<div>Background: Maharashtra ranks first in onion (Allium cepa L.) production with a share of 28.32%. However, the productivity of onion is low as compared to other countries. In order to enhance onion productivity, new and innovative agri-inputs are being tried continuously like providing humic acid, fulvic acid, plant growth regulators (PGR), auxin/amino acid spray, seaweed extract, biofertilizers, sulphur application etc. PGRs are considered to be one of the novel inputs that can help in increasing the productivity of onion in India economically. Plant growth regulators are considered as a new generation of agrochemicals when added in small amounts, modify the growth of the plants usually by stimulation or modifying one part of natural growth regulatory system, thereby increasing the crop yield. Most of the research data available is based on biochemical, seaweeds etc. Almost negligible literature is available pertaining to a PGR made with formulation of Seaweed extract and Protein Hydrolysate. An attempt has been made in this research work to evaluate the effect of PGR formulated with seaweed extract and Protein Hydrolysate as major constituents on onion bulb yield through both foliar and drenching application. 
 
Methods: A field experiment for evaluating the effect of plant growth regulator (PGR) formulated by Research and Development Department, M/s Rashtriya Chemicals and Fertilizers Limited was conducted at Chilli and Vegetable Research Farm, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (MH). During the experiment, the effect of different concentration of PGR viz., 0.2%, 0.4%, 0.6% and 0.8% and 1.0%, 1.2%, 1.4% and 1.6% through foliar and drenching application, respectively were studied. 
 
Result: Statistically, significant results of plant growth regulator application on vegetative growth, yield and qualitative characters of onion crop were observed. Significantly, maximum bulb yield was observed in the treatment PGR @ 0.6% (255.41 kg/ha) through foliar application which is at par with the treatment PGR @ 1.4% (246.67 kg/ha) through soil drenching along with RDF. According to the results, the suitable PGR dose for studied characters of onion under prevailing conditions was 0.6% foliar spray and 1.4% soil drenching along with recommended dose of fertilizers.</div>

​Response of Plant Growth Regulator on Bulb Yield of Onion (Allium cepa L.)

<div style="text-align:justify">Background: Onion (Allium cepa L.) is a major bulbous vegetable as well as condiment of family Alliaceae grown in India, originated in Iran and Pakistan. Seed pelleting is a mechanism of applying various materials to the seed that can enhance the seed quality with respect to physiological, physical and health attributes. Seed pelleting make it easy to handle small and irregular shaped seeds. Methods: The present investigation was conducted in the field of Department of Seed Science and Technology, Dr. Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan during seasons of 2016-17 and 2017-18.&nbsp; Result: This experiment comprised of pelleted seeds with different botanicals carried out to determine the effect of sowing dates and seed pelleting and their interactions on plant growth, yield and quality of bulb crop. All the factors in the experiment as well as their interactions showed significant influence on plant growth, yield and yield contributing characters in onion. The seeds pelleted with Azadirechta indica leaf powder + clay and Melia azedarach &nbsp;leaf powder + clay sown directly showed maximum values w.r.t. emergence (91.50 %), plant height at 60 days after sowing (35.35 cm), average leaf length (38.43cm), number of leaves per plant (8.67), number of days to harvesting (233.49),&nbsp;polar diameter (46.72 mm), equatorial diameter (57.77 mm), bulb size index (2699.74 ), neck thickness (12.12 mm), number of bulb per plot (89.00) average bulb weight (75.24 g), bulb yield (6.67 kg per plot or 400.01 q per ha), plant height before neck fall stage (58.55 cm). From the present studies, it can be concluded that onion seeds pelleted with Azadirechta indica leaf powder + clay and Melia azedarach leaf powder + clay showed significant effects for enhancing bulb quality, growth, quality and yield of bulb crop raised through direct seeding.</div>

<div style="text-align: justify;">Effect of Sowing Dates and Botanical Seed Pelleting on Plant Growth, Bulb Yield and Quality of Onion (Allium cepa L.)</div>

Background: In Ethiopia, onion (Allium Cepa L.) is a major vegetable crop. However, due to erratic cultivation, rising mineral fertilizer prices and inadequate soil fertility management, its productivity is declining. Integrated nutrient management is a cost-effective approach to fertilizing soil. If used properly, the combination of vermicomposting with mineral fertilizers is one of the most promising options. Nonetheless, in the study areas, the appropriate application rate of vermicompost and NPSZn fertilizer on onion production has not been well examined. 
 
