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Open Access
Standardisation of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)].
(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ajmal Fayique, C; KAU; Usha C, Thomas
The study entitled “Standardization of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)]” was conducted at College of Agriculture, Vellayani, Kerala during Kharif 2017 to standardize the spacing and nutrient requirement of fodder rice bean and to study its impact on growth, yield and quality of the crop. The experiment was laid out in Randomised Block Design (33 confounded factorial) with three replications.The treatments consisted of three spacings (s1 - 30 cm x 10 cm, s2 - 30 cm x 20 cm and s3 - 30 cm x 30 cm), three levels of nitrogen (n0 - 0 kg ha-1, n1 - 20 kg ha-1 and n2 - 30 kg ha-1) and three levels of phosphorous (p0 - 0 kg P2O5 ha-1, p1 - 20 kg P2O5 ha-1 and p2 - 40 kg P2O5 ha-1) . FYM @ 5 t ha-1 and K2O @ 30 kg ha-1 were applied uniformly to all treatments as basal. The treatment s1 resulted in the highest plant height at 30 DAS and leaf: stem ratio at harvest. Application of N @ 20 kg ha-1 registered the highest plant height and was on par with 30 kg N (n2) while leaf stem ratio was the highest at n2. Levels of P had no significant impact on growth characters. The treatment combination s2n2p1 produced the tallest plants (173.17 cm) at harvest and treatments s1n0p1 and s1n2p2 recorded the highest leaf: stem ratio (0.82) but were on par with s1n0p0, s2n0p0, s n0p2, s1n1p0, s2n0p2 and s3n0p1. At 30 DAS, s1 produced the highest LAI (2.27) while at harvest, s2 was found superior. The highest NAR was observed at s1 and was on par with s3. Closer spacing (s1) enhanced the CGR at 30 DAS and harvest. Application of 30 kg N ha-1 (n2) enhanced LAI at both stages. At 30 DAS and at harvest, higher NAR were observed at n1 and n2. At 30 DAS, n2 and p1 registered the highest chlorophyll contents. The treatment s1 n2 p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1) resulted in the highest LAI, CGR and chlorophyll content at 30 DAS. Spacing and N levels had significant impact on green fodder yield (GFY) and dry fodder yield (DFY). The highest GFY (12.95 t ha-1) and DFY (2.59 t ha-1) were produced at s1 (30 cm x 10 cm) and was on par with s2. The highest GFY (13.66 t ha-1) and DFY (2.73 t ha-1) were produced at n2 (30 kg N ha-1) and was on par with n1. The S x N x P interaction s1 n2 p1 (30 cm x 10 cm + 30 kg N ha-1 + 20 kg P2O5 ha-1) recorded highest GFY (17.29 t ha-1) and DFY (3.46 t ha-1). The different spacing had no impact on crude protein (CP) but the lowest crude fibre (CF) was observed at s1. Application of 30 kg N ha-1 (n2) resulted in the highest CP content and the lowest CF content was estimated at 0 kg N ha-1. Among P levels, p2 recorded the highest CP (17.69%) and was on par with p1. The lowest CF (16.43 %) was observed at s2n0p1 (30 cm x 20 cm spacing + 20 kg P205 ha-1) and was on par with s1n0p0, s1n0p1, s1n2p0, s2n0p0, s2n0p2, s3n0p0 and s3n0p1. No variation in N uptake was observed due to treatments. Uptake of P varied with N levels only and n1 and n2 recorded the highest P uptake. Spacing and P levels influenced K uptake by the crop and the highest uptake was observed at s1 and p2 but p2 was on par with p1. The three factor interaction s1n2p1 registered the highest P and K uptake. However, it was on par with s1n1p2, s1n1p0, s2n1p1 and s3n0p2 in P uptake and with s1n2p2 in K uptake. Increasing N levels increased pH and EC of soil after the experiment. Soil available N after the experiment was the highest at s3 (on par with s2) and n2 (on par with n1). At wider spacing, application of N enhanced the availability of N in the soil after the experiment. Available P in the soil varied with S x P interaction but all treatment combinations were on par except s2p0 and s3p2. The highest soil available K was observed at n0 among N levels and at p1 among P levels. The interactions S x N, S x P and N x P significantly influenced available K in the soil. Economic analysis revealed the highest net income (₹ 35762) and BC ratio (3.22) at s1n2p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1). From the study, it can be concluded that fodder rice bean can be profitably cultivated at a spacing of 30 cm x 10 cm with application of 30 kg N ha -1 in two splits at 15 and 30 DAS and basal application of 20 kg P2O5 ha-1, 5 t ha-1 of FYM and 30 kg K2O ha-1.
