to the late blight pathogen, the full yield potential of the indeterminate cultivars was not realized at all locations. Disease severity caused by Verticillium wilt (Verticillium dahliae Kleb., Verticillium albo-atrum Reinke & Berthold) was lowest for cultivar Mountain Heritage at two of three locations. Results from this study emphasize the importance of conducting evaluations of grafted tomato plants at multiple locations, including on farm, to optimize the benefits associated with their use.

Optimal choice of cotton cultivar for rainfed conditions in Sahelo-Sudanian climate with late planting: a case study in Senegal

AbstractLate planting due to erratic onset of the rainy season is becoming more frequent in the Sahelo-Sudanian climate where cotton is grown, causing seed cotton yield (SCY) loss and higher risk of drought at the end of the crop cycle. Therefore, cultivars should be adapted to late (from July 10) planting date (PD) in Senegal. The aim of this study was to analyse the interaction between genotypes and PD on SCY in Senegal under rainfed conditions. Field experiments were conducted in 2018 and 2019 using a split-plot design (two PDs, eight cultivars) at three experimental stations. Robust analysis of SCY was used to moderate the effect of potential outliers. The average SCY was 1404 kg/ha under early planting, and 714 kg/ha under late planting. The best SCY was obtained under early planting conditions, in environments with good rainfall. The loss due to late planting was significantly affected by cultivar choice. None of the cultivars performed best under both early and late PD. Under early PD, cultivar CS 50 gave the best SCY, while under late PD it was cultivar IRMA Q302. The best performing cultivar on average depended on the proportion of early plantings. A model was developed to identify the best overall cultivar based on the expected proportion of early planting, as a decision support tool for the cotton development company, if only one cultivar is released. The benefit of releasing a second cultivar for late-planted fields is considered.

Grain yield response to planting date and cutting height of the first crop in rice ratooning

AbstractRice (Oryza sativa L.) ratooning is one of the most essential production strategies to increase grain yield. Field experiments were conducted in southwestern Japan in 2021 and 2022 to determine the effects of planting date and cutting height of the first crop on grain yield. Grain yield of the second crop was higher at early planting date than at late planting date in 2021, but the yield difference was narrowed in 2022. The higher grain yield at early planting date resulted from the higher number of spikelets and percentage of filled spikelets due to the higher stubble nonstructural carbohydrate (NSC) content, leaf area index (LAI), and air temperatures. Grain yield of the second crop was higher at high cutting height than at low cutting height in 2021, but the yield difference was narrowed in 2022. The higher grain yield at high cutting height resulted from the higher number of spikelets due to the higher NSC content and LAI. In the weather conditions, grain yield had a strong positive correlation with the air temperature, which had positive correlations with the number of panicle and percentage of filled spikelets. In the stubble conditions, grain yield had a strong positive correlation with NSC content, which had positive correlations with the number of panicle and percentage of filled spikelets. Therefore, early planting, which secures high air temperatures, and high cutting height, which produces high NSC content, are recommended to increase grain yield of the second crop.

Nano-Fe nutrition improves soybean physiological characteristics, yield, root features and water productivity in different planting dates under drought stress conditions

Soybean production as an oil and protein crop, especially in water limited conditions, is of global importance. Suitable Nano-iron fertilizer application method can be a useful nutrition technique under water limitation stress. The aim of this study was to investigate the response of yield, physiological and morphological characteristics of soybean to drought stress, planting date and nutrition with iron Nano-oxide in two separate experiments (i.e. 2-year field and a pot) in 2021–2022. Field experiments included planting date (April 09: early planting date, May 05: optimum planting date and June 10: late planting date), nutrition with iron Nano-oxide (control, seed priming 300 ppm, foliar spraying 15 ppm, priming 300 ppm + foliar spraying 15 ppm) and drought stress (100 %, 75 % and 50 % FC). In the pot experiment, all field treatments were applied except planting date. Then, morphological and biochemical characteristics of the root were investigated. The results showed that drought stress, planting date and different methods of iron Nano-oxide nutrition had significant effects on gas exchanges, chlorophyll fluorescence, antioxidant activity and grain yield. The highest gas exchanges, net photosynthesis rate, the maximum photosystem quantum efficiency (FV/Fm) and grain yield were obtained by iron Nano-oxide nutrition as seed priming + spraying in optimum planting date and 100 % FC. However, these traits were decreased with increasing drought intensity (50 % FC), non-use of iron Nano-oxide (control) in early planting date. By increasing the drought severity in the field to 50 % FC, the antioxidant enzyme’s activity increased. The highest activity of catalase and superoxide dismutase were observed in early planting date + non-use of iron Nano-oxide +50 % FC. Based on the results of the pot test, the highest root length, number of nitrogen-fixing nodules, root dry weight, and nitrogenase activity were observed by iron Nano-oxide nutrition (nano priming 300 ppm + 15 ppm spraying) under 100 % FC. The mentioned parameters were reduced by drought, but the number of root branches increased. Combined nutrition (priming + spraying) had more positive effects on the root's morphological and biochemical properties compared with iron spraying only. The water productivity increased due to late plantings, but the negative effect of early planting on this indicator was higher. The maximum water productivity (0.73 kg/m3) obtained from iron Nano-oxide nutrition (seed priming 300 ppm + foliar spraying 15 ppm) in late planting date under 50 % FC conditions and its lowest (0.35 kg/m3) in no iron Nano-oxide nutrition in early planting date under 100 % FC. In general, the optimum planting date (05 May), supply of 100 % FC and combined iron Nano-oxide nutrition (seed priming + foliar application) is suggestible for soybean (Kosar cultivar) production in the climate conditions like the present study.

