Early-sown Crops Research Articles

Timely sowing effect on incidence of aphid, Rhopalosiphummaidis in blond psyllium, Plantaga ovata, Forsk

To find out the effect of different sowing dates on Rhopalosiphum maidis of blond psyllium, P. ovata, (Forsk) crop to determine the optimum sowing of dates. It is seen that the incidence and population fluctuation of R. maidis was dependent on the prevailed climatic conditions of the cropping seasons. The five different sowing dates revealed that early sown crop (9th November) had the minimum infestation (21.84 aphid/tiller) of aphids and highest seed yield (7.32 q ha-1) was obtained as compared to the late sowing crop 30th December (51.02 aphids/tiller) whereas, minimum seed yield was obtained on sown crop 7th December (4.03 q ha-1).

Development and validation of weather based prediction model for Helicoverpa armigera in chickpea

Weather based prediction model for Helicoverpa armigera was developed and validated using pheromone trap catches data collected in chickpea crop sown on three different dates during 2015-16 and validated for 2016-17. The first catch of male moth of H. armigera was recorded during 1st standard meteorological week (SMW) in early sown crop, while in normal and late sown the first trap catches were noticed during 3rd and 5th SMW respectively. H. armigera adult trap catches then increased gradually and reached their peaks simultaneously during 12thSMW with 32.3, 37.3 and 44.3 moths/trap/week in early, normal and late sown chickpea crop respectively. Male moth population had highest significant positive correlation with maximum and minimum temperature of 2-lag week in early and normal sowing of chickpea. Morning relative humidity and evening relative humidity of current, 1-lag and 2-lag week were negatively correlated with trap catches. The rainfall of 1-lag week and sunshine hours of current week exhibited maximum positive association with male moth population. Weather based prediction models were developed for male trap catches of crop under normal date of sowing and weather factors of current, 1-lag and 2-lag week. By stepwise regression, Tmin, RH1 and SSH were found to be importantweather factors that influenced the trap catches of H. armigera. The pest-weather model was validated satisfactorily with R2 = 0.751, RMSE=2.13%, MBE=-1.08% and MAE= 1.51%.

Influence of sowing dates on the incidence of powdery mildew of chilli

A field experiment was conducted during kharif, 2005 at Agricultural Research station, Devihosur, Haveri, Karnataka to assess the progress of powdery mildew at different time interval of sowing dates. Totally 20 different dates of sowings were imposed in the experiment at an interval of 10 days. The crop sown on last week of May to mid of June recorded minimum disease severity compared to rest of the date of sowings. This clearly indicated that crop sown during this period suffers less, which may be due to low inoculum potential, whereas late sown crop suffers more because of the readily available inoculum in the early sown crops. Low disease severity in last week of May to mid of June sowing may be attributed to the non-congenial weather factors for the development of the disease.

Wheat Monitoring by Using Kernel Based Possibilistic c-Means Classifier: Bi-sensor Temporal Multi-spectral Data

The existence of mixed pixels in the satellite images has always been an area of concern. Adding to the challenge is an occurrence of non-linearity between the classes, which is generally overlooked. The study makes an attempt to solve the two frequently occurring problems by kernel based fuzzy approach. This research work deals with Possibilistic c-Means (PCM) classifier with local, global, spectral angle and hyper tangent kernels for wheat crop (Triticum aestivum) identification in Haridwar, Uttarakhand, India. The multi-temporal vegetation index data of Formosat-2 have been used which covers the whole phenology of wheat crop. The additional sensor Landsat-8 OLI imagery has been filled the crucial gap of Formosat-2 temporal datasets. Nine types of proposed kernels based PCM classifier have been applied on three temporal datasets (four, five and six date combinations) to classify two classes early sown and late sown wheat crop. These test results have been concluded that at optimized weighted constant KMOD and polynomial kernel was found effective to separate wheat crop. The five and six date combination were sufficient to discriminate early sown and late sown wheat crop.