Open Access
Customized fertilizer and nutrient scheduling for okra (abelmoschus esculentus (L.) moench)
(Department of Agronomy, College of Horticulture, Vellanikkara, 2016) Yansin, Luikham; KAU; Anitha, S
Multinutrient deficiencies in soil are common nowadays due to imbalanced use and extensive mining of nutrients, which have also led to the decline of soil and crop productivity over time. Customized fertilizers (CF), which are multinutrient carriers facilitating the supply of complete range of nutrients in right proportion for the crop grown in a particular soil, have come up as an alternative to tide over these problems. Scheduling of nutrients by split application promotes efficient utilization of nutrients in a need based manner and helps to reduce nutrient losses from the soil. An investigation entitled “customized fertilizer and nutrient scheduling for okra (Abelmoschus esculentus (L.) Moench)” was carried out at the Water Management Research Unit, Vellanikkara, Thrissur from May to September, 2015 with the objective of developing a customized fertilizer and studying its techno- economic feasibility and nutrient scheduling in okra. The investigation consisted of 12 treatments viz., FYM + 75% CF (2 splits at 30 days interval), FYM + 75% CF (4 splits at 15 days interval), FYM + 100% CF (2 splits at 30 days interval), FYM + 100% CF (4 splits at 15 days interval), FYM + 125% CF (2 splits at 30 days interval), FYM + 125% CF (4 splits at 15 days interval), FYM + soil test based NPK application (N & K as 2 splits at 30 days interval), FYM + soil test based NPK application (N & K as 4 splits at 15 days interval), FYM + NPK as per POP (N & K as 2 splits at 30 days interval), FYM + NPK as per POP (N & K as 4 splits at 15 days interval), FYM alone based on N recommendation of POP (2 splits at 30 days interval) and absolute control. Biometric observations were recorded and nutrient contents and uptake were estimated at 30 DAS, 60 DAS and 90 DAS. A customized fertilizer grade was developed based on the initial analysis of macro and micronutrient contents of soil and nutrient requirement of okra. Water soluble fertilizers and straight fertilizers were used for the preparation of CF. Based on the soil fertility rating and nutrient recommendation for okra, the actual nutrients needed for the experimental site was worked out in kg ha-1 as 59N: 9P: 34K: 16Mg: 1B. Based on this, CF grade 22.01N: 3.35 P: 12.68K: 5.97Mg: 0.37B was developed. The study revealed that application of 125 per cent CF either as two or four splits was equally effective and recorded the highest yield compared to lower doses of CF and other nutrient management practices. Application of 125 per cent CF resulted in a yield increase of 32.11 per cent, 35.16 per cent and 49.84 per cent compared to soil test based application, application of nutrients at recommended dose and application of FYM alone respectively. Application of 100 per cent CF recorded higher yield compared to nutrient application based on soil test based NPK and NPK as per POP. The yield increase in 125 per cent CF was due to the better development of growth and yield parameters and higher nutrient uptake including that of Mg and B in customized fertilizer doses. The lower doses of CF (75%) performed equally well as soil test based NPK and NPK as per POP with respect to yield. The combined application of fertilizers along with FYM gave better yield than application of FYM alone as a source of nutrients. Faster delivery of nutrients could be achieved through fertilizers since FYM alone could not meet the huge requirement of nutrients by okra. In this study, application of CF and other fertilizers in more splits did not show significant increase in yield of okra. Application of CF showed a positive effect on the soil fertility status except for nitrogen. The improvement in nutrient status could be attributed to application of optimum dose of CF along with FYM to maintain adequate supply of nutrients. The application of higher levels of CF was cost effective and economically beneficial due to higher yield despite increased cost of cultivation owing to higher cost of inputs. Nutrient application in lower splits was more economical due to reduced labour. The study indicated that application of multinutrient carriers such as customized fertilizers are a technologically and economically viable practice for increasing soil and crop productivity. The quantities of NPK required as CF are much lower than the POP recommendations, and therefore fertilizer doses can be reduced substantially.
Open Access
Weed management in upland rice (Oryza sativa L.) intercropped in coconut
(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ravikiran; KAU; Elizebeth Syriac, K
The investigation entitled “Weed management in upland rice (Oryza sativa L.) intercropped in coconut” was undertaken during the period, 2017 - 2018 at College of Agriculture, Vellayani, Thiruvananthapuram to standardise an eco-friendly and economic weed management strategy for upland rice intercropped in coconut. The field experiment was carried out at Coconut Research Station, Balaramapuram, Thiruvananthapuram district during the period from June to October 2017. The variety used was Prathyasa (MO-21) released from Rice Research Station, Moncompu. The experiment was laid out in randomized block design (factorial) with sixteen treatment combinations and three replications. The treatments consisted of two stale seedbed methods viz., stale seedbed with mechanical removal of weeds (s1) and no stale seedbed (s2) and eight weed management methods i.e., penoxsulam @ 20 g ha-1 at 10-15 days after sowing (DAS) fb hand weeding (HW) at 35-40 DAS (m1), penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2), penoxsulam @ 30 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m3), penoxsulam @ 20 g ha-1 at 10-15 DAS fb metsulfuron methyl + chlorimuron ethyl (MM+CE) @ 4 g ha-1 at 35-40 DAS (m4), penoxsulam @ 25 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m5), penoxsulam @ 30 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m6), HW twice at 15 and 35 DAS (m7) and weedy check (m8). Study of the weed flora of experimental area indicated the dominance of broad leaved weeds (eight spp.) followed by grasses (six spp.) and sedges (two spp.). Stale seedbed method (s1) recorded significantly lower weed density at all stages of observations (15, 30 and 60 DAS), weed dry weight at 15 and 30 DAS and higher weed control efficiency (WCE) at 30 and 60 DAS compared to no stale seedbed. Among the weed management methods, at 60 DAS, all the penoxsulam doses i.e., 20, 25 and 30 g ha-1 at 10-15 DAS fb either HW at 35-40 DAS or MM+CE at 35-40 DAS (m 6, m4, m3, m5, m1 and m2) were on par in their effect on total weed dry weight and WCE. Stale seedbed method (s1) registered significantly higher plant height at 60 DAS, number of tillers m-2 at 30 DAS and at harvest, dry matter production at harvest and LAI at 60 DAS compared to no stale seedbed (s2). Penoxsulam at different doses fb HW treatments (m 1, m2 and m3) recorded higher plant height at 30 and 60 DAS and at harvest, number of tillers m-2 at 30 DAS, DMP at harvest and LAI at 30 DAS. None of the herbicide treated plots showed any phytotoxicity symptom on rice crop. The yield attributes viz., number of spikelets panicle-1, per cent filled grains and thousand grain weight were significantly higher for stale seedbed, compared to no stale seedbed (s2). Weed management methods also significantly improved yield attributes viz., panilces m-2, spikelets panicles-1, per cent filled grains and thousand grain weight compared to weedy check treatment. Penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest values for per cent filled grains and thousand grain weight. Stale seedbed method (s1) recorded significantly higher grain yield, straw yield and lower weed index compared to no stale seedbed method (s 2). Though penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest grain yield (3.23 t ha-1), it was on par with the other penoxsulam fb HW treatments viz., m1 and m3. None of the s x m interactions were found statistically significant. Regarding weed index also m2 registered the lowest value and it was significantly superior to all other weed management methods. Higher net income (₹ 27, 848/-) and B:C ratio (1.48) were obtained with stale seedbed method (s1), compared to no stale seedbed (s2). Application of penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest net income (₹ 36,090/-) and B: C ratio (1.63). The s1m2 registered the highest net income (₹ 44,433/-) and B: C ratio (1.77), among the interactions. The results on soil microbial population revealed that population of fungi, bacteria and actinomycetes increased in all the herbicidal treatments compared to pre-treatment population. Activity of dehydrogenase enzyme also increased significantly in the herbicide applied plots implying the safety of the tested chemicals on soil health. Based on grain yield, weed index and economic analysis, integration of stale seedbed method with the broad spectrum herbicide penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS can be recommended as an eco-friendly and economic weed management practice in upland rice.
