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Development of diagnosis and recommendation integrated system (DRIS) in black pepper (Piper nigrum L.) in relation to yield and quality characteristics
(Department of Agronomy, College of Horticulture, Vellanikkara, 1998) Sreekumaran, V; KAU; Neelakandan Potty, N
An investigative analysis was undertaken during 1993-96 to work out an objective and effective technology for nutritional management of black pepper based on cause and effect relationship. A critical and comparative evaluation of the available methods in this connection, viz. critical level concept, DRIS concept and management based on soil test data, soil analysis was envisaged. Approved standard procedures m estimating soil available and plant contents of nine elements, viz. N P K Ca Mg S Fe Zn and Mn and standard statistical methods were used in the study. A total of 1200 plants aged 14 years maintained at RARS, Ambalavayal were used as the test material in the study. A non-genic variability in yield ranging from 0.16 to 13.8 kg plant-1 was manifested by tile crop which indicated that variability shall be bridged upwards through managerial techniques. The range of available status of the elements in the soil analysis was very high. The lowest range of 0.9 to 4.5 ppm and the highest range of 144 to 1324 ppm were recorded by Zn and Ca, respectively. Soil pH ranged from 4.3 to 6.8. These were at the individual plant level. Foliar content as well as the range of the elements were much less and did not exactly related to soil available contents. Results also indicated that elements showed significant and specific interactions among themselves which varied with the elements. The pattern and magnitude of interactions at soil and plant level were different. Evaluation of soil test data of the study against approved soil test 0 - 9 scale classification showed that rhizosphere environments belonged to medium rich to very rich class and that it could not explain the yield variability and hence could not be a reliable basis of nutritional management in fertile soil. Examination of the foliar content of elements and their comparison with critical levels and ranges fixed by De Waard (1969) and Nybe (1986) respectively, showed that foliar content of all the elements in the study were above the critical levels which suggested that the critical level concept cannot be an adequate guiding principle in nutritional management of black pepper. It may be adequate only in situations where any element becomes specifically critical. Its inadequacy may also be due to the positive and negative interactions of elements in the plant system as well as due to the fact that yield is the resultant of a process involving several elements simultaneously. Negative relationship of P in the early stages and yield level of 6.5 and <1 kg berries at 2.33 and 2.35 per cent level and similar observations confirmed the above contention. DRIS concept was found to be more adaptable to explain the yield variability as it takes into account the content as well as interaction represented by ratios of every element with the others of the high yielding plants and tries to simulate them in low yielding plants. Results of the present study showed that by employing the DRIS concept and nutrient ratios, the content of every element can be identified at any time as absolutely deficient, relatively deficient, relatively sufficient, relatively excess and absolutely excess. This classification enabled to define the nature of recommendation as additive, deletive or ameliorative/corrective. Testing of the classification of the population into discriminative low and high - yielding sub-populations employing mean ± one SD showed that the system may be perfect when the magnitude of yield limiting factors in the entire range of low yield is the same. Possibility of variability in yield limiting factors could be accommodated by sub-dividing the lower yield group into smaller groups as was done in deciles in the study. The results appeared to show that the per plant variability can be accommodated with reasonable accuracy in such a system of micro level yield group identification and application of DRIS norms to them. The unique advantage of the DRIS system to reach the maximum realizable yield through progressive diagnosis based on progressive experimentation shall be substituted by the decile classification proposed in the study to a very good extent. Results of the present study showed that yield and quality factors are largely independent of each other and both can be improved by integrating the respective components even at the higher yield levels obtained in the present study. Analysis of inter-correlation matrix among elements at soil and plant level revealed the possibility of making specific recommendations to achieve progressive yield increases by working out quantity, intensity and rate of release characteristics. of elements in the soil in relation to absorption. Results in the present study showed that scientifically speaking the captions of DRIS indices or index values as " order of requirement" be modified as "order of limiting influences" - the former part of which is relative to metabolic deficiencies and the latter part to the metabolic excess. Imbalance indices have to be viewed as qualitative and not quantitative indices as they are relative, primarily based on the relative deficiencies and excesses which in turn are dependent upon the relative contents and valencies of the ions. The results of the study also revealed that with progressive increase in yield, causing .higher nutrient removal, will make the soil not only more deficient but also increase the frequency of application of nutrients more. The progressive increase in the number of limiting factors with yield improvement caused by higher rate of removal calls for more frequent monitoring and not treating the norm as static for a long period. The results of the experiment have brought to light a graded pattern of nutritional management for black pepper. The primary limiting factors were found to be high native content of Fe and Mn which will have to be ameliorated. Secondly, at the low yield level the yield is limited by a relative deficiency of Zn caused by high P calling for a temporary skipping of P; supplemented with N and K which can take the yield up to 5 kg plant-1. Excess S through the incidental application of prophylactic sprays of Bordeaux mixture and shortage of Ca and Mg appear to be the limiting factors at the higher yield class. Amelioration of acidity by supplying Ca + Mg carbonate, substitution of S containing fungicides and application of N and K shall constitute the recommendation, beyond which P may have to be applied.
