Plant Dry Matter Production Research Articles

PLANTING DENSITIES AND THE USE OF LOCAL WEEDS AS AN ALTERNATIVE TO ACCELERATE THE INCORPORATION OF GREEN MANURES

<p><strong>Background. </strong> Tropical legumes used as green manure require between 2.5 and 4.5 months of growth to be incorporated into the soil, an increase in planting density and the use of weed biomass is expected to help reduce the time required for the incorporation of legumes. <strong>Objective. </strong>To determine plant survival and dry matter production of five tropical legumes produced in conjunction with local weeds, as a function of planting density and legume age, to identify the most appropriate alternative to accelerate the incorporation of plant biomass in tropical regions. <strong>Methodology. </strong>The legumes <em>Canavalia ensiformis</em>, <em>Crotalaria juncea</em>, <em>Cajanus cajan</em>, <em>Sesbania</em> sp. and <em>Mucuna aterrima</em> were established in Veracruz, Mexico. Each species was established at five planting densities and biomass was collected at four ages, 30, 60, 90 and 120 days after sowing (DAS). <strong>Results.</strong> Plant height, leaf/stem ratio, percentage of broadleaf and narrowleaf weeds, as well as dry matter produced by legumes, weeds, and the total of both, changed as a function of plant age. <strong>Implications.</strong> To use green manures in a crop rotation system under rainfed conditions, it is necessary to know the amount of biomass of local weeds and legumes produced over time. The results of the study will help to define the most appropriate cutting age for each of the green manure species evaluated. <strong>Conclusion. </strong>It is concluded that, independent of planting density, as the age of the legumes increases, plant survival and the leaf/stem ratio decrease, but the amount of dry matter increases. <em>C. cajan</em> and <em>C. juncea</em> have a greater capacity to compete with local weeds, which is attributed to the height they can reach in the first 30 DAS. Regardless of the species and planting density, the maximum production of total dry matter per hectare is achieved between 30 and 60 DAS, when it is recommended to incorporate the biomass to produce under rainfed conditions.</p>

Potential of novel Rhizobium strains as biofertilizer for improved groundnut (Arachis hypogaea L.) cultivation in Eastern India

ABSTRACT Comprehensive assessments were conducted on eight fast growing, novel Rhizobium isolates, short listed from a preliminary selection of 68 isolates obtained from root nodules of groundnut plants grown in diverse agro-climatic regions of eastern India. Additionally, two conventional rhizobia strains, viz. IGR6 and GN2, (collected from the Nodule Research Center, BCKV), were utilized for comparative analysis. Cluster analysis, based on carbon utilization and biochemical parameters, grouped all the test isolates with an average similarity level of 73%. The ability of the isolates to utilize a wide range of carbon sources, including hexoses, pentoses, and disaccharides, confirms their fast-growing nature. Further analysis through 16S rDNA extraction and nucleotide sequencing revealed that the promising fresh isolates exhibited 95–99% similarity to known Rhizobium species in public databases. When evaluated in pot culture experiments using new alluvial soil from the Gangetic Plains in eastern India, the native fresh isolate NRA1(PP355674) outperformed other isolates and conventional strains in terms of nodulation efficiency, plant dry matter production, and plant nitrogen uptake. This study highlights the significant potential of native Rhizobium isolates to surpass conventionally used strains in biological nitrogen fixation, supporting the development of sustainable, environmentally-friendly, and cost-effective agricultural practices.

The role of red and white light in optimizing growth and accumulation of plant specialized metabolites at two light intensities in medical cannabis (Cannabis sativa L.).