Evaluating the impact of at-plant termination of a cereal rye cover crop with different corn planting dates on arthropod activity.

Greater cover crop biomass is expected to result in a favorable microhabitat for beneficial arthropods. Natural Resources Conservation Service (NRCS) cover crop termination guidelines are based on the cash crop planting date. Therefore, a delay in cash crop planting could result in greater cover crop biomass. However, studies on delays in cash crop planting and greater cover crop biomass have led to a decrease in cash crop yield. Thus, a field study was conducted in eastern Nebraska over two years to evaluate the impact of early and late corn planting dates with at-plant cover crop terminations on pest potential, beneficial arthropod activity, and agronomic parameters. To measure arthropod activity and pests in the system, pitfall traps, and corn injury assessments were performed during the early stages of corn development. A total of 11,054 and 43,078 arthropods were collected in 2020 and 2021, respectively. The results have shown no impact of the corn planting dates with at-plant cover crop termination on arthropods but identified that cereal rye cover crop supports greater Araneae activity while its alternative prey varied when compared to the no-cover treatment. Significant yield penalties were observed when cover crop was used regardless of the corn planting dates. Pest pressure was not significant in any year, however, future research using cereal rye and different cover crop species should be used in this system with an artificial infestation of a pest to be able to evaluate the trade-offs between possible cash crop yield reductions and potential biological control of pests.

Integrating Field Data and a Modeling Approach to Inform Optimum Planting Date × Maturity Group for Soybeans under Current and Future Weather Conditions in Kansas

Optimizing planting date by maturity group (PD × MG) is critical to increase productivity and reduce production risks. Understanding the effect of management, not only under current, but also future weather conditions, is even more relevant for developing effective mitigation strategies. This paper provides an analysis of the optimum combinations of soybean PD × MG management in the central-eastern region of Kansas (United States) for both current and future weather conditions. Three geographical clusters illustrating the main environmental and management characteristics were defined within the central-eastern region of Kansas. The Agricultural Production Systems Simulator platform was employed to explore PD × MG combinations (PD from mid-April to mid-July; MG from III to VI) comparing current (2011–2021) and future (2042–2052) weather conditions. Overall, early planting dates produce greater yields, but reduce their stability over time (with a 15% increase in yield variation relative to late planting) across the clusters. Late planting dates resulted in a reduction close to 27% for soybean yields relative to those obtained by planting at early dates under current weather conditions. Furthermore, longer maturity groups (IV, V, and VI) resulted in a reduced yield penalty when planting time was delayed under the current weather conditions. However, this combination did not always represent the strategy that maximized yields.

УРОЖАЙНОСТЬ КАРТОФЕЛЯ СОРТА КАВАЛЕР В ЗАВИСИМОСТИ ОТ СРОКА, СПОСОБА И ГЛУБИНЫ ПОСАДКИ В ЛЕСОСТЕПНОЙ ЗОНЕ ЧЕЛЯБИНСКОЙ ОБЛАСТИ

The yield of potatoes of the Kavaler variety in the northern forest-steppe zone of the Chelyabinsk region in the period 2020-2022 largely depended on the weather conditions of the growing season (factor contribution – 15%), planting time (52%), seed placement depth (11%), somewhat less – on the method of planting (4.2%) and the interaction of factors " year” and “planting depth” (7.2%). According to the years of research, the planting time had the greatest influence on the yield, which determines 79% of the variation in 2020, 38% in 2021 and 65% in 2022, as well as the method of planting potatoes, which controlled 6.5%, 11.4%, and 4.0% respectively of the total variation of this trait. A significant effect of the depth of planting seed tubers on the yield of potatoes was noted only in the dry conditions observed in 2021 (factor contribution of – 44.4%). The potatoes achieved high yields due to the well timed planting (May 10-12th). The Kavaler variety exhibited an average productivity of 25.04 t/ha over a three-year period, showing a 4.11 t/ha increase in yield compared to the late planting dates (June 5- 6th). Ridge planting was more advantageous in the conditions of 2020 and 2022, whereas in the dry year of 2021, flat planting proved to be more effective.

