How Does Nitrogen Application Rate Affect Plant Functional Traits and Crop Growth Rate of Perennial Ryegrass-Dominated Permanent Pastures?

High doses of nitrogen (N) fertiliser input on permanent pastures are crucial in terms of N surplus and N losses. Quantitative analyses of the response of plant functional traits (PFT) driving crop growth rate (CGR) under low N input are lacking in frequently defoliated pastures. This study aimed to understand the significance of PFTs for productivity and N uptake in permanent grasslands by measuring dynamics in tiller density (TD), tiller weight (TW), leaf weight ratio (LWR), leaf area index (LAI), specific leaf area (SLA), as well as leaf N content per unit mass (LNCm) and per unit area (LNCa) in perennial ryegrass (Lolium perenne)-dominated pastures, in a simulated rotational grazing approach over two consecutive growing seasons. Annual N application rates were 0, 140 and 280 kg N ha−1. The phenological development of perennial ryegrass was the main driver of CGR, N uptake and most PFTs. The effect of N application rate on PFTs varied during the season. N application rate showed the greatest effect on TD, LAI and, to a lesser extent, on SLA and LNCm. The results of this study highlight the importance of TD and its role in driving CGR and N uptake in frequently defoliated permanent pastures.

Assessment of improving irrigation efficiency for tomatoes planted in greenhouses in Lam Dong Province, Vietnam

This study was conducted to investigate the developmental processes of tomato plants in greenhouses covered with polyethene agricultural film that applied a smart irrigation system. The study tested applying different irrigation water levels (IWLs) of 60, 80, 100, and 120% of crop evapotranspiration (ETc). Based on the findings for the tomato rows sampled to collect information about leaf area, biomass, and yield, maximal growth of tomatoes varied from 80 to 90 days after transplanting (DAT) for all IWLs. Among the applied IWLs, approximately 80% of ETc was recorded as the most appropriate for the crop growth rate (CGR), leaf area index (LAI), and yield, while the IWLs with 60%, 100%, and 120% of ETc also gave an equivalent output. The results of this work can provide useful information for farmers to make the right decisions about the amount of irrigation water to use.

EFFECT OF SEEDS SOAKING AND VEGETATIVE PARTS NUTRITION WITH ACIDS OF ASCORBIC, CITRIC AND HUMIC ON MAIZE GROWTH

A field experiment was carried out during two spring seasons in 2019 and 2020. This study was aimed to increase dry matter weight and crop growth rate of maize. First factor in main plots was nutrition vegetative parts with ascorbic and citric (100 mg l-1) for both of them and humic (1 ml l-1), in addition to the control treatment (spraying of vegetative parts with distilled water only). Second factor in sub-plots was seeds soaking with same acids above, as well as the control treatment (soaking the seeds with distilled water only). Randomize complete block design in split plot arrangement was used with three replications. The results showed a significant superiority of seeds soaking in humic acid for traits of number of days from planting to 75% anthesis and silking (66.4 and 66.3 day) and (72.3 and 72.3 day), plant height (194.0 and 230.8 cm), leaves area plant-1 (6969.5 and 6570.2 cm2), leaf area index (3.71 and 3.50), dry matter weight (11.6 and 12.2 ton ha-1), crop growth rate (3.0 and 3.2 g cm-2 day-1) and chlorophyll leaf content (60.2 and 69.5 SPAD) for both seasons, respectively. Effect of vegetative parts nutrition and interaction effect of both studied factors was non-significant for most traits. It can be concluded that seeds soaking in humic acid improved growth traits. It can be recommended to soak seeds of maize before planting in humic acid at concentration of 1 ml l-1.

Development of Growth Estimation Algorithms for Hydroponic Bell Peppers Using Recurrent Neural Networks

As smart farms are applied to agricultural fields, the use of big data is becoming important. In order to efficiently manage smart farms, relationships between crop growth and environmental conditions are required to be analyzed. From this perspective, various artificial intelligence algorithms can be used as useful tools to quantify this relationship. The objective of this study was to develop and validate an algorithm that can interpret the crop growth rate response to environmental factors based on a recurrent neural network (RNN), and to evaluate the algorithm accuracy compared to the process-based model (PBM). The algorithms were trained with data from three growth periods. The developed methods were used to measure the crop growth rate. The algorithm consisted of eight environmental variables days after transplanting and two crop growth characteristics as input variables producing weekly crop growth rates as output. The RNN-based crop growth rate estimation algorithm was validated using data collected from a commercial greenhouse. The CropGro-bell pepper model was applied to compare and evaluate the accuracy of the developed algorithm. The training accuracies varied from 0.75 to 0.81 in all growth periods. From the validation result, it was confirmed that the accuracy was reliable in the commercial greenhouse. The accuracy of the developed algorithm was higher than that of the PBM. The developed algorithm can contribute to crop growth estimation with a limited number of data.