The cultivation of medical cannabis (Cannabis sativa L.) is expanding in controlled environments, driven by evolving governmental regulations for healthcare supply. Increasing inflorescence weight and plant specialized metabolite (PSM) concentrations is critical, alongside maintaining product consistency. Medical cannabis is grown under different spectra and photosynthetic photon flux densities (PPFD), the interaction between spectrum and PPFD on inflorescence weight and PSM attracts attention by both industrialists and scientists. Plants were grown in climate-controlled rooms without solar light, where four spectra were applied: two low-white spectra (7B-20G-73R/Narrow and 6B-19G-75R/2Peaks), and two high-white (15B-42G-43R/Narrow and 17B-40G-43R/Broad) spectra. The low-white spectra differed in red wavelength peaks (100% 660 nm, versus 50:50% of 640:660 nm), the high-white spectra differed in spectrum broadness. All four spectra were applied at 600 and 1200 μmol m-2 s-1. Irrespective of PPFD, white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased inflorescence weight, compared to white light with a single red peak of 660 nm (7B-20G-73R/Narrow) (tested at P = 0.1); this was associated with higher total plant dry matter production and a more open plant architecture, which likely enhanced light capture. At high PPFD, increasing white fraction and spectrum broadness (17B-40G-43R/Broad) produced similar inflorescence weights compared to white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks). This was caused by an increase of both plant dry matter production and dry matter partitioning to the inflorescences. No spectrum or PPFD effects on cannabinoid concentrations were observed, although at high PPFD white light with a dual red peak of 640 and 660 nm (6B-19G-75R/2Peaks) increased terpenoid concentrations compared to the other spectra. At low PPFD, the combination of white light with 640 and 660 nm increased photosynthetic efficiency compared with white light with a single red peak of 660nm, indicating potential benefits in light use efficiency and promoting plant dry matter production. These results indicate that the interaction between spectrum and PPFD influences plant dry matter production. Dividing the light energy in the red waveband over both 640 and 660 nm equally shows potential in enhancing photosynthesis and plant dry matter production.

Impact of Foliar Application of Boron on Yield and Yield Attributes, Assimilate Supply, Production Efficiency and Fertilizers Productivity of Indian Mustard (Brassica juncea) in Field Experiments

Field experiments were conducted for three consecutive rabi seasons from 2018 to 2020 to assess the impact of foliar application of boron fertilizer on yield and yield attributes, assimilate supply, production efficiency and fertilizers productivity of Indian mustard [Brassica juncea (L.) Czern. &Coss.]. The results showed that the number of primary branches/ plant (7.00 to 8.08), number of siliquae/plant (427.2 to 468.8), number of seeds/siliqua (13.03 to 14.01), test weight of seed (3.60 to 3.80 g) and plant dry matter production (38.10 to 41.20 g/plant) were significantly increased with T2 treatment (100% NPKS + foliar application of Boron @ 0.5% Borax) as compared to farmer’s practice T1 (100% NPKS + without boron) during three years of experiments. Significantly higher seed yield (22.5 to 24.7 q/ha) of the mustard crop was also reported with T2 (100% NPKS + foliar application of Boron @ 0.5% Borax) as compared to farmers’ practice T1 (100% NPKS + without boron) (seed yield 19 to 22.5 q/ha) during the studies. Similarly, Treatment T2 resulted in significantly higher production efficiency and assimilates supply of mustard crop than that of T1 (farmer’s practice). The fertilizer productivity in the mustard crop that is directly related to seed yield and the partial factor of productivity of N, P, K and S fertilizers (PFPNPKS) were also increased significantly with the T2 compared to farmers practiceT1(farmer’s practice), during 3 years of studies. The highest gross return and net return and benefit-cost ratio were obtained with T2 (100% NPKS + foliar application of Boron @ 0.5% Borax) treatment over T1 (100% NPKS + without boron).