Effect of foliar application of boron and tiba on crop phenology and solar energy utilization efficiency of spring sunflower under staggered sowing

Sunflower (Helianthus annuus L.) is a thermo-and photo-insensitive crop but environmental, nutritional and hormonal factors can cause variation in phasic development and energy utilization efficiency of crop. A study was conducted to investiagate crop phenology and thermal energy utilization efficiency of spring sunflower in relation to foliar application of boron and TIBA under staggered sowing (20 January, 10 February and 2 March). Early sown crop took significantly more number of days to attain all phenological stages. Foliar application of boron and TIBA increased the number of days to attain flowering and subsequent stages. The thermal units required to attain various phenological stages increased progressively due to delay in sowing but accumulated growing degree days for physiological maturity decreased with delay in sowing. Boron and TIBA treatments recorded markedly higher thermal units accumulation as compared to control for physiological maturity. Phenothermal index gradually increased from star bud to physiological maturity under all treatments. Late sown crop exhibited higher heat use efficiency at 30 DAS, but at 90 DAS and at harvest foliar application of boron and TIBA improved heat use efficiency of the crop.

Effect of staggered sowing on the sucking pests and natural enemies in Okra

Field experiment conducted to study the effect of staggered sowing on the incidence of sucking pests in okra and their natural enemies revealed that the early sown crop had significantly less incidence than the late sown one. Two years data revealed that the least incidence of jassids, whiteflies, mites and natural enemies i.e., Coccinella septempunctata and Chrysoperla carnea occurred in the 20th January sown crop, with least incidence of aphids occurring in 6th February sown crop. The highest incidence of jassids and aphids was in the 8th April and 21st February sown crops, respectively, with highest incidence of whiteflies and mites being in 8th March sown crop.

Effect of row spacing and sowing time on seed yield, quality parameters and nutrient uptake of guar [Cyamopsis tetragonoloba (L.) Taub] in semi arid climate of Southern Telanagana, India

A field experiment was conducted during kharif 2013 and 2014 to study the effect of row spacing and sowing time on seed yield, galactomannan and protein content and nutrient uptake of guar in semi arid climate of Southern Telangana. The crop sown at row spacing of 30 cm recorded significantly higher seed yield than that of 45 cm and 60 cm spacing. Production and rainfall use efficiency and harvest index besides growth and yield attributes, galactomannan and protein yields, N, P and K uptake were also significantly higher at 30 cm spacing. Sowing of guar during first or second fortnight of July resulted in significantly higher seed yield than first fortnight of August sowing. Production efficiency, plant height, number of clusters plant-1 and protein yield followed the similar trend of seed yield. Negative relationship was observed between galactomannan content and sowing time. Though powdery mildew infection was higher in early sown crop and close crop spacing, higher plant population and biomass production resulted in higher seed yield of guar when compared to late sown crop and wider spacing.

Emergence and growth dynamicsof springsunflower(Helianthus annuusL.) in relation to sowing dates, densities and nitrogen rates

Emergence and growth dynamics of sunflower were studied at Punjab Agricultural University, Ludhiana during spring seasons of 2014 and 2015. The experiment consisted of three sowing dates (D1-January 20, D2-February 10 and D3-March 2), two intra row spacing (S1–30 cm and S2-24 cm) and four nitrogen (N) doses (N0-0, N45-45, N60-60 and N75-75 kg ha−1). Results revealed reduction in number of days taken for initiation and completion of emergence vis-a-vis emergence percentage with concomitant increase in emergence rate and vigour index due to delayed sowing. Late sown crop (D3) exhibited higher absolute growth rate (AGR), crop growth rate (CGR) and specific leaf weight (SLW) during initial phases of crop growth but early sown crop (D1) surpassed the late sown crop 50 days onward up to maturity. Early sown crop maintained higher relative growth rate (RGR) throughout the crop growth. Wider sown crop showed higher AGR, whereas CGR was higher under closer sowing. Application of N improved the AGR, CGR and RGR but SLW was improved during later growth stages (50 days onwards) only. Net assimilation rate (N AR) decreased progressively due to each delay of sowing during later growth stages. Application of N improved the NAR up to 75 DAS but between 75 DAS and maturity, application of N lowered NAR as compared to control. Correlation studies indicated significant positive correlation of seed yield with AGR, CGR and RGR between 50 and 75 DAS, emphasizing the importance of higher growth rate during grand growth period for best yield accrual in sunflower.