Impact of integrated nutrient management on production potential of mungbean

Mungbean is one of the important grain legume crops in Pakistan due to its vigorous growth even in adverse environment. Mungbean is part of daily cuisine in the country but its production is low mostly due to imbalance fertilization. The study was carried out to find best combination of nitrogen (N), phosphorus (P) and potassium (K) for maximum production under less fertile soils during 2017-2018. In this study, three combinations of NPK (i.e., 30:30:0, 30:60:0 and 30:60:30 kg ha-1 ) were compared with control (without fertilization). Maximum pods per plant (22.43), pod length (9.51 cm), seeds per pod (8.97), 1000 seed weight (44.07 g), seed yield (1163 kg ha-1 ), biological yield (5231 kg ha-1 ) and harvest index (24.63 %) were obtained from 30:60:30 kg NPK ha-1 during 2017 and similar trends were found during 2018. Maximum leaf area duration (212.64, 215.09 days), crop growth rate (3.99, 4.02 g m-2 d -1 ), net assimilation rate (2.46, 2.54 g m-2 d -1 ) and fraction of intercepted radiation (0.89, 0.88 MJ m-2 ) were obtained from mungbean plant under 30:60:30 kg ha-1 NPK application during 2017 and 2018, respectively. These results are suggesting that integrated application of nitrogen, phosphorous and potash is very imperative to attain higher production of mungbean under semi-arid environments. It is concluded from the findings that farmers can harvest maximum final outputs of mungbean by the application of 30:60:30 kg ha-1 NPK, respectively.

Effect of Integrated Nutrient Management on Yield Attributes and Yield of Black Gram Cv. Pu-31

Background: The main pulses grown in India are chickpea, arhar, lentil, black gram, mung bean, moth bean, horse gram, pea, khesari, cowpea, etc. Black gram is fourth major pulse crop in India, that contributes 13 and 10 per cent of total area and production respectively. This is annual plant that attains 30-100 cm height and its stem is covered with brown hairs and much branched from the base. The pods are long and cylindrical being 5-6 cm length and 4-10 seed in pods. The seeds are generally black, very dark brown. Methods: The field experiment was conducted in kharif-2019 at research farm of Tirhut College of Agriculture Dholi, to study the effect of integrated nutrient management on growth, yield parameters and the yield of black gram cv-PU-31, by the use different sources of nutrient in a integrated manner such as three level of fertilizer i.e. F1-75, F2-100 and F3-125% RDF and two levels of organic manure i.e. M1-control and M2-FYM @ 5 t ha-1 and three levels of biofertilizer i.e., B1-rhizobium, B2-nutrient mobilizer, B3-rhizobium+ nutrient mobilizer. The treatments were allocated in randomized block design (factorial) and replicated thrice. Result: The results revealed that F3 produced taller plants, more dry matter, crop growth rate (CGR) yield attributes resulting higher yield of grain and straw (10.78, 22.61 q ha-1 respectively) which was statistically at par with plant height, dry matter, crop growth rate, yield attributes and yield of grain, straw and highest harvest index (10.73, 22.20 q ha-1 and 32.58% respectively) to F2. Among addition of organic manure significantly maximum plant height, dry matter and crop growth rate and yield attributes resulting maximum yield of grain, straw and harvest index (11.2, 22.79 q ha-1 and 33.31% respectively) was found in M2 over M1. In biofertilizer treatments, B3 recorded higher plant height, dry matter and crop growth rate, yield attributes resulting in significantly higher yield of grain, straw and harvest index (10.26, 21.90 q ha-1 and 31.92% respectively) over B1 and B2.

Pengaruh Substitusi Nutrisi ABmix dengan Pupuk Daun Terhadap Pertumbuhan Tanaman Sawi Caisim (Brassica juncea L .) Varietas Tosakan

Tujuan dari penelitian ini adalah mengetahui efektifitas substitusi nutrisi ABmix dengan pupuk daun terhadap pertumbuhan tanaman sawi caisim. Penelitian ini menggunakan rancangan acak lengkap dengan 3 perlakuan dan diulang sebanyak 10 kali. Parameter dalam penelitian ini terdiri dari tinggi tanaman, luas daun, jumlah daun, indeks luas daun, total klorofil. Parameter hasil terdiri dari bobot basah tanaman, bobot kering tanaman, laju asimilasi bersih, Crop Growth Rate, Relative Growth Rate, Indeks panen. Hasil penelitian menunjukkan rata - rata data Tinggi Tanaman ( 52,290 – 54,110 cm ), Jumlah Daun ( 11,5 – 11,7 ), Luas Daun Optimal ( 253,84 – 346,39 cm2 ), Indeks Luas Daun ( 0,6414 - 0,7673 ), Total Klorofil ( 1,03 – 1,2 mg/g ), bobot segar tanaman ( 129,37 – 205,44 gram ), Bobot Kering Tanaman ( 6,63 – 9,115 gram ), Laju Asimilasi Bersih ( 10,028 – 10,8703 mg/ /minggu ), Crop Growth Rate ( 11,803 – 16,425 mg// minggu ), Relative Growth Rate ( 2,1235 – 2,3893 g/g/ minggu ), Indeks Panen ( 19,327 – 22,675 ).