Effect of Crop Establishment Methods and Weed Management Practices on Productivity and Bioenergetics of Rice

Background: SRI and aerobic rice are one of the techniques of growing rice under water scarcity areas where meeting water requirement is becoming a global threat. Weeds are another threat to yield of rice irrespective of different establishment methods. Until checked, it can decline rice yield and quality up to more than 70%. SRI and aerobic rice have different densities of weeds and integrated weed management can be applied to suppress the weeds. Considering the current scenario, research was conducted to investigate growth, yield and bioenergetics of rice under different establishment methods and weed management. Methods: The experiment entitled “Effect of crop establishment methods and weed management practices on productivity and bioenergetics of rice” was carried out in split plot design with main plots, viz., M1- aerobic rice (AR) and M2- system of rice intensification (SRI) and five subplots W1- pre-emergence (pendimethalin @1 kg a.i ha-1) fb post-emergence (bispyribac-sodium @20g a.i ha-1) (PE+POE), W2- pre-emergence (pendimethalin @1 kg a.i ha-1) fb cono weeding at 15, 30, and 45 DAT/ DAS (PE+CW), W3- weed free (WF), W4- weedy check (WC), W5- stale seedbed followed by post-emergence herbicide (bispyribac-sodium 10% SC 20 g a.i ha-1) (SSB+POE) in split plot design with three replications taking the variety ‘Pusa Basmati-1121’ as a test crop. Result: Among the establishment methods, SRI recorded significantly higher growth attributes like plant height and dry matter production and yield attributes like number of panicles per hill, panicle length, number of grains per panicle, test weight, grain yield, straw yield, biological yield, and harvest index. Among the weed management treatments, WF recorded significantly higher growth attributes like plant height, number of tillers per hill, dry matter production and yield attributes like number of panicles per hill, panicle length, number of grains per panicle, test weight, grain yield, straw yield, biological yield, and harvest index that was followed by treatment PE+CW. Maximum net return and B:C ratio was observed in the treatment combinations M2W2- SRI + (PE+CW). The maximum total energy input was found in the treatment combination M1W1- AR+ (PE+POE) and the maximum total energy output was found in the treatment combination M2W3- SRI + WF. The energy intensiveness was observed to be maximum in the treatment combination M1W4- AR + WC and the maximum energy efficiency index was observed in the treatment combination M2W3- SRI+WF.

Bioactivation of Legacy Phosphorus in Calcareous Soil by P-Activators and Its Effect on Maize Growth

ABSTRACT Soil legacy phosphorus (P) accumulated due to the long-term continuous application of P fertilizers in agricultural fields accumulated in the soil for years, as sparingly soluble forms. This can be made as a possible soil P source using P-activators. In this study, a laboratory incubation and a pot experiment were conducted to evaluate the potential of some P activators (Phosphorus solubilizing bacteria, phytase, humic acid, oxalic acid) in increasing the availability of residual phosphorus in calcareous soil. For the incubation experiment, the P activators were applied alone and in combination. Soil samples were analyzed at subsequent intervals for soil available P, alkaline phosphatase activity, and sequential P fractions. The results showed that phytase application with humic acid (HA) increased the available soil P (12.4 kg ha−1) and alkaline phosphatase activity (47.42 µg p-nitrophenol released g−1 soil hr−1) followed by phosphorus solubilizing Bacteria (PSB) with humic acid and PSB with phytase treatments. All treatments have a significant effect on different soil P-fractions. A greater reduction in calcium phosphate fraction was noted in phytase and humic acid application. The combined application of P-activators performed better than their sole application. The best three treatments selected from the laboratory incubated experiment were used for the pot experiment with maize, along with the different dosages of P fertilizer. The morphological parameters were observed on the 30th and 60th days of the maize crop. The results of plant height, chlorophyll index, and dry matter production showed that the application of phytase and HA with 100% recommended dose of P was statistically comparable with phytase and HA with 75% recommended dose of P. The findings have illustrated the extent of P release by different P activators in increasing the legacy P availability. The application of phytase and HA with 25% reduced dose of P fertilizers will promote the availability of legacy P in calcareous soils through solubilization.

Assessment of System of Mustard Intensification (SMI) with Plant Geometry and Age of the Seedlings in Enhancing Growth and Yield Attributes of Mustard (Brassica juncea L.)