Re-evaluating sowing time of spring canola (Brassica napus L.) in south-eastern Australia—how early is too early?

Optimising the sowing date of canola (Brassica napus L.) in specific environments is an important determinant of yield worldwide. In eastern Australia, late April to early May has traditionally been considered the optimum sowing window for spring canola, with significant reduction in yield and oil in later sown crops. Recent and projected changes in climate, new vigorous hybrids, and improved fallow management and seeding equipment have stimulated a re-evaluation of early-April sowing to capture physiological advantages of greater biomass production and earlier flowering under contemporary conditions. Early–mid-April sowing generated the highest or equal highest yield and oil content in eight of nine field experiments conducted from 2002 to 2012 in south-eastern Australia. Declines in seed yield (–6.0% to –6.5%), oil content (–0.5% to –1.5%) and water-use efficiency (–3.8% to –5.5%) per week delay in sowing after early April reflected levels reported in previous studies with sowings from late April. Interactions with cultivar phenology were evident at some sites depending on seasonal conditions. There was no consistent difference in performance between hybrid and non-hybrid cultivars at the earliest sowing dates. Despite low temperatures thought to damage early pods at some sites (<−2°C), frost damage did not significantly compromise the yield of the early-sown crops, presumably because of greater impact of heat and water-stress in the later sown crops. A validated APSIM-Canola simulation study using 50 years of weather data at selected sites predicted highest potential yields from early-April sowing. However, the application of a frost-heat sensitivity index to account for impacts of temperature stress during the reproductive phase predicted lower yields and higher yield variability from early-April sowing. The frost–heat-limited yields predicted optimum sowing times of mid-April at southern sites, and late April to early May at the northern sites with lower median yield and higher yield variability in crops sown in early April. The experimental and simulation data are potentially compatible given that the experiments occurred during the decade of the Millennium drought in south-eastern Australia (2002–10), with dry and hot spring conditions favouring earlier sowing. However, the study reveals the need for more accurate and validated prediction of the frost and heat impacts on field-grown canola if simulation models are to provide more accurate prediction of attainable yield as new combinations of cultivar and sowing dates are explored.

Genotypic Variation in Physiological Traits Under High Temperature Stress in Maize

Maize (Zea mays L.) is a major cereal crop in India and worldwide whose production and productivity are greatly affected by high temperature stress. Twenty-one maize genotypes were staggered sown and evaluated for the variations in different physiological traits under high temperature stress. Observations were recorded for net photosynthetic rate, transpiration rate, stomatal conductance, leaf temperature, canopy temperature, maximum quantum yield PSII photochemistry (F v/F m), SPAD, ASI, stover and grain yield. Meteorological data of cropping season for first and second date of sowings showed maximum and mean day time temperature of 37.6, 37.2 and 41.4, 37.5 °C, respectively, during reproductive stage. These temperatures were optimal for photosynthesis, fertilization and grain filling in early sown crop, while for the late sown crop, it was optimal for photosynthesis but above threshold and detrimental for fertilization and grain filling. Combined analysis of ANOVA showed that all the parameters were found significant with respect to genotypes (G), date of sowings (T) and their interaction (G * T) except leaf temperature. The high temperature stress increased the plant stover weight due to increased photosynthesis coupled with maximum quantum yield PSII photochemistry which may improve the total plant growth. Results revealed that high temperature promoted the growth of vegetative plant parts but affected yield-related parameters. Higher temperatures during vegetative growth improved net photosynthetic rate resulting in higher total stover yield (28 %) at maturity. It impacted pollen viability and source to sink supply of photosynthates leading to reduced grain yield (13 %) in all genotypes.

Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L.) Planted under Early and Optimum Sowing Conditions.

Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage) and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET), improved emergence index (EI) and final emergence percentage (FEP). Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.

Studies on varietal screening and date of sowing of Helicoverpa armigera (Hub.) on chickpea [Cicer arietiinum (L.)

Investigations on screening of chickpea varieties/genotypes, dates of sowing of H. armigera (Hub.) on chickpea were conducted at Experimental Farm, College of Agriculture during Rabi season in 2005-06. Ten varieties/genotypes of chickpea were tested for relative incidence of the pest. Among these varieties RSG-44 and RSG-945 were found to be highly susceptible followed by CSJ-104, RSG-959, RSG-895, RSG-888, RSG-897 and RSG-973 as moderately susceptible while, CSJD-884 and RSG-931 as least susceptible. The maximum yield was obtained in CSJD-884 (14.54 q ha-1) at par with RSG-931 (14.36 q ha-1), while lowest yield was from RSG-44 (11.13 q ha-1).The experiment on dates of sowing revealed that early sown crop (5th October) had the lowest larval population (2.50 larvae/five plants) of gram pod borer, minimum pod damage (14.50%) with relatively better yield (13.04 q ha-1) as compared to late sown (20th November) crop with higher larval population (6.13 larvae/five plants), higher pod damage (28.96%) and lower yield (9.77 q ha-1).

Quantification of Soil Water Competition and Compensation Using Soil Water Differences between Strips of Intercropping

Synergistic regulation on water competition and compensation is critical to effective use of water for sustainable intercropping systems in arid areas. Field experiment was carried out in 2009, 2010, and 2011 in Hexi Corridor, northwest China. Two late-sown crops [maize (Zea mays) and soybean (Glycine max)] intercropping with three early-sown crops [pea (Pisum sativum), rape (Brassia campestris), and wheat (Triticum aestivum)] were designed in comparison with the respective sole crops. Differences in soil water (soil water of late-sown crops minus that of early-sown crops in intercropping) were found to be mostly positive during the co-growth period which changed to negative during the fallow period of early-sown crops. Absolute values of the difference between wheat and maize strips both in co-growth and fallow period were the greatest among treatments, followed by maize–pea intercropping, while they were lowest in soybean–wheat intercropping in 2009 and 2010 and in maize–rape intercropping in 2011. In the co-growth period, the mean soil water competition for wheat strips in maize–wheat intercropping across 3 years was 71 mm, while it was 16 mm and 27 mm, respectively, for maize–rape and maize–pea intercropping. Sole wheat recharged the greatest amount of soil water from wheat harvest to maize harvest. In each year, intercropped wheat, rape, and pea recharged 24–76, 42–67, and 32–49 mm soil water, respectively. It was concluded that the methodology to calculate soil water competition and compensation was a very useful tool for evaluating the amount of soil water movement in intercropping systems.

Relationship between ascochyta blight on field pea (Pisum sativum) and spore release patterns of Didymella pinodes and other causal agents of ascochyta blight