Methods: A field experiment was conducted in the irrigated soil conditions of Kilte-Awulaelo and Raya Azobo districts. The study used a randomized complete block design with three replications and twelve experimental treatments (4.5, 3 and 1.5 t ha-1&nbsp;vermicompost rates combined with NPSZn 75, 50 and 25 kg ha-1).&nbsp; Full recommended 6 t ha-1&nbsp;vermicompost, 100 kg ha-1&nbsp;NPSZn fertilizer and absolute control were used. The collected agronomic data were subjected to ANOVA using SAS statistical software (SAS 9.0) and mean separation was done using LSD. 
 
Result: Most of the measured onion growth and yield parameters were significantly affected by the joint application of vermicompost and NPSZn. It varies among districts. Maximum bulb yields of 51.2 t ha-1&nbsp;in Kilte-Awulaelo and 42.5 t ha-1&nbsp;in Raya Azobo district were obtained from the application of 4.5 t ha-1&nbsp;vermicompost with 50 kg ha-1&nbsp;NPSZn and 4.5 t ha-1&nbsp;vermicompost with 75 kg ha-1&nbsp;NPSZn respectively. The combined application of vermicompost with NPSZn fertilizer enhanced onion growth and yield.

Response of Onion (Allium cepa L.) Bulb to the Combined Effect of Vermicompost and Mineral Fertilizer under Irrigated Soil Condition in Raya Azobo and Kilte-Awulaelo Districts South and Eastern Tigray, Ethiopia

The bulbous vegetable onion Allium cepa Var. aggregatum L. (2n=16) is the most important species of Allium group and is regarded as the single most important vegetable spices as it forms an indispensable part of many diets, both vegetarian and non-vegetarian. Onion is valued for its bulbs having characteristic odour, flavor and pungency. Onion is regarded as a highly export oriented crop and earns a valuable foreign exchange for the country. Weeds are of great menace as they interfere with production of crop and add to the cost of cultivation. The reduction in crop yield has direct correlation with weed competition. Onion exhibits greater susceptibility to weed competition as compared to other crops due to its inherent characteristics such as their slow growth, small stature, shallow roots and lack of dense foliage. The effective weed control involves identification of weed flora, method of weed control and judicious combination of effective weed control methods. Hand weeding in onion is a common practice in India, but it is a tedious, expensive and time consuming task due to closer spacing and shallow root system. Non-availability of labourers during critical period of crop makes hand weeding difficult leading to heavy yield losses. Spraying of pre-emergence herbicides keeps the crop in weed free conditions during the early stages. At later stage, second flush of weeds will affect the bulb formation. Hand weeding helps to keep the weed population below economic threshold level throughout the crop growth period. Pre-emergence combined with hand weeding may be costly because of the reduced labour availability and higher labour cost. After bulb formation manual or mechanical methods of weed control will damage the bulb. Application of early post emergence may be helpful to reduce damage to the bulb, weed competition and cost of weeding. Hence a brief review was presented to find out the effect of different weed management method in onion.

Weed management in onion: A review

<div>Background: Onion (Allium cepa L.) is an important and indispensable item of every kitchen. It is used as a vegetable, spice and condiment and commands an extensive internal market. Even though onion is one of the major crops in India, its cultivation is not yet popular in Kerala. Successful onion production depends on the selection of varieties that are adapted to different conditions imposed by specific environment and best planting time. In this background, the current study aimed to evaluate five onion varieties in the tropical planes of Kerala and also to study the effect of different planting time and varieties on the performance of onion in Kerala. 
 