Open Access
Fertigation and mulching in oriental pickling melon (Cucumis melo var. conomon (L.) Makino) under high density planting
(Department of Agronomy,Vellanikkara, 2016) Ashly, P; KAU; Joseph, P A
A field experiment was conducted to study the eficcts of 'Fertigation and mulching in oriental pickling melon {Cucumis melo vor.conomon (L.) Makino ) under high density planting and LDPF mulching in the summer rice fallow at the Agricultural Research Station (ARS) , Mannuthy from December 2014 to February 2015. High density planting of short duration less spreading high yielding variety of op melon at 33,333 plants per hectare was found to increase the yield of op melon more than double the yield at the recommended population of 10,000 plants per hectare. Under high density planting there is a proportionate increase in the demand of water and nutrients, which are crucial for the balanced growth, development and yield of the crop. The purpose of this experiment was to find out an optimum level of irrigation, fertilizer which will be supplied as drip fertigation for the highest yield and quality of fruits under polythene mulched condition. There were nine drip fertigation combinations with three levels of irrigation (75, 100 and 125 per cent Ep ) and 3 levels of fertilizers (200, 250 and 300 per cent of RDF), and one control which were laid out in Randomized Block Design with three replications. There was a significant increase in the characters like length of vine, number of leaves per vine, number of secondary branches per vine, leaf area index and shoot dry matter production at harvest with increase in irrigation levels from 75 per cent Ep to 125 percent Ep. At the same lime, other growth attributes such as number of primary branches per vine and days to fust male and female flower appearance didn't show any significant effect with various drip irrigation levels. Similarly, under high density planting and polythene mulching, the length of vine, number of leaves per vine, number of secondary branches per vine, LAI and shoot dry matter production at harvest increased linearly with increase in fertilizer levels from 200 per cent to 300 per cent of recommended dose. But increase in fertilizer level did not make any significant effect on the number of primary branches of OP melon. It remained constant around 2 in all levels of irrigation and fertilizer. The interaction between irrigation and fertilizer levels was not significant in any of the characters viz., length of vine, number of leaves per vine, number of primary and secondary branches per vine and LAI and shoot dry matter production at harvest. Per hectare yield of crc^ as well as various yield attributes like number of fruits per plant, average fruit weight, average volume of fruit and fruit yield per plant were not affected significantly by various irrigation levels. However, the average weight and volume of fruits increased slightly and non significantly with increase in irrigation levels from 75 per cent Ep to 125 per cent Ep. All other parameters like number of fruits per plant, yield of fruits per plant and fruit yield per ha recorded maximum value at 100 per cent Ep and the value declined gradually when irrigation level was increased to 125 percent Ep. Even though the weight and volume of individual fruits were maximum at 125 per cent Ep, the number of fruits per plant was less in this treatment, which ultimately resulted in a raluction in per ha yield of the crop. Number of fruits per plant, fruit yield per plajit and per hectare yield of fruit showed significant increase with increase in fertilizer level from 200 per cent to 250 per cent of recommended dose of fertilizer. But a further increase in fertilizer level affected the above characters negalively.So also, among the fertilizer levels, the average weight and volume of fruits were highest at 250 per cent RDF even though the effect was non- significant. The interaction between irrigation and fertilizer levels was not significant on the weight of fruits per plant and average weight and volume of fruits. But, there was significant elTect of interaction between irrigation and fertilizer levels on characters like ftuit yield per plant and per ha. Highest fruit yield per plant and highest per ha fruit yield were recorded at IiFi which was significantly superior to all the other combinations except I3F2,. So, there was positive interaction up to 100 per cent Ep and 250 per cent of recommended dose of fertilizer level when applied together as drip fertigation with LDPE mulching. Number of days taken for the appearance of flowers and the number of days taken for harvest did not show significant variation under various levels of drip fertigation. The interaction between irrigation and fertilizer levels was also non- significant on these characters. In general, days to first male flowering and female flowering were 21 and 26 respectively in drip fertigation treatments, while they were 25 and 29 respectively in control. Fruits were harvested 63 and 68 days after planting in drip fertigation treatments and control plots respectively. There was an increase in fruit dry weight with increase in irrigation levels from 75 per cent Ep to 100 per cent Ep and then it declined with further increase in irrigation level to 125 per cent Ep and the highest fruit dry matter production was recorded with 250 per cent of RDF compared to both 200 and 300 per cent of RDF. The interaction between irrigation and fertilizer levels also significantly influenced the fruit dry matter production. The maximum was observed at a combination of irrigation with 100 per cent EP and fertilizer with 250 per cent RDF. Both nitrogen and phosphorus content of leaves at 45 DAS increased significantly with increase in irrigation levels from 75 per cent to 125 per cent Ep under drip irrigation. But the increase in potassium content with increase in irrigation levels was non- significant. But the concentration