Ascochyta blight of field pea, caused by Didymella pinodes, Phoma medicaginis var. pinodella, Phoma koolunga and Didymella pisi, is controlled through manipulating sowing dates to avoid ascospores of D. pinodes, and by field selection and foliar fungicides. This study investigated the relationship between number of ascospores of D. pinodes at sowing and disease intensity at crop maturity. Field pea stubble infested with ascochyta blight from one site was exposed to ambient conditions at two sites, repeated in 2 years. Three batches of stubble with varying degrees of infection were exposed at one site, repeated in 3 years. Every 2 weeks, stubble samples were retrieved, wetted and placed in a wind tunnel and up to 2500 ascospores g−1 h−1 were released. Secondary inoculum, monitored using seedling field peas as trap plants in canopies arising from three sowing dates and external to field pea canopies, was greatest in early sown crops. A model was developed to calculate the effective number of ascospores using predictions from G1 blackspot manager (Salam et al., 2011b; Australasian Plant Pathology, 40, 621–31), distance from infested stubble (Salam et al., 2011a; Australasian Plant Pathology, 40, 640–7) and winter rainfall. Maximum disease intensity was predicted based on the calculated number of effective ascospores, soilborne inoculum and spring rainfall over two seasons. Predictions were validated in the third season with data from field trials and commercial crops. A threshold amount of ascospores of D. pinodes, 294 g−1 stubble h−1, was identified, above which disease did not increase. Below this threshold there was a linear relationship between ascospore number and maximum disease intensity.

Benchmarking for performance assessment of small and large irrigation schemes along the Senegal Valley in Mauritania

Degradation of irrigation schemes, low and variable land productivity, and inefficient use of production inputs are major concerns in Mauritania. That prompted this benchmarking analysis of 17 small and 3 large irrigation schemes located along the River Senegal. The objectives were to establish benchmarks for both productivity and performance of irrigation schemes along the valley, and to inquire whether small schemes function better than large schemes. Cluster and data envelopment analyses enabled, respectively, grouping and ranking of irrigation schemes according to a set of pre-determined performance indicators: viz. energy costs, relative irrigation supply, irrigation intensity related to irrigable and equipped area, adequacy, and land productivity. Land productivity, which was highly variable, was compared to simulated land productivity for non-limiting conditions in order to determine yield gap variations. Few early sown crops were close to the simulated yield frontier of 10.6tha−1 and the mean yield was similar for large and small schemes (3.50tha−1 and 3.77tha−1, respectively). The analysis of the indicators revealed that, on average, large schemes performed similarly to small-scale schemes, but small schemes were more variable, particularly in input-use efficiency. Analysis of clusters identified three groups of irrigation schemes: viz. consuming and productive, precarious, and productive and economic. According to data envelopment analysis, four irrigation schemes were identified as technically efficient. Their average land productivity was relatively high (4.75tha−1) and energy costs were contained (59€ha−1). Data envelopment analysis also identified the particular efficient schemes that should be taken as reference for improvement of each inefficient scheme.

Seasonal Influence on Physiological Parameters and Yield of Dolichos Bean (Dolichos lablab (Roxb.) (L) var. typicus) Genotypes

The response of Dolichos bean genotypes to different seasons in relation to physiological parameters and yield was studied during 2009-2010. Leaf area, light interception, specific leaf weight, chlorophyll content, chlorophyll stability index and relative water content differed with genotypes and seasons. With respect to genotypes, Dbp-3 recorded the highest leaf area, total dry matter production, light interception, specific leaf weight, chlorophyll content, chlorophyll stability index and relative water content which in turn reflected on yield. The early sown crop i.e. crop sown at July-August season resulted in good development of physiological characters as well as yield. Among the treatment combinations, the highest value of physiological parameters and yield was recorded in Dbp-3 sown during July-August season.

Heat Unit Requirement of Different Rice Varieties Under Chhattisgarh Plain Zones of India

Field experiment was carried out during kharif season of 2012 at Research and Instructional Farm of Indira Gandhi Agricultural University, Raipur to examine yield and Heat unit requirement of rice with three genotypes as influenced by three sowing dates in factorial Randomized Block Design. Higher grain yield was recorded with Mahamaya as compared to Karma Mahsuri and MTU-1010 under 10th June sowing also with respect to heat units the cumulative growing degree day at maturity stage was (2410˚C) for Karma Mahsuri followed by Mahamaya (2365˚C) and MTU-1010 (2161˚C) when sown on 10th June. Maximum growing degree days were observed in early sown crop (10June) as compared to late sown crop (20 and 30June). Similar results were found in the case of photo thermal unit and helio thermal unit also. At maturity stage, highest radiation use efficiency in 10th June sowing might be due to better conversion of light in to dry matter, better yield component and harvest index in 10th June sowing as compared to 30th June sowing.

