International Journal of Plant Production
Volume:13 Issue: 2, Jun 2019

The responds of oilseed rape yield to climate changes was not reported in China, and the climate–yield statistical relationship for winter oilseed rape constructed in Jiangsu province, southeast China should be a valuable attempt. With using climate and yield data at 52 stations in Jiangsu during 1961–2012, the main findings in this study were as follows: (1) correlation analysis between oilseed rape yield and seasonal climate variables indicated that average temperature difference (TD), total rainfalls (RF), total rainy days (RD), total sunshine hours (SH), and average relative humidity (RH) in spring were the key agro-meteorological indicators significantly affecting yield; (2) according to the principal component analysis on the five selected indicators in all stations, this province was classified as four climactic sub-regions for oilseed rape production: north, central-north, central-south, and south Jiangsu, respectively; (3) the significant responses of oilseed rape yield to spring climate variability were detected in central-south and south Jiangsu, and the strong decreasing trends of RF, RD, and RH during study periods in this region had increased yield by up to 0.68%, 1.44%, and 5.68%, respectively; (4) spring RD in the central-south and south Jiangsu was screened as the leading indicator for oilseed rape, and it showed a significant decrease after 1985.

Soybean is one of the most important food crops around the world. Despite its economic importance, the effect of sowing date and climatic conditions on soybean development and productivity of grain and oil has not yet been studied in detail. Such a study can yield valuable information regarding the interaction of this crop with its environment. In this context, the aim of this study was to estimate the soybean potential productivity of grains and oil for eight sowing dates, using historical series of climate data from Piracicaba (SP), Brazil. For this a stochastic model is proposed, with truncated normal distribution for maximum, minimum and average temperature data. The information generated in this study is important in order to provide farmers with relevant information about the importance of an adequate sowing date, as well as to further understand of the influence of the climate variations on soybean production. The September 1 sowing date, without lack of water, provides more adequate conditions for accumulated dry matter, grain and oil productivity. It was concluded that: (i) the stochastic model (Potential and Depleted Model for Soybean Grain and Oil Production) can be used as a valuable tool for analyzing variability and complex interactions between plants and climate conditions. In this model, the air temperature and global radiation parameters were adequate to estimate the duration of the crop cycle, dry matter production, photoassimilates partition, and grain and oil productivity of soybean plants grown in different sowing dates in Piracicaba–SP; (ii) considering the historical data of air temperature, global radiation and other optimal ecophysiological needs for the crop, the model results define September as best period for sowing soybean in Piracicaba (SP), Brazil.

The adjustment of sowing date and seeding rate of soybean can optimize plant development and yield. It is well known that the delay of the sowing date anticipates flowering and can reduce yields. In addition, the recommended seeding rate is usually fixed for all sowing dates and the interaction of these management practices is scarce in high yield subtropical environment. So, this study evaluated how soybean yield and its attributes are affected by the management of sowing dates and seeding rates in two growing seasons. Late sowing reduced yield due to reduced shoot biomass per area, leaf area index, final plant height, bottom pod height, pods per area, seeds per area, and seed mass. Increasing seeding rate increased yield, especially in late sowing, due to increased shoot biomass per area, leaf area index, final plant height, bottom pod height, pods per area, and seeds per area. However, higher seeding rates decreased the shoot biomass per plant, leaf area per plant, pods per plant, and seeds per plant. In early sowing, the lowest seeding rate, below the standard, yielded equivalent to the higher seeding rate. In late sowing, the increase in seeding rate increased yield. For growers who aim to increase soybean yields, it is important to consider using specific seeding rates for each sowing date.