of nitrogen, phosphorus and potassium in leaves of op melon increased significantly with increase in fertilizer levels from 200 per cent RDF to 300 per cent RDF. This shows the tendency of op melon to absorb and accumulate more and more NPK in their leaves with an increase in their availability in the root zone. The interaction between the tested irrigation and fertilizer levels did not show any significant effect on the content of primary nutrients in leaves of op melon at 45 DAS. Nitrogen content of shoot at harvest increased significantly with irrigation levels from 75 per cent Ep to 125 per cent Ep and fertilizer level from 200 per cent to 300 per cent of RDF. The fruit nitrogen level at harvest remained constant with slight variation, with the different levels of irrigation and fertilizers. At the same time, the interaction between any of the tested irrigation and fertilizer levels did not make any significant effect on shoot and fruit nitrogen content at harvest. Levels of irrigation significantly influenced the total N uptake by the crop at harvest. With increase in irrigation levels, N uptake increased significantly up to band then decreased, b and b were at par. The total nitrogen uptake by the crop at harvest increased with increase in fertilizer levels upto F2 and then decreased. F2 was significantly superior to F| and F3. The interaction between irrigation and fertilizer levels didn't make an\ significant effect on the character. Phosphorus content of shoot at harvest of op melon was found increasing significantly with increase in drip irrigation levels from 75 per cent Ep to 125 per cent Ep and fertilizer from Fi to F3 levels. At the same time, the fruit phosphorus content at harvest was not significantly affected by an increased application of phosphorus in soil.Fruit P content at harvest was not influenced by levels of irrigation and fertilizers. None of the combinations between irrigation and fertilizer levels showed significant superiority in increasing either shoot or fruit phosphorus content in OP melon. Levels of irrigation significantly influenced the P uptake by the crop. With increase in irrigation levels, P uptake increased up to b- But b and b were at par and significantly superior to b- With increase in fertilizer levels, the P uptake by the crop also increased up to F3. But F2 and F3 were at par and significantly superior to Fi. The Interaction between irrigation and fertilizer levels could not make any significant effect on P uptake by the crop. Irrigation and fertilizer levels significantly influenced the potassium content of shoot at harvest, but not the content of fruit. Significantly the highest potassium content in shoot was recorded at irrigation level of 125 per cent Ep and fertilizer level of 300 % RDFfFj). The fruit potassium content remained constant with different irrigation and fertilizer levels. Levels of irrigation significantly influenced the total K uptake by the crop. With increase in irrigation levels, K uptake increased significantly up to b (100 per cent Ep) and then decreased. Similarly, total K uptake also increased significantly upto 250 per cent RDF and then decreased. The interaction between irrigation ai^d fertilizer levels didn't show any significant influence on total K up lake. With increase in drip irrigation from 75 to 125 per cent Ep field water use efficiency decreased from 215.6 ( kg ha-mm ') to 145.8 ( kg ha-mm'') . Among the fertilizer levels, highest field water use efficiency was reported by 200 per cent RBF (181.9 kg ha-mm"') . However, the variation in FWUE among the fertilizer levels was not as significant as that observed in irrigation treatments. High level of irrigation in the control practice reduced FWUE in a significant way and was the lowest at 42.7 kg ha-mm"'. Soil chemical properties such as pH and Electrical Conductivity didn't show appreciable variation due to the various levels of irrigation and fertilizer. This indicates that chemical properties of soil are not likely to be influenced by short term management practices like irrigation and fertilizer application. In all the treatments and control, soil moisture content was the highest in the surface layer of 0-15 cm and the lowest in the bottom most layer of 30-45 cm. The decrease in soil moisture content from surface to the bottom most layer was gradual. In each layer, moisture content increased with increase in drip irrigation level from 75 % Ep to 125 % Ep. The moisture content in each layer was more in the control plot as it received more moisture through flood irrigation. In each layer the variation in moisture content was negligible within every level of drip irrigation due to the influence of varying levels of fertilizers. Keeping quality of the fruits was not affected by irrigation or fertilizer levels up to 45 days after harvest under high density planting with LDPE mulching. All the drip fertigation treatments were far superior to control on increasing the net profit per hectare and also the net income per rupee invested. In all the irrigation treatments F2 fertilizer level increased the net profit per hectare as well as net income per rupee invested in a significant way as the increase in fertilizer level above Ft had negative effect on crop yield. Among the treatment combinations I2F2 recorded the highest net return of Rs. 531581 per hectare followed by I3F2 of Rs 513651. Among the treatment combinations also I2F2 recorded the highest net income of Rs 2.06 per rupee invested followed by 1.95 by both I3F2 and I}F2. The study may be concluded by stating that for the most profitable production of op melon in the summer rice fallows of Kerala, high yielding less spreading varieties like Saunhagya should be planted at a high density of 33,333 plants per hectare and managed by drip fertigation at 1 GO per cent Ep and 250 per cent RDF with LDPE mulching. This has produced the highest net profit per hectare and net income per rupee invested.