Efficiency of assimilating leaf area index into a soybean model to assess within-field yield variability

Methods for accurately estimating within-field yield are essential to improve site-specific crop management and resource use efficiencies, which would be a major step toward sustainable intensification of agricultural systems. We set out to assess the accuracy of within-field soybean yields predicted by two data assimilation methods and to assess these methods’ assimilation efficiency (AE). Yields were estimated by assimilating remotely sensed leaf area index (LAI) data from Sentinel-2 into a soybean crop growth model on a pixel basis. The LAI data was integrated into the model by Ensemble Kalman Filtering (EnKF) or by recalibrating with the Subplex algorithm (recalibration-based). An open-loop setting which only integrates information on the soil layers was used as a baseline scenario for quantifying the AE. We assessed both data assimilation techniques on eight fields (3067 pixels) in the Corn Belt region (Nebraska, Kansas and Kentucky) in the United States. The data set encompassed substantial variation in crop growth conditions: three growing seasons (2018, 2019 and 2020), rainfed and irrigated fields, and early and late planting dates. Ground truth yield acquired from combine monitors was used to validate the yield estimations. Agreement between predicted and observed yield at pixel level was two times higher for both data assimilation methods compared to the open-loop. The root mean square error (RMSE) was 476 kg.ha−1 (RRMSE of 10 %) in the recalibration-based method and 573 kg.ha−1 (RRMSE of 12 %) in the EnKF-based method. For both data assimilation methods, assimilating the LAI improved predictions for 68 % of the pixels. For a further 12 % of pixels, there was no accuracy improvement. For the remaining 20 %, AE was positive for one of the two assimilation methods. The high proportion of pixels with positive AE indicates the potential for overcoming the limitations in applying crop models at high spatial resolution by integrating a crop growth indicator. Assimilating an in-season indicator of crop growth (LAI) into a soybean model made it possible to adjust the simulation pathway, thereby greatly improving the accuracy of the yield estimations at the pixel level. This study elucidates the practical applications of data assimilation strategies for fine-scale within-field crop yield mapping.

Influence of Planting Date on Winter Rye Performance in Kentucky

Winter rye (Secale cereale L.) is a grain crop well known for its outstanding tolerance to unfavorable weather and soil conditions. Because of rye’s wide range of possible uses (e.g., cover crop, feed for livestock, bread, cookies, distilled and brewed beverages), its pro-health properties and unique flavor, interest in this crop is increasing in the United States. In 2018/2019 and 2019/2020 we tested 24 winter rye varieties that were available in the US at 3 planting dates: early, intermediate, and late. The aims of this study were to (1) identify conventional and hybrid varieties suitable for the US mid-south environment; (2) establish an optimal planting date of winter rye and (3) quantify genotype x planting date interaction. At both locations and in both growing seasons the best yielding, and most resistant to disease and lodging entries were European hybrids (KWS Serafino, KWS Daniello, KWS Bono and KWS Brasetto), and the best yielding conventional varieties were AC Hazlet and ND Dylan. There were statistically significant (p < 0.01 in 2019 and p < 0.0001 in 2020) differences in yield between planting dates both seasons. The response to planting date differed between varieties. In the 2018/2019 growing season we observed that, on average, rye performed better when planted early, but in 2019/2020, a severe May freeze caused extensive damage in early planted rye, and the best planting date was the late one. Overall, the majority of varieties analyzed individually performed the best at intermediate and late planting dates.

Reducing potato water footprint by adjusting planting date in the agro-pastoral ecotone in North China

Reducing the water footprint per unit of crop production reduces the pressure on the limited freshwater resources. This study used data from a four-year field experiment conducted in the agro-pastoral ecotone (APE) of Northern China, to calibrate and validate the APSIM-Potato model, and determine the impacts of planting dates on the water footprint (WF) of potatoes under rain-fed and irrigated conditions. Results showed that the rain-fed potato yields were 14.6, 18.9, and 19.9 t ha−1, under the early, normal, and late planting dates, respectively, and the irrigated yields were 19.7, 31.8, and 30.9 t ha−1 under the three planting daets. The blue WF of the potatoe were -25.6–0 m3 t−1, -27.2–0 m3 t−1, and -26.4–0 m3 t−1 in early, normal, and late planting dates, respectively, under rainfed condition, and the value was highest in normal planting date. Green WF of the potato was 24.4 m3 t−1, 16.0 m3 t−1, and 13.5 m3 t−1 under early, normal, and late planting dates, respectively. The total WF was 20.3 m3 t−1 under the early planting dates, which was 50.3% and 87.9% higher than that under normal and late planting dates, respectively. Under the irrigated conditions, early planting exhibited the highest blue WF (33.2–77.9 m3 t−1), followed by normal (32.1–67.4 m3 t−1), and late planting dates (26.6–61.3 m3 t−1). The green WF was 104.9 m3 t−1 under the early planting dates, which was 48.8% and 45.9% higher than that under normal and late planting dates. Furthermore, the total WF of potatoes decreased with delayed planting, with the average values of 161.1, 117.8, and 114.2 m3 t−1 under early, normal, and late planting dates, respectively. These findings suggest the potential of reducing potato WF across the APE by adjusting the planting dates.