The field experiment entitled “Assessment of system of mustard intensification (SMI) with plant geometry and age of the seedlings in enhancing growth and yield attributes of mustard (Brassica juncea L.)” was conducted at College Farm, Agricultural College, Polasa, Jagtial in Rabi, 2022. The experiment was laid out in randomized block design with eleven treatment combinations by replicating thrice. The treatment includes T1: Conventional sowing (dibbling) with spacing 45 x 15 cm without gap filling,T2: Conventional sowing (dibbling) with spacing 45 x 15 cm with gap filling, T3: 15 days old seedlings with spacing 30×30 cm, T4: 15 days old seedlings with spacing 45×45 cm, T5: 15 days old seedlings with spacing 60×60 cm, T6: 20 days old seedlings with spacing 30×30 cm, T7: 20 days old seedlings with spacing 45×45 cm, T8: 20 days old seedlings with spacing 60×60 cm, T9 : 25 days old seedlings with spacing 30×30 cm, T10 : 25 days old seedlings with spacing 45×45 cm, T11: 25 days old seedlings with spacing 60×60 cm. Thus from results obtained from present investigation it can be concluded that transplanting 25 days old seedling with 30 x 30 cm spacing under System of Mustard Intensification (SMI) resulted in higher plant height (182.5) and dry matter production (4660 kg ha-1) while Transplanting 25 days old seedling with 60×60 cm resulted in higher no. of primary and secondary branches plant-1(9.0 and 24.6), no. of siliqua plant-1 (656.3) and no. of seeds siliquae-1(14.7).

Performance Evaluation of a Cascade Cropping System

Minimum environmental impact and improved resource efficiency is attainable for soilless cascade systems where the nutrient solution drained from a primary (donor) crop is reused to fertigate a secondary (receiver) crop. However, it is not clear whether the nutrient solution drained from the primary crop can completely satisfy the needs of a secondary crop and if the productivity of the secondary crop is compromised. To test this hypothesis, a prototype soilless cascade system was developed and evaluated. To assess the performance of the system in terms of yield, water and nutrient productivity, a tomato crop was used as the primary crop, while lettuce, spinach and parsley were tested as secondary crops under different drainage management strategies. Measurements of plant growth, crop fresh and dry matter production, leaf chlorophyll and nutrient content, and photosynthesis rate were performed in the secondary crops. In addition, the water productivity and nutrient use efficiency for the fertigation of the primary and secondary crops were recorded. The results showed that the yield of the cascade spinach crop increased by up to 14% compared to the control treatment (monoculture of secondary crop fertigated by standard nutrient solution). The yield of the lettuce and parsley crop was not affected by the reuse of the tomato crop drainage solution. The water productivities of the lettuce, spinach and parsley plants fertigated with pure drainage solution were 50%, 30% and 14% higher than in the control treatment, respectively. The nitrogen and phosphorus use efficiency was improved by more than 50% compared to the control treatments.

Response of Lime and Phosphorus Application on Groundnut Growth, Yield and Soil Enzyme Activities in Acidic Soil of North Eastern India

ABSTRACT Soils in the north east Indian region are acidic in nature due to high rainfall and proper soil management is required where the common deficiencies like P, Ca and Mg have to be alleviated for a successful groundnut production. To test the effect of lime and phosphorus on groundnut yield and soil health, we conducted a field experiment during kharif season of 2014 and 2015 in ICAR RC NEH, Mizoram center farm (soil pH 5.1) using three levels of lime (0, 500 and 1000 kg CaCO3 ha‒ 1) and phosphorus (0, 25 and 50 kg ha‒ 1). Pooled data of lime and P application significantly improved the plant height and dry matter production per plant. Lime application improved number of pods by 14.8% and 26.1%, weight of pods by 19% and 30%, test weight by 5%, 8.7%, shelling percentage by 6.1%, 13% and pod yield by 26.5% and 63%. Lime application significantly raised the soil pH from 5.17 to 5.26 (L500) and 5.4 (L1000), subsequently increasing available nutrients like N, P and K whereas P @ 50 kg ha‒ 1 improved the available P status. Lime application negatively affect acid phosphatase activity while increasing the activity alkaline phosphatase, arylsulphatase, β‒glucosidase and dehydrogenase by 14.4% and 21%, 4% and 21%, 18.25% and 20.4% and 43.2% while P application decrease the acid phosphatase enzyme activity by 3 and 4.4%. Overall, multivariate PCA analysis suggests that liming has a significant role in improving soil health and groundnut productivity in acidic soil of Mizoram.