Open Access
Characterization and management of weedy rice (Oryza sativa f spontanea)
(Department of Agronomy, College of Agriculture, vellayani, 2016) Anjali, K; KAU; Ameena, M
The study entitled ‘Characterization and management of weedy rice (Oryza sativa f spontanea)’ was carried out as four separate experiments conducted at COA, Vellayani and farmers’ fields of Nemom block during 2014-16. The main objectives of the study were morpho-physiological and agronomic characterization of weedy rice morphotypes of Kerala; formulation of a management strategy and assessment of crop weed interference under elevated carbon dioxide concentration. Experiment I. ‘Morpho-physiological and agronomic characterization of weedy rice morphotypes’ was conducted as pot culture laid out in completely randomized design with eight weedy rice morphotypes collected from major rice tracts of Kerala (Trivandrum, Kuttanad, Kole lands, Palakkad, Kozhikode and Ezhome). Morphological characterization of weedy rice morphotypes using morphometric descriptors and its comparison with cultivated varieties revealed that during initial stages most of the weedy rice morphotype possess similar morphological characteristics as the cultivated varieties. Physiological characterization of weedy rice morphotypes revealed no significant variation in chlorophyll content, total soluble protein and stomatal characteristics with cultivated rice varieties. However, root growth in terms of volume and dry weight was significantly higher for most of the morphotypes collected from Trivandrum, Kuttanad, Palakkad, and Ezhome. Earliness in 50% flowering was observed in all the weedy rice morphotypes compared to cultivated rice. Sterility of weedy rice morphotypes were significantly higher (17.77 to 32.79%) compared to cultivated rice varieties (9.23 to 12.85%). All the weedy rice morphotypes collected showed a prominence in awn length ranging from 2.37 to 9.23 cm. An average grain and straw yield of 4.89 and 16.14 g plant-1 and 1000 grain weight of 20.42 g was recorded by weedy rice morphotypes. Shattering percentage expressed as grain threshebility was significantly high for weedy rice morphotypes ranging from 29.73 to 46.32%. The seeds of weedy rice recorded wide variation in longevity ranging from 4.96 to 15 months which is an indication of variable seed dormancy. Experiment II. ‘Management of weedy rice by enhancing rice competitiveness’ was undertaken as micro plot study by raising cultivated rice and most common weedy rice morphotype and maintaining a standard weedy rice population of 7 plants m-2. To enhance rice competitiveness, three levels of seed rates viz., 100,120 and 140 kg ha-1 in combination with three types of priming techniques, i.e., without priming, hydropriming and hardening (2.5 % KCl) were included.Among the treatments, seed rate of 100 kg ha-1 along with hydropriming(T2) recorded significantly higher number of grains per panicle (120.02), grain yield (4.44 t ha-1) and straw yield (6.71 t ha-1) which was on par with T5 (120 kg ha-1 + hydropriming). Confirmatory trial at farmers’ field revealed that seed rates of 100 kg ha-1 or 120 kg ha-1 along with hydropriming (T2& T5) resulted in superior yield attributes inrice viz., number of grains per panicle, grain and straw yield ha-1.Weedy rice count m-2 and dry weight were significantly lower under these treatments. T2 (100 kg+ hydropriming) along with T5 (120 kg+ hydropriming) turned out to be the most economic treatment with a B:C ratio of 1.68 and 1.64 respectively. Experiment III. ‘Effect of elevated CO2 concentration on growth of rice and weedy rice’, was undertaken as pot study under elevated CO2 concentration of 500 ppm in Open Top Chamber (Chamber A) and in ambient conditions (Chamber B and open field). The most common morphotype of weedy rice and two cultivated rice varieties (Jyothi and Uma) were selected for the study. Significant variations in vegetative (no of tillers, leaf area index and leaf area duration) as well as yield attributes and yield (no. of grain panicle-1, grain yield plant-1) were observed under elevated CO2 levels in all these three systems. Higher grain yield per plant was recorded by weedy rice in Chamber A with an elevated CO2 level (1.73 times higher than open condition), followed by Chamber B (recorded 1.19 times more than open condition). However, the extent of response varied among the cultivars under varying atmospheric situations with Uma showing a greater percentage increase in grain yield (51.4% in Chamber A and 40% in Chamber B) followed by weedy rice (42.3% in Chamber A and 16% in Chamber B). The study revealed significant variation among the weedy rice morphotypes. Cultivated rice and weedy rice exhibited morphological similarity during initial stages of growth. Seed rate of 100 kg ha-1 with hydropriming can be recommended as the most effective and economic management strategy for weedy rice. The response of weedy rice to elevated CO2 was more compared to cultivated rice varieties.
Open Access
Fertigation for precision farming in tomato (Solanum Iycopersicum L.)