Open Access
Developement of diagnosis and recommentation integrated system
(Department of Agronomy, College of Horticulture, Vellanikkara, 1998) Sreekumaran, V; KAU; Neelakandan, Potty N
An investigative analysis was undertaken during 1993-96 to work out an objective and effective technology for nutritional management of black pepper based on cause and effect relationship. A critical and comparative evaluation of the available methods in this connection, viz. critical level concept, DRIS concept and management based on soil test data, soil analysis was envisaged. Approved standard procedures m estimating soil available and plant contents of nine elements, viz. N P K Ca Mg S Fe Zn and Mn and standard statistical methods were used in the study. A total of 1200 plants aged 14 years maintained at RARS, Ambalavayal were used as the test material in the study. A non-genic variability in yield ranging from 0.16 to 13.8 kg plant-1 was manifested by tile crop which indicated that variability shall be bridged upwards through managerial techniques. The range of available status of the elements in the soil analysis was very high. The lowest range of 0.9 to 4.5 ppm and the highest range of 144 to 1324 ppm were recorded by Zn and Ca, respectively. Soil pH ranged from 4.3 to 6.8. These were at the individual plant level. Foliar content as well as the range of the elements were much less and did not exactly related to soil available contents. Results also indicated that elements showed significant and specific interactions among themselves which varied with the elements. The pattern and magnitude of interactions at soil and plant level were different. Evaluation of soil test data of the study against approved soil test 0 - 9 scale classification showed that rhizosphere environments belonged to medium rich to very rich class and that it could not explain the yield variability and hence could not be a reliable basis of nutritional management in fertile soil. Examination of the foliar content of elements and their comparison with critical levels and ranges fixed by De Waard (1969) and Nybe (1986) respectively, showed that foliar content of all the elements in the study were above the critical levels which suggested that the critical level concept cannot be an adequate guiding principle in nutritional management of black pepper. It may be adequate only in situations where any element becomes specifically critical. Its inadequacy may also be due to the positive and negative interactions of elements in the plant system as well as due to the fact that yield is the resultant of a process involving several elements simultaneously. Negative relationship of P in the early stages and yield level of 6.5 and <1 kg berries at 2.33 and 2.35 per cent level and similar observations confirmed the above contention. DRIS concept was found to be more adaptable to explain the yield variability as it takes into account the content as well as interaction represented by ratios of every element with the others of the high yielding plants and tries to simulate them in low yielding plants. Results of the present study showed that by employing the DRIS concept and nutrient ratios, the content of every element can be identified at any time as absolutely deficient, relatively deficient, relatively sufficient, relatively excess and absolutely excess. This classification enabled to define the nature of recommendation as additive, deletive or ameliorative/corrective. Testing of the classification of the population into discriminative low and high - yielding sub-populations employing mean ± one SD showed that the system may be perfect when the magnitude of yield limiting factors in the entire range of low yield is the same. Possibility of variability in yield limiting factors could be accommodated by sub-dividing the lower yield group into smaller groups as was done in deciles in the study. The results appeared to show that the per plant variability can be accommodated with reasonable accuracy in such a system of micro level yield group identification and application of DRIS norms to them. The unique advantage of the DRIS system to reach the maximum realizable yield through progressive diagnosis based on progressive experimentation shall be substituted by the decile classification proposed in the study to a very good extent. Results of the present study showed that yield and quality factors are largely independent of each other and both can be improved by integrating the respective components even at the higher yield levels obtained in the present study. Analysis of inter-correlation matrix among elements at soil and plant level revealed the possibility of making specific recommendations to achieve progressive yield increases by working out quantity, intensity and rate of release characteristics. of elements in the soil in relation to absorption. Results in the present study showed that scientifically speaking the captions of DRIS indices or index values as " order of requirement" be modified as "order of limiting influences" - the former part of which is relative to metabolic deficiencies and the latter part to the metabolic excess. Imbalance indices have to be viewed as qualitative and not quantitative indices as they are relative, primarily based on the relative deficiencies and excesses which in turn are dependent upon the relative contents and valencies of the ions. The results of the study also revealed that with progressive increase in yield, causing .higher nutrient removal, will make the soil not only more deficient but also increase the frequency of application of nutrients more. The progressive increase in the number of limiting factors with yield improvement caused by higher rate of removal calls for more frequent monitoring and not treating the norm as static for a long period. The results of the experiment have brought to light a graded pattern of nutritional management for black pepper. The primary limiting factors were found to be high native content of Fe and Mn which will have to be ameliorated. Secondly, at the low yield level the yield is limited by a relative deficiency of Zn caused by high P calling for a temporary skipping of P; supplemented with N and K which can take the yield up to 5 kg plant-1. Excess S through the incidental application of prophylactic sprays of Bordeaux mixture and shortage of Ca and Mg appear to be the limiting factors at the higher yield class. Amelioration of acidity by supplying Ca + Mg carbonate, substitution of S containing fungicides and application of N and K shall constitute the recommendation, beyond which P may have to be applied.