Growth and Yield of Rice as Influenced by Nitrogen and Water Management Approaches

Achieving sustainability of the rice production in the irrigated areas in eastern India in general and Odisha in particular, under progressive climate change and variability, necessitates adoption of practices and technologies that increase food production, adaptation and mitigation in a feasible way. A field experiment was carried out for two consecutive years during 2020-21 and 2021-22 with kharif rice in the research farm of OUAT, Bhubaneswar. The experiment was conducted in a strip plot design having four each of water and nitrogen management approaches replicated four times. All the growth attributes like plant height, tillers/hill, LAI and dry matter production were superior under 3DADPW and INM treatments in water and nitrogen management approaches, respectively. Rotational irrigation 3 DADPW in rice resulted in higher grain yield (5.28 t/ha) followed by soil saturation. Similarly, INM practices comprising of Green manuring + 75% STBNR produced higher grain yield (5.45 t/ha) as compared to other N-management options and was closely followed by STBNR.

Screening of Herbicides in Transplanted Finger Millet [Eleusine coracana (L.) Gaertn

Background: Weeds smother the finger millet due to crop’s slow growth during the initial stages which reduces the yield substantially by 5-70%. Intensive use of herbicides is gaining popularity among the farmers now a days due to its effectiveness in controlling weeds, timeliness and reduced cost. Methods: The current field experiment was conducted at Tamil Nadu Agricultural university during kharif season, 2021 under irrigated condition with twelve herbicide treatments laid out in Randomized Complete Block Design (RCBD) with three replications. Result: Pre-emergence application of pyrazosulfuron ethyl 15 g ha-1 significantly reduced the total weed density and total weed dry weight at 90 days after transplanting over all the other herbicides used. This treatment also considerably improved the plant parameters such as plant height, total number of tillers, plant dry matter production, Grain and stover yield and yield parameters such as productive tillers, ear head weight of transplanted finger millet which was statistically followed by the application of pendimethalin 750 g ha-1 as pre-emergent spray. Similar trend was followed in case of net returns and B: C ratio. while lower plant parameters were observed with the application of tembotrione 12 g ha-1.

Climate Smart Agriculture with Drought Resistant Tomato (Solanum lycopersicum) Cultivars under Subtropical Climate

Climate smart agriculture focus on crop production under climate stress. Climate change adaptation potential was investigated in medium textured soil to evaluate the drought/water stress effect on different cultivars of tomato. The imposed stress levels were 82 -100% (T0), 69-85% (T1), 53-67% (T2) and 40-50% (T3) of the FC (Field Capacity). In water stressed condition no significant influence was observed in production of plant dry matter and increased acids & soluble sugars and consequently improved the fruit quality. Water stresses did not show any significant effect on height, yield and increased in BR-5, probably due to its tolerance to water stress.
 Also, none of the stress- treated tomatoes showed deteriorated visual quality of the fruits and were red over 90%. No bruising and internal damages in tissues were detected due to stress. Water stresses enhanced the sweetness of the fruits by increasing their organic solute contents as glucose, fructose and sucrose contents and improved the quality by increasing the amount of important acids such as citric acid, malic acid and ascorbic acid, showed the adaptation responses of the crop to climatic stress due to conspicuous tendency of tomato plants to adjust osmotically against drought stress.