(Department of Agronomy, College of Agriculture, vellayani, 2016) Amala, J; KAU; Elizabeth, K Syriac
The investigation entitled “Fertigation for precision farming in tomato (Solanum lycopersicum L.)” was carried out at College of Agriculture, Vellayani during the period 2015-2016 to standardize a fertigation schedule for precision farming in tomato and to assess the impact of precision farming practices on growth and yield and also to work out the economics. The field experiment was conducted during the summer season of 2015 (February to June) in farmer’s field at Pirappancode, Thiruvananthapuram district. The experiment was laid out in split plot design with eight treatment combinations and two controls, with four replications. Four levels of nutrients (l1- 75 per cent RD of N and K, l2- 100 per cent RD of N and K, l3- 125 per cent RD of N and K, l4- 150 per cent RD of N and K) constituted the main plot treatments and two fertigation intervals (i1- fertigation once in four days, i2- fertigation once in eight days) constituted the sub plot treatments. The two control treatments were, control 1 (KAU ad hoc POP for precision farming) and Control 2 (KAU POP for conventional farming). The hybrid tomato Lakshmi grafted on wild brinjal was used for the study. Among different nutrient levels, l3 (125 per cent RD of N and K) recorded the highest DMP (219.42 g plant-1), number of fruits plant-1(33.67), fruit set percentage (62.77) , fruit yield (1.54 kg plant-1 and 42.36 t ha-1) and was significantly superior to other nutrient levels tested. Fertigation at four days interval (i1) recorded the highest LAI, DMP (224.21 g plant-1), number of fruits plant-1 (35.53), fruit set percentage (60.74) and fruit yield (1.61 kg plant-1 and 44.25 t ha-1) and was significantly superior to i2 (fertigation at eight days interval). Moisture studies indicated that both WUE and water productivity significantly varied with nutrient levels and fertigation intervals. The highest WUE (40.62 kg ha mm-1) and water productivity (5.26 kg ha mm-1) were observed at 125 per cent RD of N and K. Fertigation at four days interval (i1) registered significantly higher WUE and water productivity than i2. Application of 125 per cent RD of N and K (l3) recorded the highest root weight of 10.27 g and the highest root volume of 26.58 cm3 and was statistically on par with 150 and 100 per cent RD of N and K. The treatment i1 was significantly superior to i2 for all root characteristics. Uptake of N, P and K varied significantly with nutrient levels and fertigation intervals. The treatment l3 recorded the highest N, P and K uptake and it was statistically on par with l4. Fertigation at four days interval (i1) was significantly superior to i2, in nutrient uptake. Among different interactions, 125 per cent RD of N and K at 4 days interval (l3i1) registered the highest DMP (245.28 g plant-1) and was statistically on par with 150 per cent RD of N and K at four days interval (l4i1). Also, l3i1 recorded the highest fruit yield (1.92 kg plant-1 and 52.70 t ha-1) and number of pickings (7.33) and was significantly superior to other interactions studied. Economics of the study showed that l3i1 (125 per cent RD of N and K at four days interval) registered the highest net income of ₹ 6,61,515 ha-1 and B:C ratio of 2.69 and it was significantly superior to all other interactions. KAU ad hoc POP for precision farming (Control 1) was significantly superior to KAU POP for conventional farming (Control 2), for all growth attributes, yield attributes and yield. The treatment combination 125 per cent RD of N and K given as fertigation at four days interval (l3i1) was superior to control 1 and control 2 with respect to yield attributes, yield and economics. Based on the results of the present field investigation, it can be concluded that application of 125 per cent RD of N and K (93.75 kg N and 31.25 kg K ha-1) as urea and muriate of potash respectively, in 30 splits through fertigation at four days interval along with basal application of FYM @ 25 t ha-1 and P @ 40 kg ha-1 as rock phosphate is the best schedule for hybrid tomato under precision farming.
Open Access
Varietal suitability and crop geometry of baby corn (Zea mays L.) in coconut garden
(Department of Agronomy, College of Agriculture, vellayani, 2016) Dona Scaria; KAU; Rajasree, G
The experiment entitled “Varietal suitability and crop geometry of baby corn (Zea mays L.) in coconut garden” was undertaken at the Coconut Research Station, Balaramapuram, Thiruvananthapuram, during the summer season (March to May) and the Kharif season (August to October) of 2015. The main objectives of the study were to understand the feasibility of introducing baby corn as intercrop in coconut garden, to assess the effect of varieties and spacings on its growth and productivity and to work out the economics of cultivation. The field experiment was laid out in Randomised Block Design with 9 treatments replicated thrice. The treatments comprised of combinations of three varieties and three spacings. The three varieties were Rasi 4212 (V1), G 5414 (V2) and CO-6 (V3) and the three spacings were 30 cm x 20 cm (S1), 45 cm x 20 cm (S2) and 60 cm x 20 cm (S3). The variety G 5414 recorded significantly higher baby cob weight with husk of 47.01 g cob-1 and 35.74 g cob-1, cob yield with husk of 10.97 t ha-1 and 9.98 t ha-1 and marketable baby cob yield of 3.67 t ha-1 and 3.36 t ha-1 in summer and Kharif respectively. This variety took less number of days from tasseling to harvest (2.11) and recorded the highest net income of RS. 133698 ha-1 and RS. 116629 ha-1 and B:C ratio of 2.70 and 2.49 in summer and Kharif seasons respectively. The variety G 5414 was followed by CO-6 in producing higher baby cob yield with husk and marketable baby cob yield. The growth attributes viz., plant height, number of leaves and leaf area index (LAI) at 15, 30 and 45 days after emergence (DAE), dry matter content and light interception were significantly higher for the variety CO-6. Green Stover yield was significantly higher for CO-6 (19.39 t ha-1 and 17.86 t ha-1 in summer and Kharif respectively) followed by G 5414 (16.08 t ha-1 and 14.35 t ha-1 in summer and Kharif respectively). The study revealed that spacing significantly influenced the growth attributes viz., plant height, number of leaves and LAI. The row spacing of 45 cm x 20 cm recorded the highest baby cob yield with husk of 10.90 t ha-1 and 9.63 t ha-1, marketable baby cob yield of 3.49 t ha-1 