Methods: Five onion varieties were evaluated in four different dates of planting with an interval of fifteen days. Planting commenced from 10th November to 25th December 2017 in a split plot design with four replications. Yield attributing characters such as number of leaves per plant, leaf length, bolting percentage, neck thickness, bulb weight and yield were noted. 
&nbsp; 
Result: All the parameters showed a significant variation over different dates of planting. There was a significant variation in number of leaves per plant, leaf length, bolting percentage, total bulb yield and neck thickness among the varieties. Interaction effect of varieties and dates of planting was significant only for leaf length and total bulb yield. Highest bulb weight was recorded in 25th Nov. planting. Highest yield was recorded in 25th Nov. which was on par with 10th Dec. and 10th Nov. plantings. Arka Kalyan recorded a highest yield, which was statistically on par with Agrifound Dark Red and Arka Pragati. Varieties when planted on 25th Dec. recorded a lowest neck thickness. Agrifound White exhibited a non-bolting behavior in all the dates of planting. Overall performance and yield of onion was found to be better when planting was done on 25th November.</div>

<div>Effect of Varieties and Planting Time on the Performance of Onion under Tropical Planes of Kerala</div>

Genetic variability, correlation coefficient and path coefficient were studied in onion involving 23 genotypes. High estimates of PCV were recorded in marketable bulb yield, total bulb yield, collar height and average bulb weight. While, GCV were highest in marketable bulb yield and total bulb yield. High heritability coupled with high genetic advance as per cent of mean were observed for total bulb yield, marketable bulb yield, average bulb weight and collar height. Correlation coefficient analysis revealed that total bulb yield had positive significant correlation with number of leaves/plant, plant height, collar height, polar and equatorial diameter of bulb, average bulb weight and marketable bulb yield. Path coefficient analysis revealed that number of leaves/plant, plant height, leaf thickness, TSS, polar and equatorial diameter of bulb, average bulb weight and marketable bulb yield exhibited positive direct effect on total bulb yield. In addition to this, neck thickness, collar height and leaf length showed negative direct effect on total bulb yield at phenotypic levels and could be utilized as selection criteria in onion improvement programme for Chhattisgarh plains.

GENETIC VARIABILITY, CORRELATION AND PATH COEFFICIENT ANALYSIS OF DIFFERENT KHARIF ONION GENOTYPES IN CHHATTISGARH PLAINS

<div style="text-align: justify;">India is the second largest producer of onion in the world next after China. Mechanization of farming is increasing day by day to produce yield of crop for gaining the profit. This study was related to the development of an onion bulblet planter for vertisol. The development and fabrication of different furrow opener for matching to the existing inclined plate metering device for planting of onion bulblet. The performance of onion bulblet planter in term of depth and width of planting, missing index percentage, multiple percentage, seed damage , actual field capacity and field efficiency. The result indicated that the field efficiency was maximum 83.33% with minimum seed damage 10.2%. Multiple index was 5.1%, missing index was 2.2 % and bulb to bulb spacing was 10.66 cm in chisel type furrow opener at 1.8 km/h speed with moisture content 17.2 %.&nbsp;</div>