Weed management and fertilization limit the potential of cassava productivity in subtropical environment

The objectives of this study were to evaluate the response to fertilization and different weed control periods in the accumulation of dry matter of cassava leaves, stems, roots, and fresh mass roots yield. Two experiments were carried out on commercial fields in Ibarama, and Santa Maria municipalities located at the Rio Grande do Sul State, South Brazil, during the 2018/2019 growing season. Five treatments, varying chemical fertilizer applications and herbicides were used to represent management practices commonly used by farmers in Southern Brazil. The Simanihot process-based model simulated cassava growth, development, and productivity under potential conditions. Results show that the recommended dose of fertilizers and liming combined with pre-emergent herbicide and three mechanical weed clear management showed a 72% increase in root productivity compared to the management used by the average yield of smallholder farmers. Therefore, it is possible to reach 80% of the potential productivity by keeping the cassava crop free from weed interference and applying fertilizers. The presence of weeds during the first 100 days after planting reduced about 50% of the plant dry matter production in Ibarama and Santa Maria. Interestingly, it also affects 79.2% of fresh roots productivity in Ibarama. The objectives of this study were to evaluate the response to fertilization and different weed control periods in the accumulation of dry matter of cassava leaves, stems, roots, and fresh mass roots yield. Two experiments were carried out on commercial fields in Ibarama, and Santa Maria municipalities located at the Rio Grande do Sul State, South Brazil, during the 2018/2019 growing season. Five treatments, varying chemical fertilizer applications and herbicides were used to represent management practices commonly used by farmers in Southern Brazil. The Simanihot process-based model simulated cassava growth, development, and productivity under potential conditions. Results show that the recommended dose of fertilizers and liming combined with pre-emergent herbicide and three mechanical weed clear management showed a 72% increase in root productivity compared to the management used by the average yield of smallholder farmers. Therefore, it is possible to reach 80% of the potential productivity by keeping the cassava crop free from weed interference and applying fertilizers. The presence of weeds during the first 100 days after planting reduced about 50% of the plant dry matter production in Ibarama and Santa Maria. Interestingly, it also affects 79.2% of fresh roots productivity in Ibarama.

Effect of Sowing Windows and Nutrient Levels on Growth Parameters of Sunnhemp (Crotalaria juncea)

Sunnhemp is the important multifaceted legume crop which is used as fodder, fibre and green manure. While incorporation into the soil, it supplies Nitrogen, Phosphorous and Potassium at the level of 50-75 kgha-1, 15-20 kgha-1 and 40-65 kgha-1 respectively. In sunnhemp, the seed production was highly affected by improper agronomic management practices and less availability of quality seeds. Hence the present study was carried out to find the suitable agronomic practice for sunnhemp. A field experiment was conducted to study the suitable sowing windows and nutrient levels on growth parameters of sunnhemp during split-plot design with 12 treatments and replicated thrice. Three sowing dates were studied under main plots and four different nutrient levels under sub plot. Growth attributes such as plant height, leaf area index and dry matter production were recorded. From the above study, it is concluded that delayed sowing on February 2nd week and the application of nutrients at 30:60:30 NPK kg ha-1 recorded higher plant height and dry matter production at harvest over other treatments.

The relationships between maize (Zea mays L.) lodging resistance and yield formation depend on dry matter allocation to ear and stem

Lodging is a critical constraint to yield increase. There appear to be tradeoffs between yield formation and lodging resistance in maize. Hypothetically, it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments. A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018–2020. Lodging-susceptible (LS) cultivars on average yielded more than lodging-resistant (LR) cultivars when lodging was not present. The yield components kernel number per ear (KN) and thousand-kernel weight (TKW) were both negatively correlated with lodging resistance traits (stalk bending strength, rind penetration strength, and dry matter weight per internode length). Before silking, the LR cultivar Lishou 1 (LS1) transported more assimilates to the basal stem, resulting in a thicker basal stem, which reduced dry matter allocation to the ear and in turn KN. The lower KN of LS1 was also due partly to the lower plant height (PH), which increased lodging resistance but limited plant dry matter production. In contrast, the LS cultivars Xianyu 335 (XY335) and Xundan 20 (XD20) produced and allocated more photoassimilates to ears, but limited dry matter allocation to stems. After silking, LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear. The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height (EH). High-yielding and high-LR traits of Fumin (FM985) were related to optimized EH and stem anatomical structure, higher leaf productivity, low assimilate demand for kernel formation, and assimilate partitioning to ear. A high pre-silking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength. Post-silking temperature influences lodging resistance and yield more than other environmental factors. These results will be useful in understanding the tradeoffs between KN, KW, and LR in maize and environmental influences on these tradeoffs.