and 3.24 t ha-1 along with the highest net income of RS. 125839 ha-1 and RS. 114287 ha-1 and B:C ratio of 2.69 and 2.55 in summer and Kharif respectively. Baby cob weight with husk was significantly higher at 45 cm x 20 cm and baby cob-baby com ratio was the most desirable at 30 cm x 20 cm in summer. In summer, the interaction of CO-6 at 45 cm x 20 cm recorded the highest baby cob weight with husk (56.25 g cob-1), marketable baby cob yield (4.21 t ha-1) and B:C ratio (3.16). Net income was the highest with G 5414 at 45 cm x 20 cm and was on a par with CO-6 at 45 cm x 20 cm. In Kharif, CO-6 at 45 cm x 20 cm resulted in the highest baby cob yield with husk (11.16 t ha-1), marketable baby cob yield (3.68 t ha-1), net income (RS.145237 ha-1) and B:C ratio (3.03). The variety G 5414 at 45 cm x 20 cm was on a par with the variety CO-6 at 45 cm x 20 cm with respect to baby cob yield with husk (9.91 t ha-1) and marketable baby cob yield (3.49 t ha-1). The study revealed that, among the varieties tested, the variety G 5414 was superior and among the spacings, 45 cm x 20 cm was significantly superior in both summer and Kharif seasons. The interaction effects revealed that the variety G 5414 at 45 cm x 20 cm and the variety CO-6 at 45 cm x 20 cm were equally superior in terms of yield and economics. In baby com cultivation, detasseling is an important operation which is labour intensive. The variety G 5414 exhibited 50 per cent silking prior to tasseling and hence the detasseling before first harvesting could be avoided. This variety had a better appearance and uniformity compared to CO-6. In general, the baby com yield was higher in summer season compared to Kharif season. To conclude, the result of the study indicated that baby corn can be profitably intercropped in coconut gardens in summer and Kharif seasons. The baby corn hybrid G 5414 at 45 cm x 20 cm spacing resulted in higher baby cob yield with husk, marketable baby cob yield, net income and B:C ratio during both seasons in southern Kerala. The maize variety CO-6 also performed well in coconut garden during both summer and Kharif seasons.
Open Access
Irrigation scheduling and live mulching in upland rice (Oryza sativa L.)
(Department of Agronomy, College of Horticulture, Vellayani, 2018) Aparna, R A; KAU; Jayakrishnakumar, V
The experiment entitled ‘Irrigation scheduling and live mulching in upland rice (Oryza sativa L.)’ was undertaken at farmer’s field at Peringammala, Kalliyoor, Thiruvananthapuram during Virippu 2017 to standardize irrigation schedule for economizing water use and study the effect of live mulching with cowpea on growth and yield of upland rice. Prathyasa (MO 21) was used as the variety. The experiment was laid out with 14 treatment combinations involving seven irrigation treatments (I1 - irrigation at 3 cm depth at 10 mm CPE, I2 - irrigation at 3 cm depth at 20 mm CPE, I3 - irrigation at 3 cm depth at 30 mm CPE, I4 - irrigation at 2 cm depth at 10 mm CPE, I5 - irrigation at 2 cm depth at 20 mm CPE, I6 - irrigation at 2 cm depth at 30 mm CPE and I7 - rainfed control) and two mulching treatments (M1 - no live mulching, M2 – live mulching with cowpea) with three replications in randomized block design. The results revealed that I1 recorded the highest value for the growth characters viz., plant height at 60 DAS, tiller number m-2 at 60 DAS, LAI at 60 DAS and DMP at harvest. At harvest, the tallest plants were produced by I4. M2 registered the highest dry matter production at harvest. The interaction i1m2 recorded the highest tiller number m- 2 . The yield attributes and yield were significantly influenced by the irrigation treatments. The treatment I1 recorded the highest length of panicle, weight of panicle, number of filled grains panicle-1 and thousand grain weight. M2 produced the highest productive tillers m-2. I1 registered the highest grain yield (2949 kg ha-1), straw yield (3100 kg ha-1) and harvest index (0.49). The grain and straw yields were the highest for M2. The grain yield (3057 kg ha-1) was the highest for i1m2 and significantly superior to other treatments. It was noticed that I1 recorded the highest relative leaf water content and I7 registered the highest proline content. The uptake of N, P and K differed significantly. I1 and M2 recorded the highest NPK uptake. The interaction effect i1m2 registered the highest values for N and P uptake. The root characters viz., root volume, root dry weight and root shoot ratio were significantly increased due to irrigation and I1 recorded the highest values. The root length was the highest for I7. Among the mulches, M2 recorded the highest root length and root shoot ratio. The highest consumptive use was recorded by I1, M2 and their interaction i1m2. The highest water use efficiency (3.72 kg ha-1 mm-1) was recorded by I5 and was on par I3 and superior to other treatments. M2 registered the highest WUE (3.51 kg ha-1 mm-1) and superior to M1. The available N, P and K status were the highest for I7. The available soil N and K were the highest for M2. The interaction effect i7m2 registered the highest values for available soil N and K. The highest weed dry weight was recorded by I1, M1 and their interaction i1m1. The highest net income was obtained with I1 and was on par with I2 and I4. The highest BCR was recorded by I2 and was on par with I4 and I1. M2 recorded the highest net income and BCR. The interaction i1m2 recorded the highest net income and was on par with i4m2. The interaction i1m2 registered the highest BCR (1.46) and was on par with i2m1, i2m2, i4m2 and i5m2. The results revealed that frequent irrigation especially at 3 cm depth at 10 mm CPE in combination with live mulching of cowpea favourably influenced most of the growth, yield attributes, yield, physical, chemical properties of the soil and economics of cultivation. Although the highest grain yield was recorded by i1m2, it was found that i1m2 was on par with i4m2 for net income suggesting that irrigation at 2 cm depth at 10 mm CPE with live mulching of cowpea is as good as i1m2. For BCR, i1m2 was on par with i2m1 , i2m2 , i4m2 and i5m2 suggesting that irrigation at 2 cm depth at 20 mm CPE with live mulching of cowpea is as good as i1m2. For higher water use, irrigation at 2 cm depth at 20 mm CPE (I5) and live mulching of cowpea (M2) can be recommended. From farmer’s point of view, irrigation at 2 cm depth at 10 mm CPE with live mulching of cowpea is beneficial for higher economic returns in acute water deficit areas.