High temperature combined with drought affect rainfed spring wheat and barley in south-eastern Russia: Yield, relative performance and heat susceptibility index

Among all abiotic stresses, drought is undoubtedly the major factor, which, individually or combined with heat stress, limits crop productivity worldwide. Considering these facts, four spring barley and two spring wheat genotypes were evaluated under two stress (early and late) conditions in a southern arid region of Russia in order to identify suitable spring wheat and barley genotypes for that region and to assess the optimum sowing time for specific genotypes. High temperature followed by deficit soil moisture affected all stages from germination through to reproduction of crop when sown late, finally drastically reducing yield. On the other hand, due to low temperature, germination and stand establishment of crop sown early were highly affected, resulting in lower grain yield. Thus, high temperature (air and soil) followed by drought (deficit soil moisture) in the late-sown crop (from germination to reproductive stages) and low temperature in germination through vegetative stages of the early-sown crop are the most important constraints for crop production in this arid region. From the overall performance (yield, relative performance and stress susceptibility index), genotype ‘Zernograd.770’ is recommended for both early and late drought stressed areas and ‘Ratnik’ were sensitive to stress both at low temperatures when sown early and high temperatures followed by drought when sown late. Key words: High temperature, drought, spring wheat, barley, Russia.

Agrometeorological indices of white clover (Trifolium repens) in western Himalayas

Field experiments were conducted during 2009-2010 and 2010-2011 to study the growth performance of white clover (Trifolium repens L.) under different temperature regimes over the crop growth period. The agroclimatic indices for temperature viz., growing degree days (GDD), heliothermal units (HTU) and photothermal units (PTU) were computed for different phenological stages of the crop. Changes in weather parameters concomitant to different sowing time caused significant variation in the performance of the crop. The results indicated that the early sown crop had longer crop span (205 days) than the late sown (142 days). From emergence to seed maturity, white clover accumulated GDD of 2314±72 °C days, HTU of 17791±409 °C days hour and PTU of 29412±742 °C days hour, respectively. Positive correlations were found between fresh leaf weight, fresh stem weight and fresh root weight for GDD, HTU and PTU.

Homobrassinolide-Induced Thermotolerance in Brassica Species

The Brassica crop encounters high temperatures during harvest leading to fruit shattering. Early sowing of the crop may help in overcoming this problem. However, the early sown crop may be exposed to high temperature during seedling stage, and high soil temperature may cause profound modification of growth and metabolic processes in young seedlings. Growth regulators have widely been used for acquisition of thermotolerance in a variety of crops, so efficacy of homobrassinolide (HBR) in inducing thermotolerance was tested in different cultivars of Brassica, namely RL-1359 (Brassica juncea), PBR-210 (Brassica juncea), and PC-5 (Brassica carinata). Application of homobrassinolide HBR at 0.1 and 0.2 μg ml−1 as pretreatment to four-day-old Brassica seedlings before exposing them to lethal temperatures increased the values of the following characteristics: seedling length, vigor index of seedlings, total soluble sugar content, and enzymatic activities, and caused remarkable reduction in relative injury of membranes measured by electrolyte leakage. Separation of proteins through SDS-PAGE revealed the accumulation of some new proteins in HBR-treated seedlings. Activities of enzymes peroxidase and invertase increased remarkably, whereas catalase showed a reduction in activity. The scavenging of reactive oxygen species like H2O2 and superoxide ions by antioxidant enzymes plays a key role in imparting thermotolerance. Thus high peroxidase activity, high invertase activity, and low electrolyte leakage of membranes could be directly linked with enhanced tolerance to heat-induced oxidative damage and could be involved in the processes leading to acclimation during heat stress. These features could be exploited to improve thermotolerance of crop plants by suitable breeding strategies.