Open Access
Nutrient- growth regulator interaction in snakegourd (Trichosathes anguina L.) under drip irrigation system
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Elizabeth K, Syriak; KAU; Raghavan Pillai, G
Two field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, to study the effect of varying levels of nitrogen (n), ethephon (g) and drip irrigation frequency (i) on the productivity of snakegourd. The influence of the treatments on the size, quality and shelf life of the produce and also on the physico-chemical properties of soil was investigated. The trials were conducted during the summer seasons (December to April) of 1994-'95 and 1995-'96. The experiments were laid out in 4 2x2 + 2 asymmetrical confounded factorial design with two replications and each replication included two blocks. Combinations of four levels each of N (35, 70, 105 and 140 kg ha'), ethephon (0, 50, 100 and 200 ppm) and two frequencies of drip irrigation (5 mm CPE and 10 mm CPE) constituted the treatments along with two controls (nogoiI and llogoi2) in each block. The highest order interaction NOI was confounded in both the replications. Results of the field experiments revealed that during both the years of experimentation, nitrogen, ethephon and irrigation frequency exerted significant positive influence on the fruit yield of snakegourd. During both the years, the higher levels of nitrogen (105 and 140 kg N ha') were found to be significantly superior to the lower levels (70 and 35 kg N ha'). Pooled analysis of the yield data also revealed a similar trend. Growth characters like internodal length, number of leaves plant" and dry matter production showed significant enhancement due to N application. The positive significant effect of N was manifested in the yield attributes viz., number of fruits plant" and average fruit weight. Significant increase in the WUE of the crop due to N application was also observed. The content and uptake of major nutrients also increased substantially due to applied N. Nitrogen improved the quality of fruits, significantly, in terms of crude protein, total sugars, reducing sugars and ascorbic acid content. However, the shelf life was adversely affected by it. The highest net profit and B:C ratio were recorded by 105 kg N ha' (Rs. 74,636/- and 2.37, respectively) compared to the other levels of N. Considerable improvement in the physico-chemical properties of soil due to applied N was also noticed. The results of the field experiments also indicated significant yield . increase in snakegourd due to ethephon application. The higher levels of ethephon ie., 100 and 200 ppm, were found to be significantly superior to the lower levels in this regard. Growth and yield attributes as well as quality of fruits were favourably influenced by ethephon. Through its indirect positive effect on fruit yield, the higher levels of ethephon improved the WUE of the crop significantly over its lower levels. The economic analysis also revealed the positive effect of ethephon on the net profit and B:C ratio and the highest values were registered by 200 ppm ethephon (Rs. 71,194/- and 2.31, respectively). With respect to irrigation frequency, il (irrigation at 5 mm CPE) registered significantly higher fruit yield compared to i2 (irrigation at 10 mm CPE): Growth characters and also the quality of fruits exhibited a similar trend. More frequent irrigation treatment (i.) exerted its positive significant effect on yield attributes viz., number of fruits plant:' and mean weight and girth of fruits. The physical optima for N at il were worked out to be 100 and 115 kg ha" during the first and second year, respectively. Economic analysis also revealed the favourable effect of frequent drip irrigation, with il registering substantially higher net profit and B:C ratio (Rs. 70,038/- and 2.28, respectively) compared to i2 (Rs. 61,615/- and 2.14, respecti vel y) .. A perusal of the data on fruit yield and economics of the treatment combinations elicited the favourable effect of n3g4il which registered the highest fruit yield, net profit and RC ratio (31.06 t ha", Rs. 1,04,271/- and 3.04, respectively) and hence this combination could be adjudged as the best one for snakegourd cultivation.