Open Access
Magnesium sulphate fertilization for yield enhancement in direct seeded rice
(Department of Agronomy, College of Agriculture, Vellayani, 2018) Daly George; KAU; Girija Devi, L
The study entitled “Magnesium sulphate fertilization for yield enhancement in direct seeded rice” was conducted at College of Agriculture, Vellayani, Thiruvananthapuram, Kerala from 2016 - 2018 July, to determine the optimum dose, time and method of application of magnesium sulphate (MgSO4) for growth and yield enhancement in rice. The study was conducted in farmer’s field at Kalliyoor Panchayat, Thiruvananthapuram district during May to September 2017. The experiment was laid out in randomized block design (RBD) with fourteen treatments and three replications. The variety used was Sreyas (MO 22) released from Rice Research Station, Moncompu, Kerala. The treatments were; T1 -MgSO4 @ 20 kg ha-1 at 20 days after sowing (DAS), T2 -MgSO4 @ 30 kg ha-1 at 20 DAS, T3 -MgSO4 @ 40 kg ha-1 at 20 DAS, T4 -MgSO4 @ 20 kg ha-1 in two equal splits at 20 and 40 DAS, T5 - MgSO4 @ 30 kg ha-1 in two equal splits at 20 and 40 DAS, T6 - MgSO4 @ 40 kg ha-1 in two equal splits at 20 and 40 DAS, T7 -MgSO4 @ 10 kg ha-1 at 20 DAS and 1 % MgSO4 at 40 DAS as foliar spray, T8- MgSO4 @ 15 kg ha-1 at 20 DAS and 1 % MgSO4 at 40 DAS as foliar spray, T9- MgSO4 @ 20 kg ha-1 at 20 DAS and 1 % MgSO4 at 40 DAS as foliar spray, T10 -MgSO4 @ 10 kg ha-1 at 20 DAS and 2 % MgSO4 at 40 DAS as foliar spray , T11-MgSO4 @ 15 kg ha-1 at 20 DAS and 2 % MgSO4 at 40 DAS as foliar spray, T12- MgSO4 @ 20 kg ha-1 at 20 DAS and 2 % MgSO4 at 40 DAS as foliar spray, T13 -MgSO4 @ 80 kg ha-1 as basal (ad hoc recommendations of Kerala Agricultural University (KAU)) and T14- Control (Package of Practices Recommendations crops 2016 Kerala Agricultural University (KAU PoP) without Mg). All the treatments were given a uniform dose of FYM @ 5 t ha-1, lime @ 600 kg ha-1 in two splits and NPK @ 90: 45: 45 kg ha-1 (KAU, 2016). The results revealed that growth attributes like plant height and tillers m-2 at maximum tillering, panicle initiation (PI) and harvest stages and the leaf area index (LAI) at panicle initiation stage were significantly influenced by MgSO4 fertilization. At maximum tillering stage, the height of the plant was the highest in T2, at panicle initiation stage it was the highest in T10. At both maximum tillering and panicle initiation stages, tillers m-2 were the highest in T9, while at harvest it was the highest in T4. The LAI at panicle initiation stage was found the highest in T6. Early flowering was observed in T6, similarly the root shoot ratio was also found the highest in T6. Late flowering and the lowest root shoot ratio were observed in T14 (control -KAU PoP without Mg). Chlorophyll content at panicle initiation and boot leaf stages were significantly higher in Mg applied treatments compared to control. The yield and yield attributing characters were also significantly influenced by the dose, time and method of application of MgSO4. The panicle weight (2.89 g), number of filled grains panicle-1 (133.2), grain yield (9.6 t ha-1) and harvest index (0.463) were the highest in T6. The availability of primary and secondary nutrients in soil and its uptake at maximum tillering, panicle initiation and harvest stages were also influenced by the treatments. The availability of Mg in soil at harvest was slightly increased due to MgSO4 fertilization. The uptake of K and Mg showed an antagonistic interaction and Mg uptake at all stages was lower in control (KAU PoP without Mg). The quality attributes like protein and Mg content in grain were also higher in treatments receiving Mg. Economic analysis showed the significance of Mg application and also its split application over control (KAU PoP without Mg) and T13 (MgSO4 @ 80 kg ha- 1 as basal (ad hoc recommendations)). The B:C ratio in T6 was 3.01 whereas in control it was 2.46 and in T13 it was 2.42. From the study, it can be concluded that MgSO4 fertilization significantly enhanced the yield and quality of rice irrespective of method of application. However considering the net income and B:C ratio, soil application of MgSO4 @ 20 or 40 kg ha-1 in two equal splits at 20 and 40 DAS (depending upon Mg availability in soil) can be given as recommendation for farmers for getting higher grain yield.

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