Australian Lentil Breeding Between 1988 and 2019 Has Delivered Greater Yield Gain Under Stress Than Under High-Yield Conditions

The contemporary lentil (Lens culinaris ssp. culinaris) industry in Australia started in the late 1980s. Yield in farmers’ fields averages 1.2 t ha–1 nationally and has not increased over three decades. Lack of yield progress can be related to a number of non-mutually exclusive reasons: expansion of lentil to low-yielding environments, lack of genetic gain in yield, lack of progress in agronomic practices, and lack of adoption of superior technologies. The aims of this study were to (i) quantify the genetic gain in lentil yield since 1988, (ii) explore the variation in the expression of genetic gain with the environment, and (iii) identify shifts in crop phenotype associated with selection for yield and agronomic adaptation. We grew a historic collection of 19 varieties released between 1988 and 2019 in eight environments resulting from the factorial combination of two sowing dates, two water regimes, and two seasons. Across environments, yield varied 11-fold from 0.2 to 2.2 t ha–1. The rate of genetic gain averaged 20 kg ha–1 year–1 or 1.23% year–1 across environments and was higher in low-yield environments. The yield increase was associated with substantial shifts in phenology. Newer varieties had a shorter time to flowering and pod emergence, and the rate of change in these traits was more pronounced in slow-developing environments (e.g., earlier sowing). Thermal time from sowing to end of flowering and maturity were shorter in newer varieties, and thermal time from pod emergence to maturity was longer in newer varieties; the rate of change in these traits was unrelated to developmental drivers and correlated with environmental mean yield. Genetic gain in yield was associated with increased grain number and increased harvest index. Despite their shorter time to maturity, newer varieties had similar or higher biomass than their older counterparts because crop growth rate during the critical period increased with the year of release. Genotype-dependent yield increased over three decades in low-yield environments, whereas actual farm yield has been stagnant; this suggests an increasing yield gap requiring agronomic solutions. Genetic improvement in high-yield environments requires improved coupling of growth and reproduction.

Response of Physiological Parameters in Greengram (Vigna radiata L. Wilckzek) cv. GAM-5 to Source Manipulation, Plant Growth Regulators and Chemical

Background: Among the pulse crops mungbean is one of the richest sources of protein. There is great loss in the yield of mungbean due to various reasons may be biotic or abiotic constraints. To overcome the yield loss various physiological activities are studied. Physiological activities of the plant are greatly influenced by the source manipulation, plant growth regulators and chemical in mungbean. In correspondence to this, an experiment was conducted to study the physiological parameters in greengram.Methods: A factorial randomized block design in two respective years, i.e. 2016 and 2017 to study the response of source manipulation (nipping, 25% defoliation and 50% defoliation), plant growth regulators (GA3 and NAA at 25 and 50mg/l respectively) and chemical (Thiourea 500 and 1000mg/l) on the physiological parameters like Crop Growth Rate (CGR), Relative Growth Rate (RGR), Net Assimilation Rate (NAR) and Leaf Area (LA) in greengram at 30, 45, 60 and 75 DAS/harvest at Regional Research Station, Anand Agricultural University, Anand. Result: From the obtained results it can be proposed that the physiological parameters like crop growth rate, relative growth rate and net assimilation rate increased with the increasing phase and decreased at harvesting stage. While leaf area increased significantly at each growth phase. The treatment of nipping M2 was noted significantly higher value for CGR i.e., 8.42, 16.17 and 11.48 g/cm2/day/10, for RGR i.e., 0.544, 2.967 and 1.290 g/day, for NAR i.e., 0.466, 2.959 and 1.484 mg/cm2/day and for LA i.e. 96.87, 218.94, 381.88 and 588.78 cm2. While the treatment S2 GA3 25 mg/l was noted significantly higher value for CGR i.e, 8.60, 16.67 and 11.69 g/cm2/day/10, for RGR i.e., 0.568, 2.938 and 1.202 g/day, for NAR i.e., 0.372, 3.043 and 1.529 mg/cm2/day and for LA i.e., 96.61, 224.75, 382.20 and 580.42 cm2 contributing to the higher seed yield under M2 nipping treatment i.e., (1719.7 kg/ha) and S2 treatment i.e., GA3 25 mg/l (1714.1 kg/ha). Thus, GAM-5 had a better source-sink partitioning efficiency.