Open Access
Integrated nutrient management for rice based cropping systems of Onattukara tract
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Shalini Pillai, P; KAU; Muraleedharan Nair, V
An investigation was carried out at the Rice Research Station, Kayamkulam to identify the most suitable rice based cropping system for the Onattukkara tract and to evolve a suitable ecologically and economically viable integrated nutrient management practice for the system. The experiment was laid out in a 4x6 factorial strip plot design and was carried for two consecutive years extending from April, 1994 to May 1996. The treatments consisted of four cropping systems (rice-rice-sesamum, rice-rice-groundnut, rice-rice-cowpea and rice-rice-bhindi) and six nutrient management levels (N1 farmers' practice, N2 - Package of practices recommendations, N3 three-fourth recommended N as chemical + one-fourth as FYM, N4 - three-fourth recommended N as chemical + one-fourth as FYM + Azospirillum, N5 - three-fourth recommended N as chemical + one-eighth as FYM + one-eighth as vermicompost and N6 - three fourth recommended N as chemical + one - eighth as FYM + one - eighth as vermicompost + Azospirillum). During the third crop season the treatments N2 to N6 was package of practices recommendations (for the respective crops) while N1 was farmers' practice itself. Among the different nutrient management levels tested, the treatment wherein one-fourth recommended N was substituted with FYM and vermicompost along with Azospirillum recorded the maximum grain yield for first crop rice and second crop rice (irrespective of cropping system). The same treatment also supported a better straw yield by maintaining a favourable grain:straw ratio. In ricc-rice-'sesamum, the production efficiency was highp.st when one-fourth recommended nitrogen was supplied through farmyard manure and vermicompost along with Azospirillum. The BCR was maximum when the same treatment was applied without Azospirillum. In rice-rice-groundnut, rice- rice cowpea and rice-rice-bhindi, the same trend followed. Rice-rice-bhindi cropping system recorded the maximum production efficiency followed by rice-rice-groundnut during both the years, and rice-rice-sesamum recorded the minimum value. The overall mean returns was maximum with the cropping system,rice- rice-groundnut. It was followed closely by the rice-rice-bhindi cropping system. While rice-rice-cowpea recorded the meaning of economic returns during the first year, rice- rice sesamum recorded the same during the second year. Studies on the physico-chemical properties of the soil showed that the cropping system, rice-rice-sesamum resulted in a slight increase in bulk density, water holding capacity and water stable aggregates. The organic carbon, total nitrogen and available phosphorus content of the soil increased, while the soil pH, available nitrogen and available potassium contents decreased. The cropping system, rice-rice- groundnut resulted in an increase in bulk density, water holding capacity, water stable aggregates, organic carbon, soil pH, total nitrogen and available phosphorus and a decrease in the available nitrogen and available potassium contents. While there was an increase in the water holding capacity, water stable aggregates, organic carbon, total nitrogen, available nitrogen and available phosphorus there was a slight decrease in bulk density and soil pH in the cropping system, rice-rice- cowpea. The rice-rice-bhindi cropping system resulted in a decrease in the bulk density and soil pH and available potassium and an increase in the water holding capacity, water stable aggregates, organic carbon, total nitrogen, available nitrogen and available phosphorus. The balance sheet of nitrogen showed•a positive balance in the cropping systems rice-rice-groundnut and rice- rice-cowpea and a negative balance in the other two systems. All the cropping systems tested resulted in a negative balance for available phosphorus and a positive balance for available potassium. The cropping system, rice-rice-groundnut was observed to be the most efficient one. followed by rice-rice-bhindi based on the productive efficiency, benefit cost ratio and soil sustainability. The marginal benefit cost ratio for the different nutrient management practices showed that the treatment comprising three fourth recommended dose of N as chemical + one-eighth as FYM + one-eighth as vermicompost (for first and second crop rice) and package of practices 1ecommendations for groundnut (third crop) was the most economic. However, for the rice-rice-bhindi cropping system, the package of practices recommendations was observed to be more economical.