The delayed planting suppresses germination, growth and productivity of chickpea due to low temperature. Seed priming may improve the germination and growth of chickpea; however, no study has reported the effect of seed priming techniques on germination indices, growth and productivity of late-sown chickpea. This study was conducted to evaluate the influence of seed priming in improving performance of late sown chickpea. Chickpea seeds were subjected to on-farm priming, hydropriming and osmopriming (CaCl2). In experiment I, seeds of chickpea cultivars Punjab-2008 and Thal-2006 were sown in soil filled pots. Seed priming improved crop stand establishment and seedling dry weight owing to priming-induced improvement in sugars’ metabolism. In the second experiment, primed and untreated seeds of both chickpea cultivars were sown on Dec 03 and 18, and Jan 03 at Faisalabad and Multan, Pakistan during three growing seasons. Delay in planting decreased the germination indices, crop stand, growth and yield at both sites during all 3 years. Seed priming improved crop stand and growth of both chickpea cultivars resulting in increase in grain yield and net economic returns, and osmopriming was the most effective. Chickpea cultivars differed for yield and net economic returns and Punjab-2008 had better grain yield and economic returns compared to Thal-2006. Therefore, chickpea cultivar Punjab-2008 should be planted after osmopriming to harvest better yield and profitability from late sown chickpea.

A comparative study on the effect of elevated CO2 environment on soil nitrogen availability in different rice planting system is needed to develop nutrient management strategies in future climate scenarios. A field experiment was conducted inside open top chambers (OTC) to study the effect of elevated CO2 environment with varying nitrogen management on soil NH4+–N and NO3−–N status in two planting system of rice, direct-seeded rice (DSR) and puddled transplanted rice (PTR). The nitrogen management included chemical fertilizer (CF) at 100% (CF100) and 150% (CF150) of the recommended dose, integrated nitrogen management including organic fertilizer (OF) and CF as CF75+ OF75, and site-specific N management through CF using SPAD meter. The soil NH4+–N content was higher in PTR, but NO3−–N was higher in DSR. The soil NH4+–N and NO3−–N content decreased significantly under elevated CO2 environment as compared to ambient in both planting system, except the NO3−–N content at flowering in DSR. The decrease was around 8% for NH4+–N and 5% for NO3−–N content. Soil nitrogen content in DSR can be maintained by following integrated nutrient management (CF75 + OF75) and SPAD-based nitrogen management for sustainable yield. Grain yield, in general, increased with CO2 elevation in both planting system. Under ambient environment, CF150 increased the grain yield by 23% as compared to CF100 in DSR, but no change was noted in PTR. However, under elevated CO2 environment, CF150 increased the grain yield by 13% in PTR. Under elevated CO2 environment, the yield increase of the hybrid rice to additional N fertilizer application was noted in PTR but not in DSR. This study suggests that for sustainable rice production under increasing CO2 environment in future climate scenarios, higher dose of N fertilizer is recommended in PTR, but normal dose in DSR production system.

Drought is a problem for peanut production as drought at any growth stage generally reduces pod yield and alters protein and amino acid compositions in kernels. The aim of work was to examine effects of terminal drought on arginine content in kernels of peanut genotypes with different levels of drought tolerance. Five peanut genotypes were planted under two water treatments, field capacity (FC) and 1/3 available water (1/3 AW). Arginine content, physiological traits and pod yield were recorded at harvest. The results showed that drought increased arginine content in sensitive and resistant genotypes, and the increase in arginine content was highest in sensitive genotype (Tainan 9). The variation in arginine content in peanut depended on peanut genotype rather than the level of drought resistance. No correlation between arginine content and drought-resistance physiological traits and pod yield were not found. These findings indicated that arginine content and resistance to terminal drought in a peanut may be improved simultaneously through selection in a breeding program.

Water stress and soil salinity have detrimental effects on crop productivity, water use efficiency as well as soil properties. In attempt to elucidate whether salicylic acid (SA) could ameliorate the detrimental effects of water stress on wheat under salt affected soil, two seasons (2015/2016 and 2016/2017) of field experiments were investigated using six combinations of two salicylic acid levels (zero and 200 ppm SA) and three irrigation treatments (50, 70 and 90% depletion of the available soil moisture). Results showed that exogenously applied SA inhibited Na uptake and stimulated N, P and K uptake under stress conditions. Under water stress, the foliar application of SA effectively increased the relative water content and proline content whilst decreased stomatal conductance compared to the untreated ones. These changes resulted in increment the yield-related traits viz., number of grains spike−1, 1000-grain weight and number of spikes m−2. Water use efficiency attained the maximal values under 50% DAM plus 200 ppm SA, which was on par with 70% DAM plus 200 ppm SA. It was concluded that the potency of SA–treated wheat crop can relatively convert used water into grain yield under water stress conditions as well–watered..