Development and performance evaluation of an onion bulblet planter for vertisol

<div style="text-align: justify;">Onion (Allium cepa L.) is one of the most important bulb crops in India, which plays a major role in supplementing the income of small and marginal farmers of Sikar District in Rajasthan. In the district one of the major constraints in onion cultivation is poor keeping quality of local variety. Most of the farmers in the district are still using the locally self produced seeds of unknown source. The cultivation of recommended /released varieties is very limited. To replace this anomaly Krishi Vigyan Kendra, Fatehpur-Shekhawati, Sikar has introduced improved variety of onion through front line demonstration in selected villages of Sikar district with the objective of getting higher production with good storage potentials under real farm situation. The result showed that maximum TSS (13.1%) and average keeping quality (5-6 months) was recorded in demonstration variety whereas, it was very less in farmers practices. On an average the bulb yield achieved by adopting improved production technology was 347.62q/ha, whereas, the corresponding yield ranges under farmers practices was to 343.20q/ha. The economics of data indicated that an average of Rs. 160834/ha was recorded net profit under recommended practices, while it was Rs 62030/ha under farmer practices. Cost benefit ratio was 2.34 under demonstration, while it was 1.90 under farmer practices. The study suggests that front line demonstration is one of the key extension tools for transfer of technology at grass root level that directly impact the horizontal spread of technology. This can be also a good option for enhancing farmers&rsquo; income.</div>

<div style="text-align: justify;">Impact of front line demonstration on yield and economics of onion</div>

<div>Background:&nbsp;Onion is a widely accepted as vegetable as well as spice crop, sharing a 14.31 lakh ha area with 267.3 lakh MT production in 2020. Improved management structure and healthy seedling are important factors in overcoming the cause and even developing effective transplanter. The information of morphological properties is essential before designing modern farming equipment. 
 
Methods: Present study focuses on the properties and age of seedlings for automated transplanting, five majorly cultivated varieties of onion Light red gavran, N-53 Nasik red, AFDR, KSP-117 and Nafed were selected. The morphological (height, weight, diameter) and mechanical (compressive strength and static coefficient of friction) properties were measured under 10 days intervals to compare 30-70 days seedling. 
 
Result: Bulb and stem diameter were in the range from 2.82 to 3.82 mm and 0.86 to 2.12 mm, respectively. The model was found significantly different with concerning days. Plywood and aluminium had less influence on the seedling&rsquo;s outer surface moisture content. The morphological parameters and compressive strength increased while a static coefficient of friction reduced with an increase in the age of the seedling. Regression and ANN (using FFBP method) models were developed for the prediction of compressive strength of seedling stem as well as a bulb with respect to the age and diameter. The ANN model was found best with the coefficient of determination of 0.76. It is concluded that 60 and 70 days, seedling is best suited for mechanical or automated transplanting.</div>

Morphological and Mechanical Characteristics of Onion Seedlings Insight to Mechanized Transplantation

<div style="text-align: justify;">To investigate the effect of planting methods and irrigation levels on irrigation water productivity and onion (Allium cepa L.) yield, a field experiment was conducted on sandy loam soil at the Research Farm of Department of Soil Science, Punjab Agricultural University, Ludhiana during rabi 2011-12. Three planting methods tested include drip irrigated beds, furrow irrigated beds and flat flood irrigation. In drip irrigated beds and furrow irrigated beds three onion rows were planted on 55 cm wide beds at a spacing of 15 cm from row to row. Three levels of irrigation water were tested i.e. IW/PAN-E ratio of 0.3, 0.4 and 0.5 in drip irrigated onions and 1.2, 1.6 and 2.0 in both bed furrow and flat flood methods of irrigation. The results of the experiment indicated that in drip irrigated beds by applying same quantity and 50 per cent of water as of flat flood irrigation, the yield was increased by 43 and 25 per cent, respectively. Irrespective of irrigation levels, highest onion yield (32.5 t ha-1) was recorded under drip irrigated beds followed by furrow irrigated beds (28.5 t ha-1) and least under flat flood irrigation method (25.0 t ha-1). The onion yield increases with the increase in irrigation level in all the planting methods. The highest irrigation water productivity was observed under drip irrigated beds (1.26 t ha-1 cm) followed by furrow irrigated beds (0.84 t ha-1 cm) and least under flat flood irrigation (0.48 t ha-1 cm) with equivalent IW/PAN-E ratios. Bigger size onions (40 mm and 50 mm) were observed under drip irrigated beds followed by furrow irrigated beds and smallest size bulbs under flat flood method of irrigation. The results revealed that drip irrigation could successfully be used for onion production with significant water saving and higher production. &nbsp;</div>