Open Access
Influence of high background radiation on coconut nutrition
(Department of Agronomy, College of Horticulture, Vellenikkara, 1998) Rekha, C; KAU; Balachandran, P V
An investigation on the influence of high background radiation on coconut palms was conducted during 1994-97 at the College of Horticulture, Vellanikkara. This study was carried out in the high background radiation areas of the coastal Kollam district. A pot culture experiment was also conducted at the College of Horticulture, Vellanikkara. Soil collected from the high background radiation area (Chavara) was used for the study. The radiation exposure of coconut roots and its influence on the root activity of coconut palms, radiation profile of coconut rhizosphere, radionuclide accumulation by coconut palms and the influence of organic matter application on absorption of radionuclides by coconut palms were assessed. The main findings are given below. A wide variation in natural background radiation ranging from 200-8 200 nGy h-1 was observed in Chavara and adjoining areas. The radiation levels were generally higher in the coastal areas compared to the inland. 232 Th was the major radionuclide contributing to the high radiation and its content in soil ranged from 144 to 3580 ppm. The results from root exposure studies indicated that plant roots are continuously exposed to high radiation levels and a significant reduction in radiation exposure occurred only at a depth of 1 m. Correlation and regression analyses revealed a significant positive relation between surface radiation and the radiation exposure at different soil depths. The root activity studies employing 32P soil injection technique revealed that the root activity of coconut palms in the high radiation areas was comparable with that in the low radiation areas. The studies on 232Th uptake and its distribution within coconut palm pointed out that considerable accumulation of the absorbed 232Th occurs in roots and that only a small fraction of it is translocated up to the leaves and nuts. Application of organic matter, especially green leaf manure was found to be highly effective in reducing the 232Th uptake by coconut seedlings growing in monazite rich soil.
Open Access
Varietal reaction to nutrient and moisture stress in Cashew (Aracardium occidentale L.)
(Department of Agronomy, College of Horticulture, Vellenikkara, 1998) Latha, A; KAU; Abdul Salam, M
Five experiments were conducted at Cashew Research Station, Kerala Agricultural University, Madakkathara during 1996-98 to identify drought tolerant varieties of cashew, to study the response of cashew to applied N at different levels of drip irrigation and to assess the tolerance of cashew varieties to N, P and K deficiency in soil. The abstract of the experiments is given below. Exp. I. Varietal variation in drought tolerance The varieties H-1591, M-26/2, V-5 and M-44/3 are drought tolerant and K-22-1 is drought sensitive. Exp. II. Response of cashew to applied N at different levels of irrigation (drip) N application @ 1500 g per tree per year along with irrigation @ 80 litres per tree per day (through drip) is essential in the state of Kerala for obtaining best results from cashew. Exp . lIl. Tolerance of cashew varieties to N dificient soils The varieties H-1591 and M-2612 are efficient for N deficient soils. The N use efficiency of cashew seedlings grown under pot culture was 24.7 per cent. Exp. IV. Tolerance of cashew varieties to P deficient soils H-1591 is an efficient variety for P deficient soils. The P use efficiency of cashew seedlings grown under pot culture was 8.02 per cent. Exp. V. Tolerance of cashew varieties to K deficient soils The varieties H-1591, M-26/2 and H-1598 are efficient for K deficient soils. The K use efficiency of cashew seedlings grown under pot culture was 12.17 per cent. N, P and K absorption of a six month old cashew seedling was in the order of 151.95 mg N, 21.58 mg P and 49.48 mg K per plant with a nutrient absorption ratio of7: 1:2 (approximately). The variety H-1591 is a super variety capable of tolerating not only drought but also N, P and K deficient soils. The variety M-26/2 is capable of tolerating drought as well as N and K deficiency in soils. The variety K-22-1 is drought sensitive.
Open Access
Integrated plant nutrition system (IPNS) for maximising yield in banana,musa (Aab group) nendran
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Geetha, K; KAU; Ravindran Nair, R
Field experiments were conducted at the Regional Agricultural Research Station, Kumarakom during 1994 – 1995 and 1995 – 1996, in order to formulate an Integrated Plant Nutrition System (IPNS) for increasing yield and quality of banana cv. Nendran. The optimum combination of various nutrient resources for the crop was arrived at in this study. The treatments comprised of three types of organic inputs (Azospirillum, cowpea and vermicompost) along with a control and four levels each of fertilizer N (0,95,143 and 190 g plant-1) and 2, 4-D (0,15,30 and 45 ppm). The design of the experiment was 43 factorial confounding the highest order interaction. There were two replications. The results revealed that cowpea (green manure) and vermicompost influenced the yield response to applied N significantly. The organic inputs helped to increase the bunch yield and net returns and reduced the chemical N requirement to 85 per cent of the present recommended dose (190 g plant-1). Besides, they improved the physical and chemical properties of the soil at the end of the experiment. Application of 2, 4-D at the rate of 30 ppm was beneficial for higher yield, particularly at the lower doses of fertilizer N. The growth regulator did not give any residue in the fruit. The effect of interaction between organic inputs and fertilizer N was clearly evident in the growth attributes. The influence of organic inputs was significant on TSS, acidity and reducing and non reducing sugars. Applied N and 2, 4-D influenced all the quality parameters. An IPN package consisting of either cowpea (green manure) or vermicompost, 85 per cent of the present recommended dose of fertilizer N (190 g plant-1) and 30 ppm of 2, 4-D is suggested for achieving high economic returns from banana cultivation.

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