Impact of planting date on CO2 fluxes, evapotranspiration and water-use efficiency in peanut using the eddy-covariance technique

The combination of increased climate variability with changing weather patterns heightens the importance of the role of planting date on water use in peanut production. Experiments addressing different peanut planting dates were conducted over three years and daytime ecosystem water-use efficiency was determined using the eddy-covaraince method. Results suggest that during the early growing stage in all three planting dates, a late planting date presented by far the highest CO2 fluxes and daytime ecosystem water-use efficiency. Of immediate significance, the latest planting date was also found to exhibit the highest yield in two of the three years in the experiment. Furthermore, an examination of the last 20 years (2001-2020) of climatological records suggests that a late planting date carries a risk of 40% chance of sub-optimal low temperatures in early fall, potentially reducing the yield in those years. In addition, the late planting date carries 15% probability of ten or more consecutive rainy days in the narrow harvest window, potentially impacting a timely harvest.

Optimizing planting dates and cultivars can enhance China's potato yield under 1.5 °C and 2.0 °C global warming

Rising temperatures and varying precipitation patterns pose huge challenges to the global potato supply. Understanding the adaptation potential of potato to climate change is urgently needed to help develop effective measures for future agriculture and food security. In this study, we evaluated future potato yield changes under 1.5 °C and 2.0 °C warming scenarios, and explored potential adaptation strategies by optimizing planting dates (PD) and cultivars across China's potato production regions. Compared with the baseline period (1986–2015), potato yields would increase in North single (NS) and Central double (CD) cropping system zones, but would decrease in South winter (SW) and Southwest mixed (SWM) cropping system zones under the 1.5 °C warming scenario without considering adaptation measures. Under the 2.0 °C warming scenario, potato yield would increase across China's potato planting zones except for SWM. Adjusting PD would be more effective for increasing rainfed potato yield across China than changing cultivars under the two warming scenarios. Overall, late PD coupled with a late-maturing cultivar would be the optimal selection for rainfed potato production. For irrigated potato, adjusting PD would be more effective than changing cultivars in NS and SW, but the opposite would be true in CD. The optimization of a single measure would have little impact on yield in SWM. The optimum PD would be early PD in NS and late PD in SW and SWM. The optimum cultivar would be late-maturing in NS, CD, and SWM, and middle-maturing in SW. Under the optimal combination, rainfed and irrigated potato yield would increase by 3.4–44.2% and 2.6–49.3%, respectively, under the 1.5 °C warming scenario, and would increase by 7.1–51.6% and 8.5–65.2%, respectively, under the 2.0 °C warming scenario. Our study results provide valuable information for policymakers and stakeholders involved in potato production to aid in planning agricultural strategies to safeguard potato production.

Impact of planting dates on yield and pod quality traits of snap bean under short-temperate season climates

Snap bean, a warm-season crop, have low frost tolerance. The optimal temperature for seed emergence and plant growth is important. Therefore, appropriate planting dates for adapted varieties has paramount significance in improving pod yield and quality of snap bean under short cool season climates. Three snap bean cultivars planted at 3 different dates were examined to evaluate the effects of planting dates on snap bean pod yield and quality traits in a 2-year study in a short season climate in Manitoba, Canada. Results of this study showed that three, two weeks apart, planting dates had a non- significant effect on marketing yield of three different cultivars tested in this study. Planting dates showed significant effect on un-marketable yield, pod fresh weight, pod length and total soluble solids. Higher marketable and un-marketable yields along with longer pod length and soluble solids, in all three cultivars, were more profound when seeded at mid and late planting dates. Snap bean grew under higher temperature and accumulated more growing degree days (GDD) when planted in mid June and early July when compared to early June planting. These results conclude that marketable yields of snap bean were not significantly affected by planting dates when seeded-two weeks apart-in shorter growing environments which allow commercial and market gardeners, in northern areas with shorter growing seasons to optimise planting snap bean, without reducing pod yield and quality.