Effect of seedling age on productivity and profitability in traditional rice landraces

A field experiment was conducted at Tamil Nadu Agricultural University, with an objective to study the effect of seedling age on productivity and profitability in rice landraces under irrigated rice ecosystem. The experiment was laid out in split plot design with three replications. The treatments in main plot were three age of seedlings viz., 15, 20 and 25 days old seedlings and in sub plot eight rice landraces viz., Chandikar, Kuliyadichan, Kuruvaikalanjiyam, Norungan, Nootripathu, Black Kavuni, Red Kavuni, Njavara and CO(R) 50 (one high yielding variety). Observations were recorded on growth parameters such as plant height, tiller numbers and dry matter production. The yield attributes like productive tillers, total spikelet, filled grains, unfilled grains, spikelet sterility percentage, thousand grain weight, grain yield and straw yield were recorded at the time of harvest. From the study it was observed that 15 days old seedlings in all the eight rice landraces and one high yielding variety, recorded higher growth and yield attributes. In rice landraces, Red Kavuni recorded higher grain, straw yield and B:C ratio. Based on quality parameters, CO(R) 50 rice variety and landraces viz., Red Kavuni, Black Kavuni, Nootripathu, Chandikar recorded optimum values and were suitable for cooking purpose.

Effect of Nitrogen and Silica on Growth and Yield of Paddy (Oryza sativa L.) Variety CO 51

World agriculture is facing increasing demand due to multiple challenges. The biggest challenge is to attain food security in the ever increasing growing population. Rice (Oryza sativa L.) is a staple food crop for half of the world's population and one of the world's most significant food crops. Farmers must produce more rice with enhanced quality in order to ensure food security in rice-consuming countries across the world. Rice (Oryza sativa L.) is considered to be a Si accumulator plant and tends to actively accumulate Si into tissue up to concentrations of 5% or even higher. The present study aimed to use different forms of N and Si sources at different levels to improve the growth traits contributing to the increase yield of rice. A pot experiment was conducted in glasshouse, TNAU, Coimbatore to assess the response of nitrogen and silica on paddy during October 2020 – January, 2021. The treatments comprised of the two factors, nitrogen and silica with three replications. The growth parameters like plant height, number of tillers per plant and total dry matter production were recorded at all stages and yield traits at harvest stage. The treatment, T11 - N2S2 (53.4 and 110.2 g pot-1 respectively) significantly enhanced the grain yield (34%) and straw yield (40%) than control in the pot experiment. Highest growth and yield parameters were recorded with application of combined fertilization of nitrogen and silica (T11-N2S2) which comprises150 kg ha-1of urea and 200 kg ha-1 of calcium silicate compared to control.

Screening for Drought Tolerance through Root Morphology and Yield Characters of Groundnut (Arachis hypogaea L.) Genotypes

Drought affects the rainfed groundnut (Arachis hypogaea L.) at different phases of development and it is the serious threats on groundnut productivity causing losses than any other abiotic factor under rainfed agriculture. In the world's semiarid regions, groundnut accounts for 90% of worldwide production. Drought mainly affects the pace and pattern of nutrient and water intake from the soil, affecting the architecture of the groundnut root system. Plant selections with desirable root trait have been a major focus in developing drought resistant Groundnut cultivars. In 2019, 60 groundnut genotypes were cultivated in root block design with two different soil water treatments, as well as in the field during the year under same circumstances. The purpose of this study was to see how different groundnut cultivars fared in terms of yield, yield contributing features, root characters, and their relationships with drought tolerance. Drought resistant genotypes had thicker roots, larger roots, and a deeper root system than susceptible genotypes. Recent series in groundnut genotypes of 60 numbers were sown during kharif 2019 (july-september) under rainfed condition (It includes life irrigation and rainfall received during cropping season). Groundnut genotypes were semi spreading with the duration of 110-120 days. Observation on root morphological character viz., roots length, root volume after 20 days of stress imposition of the crop and yield parameters were observed at the harvest. Among the 60 genotypes, 20 genotypes (VG 17008, VG 17046, VG 18005, VG 18102, VG 18077, VG 19572, VG 19709, VG 18111, VG19561, VG19576, VG 19620, VG 19681, VG 19688 etc.,) similarly, yield character were observed for 60 genotypes and all the genotypes given above recorded higher value in Total number of pods per plant, Number of double seeded pods per plant, Pod yield per plant, Harvest index and Total dry matter production. The methods used in this study identified correlation between yield character and root characters. Groundnut genotypes by assessing yield metrics and their relationship with root trait. These findings lay the groundwork for future study aimed at deciphering the molecular pathways underpinning Groundnut drought resistance.

Grain Yield, Nutrient Uptake and Post-harvest Soil Properties of Browntop Millet under Varying Sowing Windows and Nitrogen levels

A field experiment was conducted during rainy season (June to October, 2019) at College of Agriculture, Rajendranagar, Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad, Telangana State, India to find the effect of sowing windows and nitrogen levels on yield, nutrient uptake and post-harvest soil nutrient status of browntop millet. The experiment was laid out in randomized block design with factorial concept and replicated thrice. Treatments consisted of four sowing windows (June 15th, June 30th, July 15th and July 30th) and four nitrogen levels (0, 20, 40 and 60 kg ha-1). Among sowing windows, June 15th recorded higher growth parameters (plant height, leaf area and dry matter production), yield attributes (panicles hill-1, panicle length, weight and grains panicle-1) grain, straw yield, monetary returns and nutrient uptake at harvest (nitrogen, phosphorus and potassium). Post-harvest soil properties (pH, electrical conductivity, organic carbon content, available P and K) were not significantly influenced by sowing windows, but available soil nitrogen was significantly higher with June 15th sowing. Among nitrogen levels, application of 60 kg ha-1 recorded significantly higher growth parameters (plant height, leaf area and dry matter production), yield attributes (panicles hill-1, panicle length, weight and grains panicle-1), grain, straw yield, monetary returns and nutrient uptake at harvest (nitrogen, phosphorus and potassium) but, it was comparable with 40 kg ha-1. Varying nitrogen levels did not significantly influence post-harvest soil properties (pH, electrical conductivity and organic carbon content, available P and K); however, available soil N was significantly higher with the application of 40 kg ha-1.

Excess ammonium causes toxicity in watermelon and cucumber plants grown in nutrient solution

Excess nitrogen (N) in the form of ammonium (NH 4 + ) in the culture medium can induce ammonium toxicity, causing physiological disturbances in plants and resulting in impaired growth and dry matter production. Thus, the aim of this study is to evaluate the growth and dry matter production of watermelon and cucumber plants grown under different nitrogen concentrations in the ammoniacal form and in nutrient solution. The experiment was carried out at the Department of Plant Science located at the Center for Agricultural Sciences, Federal University of Piaui, during the period from October to November 2017. Two cucurbit species, watermelon and cucumber, were studied separately for each experiment using a completely randomized design, with four replicates and five treatments, corresponding to the following ammonium concentrations: 0.5; 2.2; 4.5; 8.7; and 14.0 mmol L -1 NH 4 + . Twenty-one days after transplanting the watermelon and cucumber seedlings, the following variables were analyzed: leaf area, leaf chlorophyll index, plant height, stem diameter, root volume, root length, root dry matter, and shoot dry matter. Excess ammonium in the nutrient solution causes toxicity in watermelon and cucumber plants, decreasing plant growth and dry matter production. Symptoms of ammonium toxicity are more evident in the cucumber plant, which presented chlorosis and necrosis followed by plant death after 15 days of cultivation.